Combining Clinical and Thallium Data Optimizes Preoperative Assessment of Cardiac Risk Before Major Vascular Surgery

Massachusetts General Hospital, Boston.
Annals of internal medicine (Impact Factor: 17.81). 07/1989; 110(11):859-66. DOI: 10.1097/00132586-199006000-00023
Source: PubMed


To determine whether clinical markers and preoperative dipyridamole-thallium imaging are both useful in predicting ischemic events after vascular surgery.
Retrospective, observational study.
University medical center.
Two hundred fifty-four consecutive patients referred to a nuclear cardiology laboratory before surgery. Forty-four patients had surgery cancelled or postponed after clinical evaluation and dipyridamole-thallium imaging. Surgery was not confirmed for ten. Two hundred patients receiving prompt vascular surgery were the study group.
Thirty patients (15%) had early postoperative cardiac ischemic events, with cardiac death in 6 (3%) and nonfatal myocardial infarction in 9 (4.5%). Logistic regression identified five clinical predictors (Q waves, history of ventricular ectopic activity, diabetes, advanced age, angina) and two dipyridamole-thallium predictors of postoperative events. Of patients with none of the clinical variables (n = 64), only 2 (3.1%; 95% CI, 0% to 8%) had ischemic events with no cardiac deaths. Ten of twenty (50%; 95% CI, 29% to 71%) patients with three or more clinical markers had events. Eighteen of one hundred sixteen (15.5%; 95% CI, 7% to 21%) patients with either 1 or 2 clinical predictors had events. Within this group, 2 of 62 (3.2%; 95% CI, 0% to 8%) patients without thallium redistribution had events compared with 16 events in 54 patients (29.6%; 95% CI, 16% to 44%) with thallium redistribution. The multivariate model using both clinical and thallium variables showed significantly higher specificity at equivalent sensitivity levels than models using either clinical or thallium variables alone.
Preoperative dipyridamole-thallium imaging appears most useful to stratify vascular patients determined to be at intermediate risk by clinical evaluation. For patients with one or two clinical predictors, thallium redistribution correlates with substantial change in probability of events. For nearly half the patients, however, thallium imaging may have been unnecessary because of very high or low cardiac risk predicted by clinical information alone.

8 Reads
    • "Only 5% of surgical cases got cancelled due to highly abnormal MPI. Patients with normal MPI had a very low frequency of perioperative cardiac events (1.2%), while the event rate was 5% in patients with fixed defects and increased to 15% in patients showing reversible defects in MPI.[1415161718192021] "
    [Show abstract] [Hide abstract]
    ABSTRACT: The increasing number of patients with coronary artery disease (CAD) undergoing major noncardiac surgery justifies guidelines concerning preoperative cardiac evaluation. This is compounded by increasing chances for a volatile perioperative period if the underlying cardiac problems are left uncorrected prior to major noncardiac surgeries. Preoperative cardiac evaluation requires the clinician to assess the patient's probability to have CAD, severity and stability of CAD, placing these in perspective regarding the likelihood of a perioperative cardiac complication based on the planned surgical procedure. Coronary events like new onset ischemia, infarction, or revascularization, induce a high-risk period of 6 weeks, and an intermediate-risk period of 3 months before performing noncardiac surgery. This delay is unwarranted in cases where surgery is the mainstay of treatment. The objective of this review is to offer a comprehensive algorithm in the preoperative assessment of patients undergoing noncardiac surgery and highlight the importance of myocardial perfusion imaging in risk stratifying these patients.
    No preview · Article · Mar 2014
  • Source
    • "Thus, evaluation of the cardiovascular system in patients with hypertension is important to predict perioperative morbidity and mortality before undertaking non-cardiac surgery. A variety of scoring systems and imaging strategies have been developed to predict such adverse cardiovascular events.4-8) However, low predictive accuracy and poor clinical utility have limited the use of risk indices in current clinical practice and currently, there is no gold standard to effectively predict postoperative complications, length of hospital stay, or the possibility of mortality. "
    [Show abstract] [Hide abstract]
    ABSTRACT: B-type natriuretic peptide (BNP) is an important marker for the diagnosis of heart failure and is useful towards predicting morbidity and mortality after non-cardiac surgery. Nevertheless, information on the relationship between postoperative BNP levels and perioperative prognosis after non-cardiac surgery is scarce. The purpose of the study was to assess whether postoperative BNP levels could be used as a predictor of prolonged hospitalization in elderly hypertensive patients after non-cardiac surgery. Ninety-seven (97) patients, aged 55 years or older (mean age: 73.12±10.05 years, M : F=24 : 73) were enrolled in a prospective study from May 2005 through August 2010. All patients underwent total knee or hip replacement. Postoperative BNP and other diagnostic data were recorded within 24 hours of surgery. Patients that required a prolonged hospital stay due to operative causes, such as wound infection and re-operation, were excluded. The length of hospital stay was significantly correlated with postoperative BNP levels (p=0.031). Receiver operating characteristic curves demonstrated postoperative BNP levels as predictors of hospital stay ≥30 days with areas under the curve of 0.774 (95% confidence interval: 0.679-0.87, p<0.0001). A BNP cut-off value above 217.5 pg/mL had a sensitivity of 80.6% and a specificity of 66.7% for predicting postoperative hospital stays of 30 days or more. Postoperative BNP levels may predict the length of hospital stays after non-cardiac surgery in hypertensive patients. Elevated BNP levels were associated with prolonged hospitalization after elective orthopedic surgery.
    Full-text · Article · Aug 2012 · Korean Circulation Journal
  • Source
    • "Since perioperative cardiac mortality and morbidity are the most frequently occurring adverse events in non-cardiac vascular surgery, the majority of the previously-mentioned risk indexes are focused on the evaluation of perioperative cardiac risk (Kertai et al., 2005, Eagle et al., 1989b). "
    [Show abstract] [Hide abstract]
    ABSTRACT: The ability to predict post-operative mortality reliably will be of assistance in making decisions concerning the treatment of an individual patient. The aim of this study was to test the GAS score as a predictor of post-operative mortality in vascular surgical patients. A total of 157 consecutive patients who underwent an elective vascular surgical procedure were included in the study. The Cox proportional hazards model was used in analyzing the importance of various preoperative risk factors for the postoperative outcome. ASA and GAS were tested in predicting the short and longterm outcome. On the basis of the GAS cut-off value 77, patients were selected into low-risk (GAS low: GAS<77) and high-risk (GAS high: GAS>or=77) groups, and the examined risk factors were analyzed to determine which of them had predictive value for the prognosis. None of the patients in the GAS low group died, and mortality in the GAS high group was 4.8% (p=0.03) at 30 days follow-up. The 12-month survival rates were 98.6% and 78.6% (p=0.0001), respectively, with the respective 5-year survival rates of 76.7% and 44.0% (p=0.0001). The only independent risk factor for 30-day mortality was the renal risk factor (OR 20.2). The combination of all three GAS variables (chronic renal failure, cardiac disease and cerebrovascular disease), excluding age, was associated with a 100% two-year mortality. Mortality is low for patients with GAS<77. For the high-risk patients (GAS>or=77), due to its low predictive value for death, GAS yields limited value in clinical practice. In cases of patients with all three risk factors (renal, cardiac and cerebrovascular), vascular surgery should be considered very carefully.
    Preview · Article · Jan 2009 · Scandinavian journal of surgery: SJS: official organ for the Finnish Surgical Society and the Scandinavian Surgical Society
Show more