Echocardiographic Score Versus Wall Motion Index for Risk Stratification After Acute Myocardial Infarction

Abstract

Two-dimensional echo cardiographic wall motion scores are potentially valuable prognostic indicators because of their association with subsequent mortality in patients with acute myocardial infarction. Because wall motion scores are relatively simple to obtain, they could come into widespread use. But wall motion scores have been found to have a low positive predictive accuracy in respect to one- or three-year survival and a low specificity in respect to pump failure. To clarify the value of wall motion scores in risk stratification the authors analyzed the ability of a wall motion index, in combination with other variables, to predict death within a year of acute myocardial infarction. Patients were 149 consecutive men with acute myocardial infarction. There were no exclusion criteria. By Cox regression, the variables most closely related to survival were the presence of a pericardial effusion, the age of the patient, alcoholism, and the E point septal separation. The wall motion index, by comparison, was only weakly related to survival and was therefore dropped from further analyses. The four variables most closely related to survival were then used to derive a predictive echocardiographic score. The score's negative predictive accuracy was 94%, although sensitivity and positive predictive accuracy were low. These data suggest that, even when applied nonselectively, the echocardiographic score, but not the wall motion index, appears to be an efficient way of characterizing the outcome of acute myocardial infarction, in that it reliably detects low-risk patients.