Prediction of cardiac events after uncomplicated acute myocardial infarction by clinical variables and dobutamine stress test.

OBJECTIVES: We sought to determine the relative prognostic power of several clinical and dobutamine stress test variables in patients after a first uncomplicated acute myocardial infarction (AMI).
BACKGROUND: The value of dobutamine echocardiography (DE) for determining prognosis after AMI is not yet defined. In particular, the influence of dobutamine stress test response on the outcome of these patients is unknown.
METHODS: A graded predischarge DE (from 5 to 40 microg/kg/min, plus atropine if needed) was performed in 245 patients (mean age 60 +/- 10 years) with a first uncomplicated AMI.
RESULTS: At follow-up (17 +/- 13 months), an adverse outcome occurred in 40 patients: cardiac death in 7, nonfatal myocardial infarction in 9 (hard events = 16) and unstable angina requiring hospital readmission in 24. Significant predictors of adverse outcome by univariate analysis were positive DE, ischemic wall motion score index (WMSI), angina during DE and diabetes for all events, and positive DE, ischemic WMSI and age for hard events. At multivariate analysis, the only independent predictors of adverse outcome were positive DE, diabetes and angina during DE for all events, and positive DE and age for hard events. The presence of both age >60 years and a history of diabetes identified patients at high risk of cardiac events (event rate 37%), compared with patients <60 years and no diabetes (event rate 11%). In patients with intermediate risk (only one clinical risk factor, event rate 18%), DE added prognostic information (event rate 10% in the negatives, 25% in the positives and 35% in the positives with angina).
CONCLUSIONS: After uncomplicated AMI, dobutamine stress test variables offer additional prognostic information to clinical data.