Dobutamine stress echocardiography and exercise electrocardiography for risk stratification in medically treated unstable angina.

UNLABELLED: 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.

Feasibility and prognostic value of dobutamine-atropine stress echocardiography early in unstable angina.

BACKGROUND AND AIM: Because unstable angina has always been considered a contraindication for dobutamine-atropine stress echocardiography (DSE), the role of dobutamine-atropine stress echocardiography in unstable angina is unknown. Our aim was to assess the safety and prognostic value of dobutamine-atropine stress echocardiography in unstable angina. METHODS: One hundred and thirty-two patients were studied (mean age 64+/-12 years, 29 women). Dobutamine-atropine stress echocardiography was performed on the third day after hospital admission. End-points were unstable angina, myocardial infarction or cardiac death at 1 year follow-up. RESULTS: No major complications occurred during dobutamine-atropine stress echocardiography. Ninety-six (78%) patients were on beta-blocker therapy during the test; mean maximum heart rate achieved was 106+/-23 beats x min(-1). Nine of the 21 patients (43%) with a positive dobutamine-atropine stress echocardiography presented cardiac events during follow-up: two patients died, one had a myocardial infarction and six had recurrent class III-IV angina. Among 80 patients with negative dobutamine-atropine stress echocardiography, one (1%) had myocardial infarction and six patients (7.5%) had recurrent angina. Event-free survival after 1 year for patients with a negative dobutamine-atropine stress echocardiography for ischaemia was 91% compared to 57% for those with a positive dobutamine-atropine stress echocardiography (P<0. 0001). Left ventricular dysfunction (P=0.01), prior myocardial infarction (P=0.03) and a positive dobutamine-atropine stress echocardiography (P=0.004) were independent predictors of cardiac events during follow-up. CONCLUSIONS: Dobutamine-atropine stress echocardiography is safe in unstable angina if it is performed when patients remain asymptomatic for at least 48 h. A negative dobutamine-atropine stress echocardiogram for ischaemia predicts a good prognosis in medically treated patients with unstable angina and may allow their early discharge from hospital. Good prognostic information was obtained despite the use of beta-blockers and low heart rates during dobutamine-atropine stress echocardiography.