To investigate the value of the Doppler-derived myocardial performance index to predict early left-ventricular (LV) dilation and cardiac death after a first acute myocardial infarction (AMI), Doppler echocardiography was performed within 24 h of hospital admission, on day 5, 1 and 3 months after AMI in 125 consecutive patients. The index measured on day 1 correlated well with the change in end-diastolic volume index observed from day 1 to 3 months following AMI (r = 0.66, p < 0.0001). One-year survival in patients with Doppler index <0.63 was 89%, and 37% in patients with index > or = 0.63, (p < 0.0001). Multivariate analysis identified myocardial performance index > or = 0.63 (relative risk 5.6, p < 0.0001), E-wave deceleration time <140 ms (relative risk 2.7, p = 0.008) and Killip class > or = II (relative risk 4.0, p = 0.04) to be independent predictors of cardiac death. Therefore, we conclude that the Doppler echocardiographic myocardial performance index is a predictor of LV dilation and cardiac death after a first AMI.