Obesity and survival in patients with heart failure and preserved systolic function: A U-shaped relationship

Background Studies document better survival in heart failure patients with decreased left ventricular ejection fraction (EF) and higher body mass index (BMI; kg/m2 ) compared to those with a lower BMI. However, it is unknown if this “obesity paradox” applies to heart failure patients with preserved EF or if it extends to the very obese (BMI >35). Methods We determined all-cause mortality for 1,236 consecutive patients with a prior diagnosis of heart failure and a preserved EF (≥50%). Results Obesity (BMI>30) was noted in 542 patients (44%). The mean age was 71 ± 12 years, but this varied depending on BMI. One-year all-cause mortality decreased with increasing BMI, except at BMI >45 where mortality began to increase (55% if BMI 45, P < .001). After adjustment for patient age, history, medications, and laboratory and echocardiographic parameters, the hazard ratios for total mortality (relative to BMI 26-30) were 1.68 (95% CI, 1.04-2.69) for BMI 45 ( P < .0001). Conclusions Low BMI is associated with increased mortality in patients with heart failure and preserved systolic function. However, with a BMI of >45, mortality increased, raising the possibility of a U-shaped relationship between BMI and survival.