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Determinants of the prognosis after a first myocardial infarction in a migrant Japanese population. The Honolulu
Insights
Prognosis after a first myocardial infarction (MI) depends on age and complications. Pre-MI risk factors like glucose and lung function also predict long-term survival, independent of clinical factors.
Area of Science:
- Cardiology
- Public Health
- Epidemiology
Background:
- Limited understanding of prognostic determinants after a first myocardial infarction (MI).
- Focus on the role of standard coronary heart disease (CHD) risk factors measured before MI.
Purpose of the Study:
- Investigate determinants of mortality after a first MI.
- Examine the influence of pre-MI CHD risk factors on prognosis.
Main Methods:
- Prospective study of 457 men of Japanese ancestry with first MI over 20 years.
- Multivariate logistic and Cox regression models used for early (<30 days) and late (30 days to 10 years) mortality analyses.
- Analysis included clinical variables and pre-MI CHD risk factors.
Main Results:
- Age at MI and severe complications (Killip classes 3-4) predicted early and late mortality (up to 5 years).
- Ventricular arrhythmias predicted early mortality; anterior MI, cardiomegaly/pulmonary congestion, and intraventricular block predicted late mortality (up to 5 years).
- Pre-MI serum glucose and forced expiratory volume predicted late mortality up to 5 years; systolic blood pressure predicted mortality after 5 years.
Conclusions:
- Age and clinical indicators of complications are key prognostic determinants of MI.
- Pre-MI standard CHD risk factors can predict long-term prognosis independently of age and clinical factors.
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.