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Abstract
To determine whether preoperative coronary angiography and revascularization improve short-term outcomes in patients undergoing noncardiac vascular surgery.
Decision analysis.
Patients undergoing elective vascular surgery who had either no angina or mild angina and a positive dipyridamole-thallium scan result.
Three strategies were compared. The first strategy was to proceed directly to vascular surgery. The second was to perform coronary angiography, followed by selective coronary revascularization, before proceeding to vascular surgery and to cancel vascular surgery in patients with severe inoperable coronary artery disease (CAD). The third was to perform coronary angiography, followed by selective coronary revascularization, before proceeding to vascular surgery and to perform vascular surgery in patients with inoperable CAD.
Mortality, nonfatal myocardial infarction, stroke, uncorrected vascular disease, and cost. All outcomes were assessed within 3 months.
Proceeding directly to vascular surgery led to lower morbidity and cost in the base case analysis. The coronary angiography strategy led to higher mortality if vascular surgery would proceed in patients with inoperable CAD, but led to slightly lower mortality if vascular surgery were canceled in patients with inoperable CAD. The coronary angiography strategy also led to lower mortality when vascular surgery was particularly risky.
Decision analysis indicates vascular surgery without preoperative coronary angiography generally leads to better outcomes. Preoperative coronary angiography should be reserved for patients whose estimated mortality from vascular surgery is substantially higher than average.
... In asymptomatic patients, prophylactic coronary revascularization before noncardiac surgery is not recommended by either CABG or PCI, whereas CABG has traditionally been suggested in symptomatic patients because noncardiac surgery shortly after CABG carries relatively low risk of cardiac complication. [2][3][4][5] Although many studies have also shown the perioperative cardiovascular stability of prior PCI in patients undergoing noncardiac surgery, debate still exists, and most of the former studies have compared PCI with medical therapy. [6][7][8] This study is aimed to compare the impact of prior PCI with CABG on clinical outcomes of noncardiac surgery. ...
... [13][14][15][16][17] Coronary artery bypass graft surgery has also traditionally been chosen over PCI for prophylactic revascularization before noncardiac surgery in patients with significant coronary artery disease with unstable symptoms. [2][3][4][5] Moreover, a recent ESC/ESA guideline does not recommend a routine angiography in patients with history of CABG in the past 6 years based on the analysis showing prominent protective effect of CABG. 9,18 However, safety concerns still exist for prior PCI. ...
Objective
Although safety concerns still remain among patients undergoing unanticipated noncardiac surgery after prior percutaneous coronary intervention (PCI), it has not been directly compared with coronary artery bypass grafting (CABG). The objective of this study was to compare clinical outcomes after noncardiac surgery in patients with prior (>6 months) coronary revascularization by PCI or CABG.
Methods
From February 2010 to December 2015, 413 patients with a history of coronary revascularization, scheduled for noncardiac surgery were identified. Patients were divided into PCI group and CABG group and postoperative clinical outcome was compared between 2 groups. The primary outcome was composite of all-cause death, myocardial infarction, and stroke in 1-year follow-up.
Results
The 413 patients were divided according to prior coronary revascularization types: 236 (57.1%) into PCI and 177 (42.9%) into CABG group. In multivariate analysis within 1-year follow-up, there was no significant difference in clinical outcome which was composite of all-cause death, myocardial infarction, and stroke (hazard ratio [HR]: 1.50; 95% confidence interval [CI]: 0.76-2.93; P = .24). The same result was present in propensity-matched population analysis (HR: 1.43; 95% CI: 0.68-3.0; P = .34).
Conclusions
In patients undergoing noncardiac surgery with prior coronary revascularization by PCI or CABG performed on an average of 42 months after PCI and 50 months after CABG, postoperative clinical outcome at 1-year follow-up is comparable.
... The issue regarding pre-operative coronary angiography with prophylactic coronary revascularization prior to elective PAD surgery remains controversial: it has been shown to improve survival in two studies, one in patients diagnosed with unprotected severe left main disease 11 , and another in patients deemed to be medium-high risk for surgery 19 . Other studies, however, have not found a benefit to pre-operative coronary revascularization in patients undergoing PAD surgery [27][28][29] . It has been suggested, therefore, that the decision to perform coronary angiography should be based on indications independent of the planned peripheral surgery 15,[29][30] . ...
... Other studies, however, have not found a benefit to pre-operative coronary revascularization in patients undergoing PAD surgery [27][28][29] . It has been suggested, therefore, that the decision to perform coronary angiography should be based on indications independent of the planned peripheral surgery 15,[29][30] . Other = renal or mesenteric artery stenosis, subclavian artery stenosis, extremity aneurysms or complications of prior vascular reconstruction ...
The prevalence of coronary artery disease (CAD) in patients with peripheral arterial disease (PAD) varies widely in published reports. This is likely due at least in part to significant differences in how PAD and CAD were both defined and diagnosed. In this report, the investigators describe 78 patients with PAD who underwent preoperative coronary angiography before elective peripheral revascularization and provide a review of published case series. Among the patients included, the number with concomitant CAD varied from 55% in those with lower-extremity stenoses to as high as 80% in those with carotid artery disease. The number of coronary arteries narrowed by ≥ 50% was 1 in 28%, 2 in 24%, and 3 in 19%; 28% did not have any angiographic evidence of CAD. The review of published research resulted in the identification of 19 case series in which a total of 3,969 patients underwent preoperative coronary angiography before elective PAD surgery; in the 2,687 who were described according to the location of the PAD, 55% had ≥ 1 epicardial coronary artery with ≥ 70% diameter narrowing. The highest prevalence of concomitant CAD was in patients with severe carotid artery disease (64%). In conclusion, despite sharing similar risk factors, the prevalence of obstructive CAD in patients with PAD ranges widely and appears to differ across PAD locations. Thus, the decision to perform coronary angiography should be based on indications independent of the planned PAD surgery.
... Myocardial perfusion imaging15) or dobutamine stress echocardiography16) has been reported as useful methods for the preoperative coronary risk evaluation. The invasive coronary angiography and revascularization did not improve on short-term outcomes in the patients undergoing vascular surgery.17) Decision analysis without preoperative coronary angiography generally led to better outcomes, due to its high cost and complications involved with invasive coronary angiography. ...
Background and Objectives
Vascular surgery carries high operative risk. Recently developed cardiac computed tomography (CT) provides excellent imaging of coronary artery disease (CAD), as well as myocardial perfusions. We investigated the role of stress perfusion CT with coronary computed tomography angiography (CCTA) using 128-slice dual source CT (DSCT) in preoperative cardiac risk evaluation.
Subjects and Methods
Patients scheduled for vascular surgery were admitted and underwent the adenosine stress perfusion CT with CCTA using DSCT. Patients who presented with unstable angina, recent myocardial infarction, decompensated heart failure, or renal failure were excluded. Stress perfusion CT was first acquired using sequential mode during adenosine infusion, after which, scanning for CT angiography was followed by helical mode. Perioperative events were followed up for 1 month.
Results
Ninety-one patients completed the study. Most patients (94.5%) had coronary atherosclerosis, with 36 (39.6%) patients had more than 50% coronary artery stenosis. Perfusion defects with significant stenosis were found in 12 cases (13.2%). Revascularization after DSCT was rarely performed. Four patients (4.4%) experienced cardiac events in the perioperative period: two experienced heart failure and two had non-fatal myocardial infarction.
Conclusion
We cannot conclude that the stress perfusion CT, with CCTA using DSCT, plays a significant role in preoperative risk evaluation from this study. However, the coronary atherosclerosis and the significant CAD were commonly found. The perfusion defects with significant lesions were found in only small fraction of the patients, and did not contribute to perioperative myocardial infarction or heart failure.
... 22 La coronariografía se mantiene indicada y reservada para aquellos casos en que se detecta que el estimado de mortalidad para la cirugía vascular es más alto que los promedios. 23 Hacemos firme nuestra hipótesis de la necesidad de mantener un régimen de estudio y análisis de los factores de riesgo, en los pacientes en los cuales se va a realizar cirugía reparadora por un AAA. De ser posible se deben efectuar los 4 estudios, con exclusión del de Goldman estándar y realizar el Goldman modificado. ...
A cardiological analysis of 100 patients whe underwent elective surgery due to infrarenal abdominal aortic aneurysm was made. 5 methods were used to this end: the original and modified Goldman's cardiac resk index, Eagle's coronary markers, the indications by levels recommended by Hollier and Cooperman's equation. Ischaemic heart disease was detected in 59% of the patients. 43% of them had history of myocardial infarction, 33% of stable angina under drug treatment, 6% of congestive heart failure with digitalis treatment and 11% had a nonsinusal rate detected in the EKG. Among those suffering from schemic heart disease there was a long term survival of 80% at the 1st and 2 nd year, 72% at the 5 th year, and 35% at the 10 th and 13 th year. A simple and modified algorithm of cardiological assessment was proposed for patients with abdominal aortic aneurysm.
... Coronary angiography remains the gold standard for the morphologic diagnosis of CAD and also allows revascularization during the same procedure [12, 13]. Coronary angiography is a relatively safe and effective intervention, yet it is resource-intensive, expensive , and invasive [14, 15]. Non-invasive cardiac imaging techniques such as multi-slice computed tomography (CT), high-resolution magnetic resonance imaging/angiography (MRI/MRA), electron beam angiography (EBA), or positron-emission tomography with CT (PET-CT) have an alleged high sensitivity and specificity for detecting morphologic coronary lesions, and some even claim to permit the functional assessment of myocardial perfusion. ...
Accurate, non-invasive diagnosis of, and screening for, coronary artery disease (CAD) and restenosis after coronary revascularization has been a challenge due to either low sensitivity/specificity or relevant morbidity associated with current diagnostic modalities.
