Underweight Is Associated with Poor Prognosis in Heart Failure with Preserved Ejection Fraction

The obesity paradox states higher body mass index (BMI) is associated with better outcomes than normal weight in patients with heart failure with preserved ejection fraction (HFpEF). However, underweight was defined by BMI < 18.5 kg/m(2), and results have been inconclusive, in part due to small number of participants. The number of underweight patients with HFpEF is higher in Asian than in Western countries. In this study, we aim to determine the prognostic impact of underweight in patients with HFpEF in Asian population. We enrolled 846 consecutive patients from the PURSUIT-HFpEF registry. We then divided them into three groups by BMI, namely, underweight (BMI < 18.5 kg/m(2)), normal weight (18.5 <= BMI < 23), and overweight (23 <= BMI). The underweight group consisted of 187 patients (22%). Over a mean follow-up of 407 days, 105 deaths were reported as all-cause mortality. On multivariable Cox analysis, the underweight group was determined to be significantly associated with higher risk of all-cause mortality than the normal and overweight groups (Hazard ratios [HR]: 2.33; 95% confidence intervals [CI]: 1.45-3.75, P < 0.001; HR: 3.54; 95% CI: 1.99-6.29, P < 0.001, respectively), after adjustment for age, sex, vital signs, and comorbidities. Underweight is a useful predictor of poor prognosis in patients with HFpEF in Asian population.