Prognostic value of dobutamine echocardiography in patients after q-wave or non–q-wave acute myocardial infarction

Abstract

We investigated the role of dobutamine echocardiography in predicting future spontaneous events in patients with Q-wave or non–Q-wave first acute myocardial infarction (AMI). DE was performed in 168 patients with a Q-wave AMI and 105 patients with a non–Q-wave AMI. Patients were observed for hard events (cardiac death and nonfatal reinfarction) and all spontaneous events (hard events and unstable angina). When compared to patients with a Q-wave AMI, patients with non–Q-wave AMI had a higher rate of positive dobutamine echocardiographic results (51.8% vs 80.0%, p <0.0001), greater changes in wall motion score index (WMSI) (0.31 ± 0.17 vs 0.42 ± 0.23, p = 0.001), and more remote zone ischemia (27.9% vs 43.8%, p = 0.0072). Patients with non–Q-wave infarct had a higher all-event rate, but a similar hard-event rate. In patients with a positive dobutamine echocardiogram (DE), the rate of hard or all events was similar, regardless of different infarct patterns. Patients with a negative DE had a higher event-free survival rate for all events in both Q-wave (85.2% vs 60.9%, p <0.0001) and non–Q-wave (76.2% vs 52.4%, p = 0.0083) groups. By stepwise analysis in the Q-wave group, the most important predictors were peak stress WMSI and diabetes for hard events, and a positive DE and baseline WMSI for all events. However, in the non–Q-wave group, the strongest predictors were dobutamine time for hard events and positive DE for all events. We conclude that a positive DE is a powerful predictor of future spontaneous events in patients after either a Q-wave or non–Q-wave AMI. However, for hard events, high-risk patients with different infarct patterns were recognized with variable efficiency by different dobutamine echocardiographic variables.