PROGNOSTIC VALUE OF DOBUTAMINE-ATROPINE STRESS ECHOCARDIOGRAPHY EARLYAFTER ACUTE MYOCARDIAL-INFARCTION

Objectives. The aim of this multicenter, multinational, prospective, o bservational study was to assess the relative value of myocardial viab ility and induced ischemia early after uncomplicated myocardial infarc tion. Background. Dobutamine-atropine stress echocardiography allows e valuation of rest function (at baseline), myocardial viability (at low dose) and residual ischemia (peak dose, up to 40 mu g with atropine u p to 1 mg) in one test. Methods. Dobutamine-atropine stress echocardio graphy was performed 12 +/- 5 days (mean +/- SD) after a first uncompl icated acute myocardial infarction in 778 patients (677 men; mean age 58 +/- 10 years) with technically satisfactory rest echocardiographic study results. Patients were followed-up for 9 +/- 7 months. Results. Dobutamine-atropine stress echocardiographic findings were positive fo r myocardial ischemia in 436 of patients (56%) and negative in 342 (44 %). During follow-up, there were 14 cardiac related deaths (1.8% of th e total cohort), 24 (2.9%) nonfatal myocardial infarctions and 63 (8%) hospital readmissions for unstable angina. One hundred seventy-four p atients (22%) underwent coronary revascularization (bypass surgery or coronary angioplasty). Spontaneous events occurred in 61 of 436 patien ts with positive and 40 of 342 patients with negative findings on dobu tamine-atropine stress echocardiography (14% vs. 12%, p = 0.3). When o nly spontaneously occurring events were considered, the most important predictor was myocardial, viability (chi square 9.7), Using the Cox p roportional hazards model, only the presence of myocardial viability ( hazard ratio [HR] 2.0, p < 0.002) and age (HR 1.03, p < 0.001) were pr edictive of spontaneously occurring events. When only hard cardiac eve nts were considered, age,vas the strongest predictor (chi square 3.6, p = 0.056), followed by wall motion score index (WMSI) at peak dose (c hi-square 3.31 p = 0.06) and remote ischemia (chi-square 2.25, p = 0.1 ), When cardiac death was considered, WMSI at peak dose was the best p redictor (HR 9.2, p < 0.0001). Conclusions. During dobutamine stress, echocardiographic recognition of myocardial viability is more prognost ically important than echocardiographic recognition of myocardial isch emia for predicting unstable angina, whereas WMSI at peak stress was t he best predictor of cardiac-related death. Different events can be re cognized with different efficiency by various stress echocardiographic variables. (C) 1997 by the American College of Cardiology.