Objective: The aim of this multicenter, prospective, observational study was to assess the value of inducible ischemia in a large population of survivors of a first uncomplicated myocardial infarction (MI).
Methods and results: Pharmacologic stress echocardiography either with high-dose dipyridamole (0.84 mg/kg over 10 minutes) or high-dose dobutamine (up to 40 microg/kg over 3 minutes) (DET) was performed 9 +/- 10 days after a first acute uncomplicated MI in 1681 patients (1499 males; 57 +/- 10 years) with technically satisfactory rest echocardiographic study. Patients were followed up for a mean of 16 +/- 18 months (range: 1-122). DET was positive for myocardial ischemia in 884 (52.5%) and negative in 797 (47.5%) patients. During the follow-up there were 49 deaths for all-cause mortality (2.9% of the total population), 22 of which were cardiac; 62 (3.6%) nonfatal MIs; and 164 (9.7%) hospital readmissions for unstable angina. In all, 376 patients (22%) underwent coronary revascularization (bypass operation or angioplasty).
Results: Hard events occurred in 71 of the 884 patients with positive and in 40 of the 797 patients with negative DET (8% vs 5%, P =.014). Using the Cox proportional hazards model, age (relative risk [RR] 1.07, 95% confidence interval [CI] 1.03-1.1), history of angina (RR 3.8, 95% CI 1.6-8.6), peak wall-motion score index (RR 2.2, 95% CI 1.1-4.4), and pharmacologic dose at ischemia (RR 1.5, 95% CI 1.04-2.3) were independent predictors of all-cause death.
Conclusions: In survivors of a first acute uncomplicated MI DET allows effective risk stratification on the basis of the presence, severity, and extent the induced ischemia.