Usefulness of the severity and extent of wall motion abnormalities as prognostic markers of an adverse outcome after a first myocardial infarction treated with thrombolytic therapy

The prognostic value of wall motion score index (WMSI), assessed at predischarge after a first acute myocardial infarction (AMI) in the thrombolytic era, is still not well known. One-hundred forty-four consecutive patients with a first AMI treated with thrombolytic therapy underwent exercise testing and echocardiography at rest before discharge and were followed-up for a mean period of 18 months. During follow-up, there were 32 cardiac events (12 patients had cardiac deaths, 8 had unstable angina pectoris, 1 had nonfatal reinfarction, and 11 patients had congestive heart failure). The patients who experienced any cardiac event had a higher WMSI (1.67 ± 0.15 vs 1.30 ± 0.16, p <0.0001), a higher end-systolic volume (75.1 ± 34 vs 59.5 ± 22 ml, p <0.01), and a lower ejection fraction (47 ± 16% vs 55 ± 10%, p <0.001) at predischarge than patients without events. The incidence of a positive predischarge exercise testing did not differ between patients with and without cardiac events (22% vs 24%, p = NS). Multivariate Cox regression analysis, including clinical, exercise results, and echocardiographic parameters, showed that the most powerful predictor of a subsequent event was a resting WMSI ≥1.50 before discharge (chi-square 17.8, p <0.0001). Thus, in patients with a first AMI who underwent thrombolysis, the severity and extent of echocardiographically detected wall motion abnormalities are important independent predictors of cardiac events.