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.