To assess sensitivity and specificity of a new computerized, multiphase, resting electrocardiogram analysis device (MultiFunction-CardioGram(sm) or MCG a.k.a. 3DMP) for the detection of relevant coronary stenosis (>70%), a meta-analysis of three published prospective trials performed in the US on patient data collected using the US manufactured device and analyzed using the US-based software and New York data analysis center from patients in the US, Germany, and Asia was completed. A total of 1076 patients from the three trials (US - 136; Germany - 751; Asia - 189) (average age 62 +/- 11.5, 65 for women, 60 for men) scheduled for coronary angiography, were included in the analysis. Patients enrolled in the trials may or may not have had prior angiography and/or coronary intervention. Angiographic results in all studies were classified for hemodynamically relevant stenosis (> 70%) by two US based angiographers independently.
Hemodynamically relevant stenosis was diagnosed in 467 patients (43.4%). The device, after performing a frequency-domain, computational analysis of the resting ECG leads and computer-database comparison, calculated a coronary ischemia "severity" score from 0 to 20 for each patient. The severity score was significantly higher for patients with relevant coronary stenosis (5.4 +/- 1.8 vs. 1.7 +/- 2.1). The study device (using a cut-off score for relevant stenosis of 4.0) correctly classified 941 of the 1076 patients with or without relevant stenosis (sensitivity-91.2%; specificity-84.6%; NPV 0.942, PPV 0.777). Adjusted positive and negative predictive values (PPV and NPV) were 81.9% and 92.6%, respectively (ROC AUC = 0.881 [95% CI: 0.860-0.903]). Subgroup analysis showed no significant influence of sex, age, race/nationality, previous revascularization procedures, resting ECG morphology, or participating center on the device's diagnostic performance.
The new computerized, multiphase, resting ECG analysis device (MultiFunction-CardioGram(sm)) has been shown in this meta-analysis to safely and accurately identify patients with relevant coronary stenosis (>70%) with high sensitivity and specificity and high negative predictive value. Its potential use in the evaluation of symptomatic patients suspected to suffer from coronary disease/ischemia is discussed.
EpidemiologyLong-term outcomeInvestigation of the patient with peripheral vascular diseaseIntermittent claudicatioCritical ischemiaSurgical treatment of intermittent claudication and critical ischemiaInflammatory vascular diseases - thromboangitis obliterans (Buerger's disease)
Interventional cardiology has had an extraordinary expansion in last years. This clinical guideline is a review of the scientific evidence of the techniques in relation to clinical and anatomic findings. The review includes: 1. Coronary arteriography. 2. Coronary balloon angioplasty. 3. Coronary stents. 4. Other techniques: directional atherectomy, rotational atherectomy, transluminal extraction atherectomy, cutting balloon, laser angioplasty and transmyocardical laser and endovascular radiotherapy. 5. Platelet glycoprotein IIb/IIIa inhibitors. 6. New diagnostic techniques: intravascular ultrasound, coronary angioscopy, Doppler and pressure wire. For the recommendations we have used the classification system: class I, IIa, IIb, III like in the guidelines of the American College of Cardiology and the American Heart Association.
The theme of this review article is to describe a variety of perioperative management options for patients with coronary heart disease or myocardial infarction scheduled for noncardiac surgery. The article focuses especially on the guidelines of the American College of Cardiology and the American Heart Association taskforce (1996). The perioperative evaluation and treatment of cardiac risk patients requires careful teamwork between the anaesthesiologist, the surgeon and the internal specialist. The initial history gives the best information about an increased perioperative cardiac risk. According to the history and to the surgery-specific risk, a decision must be made regarding further noninvasive and invasive testing. It is recommended to perform a 12-lead-ECG on routine basis on all patients over 45 years of age. The exercise ECG and the stress-echocardiography are the tests of choice in this context. The perioperative monitoring equipment should be selected with due consideration of the advantages and risks of the different procedures. The ECG-monitoring with ST-segment analysis, pulse oximetry, capnometry and non-invasive blood pressure recording are recommended as basic components. An online-therapy of hypo- or hypertension by an invasive blood pressure measuring is beneficial. Patients undergoing operations with high fluid loss should be monitored with a central venous catheter or pulmonary artery catheter. Troponins have been shown to be sensitive biochemical markers for the assessment of myocardial cell injury. Perioperative normothermia (>36°C) reduces the incidence of cardiovascular sensations. A prophylactic perioperative β-blockade and the application of new α2- receptor-agonists reduce the incidence of myocardial ischemia and improve the long-term survival rate. The main goal of our teamwork should be to achieve an intensive care management during the first three postoperative days for cardiac risk patients undergoing operations with high or moderate surgery- specific risk.
• Objective: To review preoperative cardiac risk stratification and management in patients undergoing noncardiac surgery. • Methods: Review of the literature, with a focus on. Heart Association guidelines and landmark papers. • Results: The updated guidelines emphasize preoperative clinical risk stratification and deemphasize routine preoperative cardiac testing in patients with known or suspected coronary disease. Most patients without active cardiovascular conditions who are not at very high risk can proceed to surgery without further testing. Use of preoperative noninvasive testing is warranted in selected very high-risk patients and/or if the results will change patient management. β-Blocker therapy is reasonable in higher-risk patients. However, the updated guidelines do not include data from the POISE trial, the results of which call into question the routine initiation of prophylactic preoperative β blockade. There is ongoing research concerning preoperative statin therapy, which appears to be beneficial, especially in vascular surgery patients. A notable change in the guidelines reflects recent evidence that intermediate-risk patients might not benefit from prophylactic preoperative revascularization. • Conclusion: An individualized multidisciplinary approach and risk-benefit discussion with each patient is the most prudent path to ensuring success. Copyright 2009 by Turner White Communications Inc. All rights reserved.
The significance of cardiovascular disease Coronary artery disease is a complex inflammatory process influenced by both genetic and environmental factors, the progression and outcome of which can be modulated in many ways [1]. Cardiac complications pose a significant risk to patients undergoing major noncardiac surgery. The prevalence of cardiovascular disease increases with age, and the proportion of the population over the age of 65 is steadily increasing. Coincidentally, this is the age group in which the largest number of surgical procedures is performed. In 1977, the overall perioperative risk of cardiac death or major cardiac complications (nonfatal myocardial infarction [MI], pulmonary edema or ventricular tachycardia) in patients aged over 40 years was 5.8% [2]. In 1995 a more selective review was done looking at MI and cardiac death [3]. To summarize: if a patient has cardiac disease, they are at higher risk of having a perioperative acute cardiac event. The ideal approach is to institute appropriate investigations to ascertain the risk, and then commence therapeutic measures so as to minimize the risk [4]. Pathophysiology Physiological factors associated with surgery predispose to myocardial ischemia which is more pronounced in patients with underlying coronary disease. These include volume shifts and blood loss, enhanced myocardial oxygen demand from elevations in heart rate and blood pressure secondary to stress from surgery, and an increase in platelet reactivity.
The basic tenet in preoperative evaluation remains that information regarding the extent and stability of disease will effect patient management and lead to improved outcome. The history should focus on cardiovascular risk factors and symptoms or signs of unstable cardiac disease states. Six independent predictors of complications have been identified: high-risk type of surgery, history of ischemic heart disease, history of congestive heart failure, history of cerebrovascular disease, preoperative treatment with insulin, and preoperative serum creatinine >2.0 mg/day, with increasing cardiac complication rates noted with increasing number of risk factors. In 2009, the American College of Cardiology/American Heart Association produced guidelines which include an algorithm to determine the indication for further diagnostic evaluation which incorporates clinical risk, surgical procedure risk, and exercise capacity. Current evidence suggests that further risk stratification in this group of patients considered at intermediate risk based on clinical history alone was unnecessary as long as perioperative beta-blockers were used, while those patients with left main disease may benefit from testing. The current evidence does not support the use of percutaneous coronary interventions beyond established indications for nonoperative patients, while advocates continuing aspirin therapy in all patients with a coronary stent and discontinuing clopidogrel for as short a time interval as possible. With respect to perioperative medical therapy, current evidence supports the continuation of beta-blockers and statins. © 2013 Springer Science+Business Media New York. All rights reserved.
