Prognostic value of predischarge exercise stress echocardiography after acute myocardial infarction

A predischarge exercise test was performed by 70 patients 7 ± 4 days (mean ± SD) after acute myocardial infarction (AMI) to determine the short- and long-term prognostic value of predischarge exercise stress echocardiography (Ex-Echo) compared with exercise stress electrocardiography (Ex-ECG). Two-dimensional echocardiograms were obtained at rest and immediately after exercise; a wall motion score index was obtained both at rest and immediately after exercise. Results of the Ex-Echo were positive in 27 patients (39%), whereas those of Ex-ECG were positive in 34 (49%). The wall motion index after exercise was lower in patients who died during follow-up (85 vs 98, p = 0.01) and in those with cardiac events, defined as death, nonfatal reinfarction, or revascularization (88 vs 98, p = 0.005). More patients with a positive Ex-Echo result had short-term cardiac events (within 2 weeks) than patients with a negative Ex-Echo (6 [22%] vs 2 [5%], p = 0.04). The same was true for long-term mortality (12 [44%] vs 3 [7%], p = 0.0002), reinfarctions (10 [37%] vs 4 [9%], p = 0.01), revascularization procedures (11 [41%] vs 7 [16%], p = 0.023), and cardiac events (22 [81%] vs 12 [28%], p < 0.0001). Survival time was shorter in patients with positive compared with negative Ex-Echo results (34% difference between groups, 95% confidence interval [CI] 10% to 58%, p = 0.002). The same applied for cumulative survival free from cardiac events (43%, p = 0.001, 95% Cl 9% to 77%). In a multivariate regression analysis, both Ex-Echo and Ex-ECG independently predicted death, death or nonfatal reinfarction, revascularization, and cardiac events. A new-onset wall motion abnormality was, however, the strongest variable predicting death (hazards ratio 9.8, 95% Cl 8.5 to 11) and deaths or non-fatal reinfarction (hazards ratio 4.3, 95% Cl 3.4 to 5.3). Thus, Ex-Echo is recommended for early risk stratification after AMI.