Dobutamine Stress Echocardiography and Exercise Electrocardiography for Risk Stratification in Medically Treated Unstable Angina

Abstract Previous reports have demonstrated the superiority of exercise echocardiography over exercise electro-cardiography (ex-ECG) for risk stratification in patients with medically stabilized unstable angina (UA). We sought to analyze the prognostic value of dobutamine stress echocardiography (DSE) compared with ex-ECG for risk stratification in patients with UA. Methods: Ninety-two patients with medically treated UA were studied (mean age 65 ± 11 years, 24 women, 42% of patients had electrocardiographic abnormalities on admission). Dobutamine stress echocardiography and treadmill ex-ECG were performed on the third day after hospital admission. End points were recurrent UA, myocardial infarction (MI), or cardiac death. Results: Mean follow-up was 24 ± 7 months. During follow-up, 22 patients had cardiac events (18 recurrent UA, 2 MI, 2 cardiac deaths). The event-free survival rate was 80% for patients with negative DSE results for ischemia and 52% for those with positive DSE results (log rank 9.57; P =.002), compared with an event-free survival rate of 79% for patients with negative ex-ECG results and 66% for those with positive ex-ECG results (log rank 2.06; P = not significant). Left ventricular dysfunction ( P =.01) and a positive dobutamine stress echocardiogram ( P =.03), but not a positive exercise electrocardiogram, were independent predictors of cardiac events during follow-up. Conclusions: Dobutamine stress echocardiography performed early in medically treated patients with UA predicts cardiac events during follow-up more accurately and with more specificity than ex-ECG does in this population. (J Am Soc Echocardiogr 2000;13:1084-90.)