In 1996 the American College of Cardiology and American Heart Association (ACC/AHA) published guidelines for perioperative cardiovascular evaluation for noncardiac surgery (1); these were updated in 2002 (2). The guidelines present an organized approach to the surgical patient with known or suspected cardiac disease, based on the presence of "clinical predictors" (history, medical conditions), functional capacity, and procedure-related surgical risk. The interaction of these factors determines the need for noninvasive test-ing, possibly leading to coronary angiography and revascularization in a small percentage of patients. Patients with a reliable history of good exercise toler-ance should rarely require assessment of coronary status (e.g., noninvasive testing or coronary angiogra-phy). Patients with risk factors and exercise tolerance that is difficult to assess should probably have nonin-vasive testing to assess for inducible ischemia. This is especially true if they are presenting for vascular surgery. Preoperative Management Preoperative "optimization" of medical status is al-ways a desirable goal, which in the case of coronary artery disease (CAD) could mean either maximum medical management to control ischemia or a revas-cularization procedure. Patients with new or changing ischemic symptoms should not have elective surgery until this has been addressed. For patients with stable symptoms or with ischemia elicited only by a nonin-vasive test, the approach is controversial. A recent study by McFalls et al. (3) found no benefit from coronary artery bypass grafting (CABG) before aortic or lower extremity vascular surgery in patients with moderate coronary disease (1 of 3 had 3-vessel dis-ease; none had 50% left main disease). The risks of coronary surgery add morbidity and cost to that of the planned surgery (4), angioplasty may be associated with adverse outcomes in some populations (5), and angioplasty/stent placement may result in acute mor-tality if surgery follows in less than a month (6). Data from two randomized clinical trials demon-strate a reduction in adverse cardiac outcomes with the use of perioperative -blockade for vascular sur-gery. In a study by Mangano and Wallace (7,8), pa-tients with risk factors for or a known history of CAD received acute perioperative -blockade with atenolol and had a reduced incidence of perioperative ischemia and fewer cardiac events on follow-up. In a study by Poldermans et al. (9), patients with positive dobut-amine stress echocardiograms received oral bisoprolol for several weeks perioperatively; the decrease in car-diac events with -blockade was striking. The actual degree of coronary disease in the Mangano study was not documented; in the Poldermans study patients with inducible wall motion abnormalities of large ar-eas of the myocardium were excluded. In a follow-up analysis of the Poldermans data, Boersma et al. (10) suggest -blockade slightly reduced ischemic events in patients with 3 risk factors for CAD (age 70 yr, angina, myocardial infarction [MI], congestive heart failure [CHF], prior cerebrovascular accident [CVA], diabetes, and renal failure) and dobutamine stress echocardiography (DSE) was of minimal value. In pa-tients with 3 or more risk factors without wall motion abnormalities on DSE, -blockade reduced events sig-nificantly, but in those with 3 or more risk factors and modest wall motion abnormalities (up to 4 motion segments), -blockade was associated with a dramatic reduction in events. Although some perioperative myocardial infarc-tions occur as a result of plaque rupture, often at noncritical lesions, Landesberg (11) has provided data suggesting most are "stress related," resulting, in part, from tachycardia, occurring without vessel occlusion. Ellis et al. (12) studied a population of patients who underwent coronary catheterization before and after surgery and found many infarctions occurred in areas distal to a preoperative occlusion, supplied by (inad-equate) collaterals, and others occurred without any occlusion being observed. These findings may explain the relative lack of benefit from revascularization pro-cedures in moderate coronary disease and the benefit from -blockade in these same patients. On the other hand, if severe 3-vessel disease or significant left main disease is identified before elective major surgery, re-vascularization ought to be seriously considered, just as it would if surgery were not planned.
Adverse cardiac events during noncardiac surgery are a major cause of morbidity and mortality. As the population ages, greater numbers of patients (including the elderly) are undergoing noncardiac surgical procedures; additional emphasis must therefore be placed on effective preoperative risk assessment. On a national level, the estimated annual expenditure for this process is already $3.7 billion.
There is a need for both the specialist and primary care provider to execute a safe, methodical, and cost efficient screening plan. This process should identify both the patients at highest risk and also those at lowest risk. Subsequently, the emphasis should attempt to minimize the overall risk of perioperative complications.
The cornerstone of risk assessment requires meticulous history taking, a thorough physical examination, and usually a chest radiograph and an ECG. Five subsequent (basic) steps for the evaluation of patients for noncardiac surgery are outlined here in assessment of clinical markers and the patient's functional capacity, risk of the surgical procedure, the need for noninvasive testing, and when appropriate, the indications for invasive testing. The AHA/ACC Practice Guidelines Committee has outlined a clinical algorithm which provides a stepwise approach to guide the clinician during the decision making process.
The purpose of preoperative evaluation is not to “give medical clearance” per se, but rather to evaluate the patient's current medical status, detect stress-induced ischemia in a cost effective manner, and to make recommendations about patient management throughout the entire perioperative period.
Objective: To analyse pre and peroperative variables for predicting mortality after abdominal aortic surgery. Study design: Prospective study. Patients: We prospectively included 658 consecutive patients undergoing abdominal aortic surgery from January 1993 to July 1997. Methods: Age, gender, hypertension, history of myocardial infarction or coronary revascularization, angina pectoris, diabetes, arrhythmia, cardiac insufficiency, serum creatinine > 150 mu mol.L-1, beta-blockers therapy, calcium channel inhibitors, angiotensin converting enzyme inhibitors were preoperative analysed variable. Type of aortic disease (anevrysms versus aortic occlusion), duration of surgery, blood loss, type of laparotomy (medium versus lombotomy) were peroperative analysed variables. Haemoglobinemia was monitored during surgery and patients were transfused if haemoglobinaemia < 80 g.L-1. Results: Thirty-three patients died after aortic surgery (5%). In multivariate analysis, angina pectoris (OR = 5.47, P < 0.001), chronic obstructive bronchopulmonary disease (OR = 2.27, P = 0.05) and duration of surgery (OR = 1.60, P < 0.001) were the independent predictive factors of mortality. Age, blood loss were predictive factors only in univariate analysis. Conclusion: Angina pectoris and COBP were the two independent preoperative factors of mortality. The duration of surgery was the only peroperative factor, Well monitored blood loss was not a predictive factor. (C) 2000 Editions scientifiques et medicales Elsevier SAS.
Le diagnostic d’infarctus du myocarde postopératoire est difficile du fait de symptômes inhabituels. Le mécanisme fait appel à un déséquilibre de la balance entre apport et consommation d’oxygène par le myocarde. Le diagnostic repose sur le dosage de la troponine I (TnI) dont l’élévation est proportionnelle à l’étendue de la nécrose et qui conditionne également le pronostic. Le traitement repose sur l’aspirine, les héparines de bas poids moléculaire, les bêtabloquants et les statines. La fibrinolyse coronaire est contre-indiquée par le contexte.
The purpose of the present study was to evaluate the benefits of a preoperative dipyridamole thallium-201 myocardial perfusion scan in patients undergoing abdominal aortic aneurysm (AAA) repair.
We retrospectively reviewed findings in a prospectively collected database of patients undergoing open or endovascular repair of AAA at the Asan Medical Center, Seoul, Korea, from January 2001 to May 2011.
Of 373 patients, 11 (2.9 %) had postoperative myocardial infarction (MI), whereas 24 (6.4 %), 17 (4.6 %), 24 (6.4 %), and 8 (2.1 %) were diagnosed with myocardial ischemia, atrial fibrillation, ventricular arrhythmia, and congestive heart failure, respectively. The incidence of 30-day cardiac-related mortality was 1.6 % (6 of 373 patients). The preoperative variables significantly associated with postoperative cardiac events in multivariate analysis were preoperative congestive heart failure (odds ratio [OR] 8.8, 95 % confidence interval [CI] 1.36-56.73, p = 0.022), long-acting nitrates (OR 8.1, 95 % CI 1.22-54.26, p = 0.03), and body mass index (BMI) higher than 26 (OR 3.6, 95 % CI 1.49-8.48, p = 0.004). The variables obtained from dipyridamole thallium-201 myocardial perfusion scan were not correlates of postoperative cardiac events. The sensitivity of reversible defects for postoperative cardiac events was 14 % and the specificity was 90 %. Subgroup analyses revealed that thallium defects were not significant variables in predicting postoperative cardiac events in patients with coronary artery disease (CAD) or in no-CAD patients.
Preoperative dipyridamole thallium-201 myocardial perfusion scans were ineffective in predicting postoperative cardiac complications in AAA patients. These results suggest that the routine use of these tests for preoperative screening of patients undergoing AAA repair may not be warranted.
Interventional cardiology has had an extraordinary expansion in last years. This clinical guideline is a review of the scientific evidence of the techniques in relation to clinical and anatomic findings.
The review includes:
1. Coronary arteriography.
2. Coronary balloon angioplasty.
3. Coronary stents.
4. Other techniques: directional atherectomy, rotational atherectomy, transluminal extraction atherectomy, cutting balloon, laser angioplasty and transmyocardical laser and endovascular radiotherapy.
5. Platelet glycoprotein IIb/IIIa inhibitors.
6. New diagnostic techniques: intravascualr ultrasound, coronary angioscopy, Doppler and preassure wire.
For the recommendations we have used the classification system: class I, IIa. IIb, III like in the guidelines of the American College of Cardiology and the American Heart Association.
Objective: To analyse pre and peroperative variables for predicting mortality after abdominal aortic surgery.Study design: Prospective study.Patients: We prospectively included 658 consecutive patients undergoing abdominal aortic surgery from January 1993 to July 1997.Methods: Age, gender, hypertension, history of myocardial infarction or coronary revascularization, angina pectoris, diabetes, arrhythmia, cardiac insufficiency, serum creatinine > 150 μmol·L–1, beta-blockers therapy, calcium channel inhibitors, angiotensin converting enzyme inhibitors were preoperative analysed variable. Type of aortic disease (anevrysms versus aortic occlusion), duration of surgery, blood loss, type of laparotomy (medium versus lombotomy) were peroperative analysed variables. Haemoglobinemia was monitored during surgery and patients were transfused if haemoglobinaemia
Each year in the USA, nearly 30 million patients are estimated to undergo noncardiac surgery, and about one third of these
patients have coronary artery disease (CAD) or risk factors for CAD.1 About one million of those patients have perioperative
cardiac complications that result in more than $20 billion in health-care expenditures.1 The current standards for preoperative
cardiac evaluation of these patients are the guidelines published by the American College of Cardiology (ACC) and the American
Heart Association (AHA), initially in 19962 and updated in 2002 3 and again in 2007.4 These guidelines were developed based
on a review of the then-available literature and the opinions of experts from the disciplines of anesthesiology, cardiology,
electrophysiology, vascular medicine, vascular surgery, and noninvasive cardiac testing.
