Prognostic value of dobutamine stress echocardiography in patients with normal left ventricular systolic function

Background: Patients with normal left ventricular systolic function are considered to be at a relatively low risk for cardiac events. There are scarce data regarding association of ischemia on stress imaging techniques with outcome in these patients. Objectives. We sought to assess the prognostic significance of dobutamine-induced myocardial ischemia for patients with normal left ventricular systolic function. Methods: We studied 528 patients with normal baseline left ventricular systolic function who underwent high-dose dobutamine-atropine stress echocardiography and were followed up for 4.7 +/- 2.1 years for occurrence of death and hard cardiac events (cardiac death and nonfatal myocardial infarction). Results: Ischemia (new wall-motion abnormalities) was detected in 127 patients (24%). Follow-up events were death in 69 patients (13%) and hard cardiac events in 55 patients (10%). The annual hard cardiac event rate was 5% for patients with ischemia and 1.1% for patients without. in a multivariate analysis model, ischemia was the only independent predictor of hard cardiac events (risk ratio [RR] 4.3, 95% confidence intervals [CI] 2.5-7.4). Predictors of all causes of mortality were advanced age (RR 1.08, CI 1.05-1-11), higher resting rate pressure product (RR 1.11, CI 1.02-1.22), and ischemia (RR 2.1, CI 1.2-3.6). Conclusion: Dobutamine-induced wall-motion abnormalities are independently associated with increased risk of all-cause mortality and hard cardiac events in patients with normal baseline left ventricular function.