Determinants of the prognosis after a first myocardial infarction in a migrant Japanese population. The Honolulu Heart Program.

Abstract

BACKGROUND Although numerous studies have been published on the prognostic assessment of myocardial infarction, little is known about determinants of the prognosis after a first myocardial infarction, especially regarding the role of standard risk factors for coronary heart disease (CHD) measured before the development of myocardial infarction. METHODS AND RESULTS In a prospective study of CHD among men of Japanese ancestry living in Hawaii, 457 patients with a first myocardial infarction (age range, 46 to 84 years) were identified during 20 years of follow-up. The relations of clinical variables and CHD risk factors to mortality in early (< 30 days) and two stages of late (30 days to 5 years and 5 to 10 years) periods after myocardial infarction in these patients were investigated. In multivariate analyses using logistic regression models (for early mortality) and Cox regression models (for late mortality), age at myocardial infarction and severe complications (Killip classes 3 and 4) were independent predictors of both early and late mortality (up to 5 years after myocardial infarction). In addition, ventricular arrhythmias predicted only early mortality, whereas anterior myocardial infarction, radiological evidence of cardiomegaly and/or pulmonary congestion, and intraventricular block predicted only late mortality (up to 5 years after myocardial infarction). Only age was an independent predictor of all-cause mortality more than 5 years after myocardial infarction. After adjusting for age at myocardial infarction and these clinical variables, preinfarction-measured risk factors such as 1-hour postload serum glucose (positively) and 1-second forced expiratory volume (inversely) were significantly associated with late mortality up to 5 years, whereas systolic blood pressure was the only independent predictor of late mortality after 5 years. CONCLUSIONS This study has confirmed the importance of age at myocardial infarction and clinical indicators of complications such as Killip class 3 or 4, radiological evidence of pulmonary congestion, and ventricular arrhythmias or intraventricular block as the prognostic determinants of myocardial infarction. In addition, some of the preinfarction-measured standard risk factors for CHD were found to predict long-term prognosis independent of age and clinical factors.