Cardiovascular death is one of the major causes of death within Europe. Perioperative complications due to cardiovascular disease as well as postoperative pulmonary complications contribute considerably to perioperative morbidity and mortality. Preoperative risk stratification is essential in initiating appropriate treatment strategies in order to reduce the risk of perioperative complications. A patient risk profile and the use of appropriate investigations as well as the implementation of guidelines for risk assessment strategies will improve the utilization of resources, improve medical treatment with a low rate of perioperative complications and therefore improve outcome. This review will discuss ways of preoperative cardiac and pulmonary risk stratification in patients having non-cardiothoracic surgery.
Examples of decision analysisApplications of decision analysis to cardiologySummaryAcknowledgment
Perioperative cardiac morbidity and mortality are of substantial medical and economic concern. Thus, the primary goal of effective
perioperative management is to implement strategies that reliably improve outcome. It is the (as yet unproven) premise that
preoperative risk stratification based on the results of preoperative cardiac testing is one of such measures that will improve
cardiac outcome, due to the modifying effects it can have on overall perioperative management.
The purpose of this chapters is to provide a review and commentary on the current state of fuzzy logic applications in medical
diagnosis. A symposium on fuzzy diagnostic and therapeutic decision support, organized by Adlassnig (2000) may be considered
a watershed in the application of fuzzy logic in medical problems. For a deeper discussion on fuzzy logic in medicine see
Szczepaniak et al. (2000).
Pre-operative cardiac interventions may be performed before a planned non-cardiac surgical procedure in order to optimize the patient's status and to reduce peri-operative morbidity and mortality (MM). The interventional procedures in patients with coronary artery disease are coronary artery bypass graft surgery and percutaneous transluminal coronary angioplasty, in patients with severe aortic stenosis, aortic valve replacement or aortic balloon valvuloplasty. These procedures can only be recommended if surgery without intervention would result in a higher peri-operative MM than the direct approach. Several aspects make the decision process difficult: lack of prospective randomized trials, specific indications for specific procedures, small cohorts of clinical studies, changing management in surgery, anaesthesiology and cardiology, and the influence on short- and long-term outcome. Excellent decision analysis models and guidelines of task forces, however, may help the clinician to obtain sufficient support for his or her pre-operative strategies. Finally, the local experience of the surgical, anaesthesiological and cardiological team has to be taken into consideration before the decision is made, if the individual patient is to benefit from the pre-operative interventional procedure.
Despite significant improvement in anesthetic and surgical techniques, the incidence of perioperative myocardial infarction (PMI) and all-cause mortality from any cardiac event during high-risk vascular surgery (abdominal aortic or infrainguinal revascularization procedures) remains high. In addition, there are significant health care costs associated with the management of PMI.
The aim of this analysis was to investigate the utility of routine preoperative myocardial stress testing prior to high-risk vascular surgery and the interventions performed based on the results of the testing. The outcome after surgery, based on sex of the patients, was also examined.
A retrospective analysis was performed on consecutive adult patients who had a positive dipyridamole-thallium stress test prior to high-risk vascular surgery in a university hospital (tertiary care center) between July 2001 and August 2004. The patients' preoperative demographic characteristics, perioperative record, and postoperative course in the hospital were analyzed. Combined major adverse outcome was defined as any incidence of MI, congestive heart failure, arrhythmias, renal failure, or death.
Of a total of 503 patients, 160 had a positive stress test prior to high-risk vascular surgery (111 men, 49 women; mean [SD] age, 68 [11] and 70 [12] years, respectively). Men with a positive stress test who had either coronary intervention or perioperative β-blockade prior to surgery had a significant decrease in the incidence of combined major adverse outcomes (P = 0.02). Conversely, women did not have a significant improvement in outcome with either of the preoperative strategies. Using logistic regression, only age and conservative management in men were found to be predictors of adverse outcomes.
In this small retrospective study, men with positive stress tests had fewer adverse events with either preoperative coronary revascularization or perioperative administration of β-adrenergic blocking drugs, compared with men who received no intervention. There were no significant differences in adverse outcomes between women with positive stress tests who received either treatment compared with those who did not receive any treatment.
It is essential that the medical profession play a significant role in critically evaluating the use of diagnostic procedures and therapies as they are introduced and tested in the detection, management, or prevention of disease states. Rigorous and expert analysis of the available data documenting
Although guidelines recommend the use of beta-adrenoceptor blocking drugs to reduce cardiac events (CEs) after major noncardiac surgery, trial results have varied between showing benefit, ineffectiveness, and harm. We sought whether optimizing beta-blockade (BB) delivery could make them more effective.
Intermediate risk patients undergoing major noncardiac surgery (n = 400) were randomized to 2 strategies of BB therapy: universal BB (UBB; n = 197) comprising an algorithm-based, nurse-led strategy to optimize dosing and adherence to bisoprolol titration over > or =1 week preoperatively versus usual care (UC; n = 203), whereby BB are continued in those already taking them or prescribed for patients identified as high risk based on ischemia (new or inducible wall motion abnormalities) at dobutamine echocardiography (DbE). Daily electrocardiogram and troponin levels were obtained on 3 postoperative days. The primary end point was a major CE (cardiac death or myocardial infarction) within 30 days.
There were 25 major CEs (6.3%), occurring in 13 (6.6%) of 197 UBB and 12 (5.9%) of 203 UC patients (OR 1.12, 95% CI 0.52-2.39). Independent predictors of CEs were baseline systolic blood pressure (beta 1.02, P = .005) and postoperative hypotension (beta 1.02, P = .03) but not treatment strategy. Those randomized to UBB had significantly better heart rate control perioperatively, at the cost of bradycardia and hypotension. The negative predictive value of DbE in this study was 95%.
These data confirm a persistent CE rate after major noncardiac surgery despite nurse-led dose titration of bisoprolol. Cardiac events were equivalent to a UC strategy based on DbE results.
The HeartVue 6S System is a recently developed novel technology that may provide non-invasive assessment of myocardial ischaemia by analysing low amplitude oscillations of the conventional ECG signals (ECG dispersion mapping). The available data to validate this new technology is limited. Therefore we performed a prospective study to assess the HeartVue 6S System for the detection of myocardial ischaemia during coronary occlusion in patients undergoing percutaneous coronary intervention (PCI).
A total of 101 patients undergoing cardiac catheterization were prospectively enrolled. HeartVue 6S System ECG dispersion mapping was obtained at baseline, and during the first balloon inflation and at the end of the procedure if PCI was performed. Parameters provided by the HeartVue 6S System were analysed.
Fifty patients who underwent PCI comprised the final study population. The mean age was 63.7 +/- 10 years and 58% were men. In 58% of cases the indication was acute coronary syndrome. In 98% of patients, PCI was successful. There were significant differences in the G7+G9 values between the first inflation and the end of the procedure, which reflect changes in ventricular depolarization (P = 0.02 by Wilcoxon signed rank test).
The HeartVue 6S System may have potential for a non-invasive assessment of ischaemia in patients with suspected coronary artery disease. Larger studies are warranted to confirm these preliminary findings.
To assess the sensitivity and specificity of a new computer-enhanced resting electrocardiographic analysis device for the detection of coronary stenosis, 189 patients (aged 61.3+/-12.9 years, 57 women) scheduled for coronary angiography from 4 Asian centers were included in an observational study. Angiographic results were independently classified for hemodynamically relevant stenosis by 2 angiographers. The device calculated a severity score from 0 to 20. The score was significantly higher for patients with coronary stenosis (5.4+/-1.8 vs 1.7+/-2.1). The study device (cutoff 4.0) identified 73 of 77 patients with stenosis (sensitivity 94.8%, specificity 86.6%). Adjusted positive and negative predictive values were 78.4% and 97.1%, respectively (receiver operating characteristic area under the curve, 0.914 [95% confidence interval, 0.868-0.961]). Subgroup analysis showed no significant influence of sex, age, previous revascularization procedures, or participating center. The new computer-enhanced, resting electrocardiographic analysis device appears to identify patients with relevant coronary stenosis with high sensitivity and specificity.
Although perfusion imaging studies are extensively used as a preoperative screening test for risk stratification of patients undergoing noncardiac surgery, no single cardiac noninvasive test has been shown to be ideal for risk stratification. We investigated the relative impact of transthoracic two-dimensional echocardiography (ECHO) compared with dipyridamole thallium scintigraphy (DT) in predicting major cardiac complications in patients undergoing non-cardiac surgery. Eighty-seven consecutive patients undergoing 96 procedures (56 vascular, 40 general) underwent preoperative evaluation first with DT and then with ECHO before surgery. Complications were prospectively defined as myocardial infarction (MI), cardiac death (of MI, heart failure, or arrhythmia), or need of revascularization before surgery. DT showed one or more reversible defects in 44 (51%) patients, whereas ECHO demonstrated a reduced left ventricular ejection fraction (LVEF) in 25 (29%) patients. Major postoperative cardiac complications occurred in 10 patients: 5 deaths (2 ventricular fibrillation, 3 fatal MIs) and 5 nonfatal MIs. Four additional patients required urgent revascularization (coronary bypass graft surgery in 3 and percutaneous transluminal coronary angioplasty in 1). Of the 20 patients with both abnormal DT and ECHO, 11 (55%) had major complications, compared with none of the 26 (0%; p < 0.01) with an abnormal DT but normal LVEF. The sensitivity of DT and ECHO were not significantly different (79% [95% Cl, 52% to 93%] vs 86% [60% to 96%], respectively), although the specificity of DT was lower (51% [40% to 62%] vs 81% [70% to 88%]; p < 0.05). The positive predictive value of DT was significantly improved from 22% (12% to 35%) to 52% (32% to 72%) when both DT and ECHO were abnormal. The results were not significantly different when the 4 patients who underwent revascularization were excluded. In conclusion, (1) in spite of similar sensitivity of ECHO and DT, ECHO appears to be relatively more specific in predicting major CC, and (2) when ECHO and DT are both abnormal, the risk of CC related to noncardiac surgery is significantly increased. Use of the combination of DT and ECHO before major noncardiac surgery can improve the identification of patients at risk for complications.
