Purpose: To determine the relationship among clinical data, attenuated treadmill stress test (ST), cinecoronaryarteriography (CINE), ejection fraction (EF) with early-late mortality in patients after acute myocardial infarction (AMI).
Methods: Prospective study in 96 consecutive patients aged < 70 with AMI that were submitted to ST and CINE. Assessment of cardiac mortality was made 1-3 years post-AMI (period I) and at the end of follow-up (7-10 years-period II).
Results: First year and 10th year mortalities were 8% and 36%, respectively. Positive predictive value for cardiac death in period I was 10% for ST, 7% for multivessel coronary artery disease (MVCAD) and 9% for left ventricular ejection fraction (LVEF) < 30, while in period II they were 45%, 42% and 50%, respectively. Actuarial survival analysis (Kaplan-Meyer) disclosed mortality rates of 53% and 20% (p = 0.06) on period II for positive and negative ST, respectively, 45% and 22% (p < 0.03) for MVCAD and single-vessel disease, respectively, and 73% and 35% (p < 0.001) for those with and without left main coronary artery obstruction, respectively. In the multivariate regression analysis (Cox's model), only MVCAD (p < 0.002), LVEF < 30 (p < 0.003), positive ST (p < 0.007) and post-AMI angina (p < 0.01) were independently related to late mortality.
Conclusion: Both attenuated ST and CINE are poor predictors of post-AMI early and late mortalities. However, multivariate regression analysis disclosed positive ST, MVCAD and LVEF < 30 as independent variables related to late mortality. This data indicate that myocardial ischemia, number of obstructed coronary arteries and poor left ventricular systolic function are the true determinants of post-infarction cardiac mortality.