Body mass index and mortality in acute myocardial infarction patients

Abstract

Background: Previous studies have described an "obesity paradox" with heart failure, whereby higher body mass index (BMI) is associated with lower mortality. However, little is known about the impact of obesity on survival after acute myocardial infarction. Methods: Data from 2 registries of patients hospitalized in the US with acute myocardial infarction between 2003-2004 (PREMIER) and 2005-2008 (TRIUMPH) were used to examine the association of BMI with mortality. Patients (n = 6359) were categorized into BMI groups (kg/m 2) using baseline measurements. Two sets of analyses were performed using Cox proportional hazards regression with fractional polynomials to model BMI as categorical and continuous variables. To assess the independent association of BMI with mortality, analyses were repeated, adjusting for 7 domains of patient and clinical characteristics. Results: Median BMI was 28.6. BMI was inversely associated with crude 1-year mortality (normal, 9.2%; overweight, 6.1%; obese, 4.7%; morbidly obese; 4.6%; P