The benefit of preoperative cardiac evaluation in the diabetic patient undergoing peripheral vascular surgery is uncertain. To investigate this issue we performed a retrospective review of 192 procedures performed in diabetic patients for chronic lower extremity arterial occlusive disease. The incidence of adverse postoperative cardiac events was determined, as well as its association with several preoperative factors including symptoms of coronary artery disease (CAD), extent and results of preoperative noninvasive cardiac evaluation, and operative site (aorta vs. lower extremity). The overall death and cardiac complication rates were 10.2% for lower extremity and 25.7% for aortic procedures (p = 0.02). For myocardial infarction and cardiac death alone, the rates were 5.1% and 5.7%, respectively (p > 0.10). Although a history of symptomatic CAD predicted the occurrence of any cardiac complication (28.3% vs. 8.2% [p < 0.01] for the aortic and lower extremity revascularization groups combined), no factor was found to be associated with the occurrence of myocardial infarction and cardiac death alone. In patients with a history of symptomatic CAD, there was no significant difference in the incidence of complications whether or not preoperative noninvasive cardiac testing was performed (28.1% vs. 28.6%, p > 0.10) or, if testing was performed, if the results were abnormal or normal (35.3% vs. 20.0%, p > 0.10). Similar results were obtained in patients with no history of symptomatic CAD. In summary, this retrospective review of our experience with noninvasive evaluation to detect CAD in diabetic patients undergoing peripheral vascular surgery failed to show any benefit in terms of reducing the incidence of postoperative cardiac events.
Dipyridamole-sestamibi (PMIBI) is recommended prior to vascular surgery in patients with > or = 1 Eagle criteria (Q waves, history of ventricular ectopy, diabetes, advanced age, and/or angina). To review our cardiac morbidity and mortality and the need for preoperative PMIBI, we reviewed 109 consecutive patients with a mean age of 59 years who underwent 145 elective major vascular procedures over a 1-year period. Seventy patients (with a mean of 0.8 Eagle criteria) underwent 92 vascular procedures without preoperative PMIBI and without coronary revascularization. Thirty-one patients (with a mean of 1.1 Eagle criteria) underwent 39 procedures without coronary revascularization following PMIBI, which showed reversible ischemia in seven and a fixed defect in 10; findings were normal in 14. Preoperative coronary bypass or angioplasty was limited to eight patients (14 procedures, mean of 1.6 Eagle criteria) who had unstable angina with (2 patients) or without (6 patients) acute myocardial infarction. There were four perioperative myocardial infarctions (2.8%), seven cardiac events overall (4.8%), and one cardiac death (0.7%). Three (43%) of the seven cardiac events occurred in patients with a normal scan or fixed defect on PMIBI imaging. In the absence of unstable angina, PMIBI had a sensitivity of only 25% and a specificity of 80% for cardiac events. We conclude that among patients without severe cardiac symptoms (1) PMIBI has a very limited ability to identify patients at risk for cardiac complications, and (2) preoperative PMIBI is neither necessary nor cost-effective.
This study was performed to determine whether comprehensive cost-cutting strategies adversely affect the outcome in patients undergoing carotid endarterectomy.
From December 1994 to December 1995, 237 consecutive patients undergoing 260 carotid endarterectomies were prospectively studied. The following variables were assessed: carotid arteriography, preoperative laboratory tests, electrocardiograms and chest x-ray films, use of carotid shunts during operation, use of pathology department, intensive care, oxygen therapy, telemetry, and hospital stay. In addition, complications were tabulated.
Previously, all variables evaluated were routinely ordered. Subsequent to initiating the cost-containment strategies, the following results were achieved: arteriography in 52 (22%) of 237 patients, preoperative complete blood cell count and SMA-7 in 161 (62%) of 260 cases, preoperative electrocardiograms in 185 (71%) of 260 cases, preoperative chest x-ray films in 190 (73%) of 260 cases, carotid shunts in 83 (32%) of 260 cases, disease in no cases (0%), intensive care in 29 (11%) of 260 cases, oxygen therapy in 34 (13%) of 260 cases, telemetry in 17 (7%) of 260 cases, and hospital stay was decreased from an average of 2.6 to 1.3 days. Total savings based on average hospital and physician charges was $2.3 million. Complications included four strokes, one myocardial infarction, and no deaths. No patient required readmission. No recurrent or new neurologic or cardiac findings were identified clinically in follow-up at 1 and 4 weeks after surgery.
The results clearly demonstrate that comprehensive cost-cutting strategies can reduce charges significantly while maintaining patient safety.
Purpose:
Because dipyridamole thallium (DT) scanning is a useful predictor of perioperative cardiac events, a positive results of a DT scan is frequently the basis for performing more invasive cardiac evaluation and for consideration for performing coronary revascularization procedures before performing peripheral vascular surgery. The rationale for this approach has been that the treatment of anatomically significant coronary artery disease would lower the risk of performing a subsequent vascular operation. However, the benefit of performing aggressive diagnostic and therapeutic cardiac procedures in such patients remains unproved. To examine this issue, data from patients who underwent coronary angiography because of thallium redistribution were compared with data from matched control subjects who underwent peripheral vascular operations without further cardiac evaluation.
Methods:
The medical records of 70 consecutive patients who underwent coronary angiography because of the presence of two or more segments of redistribution on DT scan were reviewed and compared with 70 other patients matched with respect to age, gender, peripheral vascular operation, and number of segments of redistribution on DT scan who did not undergo additional cardiac evaluation.
Results:
DT scans were performed on 934 preoperative peripheral vascular surgery patients to help in the assessment of operative risk. Ischemic responses, defined as two or more segments of redistribution, were observed in 297. Of these, 70 underwent cardiac catheterization and 25 underwent coronary revascularization procedures. Adverse outcomes affected 46% of the coronary angiography group and 44% of the control group (p = NS). Patients who underwent coronary angiography and were considered for myocardial revascularization had fewer cardiac events with a subsequent vascular operation than did the control subjects. However, any possible benefit from invasive cardiac evaluation was offset by the three deaths and two myocardial infarctions (MIs) that complicated the cardiac evaluation. There was no significant difference between the angiography group and the matched control subjects with respect to perioperative nonfatal MI (13% vs 9%), fatal MI (4% vs 3%), late nonfatal MI (16% vs 19%), or late cardiac death (10% vs 13%). In long-term follow-up, MIs occurred later in patients who underwent coronary angiography than the control subjects (p = 0.049), but this difference was not associated with an improvement in the overall survival rate.
Conclusions:
The risks of extended cardiac evaluation and treatment did not produce any improvement in either the perioperative or the long-term survival rate. For most vascular surgery patients who have a positive result of a DT scan, coronary angiography does not provide any additional useful information.
Our goal was to determine the predictive value of coronary artery calcification (CAC) on preoperative CT of the thorax for cardiac complications of noncardiac thoracic surgery.
Of 117 patients undergoing noncardiac thoracic surgical procedures between January 1, 1993, and June 1, 1995, at our institution, 75 had inpatient records and chest CTs available for retrospective review. Inpatient records were reviewed for postoperative cardiac complications (arrhythmia, hypotension with ECG changes, myocardial infarction, congestive heart failure, stroke, and death). The CT scans were scored for the presence and extent of CAC by an independent observer.
Six of the 75 patients had cardiac complications including 1 death. Thirty-nine of the 75 patients had a CAC score of > or = 7. The sensitivity, specificity, positive predictive value, and negative predictive value of a CAC score of > or = 7 for cardiac complications were 100, 71, 23, and 100%, respectively.
The presence of CAC on preoperative CT scanning is associated with cardiac complications of noncardiac thoracic surgery; however, the positive predictive value is low. The absence of CAC was a reliable predictor of a favorable postoperative cardiac course.
Whether to perform coronary angiography on the basis of preoperative noninvasive cardiac testing remains a difficult decision. We hypothesized that there are noninvasive test results for which experts have general agreement about the indication for preoperative coronary angiography. We asked 30 experts (24 in specific diagnostic tests and six in clinical cardiology) to comment on statements regarding hypothetical noninvasive test results. There was agreement that catheterization should be performed for (1) exercise electrocardiographic ischemia with a blood pressure drop > 10 mm Hg, (2) stress perfusion scan reversibility in one half or more of single-photon emission computed tomographic slices, and (3) stress echo ischemia in more than five segments, two or more coronary artery zones, or four left anterior descending coronary artery segments. Therefore coronary angiography should be performed for results of noninvasive tests that indicate large zones of myocardial ischemia and not for limited ischemia or test abnormalities without other significant findings.
The diagnosis of coronary-artery disease has become increasingly complex. Many different results, obtained from tests with substantial imperfections, must be integrated into a diagnostic conclusion about the probability of disease in a given patient. To approach this problem in a practical manner, we reviewed the literature to estimate the pretest likelihood of disease (defined by age, sex and symptoms) and the sensitivity and specificity of four diagnostic tests: stress electrocardiography, cardiokymography, thallium scintigraphy and cardiac fluoroscopy. With this information, test results can be analyzed by use of Bayes' theorem of conditional probability. This approach has several advantages. It pools the diagnostic experience of many physicians ans integrates fundamental pretest clinical descriptors with many varying test results to summarize reproducibly and meaningfully the probability of angiographic coronary-artery disease. This approach also aids, but does not replace, the physician's judgment and may assit in decisions on cost effectiveness of tests.
