Survivorship patterns in the posthospital phase of myocardial infarction.

Abstract

A prospective postinfarction follow-up study was used to identify subsets of patients with different survival patterns. Patients (940) who survived the hospital phase of an acute myocardial infarction were followed for 12-60 mo. During the 5 yr follow-up, 115 patients died of cardiac causes. Univariate analysis showed that prior myocardial infarction (PMI), left ventricular dysfunction (LVD) in the CCU [coronary care unit], one or more ventricular premature depolarizations (VPD) on a 6 h Holter recording, and anterior myocardial infarction were significantly (P < 0.01) more frequent in patients who died of cardiac causes than in survivors. Survivorship analyses revealed a variety of survival patterns, depending on the presence or absence of the risk factors PMI, LVD, VPD and anterior infarction, and their interactive combinations. A combination of anterior infarction with LVD and VPD identified a high-risk subset that made up 15% of the myocardial infarction population, and this group had 6 mo. and 3 yr survival rates of 85 and 70%, respectively. After the high-risk subset was excluded, PMI, LVD and VPD each had significant yet independent influence on survival, with PMI having a greater effect on mortality than either LVD or VPD. A low-risk subset that made up 24% of the population was identified by the absence of PMI, LVD and VPD, and this group had a 3 yr survival of 94%.