Atherosclerotic risk factors and their association with hospital mortality among patients with first myocardial infarction (from the National Registry of Myocardial Infarction)

Abstract

Few studies have examined associations between atherosclerotic risk factors and short-term mortality after first myocardial infarction (MI). Histories of 5 traditional atherosclerotic risk factors at presentation (diabetes, hypertension, smoking, dyslipidemia, and family history of premature heart disease) and hospital mortality were examined among 542,008 patients with first MIs in the National Registry of Myocardial Infarction (1994 to 2006). On initial MI presentation, history of hypertension (52.3%) was most common, followed by smoking (31.3%). The least common risk factor was diabetes (22.4%). Crude mortality was highest in patients with MI with diabetes (11.9%) and hypertension (9.8%) and lowest in those with smoking histories (5.4%) and dyslipidemia (4.6%). The inclusion of 5 atherosclerotic risk factors in a stepwise multivariate model contributed little toward predicting hospital mortality over age alone (C-statistic = 0.73 and 0.71, respectively). After extensive multivariate adjustments for clinical and sociodemographic factors, patients with MI with diabetes had higher odds of dying (odds ratio [OR] 1.23, 95% confidence interval [CI] 1.20 to 1.26) than those without diabetes and similarly for hypertension (OR 1.08, 95% CI 1.06 to 1.11). Conversely, family history (OR 0.71, 95% CI 0.69 to 0.73), dyslipidemia (OR 0.62, 95% CI 0.60 to 0.64), and smoking (OR 0.85, 95% CI 0.83 to 0.88) were associated with decreased mortality (C-statistic = 0.82 for the full model). In conclusion, in the setting of acute MI, histories of diabetes and hypertension are associated with higher hospital mortality, but the inclusion of atherosclerotic risk factors in models of hospital mortality does not improve predictive ability beyond other major clinical and sociodemographic characteristics.