Analysis of multiple noninvasive tests offers the promise of more accurate diagnosis of coronary artery disease, but discordant test responses can occur frequently and, when observed, result in diagnostic uncertainty. Accordingly, 43 patients undergoing diagnostic coronary angiography were evaluated by noninvasive testing and the results subjected to analysis using Bayes' theorem of conditional probability. The procedures used included electrocardiographic stress testing for detection of exercise-induced ST segment depression, cardiokymographic stress testing for detection of exercise-induced precordial dyskinesis, myocardial perfusion scintigraphy for detection of exercise-induced relative regional hypoperfusion, and cardiac fluoroscopy for detection of coronary artery calcification. The probability for coronary artery disease was estimated by Bayes' theorem from each patient's age, sex, and symptom classification, and from the observed test responses. This analysis revealed a significant linear correlation between the predicted probability for coronary artery disease and the observed prevalence of angiographic disease over the entire range of probability from 0 to 100% (P less than 0.001 by linear regression). The 12 patients without angiographic disease had a mean posttest likelihood of only 7.0 +/- 2.6% despite the fact that 13 of the 60 historical and test responses were falsely "positive." In contrast, the mean posttest likelihood was 94.1 +/- 2.8% in the 31 patients with angiographic coronary artery disease, although 45 of the 155 historical and test responses were falsely "negative." In 8 of the 12 normal patients, the final posttest likelihood was under 10% and in 26 of the 31 coronary artery disease patients, it was over 90%. These estimates also correlated well with the pooled clinical judgment of five experienced cardiologists (P less than 0.001 by linear regression). The observed change in probability for disease for each of the 15 different test combinations correlated with their information content predicted according to Shannon's theorem (P less than 0.001 by linear regression). These results support the use of probability analysis in the clinical diagnosis of coronary artery disease and provide a formal basis for comparing the relative diagnostic effectiveness and cost-effectiveness of different test combinations.
Objective.
—To determine the incidence and significance of intraoperative and postoperative myocardial ischemia and their relationship to preoperative ischemia and postoperative cardiac events in patients undergoing peripheral arterial surgery.
Design.
—Prospective cohort trial.
Patients.
—One hundred fifteen patients undergoing elective vascular surgery who met predefined eligibility criteria and were thought to have acceptable cardiac risk as assessed by independent cardiologists.
Interventions.
—Ambulatory electrocardiographic monitoring preoperatively, intraoperatively, and up to 72 hours postoperatively.
Measurements.
—Preoperative clinical characteristics and laboratory data were collected. Predefined adverse cardiac events were identified by an investigator who was "blinded" to monitoring results. Monitor recordings were interpreted for ST-segment depression by investigators blinded to patient information.
Main Results.
—Intraoperative ischemia was present in 21 patients (18%), and postoperative ischemia was present in 35 (30%). There were 16 postoperative cardiac events. The relative risk of suffering a cardiac event was 2.7 in patients with intraoperative ischemia and was 16 in patients with postoperative ischemia. Preoperative ischemia closely correlated with intraoperative and postoperative ischemia. Preoperative and postoperative ischemia preceded cardiac events in 14 of 16 patients.
Conclusions.
—Preoperative ischemia appears to identify high-risk patients, and subsequent perioperative monitoring detects silent ischemia that commonly precedes clinical events and that may be treatable with anti-ischemia therapy.(JAMA. 1992;268:222-227)
In an attempt to reduce early and late mortality caused by myo-cardial infarction, coronary angiography was performed in 1000 patients (mean age, 64 years) under consideration for elective peripheral vascular reconstruction since 1978. Those found to have severe, surgically correctable coronary artery disease (CAD) were advised to undergo myocardial revascularization (CABG), usually preceding other vascular procedures. The primary vascular diagnosis was abdominal aortic aneurysm (AAA) in 263 patients (mean age, 67 years), cerebrovascular disease (CVD) in 295 (mean age, 64 years), and lower extremity ischemia (ASO) in 381 (mean age, 61 years). Severe correctable CAD was identified in 25% of the entire series (AAA, 31%; CVD, 26%; and ASO, 21%). Surgical CAD was documented in 34% of patients suspected to have CAD by clinical criteria (AAA, 44%; CVD, 33%; and ASO, 30%) and in 14% of those without previous indications of CAD (AAA, 18%; CVD, 17%; and ASO, 8%). Cardiac procedures (216 CABG) were performed in 226 patients (AAA, 30%; CVD, 22%; and ASO, 19%), with 12 (5.3%) postoperative deaths. A total of 796 patients underwent 1066 peripheral vascular operations with an early mortality of 2.0% (AAA, 3.4%; ASO, 1.9%; and CVD, 0.3%), but only one death (0.8%) occurred in the group of 130 patients having preliminary CABG. The overall operative mortality for 1292 cardiac and peripheral vascular procedures was 2.6%. (C) Lippincott-Raven Publishers.
Two noninvasive tests to detect and localize coronary stenoses were compared in a fully blinded protocol. Thallium201 myocardial perfusion imaging (MPI) following maximal treadmill exercise and pharmacologic coronary vasodilation with intravenous dipyridamole (DP) was performed in 33 patients. Thallium201 imaging defects in six myocardial perfusion regions were correlated with stenoses in their respective vascular distributions. Disease severity was determined with coronary arteriograms using a computer-assisted method, 198 myocardial regions were evaluated; 101 were supplied by at least one major artery with a ≥ 50% stenosis (luminal diameter narrowing). The sensitivity and specificity for detecting a ≥50% stenosis were 85% and 64% (p < 0.005), respectively, for DP and 84% and 68% (p < 0.005) for exercise-thallium201 imaging. A particular combination of anterior and septal imaging defects was useful in detecting left anterior descending artery stenoses proximal to its first septal branch. DP administration was safe in this group of patients; however, 42% experienced transient chest pain. Although the overall sensitivity and specificity of the two methods were not significantly different, DP-MPI appeared more sensitive than exercise-MPI (70% vs 52%, p < 0.01) in detecting coronary stenoses in the 40% to 60% range. DP-thallium201 MPI provides a useful alternative test for potential coronary disease patients unable to perform maximal exercise.
During a 14-month period, 75 deaths occurring in relation to 53,581 cardiac catheterizations were consecutively and prospectively reported to the Registry Committee of the Society for Cardiac Angiography. Three of the patients died several days after their catheterization from an unrelated cause and are excluded from this analysis. There were 21 patients (group I) who arrived at the laboratory in extremis and whose deaths were expected irrespective of the catheterization. Most of these patients suffered from recent myocardial infarctions and cardiogenic shock, or had complex congenital malformations. In 35 patients (group II), a cardiovascular complication occurring during the catheterization resulted in death. In 16 patients (group III) catheterization seemed uneventful, but death occurred suddenly 10 min to 10 h after the procedure. Of these 16 patients, eight had left main coronary artery obstruction ≥ 90%, five had three-vessel disease all with 90% obstructions, one had 2-vessel disease both with 90% obstructions, and two had critical aortic stenosis.
The 51 unexpected deaths (groups II and III) were considered to be causally related to the procedure, a mortality rate of 0.10%. Subsets with an increased mortality rate (M), were patients with: (a) left main disease > 50% (M = 0.94%); (b) ejection fraction < 30% (M = 0.54%); (c) NYHA class III or IV (m = 0.24%); (d) age over 60 years (M = 0.23%); or (e) three-vessel disease (M = 0.13%).
In conclusion, catheterization related mortality occurs mostly in patients with far advanced cardiac disease. Nearly 1/3 of the unexpected deaths occurred suddenly after a seemingly uneventful procedure. Close monitoring after catheterization of patients with similar characteristics (left main disease ≥ 90%, or three-vessel disease all ≥ 90%) might disclose avenues for reducing mortality occurring after catheterization.
Thallium-201 myocardial imaging was performed at rest, after maximal treadmill exercise and during coronary vasodilatation induced by the intravenous administration of dipyridamole in 62 patients undergoing coronary angiography. Myocardial images after dipyridamole infusion were compared with rest and exercise thallium-201 images to determine the utility of pharmacologic stress for detecting coronary artery disease. Dipyridamole, 0.142 mg/min, was infused for 4 minutes with electrocardiographic and blood pressure monitoring, and thallium-201 was injected intravenously 4 minutes after infusion.
To determine which preoperative factors might affect the development of cardiac complications after major noncardiac operations, we prospectively studied 1001 patients over 40 years of age. By multivariate discriminant analysis, we identified nine independent significant correlates of life-threatening and fatal cardiac complications: preoperative third heart sound or jugular venous distention; myocardial infarction in the preceding six months; more than five premature ventricular contractions per minute documented at any time before operation; rhythm other than sinus or presence of premature atrial contractions on preoperative electrocardiogram; age over 70 years; intraperitoneal, intrathoracic or aortic operation; emergency operation; important valvular aortic stenosis; and poor general medical condition. Patients could be separated into four classes of significantly different risk. Ten of the 19 postoperative cardiac fatalities occurred in the 18 patients at highest risk. If validated by prospective application, the multifactorial index may allow preoperative estimation of cardiac risk independent of direct surgical risk.
To relate morbidity and mortality risk to preoperative severity of illness in patients undergoing coronary artery bypass grafting.
Retrospective analysis of 5051 patients using univariate and logistic regression to identify risk factors associated with perioperative morbidity and mortality. Prospective application of models to a subsequent 2-year validation cohort (n = 4069).
Cleveland Clinic Foundation.
All adult patients undergoing coronary artery bypass graft surgery between July 1, 1986, and June 30, 1988 (reference group), and July 1, 1988, and June 30, 1990 (validation group).
