Body Mass Index and Mortality in Acutely Decompensated Heart Failure Across the World

Objective To define the relationship between body mass index (BMI) and mortality in heart failure (HF) across the world and identify specific groups in whom BMI may differentially mediate risk. Background Obesity is associated with incident heart failure (HF), but is paradoxically associated with better prognosis during chronic HF. Methods We studied 6,142 patients with acute decompensated HF from 12 prospective observational cohorts followed across 4 continents. Primary outcome was all-cause mortality. Cox proportional hazards models and net reclassification index (NRI) described associations of BMI with all-cause mortality. Results “Normal” weight patients (BMI 18.5-25 kg/m2) were older with more advanced HF and lower cardiometabolic risk. Despite worldwide heterogeneity in clinical features across obesity categories, a higher BMI remained associated with decreased 30-day and 1-year mortality (11% decrease at 30 days; 9% decrease at 1 year per 5 kg/m2; P75; HR=0.82, P=0.006), decreased cardiac function (ejection fraction < 50%; HR=0.85, P