Value of myocardial viability estimation using dobutamine stress echocardiography in assessing risk preoperatively before noncardiac vascular surgery in patients with left ventricular ejection fraction <35%.
ABSTRACT Patients with heart failure (HF) scheduled for vascular surgery have an increased risk of adverse postoperative outcome, and stratification usually depends on dichotomous risk factors. A quantitative prognostic model for patients with HF was developed using wall motion patterns during dobutamine stress echocardiography (DSE). A total of 295 consecutive patients (mean age 67 +/- 12 years) with ejection fraction < or =35% were studied. During DSE, wall motion patterns of dysfunctional segments were scored as scar, ischemia, or sustained improvement. Cardiac death and myocardial infarction were noted perioperatively and during 5 years of follow-up. Of 4,572 dysfunctional segments; 1,783 (39%) had ischemia, 1,280 (28%) had sustained improvement, and 1,509 (33%) had scar. In 212 patients, > or =1 ischemic segment was present; 83 had only sustained improvement. Perioperative and late cardiac event rates were 20% and 30%, respectively. Using multivariate analysis, number of ischemic segments was associated with perioperative cardiac events (odds ratio per segment 1.6, 95% confidence interval 1.05 to 1.8), whereas number of segments with sustained improvement was associated with improved outcome (odds ratio per segment 0.2, 95% confidence interval 0.04 to 0.7). Multivariate independent predictors of late cardiac events were age and ischemia. Sustained improvement was associated with improved survival. In conclusion, DSE provides accurate risk stratification of patients with HF undergoing vascular surgery.
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ABSTRACT: Transthoracic echocardiography (TTE) is frequently ordered before noncardiac surgery, although its ability to predict perioperative cardiac complications is uncertain. To evaluate the incremental information provided by TTE after consideration of clinical data for prediction of cardiac complications after noncardiac surgery, 570 patients who underwent TTE before major noncardiac surgery at a university hospital were studied. Preoperative clinical data and clinical outcomes were collected prospectively according to a structured protocol. TTE data included left ventricular (LV) function, hypertrophy indexes, and Doppler-derived measurements. In univariate analyses, preoperative systolic dysfunction was associated with postoperative myocardial infarction (odds ratio [OR] 2.8, 95% confidence interval [CI] 1.1 to 7.0), cardiogenic pulmonary edema (OR 3.2, 95% CI 1.4 to 7.0), and major cardiac complications (OR 2.4, 95% Cl 1.3 to 4.5). Moderate to severe LV hypertrophy, moderate to severe mitral regurgitation, and increased aortic valve gradient were also associated with major cardiac events (OR 2.3, 95% CI 1.2 to 4.6; OR 2.2, 95% CI 1.1 to 4.3; OR 2.1, 95% CI 1.0 to 4.5, respectively). In logistic regression analysis, models with echocardiographic variables predicted major cardiac complications significantly better than those that included only clinical variables (c statistic 0.73 vs 0.68; p <0.05). Echocardiographic data added significant information for patients at increased risk for cardiac complications by clinical criteria, but not in otherwise low-risk patients. In conclusion, preoperative TTE before noncardiac surgery can provide independent information about the risk of postoperative cardiac complications in selected patients.The American Journal of Cardiology 04/2001; 87(5):505-9. · 3.21 Impact Factor
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ABSTRACT: Stress myocardial perfusion imaging (MPI) has become an important tool in risk stratification of patients with known coronary artery disease. A normal myocardial perfusion scan has a high negative predictive value and is associated with low annual mortality rate (< 1%). Patients with extensive ischemia (> 20% of the left ventricle), defects in more than 1 coronary vascular territory, transient or persistent left ventricular cavity dilation, and ejection fraction less than 45% have a high annual mortality rate (> 3%). Those patients should undergo coronary revascularization whenever feasible, as the cardiac event rate increases in proportion to the magnitude of the jeopardized myocardium. Stress MPI can be used to demonstrate ischemia in patients with symptoms early after coronary artery bypass surgery (< 5 years) or in those without symptoms late (>/= 5 years) after coronary artery bypass surgery. With respect to patients who underwent percutaneous interventions, stress MPI can help detect in-stent restenosis early after the intervention (3-6 months) or assess the progression of native coronary disease afterward. Since preliminary data suggest that a reduction in the perfusion defect size may translate to a reduction of coronary events, stress MPI can help assess the efficacy of medical management of coronary disease. Finally, stress MPI is indicated for perioperative cardiac risk stratification for noncardiac surgery in patients with intermediate risk predictors (mild angina, prior myocardial infarction or heart failure symptoms, diabetes mellitus, renal insufficiency) and poor functional capacity or in those who undergo high-risk surgery with significant implications in further preoperative management.Cardiology in Review 01/2003; 11(2):60-72. · 3.08 Impact Factor
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ABSTRACT: Cardiac complications are important causes of morbidity after noncardiac surgery. The purpose of this prospective cohort study was to develop and validate an index for risk of cardiac complications. We studied 4315 patients aged > or = 50 years undergoing elective major noncardiac procedures in a tertiary-care teaching hospital. The main outcome measures were major cardiac complications. Major cardiac complications occurred in 56 (2%) of 2893 patients assigned to the derivation cohort. Six independent predictors of complications were identified and included in a Revised Cardiac Risk Index: 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/dL. Rates of major cardiac complication with 0, 1, 2, or > or = 3 of these factors were 0.5%, 1.3%, 4%, and 9%, respectively, in the derivation cohort and 0.4%, 0.9%, 7%, and 11%, respectively, among 1422 patients in the validation cohort. Receiver operating characteristic curve analysis in the validation cohort indicated that the diagnostic performance of the Revised Cardiac Risk Index was superior to other published risk-prediction indexes. In stable patients undergoing nonurgent major noncardiac surgery, this index can identify patients at higher risk for complications. This index may be useful for identification of candidates for further risk stratification with noninvasive technologies or other management strategies, as well as low-risk patients in whom additional evaluation is unlikely to be helpful.Circulation 10/1999; 100(10):1043-9. · 15.20 Impact Factor