Mortality and morbidity (myocardial infarction and use of intra-aortic balloon pump, mechanical ventilation for 3 or more days, neurological deficit, oliguric or anuric renal failure, or serious infection).
Emergency procedure, preoperative serum creatinine levels of greater than 168 mumol/L, severe left ventricular dysfunction, preoperative hematocrit of 0.34, increasing age, chronic pulmonary disease, prior vascular surgery, reoperation, and mitral valve insufficiency were found to be predictive of mortality. In addition to these factors, diabetes mellitus, body weight of 65 kg or less [corrected], aortic stenosis, and cerebrovascular disease were predictive of morbidity. Logistic regression equations were developed, and a simple additive score for clinical use was designed by allocating each of these risk-factor values of 1 to 6 points. Both methods predict mortality. Increased morbidity was demonstrated with increases in score.
The logistic or clinical models developed are superior to the currently available methods for comparing mortality outcome and provide previously unavailable information on morbidity based on preoperative status. The clinical scoring system is useful for preoperative estimates of morbidity and mortality risks.
ORONARY ARTERY disease is the number one cause of death in the United States, often progressing silently until severe disease is present. It is also one of the most frequent causes of death after noncardiac surgery. Therefore, risk stratification of patients with suspected or known coronary artery disease should be performed at the time of presentation for noncardiac surgery. Occasionally, a patient’s condition will necessitate modification of the planned surgical approach or deferment in favor of a trial of medical therapy. Appropriately selected patients will benefit from preoperative coronary interventions, primarily coronary artery bypass surgery (CARG), before undergoing noncardiac surgery. This review will describe the epidemiologic aspects of perioperative myocardial infarction (MI) and cardiac death. Various methods of risk stratification will be discussed, including exercise treadmill testing with and without adjunctive radionuclide imaging, studies of left ventricular function, dipyridamole thallium scintigraphy, silent ischemia monitoring, and transesophageal echocardiography. We will also present a summary of the impact of medical and interventional therapy of coronary artery disease on perioperative cardiac complications. Finally, a general patient management strategy will be outlined.
We evaluated the safety, accuracy, and potential clinical utility of intravenous dipyridamole perfusion scintigraphy with thallium-201 in 170 patients, 78 with suspected and 92 with known unstable angina. All had coronary angiography. Noncardiac side effects (26%), induced chest discomfort (44%), and ST segment changes (12%) were similar in the two groups. No significant arrhythmias occurred. Two patients had prolonged chest pain, both with extensive reversible image abnormalities and associated creatinine kinase-MB release. Both had elective bypass surgery. Twenty-eight patients had normal coronary arteries, and 35 had single-vessel disease. Scintigraphic per patient sensitivity and specificity were 91% and 79% with a per vessel sensitivity of 74% and a per vessel specificity of 78% without between-group differences. During a brief follow-up period, 62 patients with image abnormalities had coronary revascularization, and there were seven deaths without intergroup differences. In a similar patient group that did not have angiography, scintigraphic defects were less frequent and less extensive, revascularization was not performed, and subsequent deaths occurred less often. Dipyridamole perfusion scintigraphy is an accurate alternative to exercise testing in the evaluation of patients with unstable angina pectoris. Although not without risk, the method appears relatively safe and should be considered as a guide to diagnosis, and probably to prognosis and management.
The Program on the Surgical Control of the Hyperlipidemias (POSCH), a randomized clinical trial, was designed to test whether cholesterol lowering induced by the partial ileal bypass operation would favorably affect overall mortality or mortality due to coronary heart disease. The study population consisted of 838 patients (417 in the control group and 421 in the surgery group), both men (90.7 percent) and women, with an average age of 51 years, who had survived a first myocardial infarction. The mean follow-up period was 9.7 years.
When compared with the control group at five years, the surgery group had a total plasma cholesterol level 23.3 percent lower (4.71 +/- 0.91 vs. 6.14 +/- 0.89 mmol per liter [mean +/- SD]; P less than 0.0001), a low-density lipoprotein cholesterol level 37.7 percent lower (2.68 +/- 0.78 vs. 4.30 +/- 0.89 mmol per liter; P less than 0.0001), and a high-density lipoprotein cholesterol level 4.3 percent higher (1.08 +/- 0.26 vs. 1.04 +/- 0.25 mmol per liter; P = 0.02). Overall mortality and mortality due to coronary heart disease were reduced, but not significantly so (deaths overall [control vs. surgery], 62 vs. 49, P = 0.164; deaths due to coronary disease, 44 vs. 32, P = 0.113). The overall mortality in the surgery subgroup with an ejection fraction greater than or equal to 50 percent was 36 percent lower (control vs. surgery, 39 vs. 24; P = 0.021). The value for two end points combined--death due to coronary heart disease and confirmed nonfatal myocardial infarction--was 35 percent lower in the surgery group (125 vs. 82 events; P less than 0.001). During follow-up, 137 control-group and 52 surgery-group patients underwent coronary-artery bypass grafting (P less than 0.0001). A comparison of base-line coronary arteriograms with those obtained at 3, 5, 7, and 10 years consistently showed less disease progression in the surgery group (P less than 0.001). The most common side effect of partial ileal bypass was diarrhea; others included occasional kidney stones, gallstones, and intestinal obstruction.
Partial ileal bypass produces sustained improvement in the blood lipid patterns of patients who have had a myocardial infarction and reduces their subsequent morbidity due to coronary heart disease. The role of this procedure in the management of hypercholesterolemia remains to be determined. These results provide strong evidence supporting the beneficial effects of lipid modification in the reduction of atherosclerosis progression.
The effect of intensive lipid-lowering therapy on coronary atherosclerosis among men at high risk for cardiovascular events was assessed by quantitative arteriography. Of 146 men no more than 62 years of age who had apolipoprotein B levels greater than or equal to 125 mg per deciliter, documented coronary artery disease, and a family history of vascular disease, 120 completed the 2 1/2-year double-blind study, which included arteriography at base line and after treatment. Patients were given dietary counseling and were randomly assigned to one of three treatments: lovastatin (20 mg twice a day) and colestipol (10 g three times a day); niacin (1 g four times a day) and colestipol (10 g three times a day); or conventional therapy with placebo (or colestipol if the low-density lipoprotein [LDL] cholesterol level was elevated).
The levels of LDL and high-density lipoprotein (HDL) cholesterol changed only slightly in the conventional-therapy group (mean changes, -7 and +5 percent, respectively), but more substantially among patients treated with lovastatin and colestipol (-46 and +15 percent) or niacin and colestipol (-32 and +43 percent). In the conventional-therapy group, 46 percent of the patients had definite lesion progression (and no regression) in at least one of nine proximal coronary segments; regression was the only change in 11 percent. By comparison, progression (as the only change) was less frequent among patients who received lovastatin and colestipol (21 percent) and those who received niacin and colestipol (25 percent), and regression was more frequent (lovastatin and colestipol, 32 percent; niacin and colestipol, 39 percent; P less than 0.005). Multivariate analysis indicated that a reduction in the level of apolipoprotein B (or LDL cholesterol) and in systolic blood pressure, and an increase in HDL cholesterol correlated independently with regression of coronary lesions. Clinical events (death, myocardial infarction, or revascularization for worsening symptoms) occurred in 10 of 52 patients assigned to conventional therapy, as compared with 3 of 46 assigned to receive lovastatin and colestipol and 2 of 48 assigned to receive niacin and colestipol (relative risk of an event during intensive treatment, 0.27; 95 percent confidence interval, 0.10 to 0.77).
In men with coronary artery disease who were at high risk for cardiovascular events, intensive lipid-lowering therapy reduced the frequency of progression of coronary lesions, increased the frequency of regression, and reduced the incidence of cardiovascular events.
Reduction of cardiac mortality associated with abdominal aortic aneurysm (AAA) repair remains an important goal. Five hundred consecutive urgent or elective operations for infrarenal nonruptured AAA were reviewed. Patients were divided into three groups based on preoperative cardiac status: group I (n = 260, 52%), no clinical or electrocardiographic (ECG) evidence of coronary artery disease (CAD); group II (n = 212, 42.2%), clinical or ECG evidence of CAD considered stable after further evaluation with studies such as dipyridamole-thallium scanning, echocardiography, or coronary arteriography; group III (n = 28, 5.6%), clinical or ECG evidence of CAD considered unstable after further evaluation. Group I had no further cardiac evaluation and groups I and II underwent AAA repair without invasive treatment of CAD. Group III underwent repair of cardiac disease before (n = 21) or coincident with (n = 7) AAA repair. In all instances, perioperative fluid volume management was based on left ventricular performance curves constructed before operation. The 30-day operative mortality rate for AAA repair in all 500 patients was 1.6% (n = 8). There was one (0.4%) cardiac-related operative death in group I, which was significantly less than the five (2.4%) in group II (p less than 0.02). Total mortality for the two groups were also significantly different, with one group I death (0.4%) and seven group II deaths (3.3%), (p less than 0.02). These data support the conclusions that (1) the leading cause of perioperative mortality in AAA repair is myocardial infarction, (2) correction of severe or unstable CAD before or coincident with AAA repair is effective in preventing operative mortality, (3) patients with known CAD should be investigated more thoroughly to identify those likely to develop perioperative myocardial ischemia so that their CAD can be corrected before AAA repair, and (4) patients with no clinical or ECG evidence of CAD rarely die of perioperative myocardial infarction, and thus selective evaluation of CAD based on clinical grounds in AAA patients is justified.
Adverse cardiac events are a major cause of morbidity and mortality after noncardiac surgery. It is necessary to determine the predictors of these outcomes in order to focus efforts on prevention and treatment. Patients undergoing noncardiac surgery sometimes have postoperative cardiac events. It would be helpful to know which patients are at highest risk.
