Dobutamine Stress Echocardiography for Risk Stratification After Myocardial Infarction

Abstract

Background Because dobutamine stress echocardiography (DSE) provides assessment of left ventricular function and ischemia at a distance, the major determinants of adverse outcome after acute myocardial infarction (AMI), we undertook this study to determine the role of DSE in risk stratification after AMI. Methods and Results A graded DSE in 5-minute stages was performed in 214 patients (age, 57±13 years [mean±SD]) at 2 to 7 days after AMI. Coronary angiography was performed in 193 patients. Follow-up data regarding major cardiac events were obtained through telephone interviews and chart reviews. All patients were followed for ≥500 days or until a hard cardiac event occurred. The mean follow-up interval was 494±182 days after AMI. Peak heart rate and systolic blood pressure were 115±21 bpm and 135±29 mm Hg, respectively. An adverse outcome occurred in 80 of 214 patients; cardiac death occurred in 15, nonfatal AMI occurred in 15, sustained or symptomatic ventricular arrhythmia occurred in 5, congestive heart failure occurred in 14, and unstable angina occurred in 31. Significant predictors of adverse outcome by univariate analysis were prior myocardial infarction ( P =.005), anterior infarction ( P =.006), multivessel coronary artery disease ( P <.0001), global resting left ventricular wall motion score index ( P <.0001), infarction zone nonviability based on akinesis unresponsive to low-dose dobutamine ( P <.0001), and ischemia/infarction at a distance ( P <.0001). Furthermore, the extent of infarct zone and nonviability correlated with the severity of the cardiac event. Multivariate analysis of clinical, angiographic, and DSE variables revealed that the only independent predictors of adverse outcome were ischemia/infarction at a distance ( P <.0001) and infarction zone nonviability ( P <.0001). Multivessel disease identified through DSE was more predictive of adverse outcome than was angiographically determined multivessel disease. Conclusions DSE can be used to predict adverse outcomes after AMI.