We prospectively studied 474 men with coronary artery disease (243) or at high risk for it (231) who were undergoing elective noncardiac surgery. We gathered historical, clinical, laboratory, and physiologic data during hospitalization and for 6 to 24 months after surgery. Myocardial ischemia was assessed by continuous electrocardiographic monitoring, beginning two days before surgery and continuing for two days after.
Eighty-three patients (18 percent) had postoperative cardiac events in the hospital that were classified as ischemic events (cardiac death, myocardial infarction, or unstable angina) (15 patients), congestive heart failure (30), or ventricular tachycardia (38). Postoperative myocardial ischemia occurred in 41 percent of the monitored patients and was associated with a 2.8-fold increase in the odds of all adverse cardiac outcomes (95 percent confidence interval, 1.6 to 4.9; P less than 0.0002) and a 9.2-fold increase in the odds of an ischemic event (95 percent confidence interval, 2.0 to 42.0; P less than 0.004). Multivariate analysis showed no other clinical, historical, or perioperative variable to be independently associated with ischemic events, including cardiac-risk index, a history of previous myocardial infarction or congestive heart failure, or the occurrence of ischemia before or during surgery.
In high-risk patients undergoing noncardiac surgery, early postoperative myocardial ischemia is an important correlate of adverse cardiac outcomes.
Dipyridamole thallium imaging has been proposed for cardiac risk stratification in patients undergoing peripheral vascular surgery. The purpose of this study was to define the benefit of this investigation in routine preoperative evaluation of these patients. The outcome of 86 patients undergoing vascular surgery procedures was examined in light of preoperative clinical assessment and dipyridamole SPECT thallium imaging (DST). Fifty-one patients (59%) were considered at high risk on clinical grounds, and 22 patients (26%) had perfusion defects. Ten patients suffered a perioperative coronary event, including unstable angina, myocardial infarction, or cardiac death. Seven of the patients with such events were among the 51 clinically high-risk subjects (14%). Three perioperative events occurred in the group of 19 patients with positive DST images who underwent surgery (16%), but the DST test failed to identify 7 patients who suffered coronary events. The frequency of abnormal thallium imaging was similar to the prevalence of angiographically significant coronary disease reported previously at this center, but considerably less than the rate of abnormal thallium imaging in past studies of vascular surgery patients. The application of the test to a low to moderate risk population is probably responsible for its lower predictive accuracy for coronary events. DST is not an ideal routine noninvasive technique for risk stratification in patients undergoing vascular surgery.
The prognostic importance of coronary artery disease at the time of elective abdominal aortic aneurysmectomy was evaluated among 131 residents of Olmsted County, Minnesota who underwent elective aneurysmectomy from 1971 to 1987 and were followed up to 1988 for death and cardiac events (cardiac death, myocardial infarction, coronary bypass surgery and angioplasty). Before aneurysmectomy, 75 patients (Group 1) had no clinically recognized coronary disease, 47 patients (Group 2) had suspected or overt uncorrected coronary artery disease (history of prior myocardial infarction, angina or a positive stress test) and 9 patients (Group 3) had undergone coronary artery bypass grafting or coronary angioplasty. The 30 day operative mortality rate was 3% (2 of 75) in Group 1 and 9% (4 of 47) in Group 2 (p = 0.15). According to Kaplan-Meier analysis, estimated survival 8 years after aneurysmectomy was 59% (expected rate 68%, p = 0.29) in Group 1 versus 34% (expected rate 61%, p = 0.01) in Group 2. The cumulative incidence rate of cardiac events at 8 years was 15% and 61%, respectively, for patients without and with suspected/overt coronary artery disease (p less than 0.01). Using multivariable proportional hazards analysis, uncorrected coronary artery disease was associated with a nearly twofold increased risk of death (hazard ratio 1.79, 95% confidence interval 1.06 to 3.00) and a fourfold increased risk of cardiac events (hazard ratio 3.71, 95% confidence interval 1.79 to 7.69). These population-based data support an aggressive life-long approach to the management of coronary artery disease in patients undergoing abdominal aortic aneurysmectomy.
In August 1985, the Percutaneous Transluminal Coronary Angioplasty Registry of the National Heart, Lung, and Blood Institute reopened at its previous sites to document changes in angioplasty strategy and outcome. The new registry entered 1802 consecutive patients who had not had a myocardial infarction in the 10 days before angioplasty. Patient selection, technical outcome, and short-term major complications were compared with those of the 1977 to 1981 registry cohort. The new-registry patients were older and had a significantly higher proportion of multivessel disease (53 vs. 25 percent, P less than 0.001), poor left ventricular function (19 vs. 8 percent, P less than 0.001), previous myocardial infarction (37 vs. 21 percent, P less than 0.001), and previous coronary bypass surgery (13 vs. 9 percent, P less than 0.01). The new-registry cohort also had more complex coronary lesions, and angioplasty attempts in these patients involved more multivessel procedures. Despite these differences, the in-hospital outcome in the new cohort was better. Angiographic success rates according to lesion increased from 67 to 88 percent (P less than 0.001), and overall success rates (measured as a reduction of at least 20 percent in all lesions attempted, without death, myocardial infarction, or coronary bypass surgery) increased from 61 to 78 percent (P less than 0.001). In-hospital mortality for the new cohort was 1 percent, and the nonfatal myocardial infarction rate was 4.3 percent. Both rates are similar to those for the old registry. The long-term efficacy of current angioplasty remains to be determined.
The Cholesterol-Lowering Atherosclerosis Study (CLAS) was a randomized, placebo-controlled, angiographic trial testing combined colestipol hydrochloride and niacin therapy in 162 nonsmoking men aged 40 to 59 years with previous coronary bypass surgery. During two years of treatment there was a 26% reduction in total plasma cholesterol, a 43% reduction in low-density lipoprotein cholesterol, plus a simultaneous 37% elevation of high-density lipoprotein cholesterol. This resulted in a significant reduction in the average number of lesions per subject that progressed (P less than .03) and the percentage of subjects with new atheroma formation (P less than .03) in native coronary arteries. Also, the percentage of subjects with new lesions (P less than .04) or any adverse change in bypass grafts (P less than .03) was significantly reduced. Deterioration in overall coronary status was significantly less in drug-treated subjects than placebo-treated subjects (P less than .001). Atherosclerosis regression, as indicated by perceptible improvement in overall coronary status, occurred in 16.2% of colestipol-niacin treated vs 2.4% placebo treated (P = .002).
In this article, we describe a multifactorial cardiac risk index that can be used to assess patients undergoing noncardiac surgery. The index is a modified version of an index that was previously generated by Goldman and coworkers on a set of 1001 consecutive patients and prospectively validated in our clinical setting (a general medical consultation service in a large teaching hospital) on 455 patients. We present a Bayesian approach to assessing cardiac risks by converting average risks for patients undergoing particular surgical procedures (pretest probabilities) to average risks for patients with each index score (posttest probabilities). A simple nomogram is presented for performing such a calculation.
To evaluate the severity of coronary artery disease in patients with severe peripheral vascular disease requiring operation, we performed preoperative dipyridamole-thallium imaging in 54 stable patients with suspected coronary artery disease. Of the 54 patients, 48 had peripheral vascular surgery as scheduled without coronary angiography, of whom 8 (17 per cent) had postoperative cardiac ischemic events. The occurrence of these eight cardiac events could not have been predicted preoperatively by any clinical factors but did correlate with the presence of thallium redistribution. Eight of 16 patients with thallium redistribution had cardiac events, whereas there were no such events in 32 patients whose thallium scan either was normal or showed only persistent defects (P less than 0.0001). Six other patients also had thallium redistribution but underwent coronary angiography before vascular surgery. All had severe multivessel coronary artery disease, and four underwent coronary bypass surgery followed by uncomplicated peripheral vascular surgery. These data suggest that patients without thallium redistribution are at a low risk for postoperative ischemic events and may proceed to have vascular surgery. Patients with redistribution have a high incidence of postoperative ischemic events and should be considered for preoperative coronary angiography and myocardial revascularization in an effort to avoid postoperative myocardial ischemia and to improve survival. Dipyridamole-thallium imaging is superior to clinical assessment and is safer and less expensive than coronary angiography for the determination of cardiac risk.
Among 23 clinical characteristics examined in 3,627 consecutive, symptomatic patients referred for cardiac catheterization between 1969 and 1979, nine were found to be important for estimating the likelihood a patient had significant coronary artery disease. A model using these characteristics accurately estimated the likelihood of disease when applied prospectively to 1,811 patients referred since 1979 and when used to estimate the prevalence of disease in subgroups reported in the literature. Since accurate estimates of the likelihood of significant disease that are based on clinical characteristics are reproducible, they should be used in interpreting the results of additional noninvasive tests and in quantitating the added diagnostic value.
The costs and charges for coronary artery bypass graft surgery (CABG) are discussed. A paucity of national information is available; thus, more detailed data from the Maryland hospital experience are presented. The data show the interrelationship of charges, lengths of stay, sex, age and payor category. At a time when the primary concern for health care seems to be shifting from resource use to governmental budget expenditures, the data suggest that relatively few government dollars are paying for CABG.
About 10 percent of the U.S. population undergoes noncardiac surgery each year. Although the risk of a perioperative myocardial infarction with major surgery is only 1 to 2 percent in patients over the age of 40 years,1,2 the risk is higher in those who are older or have cardiovascular disease1–3. For example, in patients with well-controlled angina who undergo major vascular surgery, the risk of a perioperative myocardial infarction is 3 to 10 percent, and the risk of death from cardiac causes is 1 to 5 percent1,4–7. Several noninvasive cardiac tests, such as preoperative . . .