Body mass index and clinical outcomes in patients with heart failure with preserved ejection fraction mediated by diastolic blood pressure status?

BACKGROUND: The “obesity paradox” has been elucidated in patients with heart failure (HF). Current guidelines introduce a target diastolic blood pressure (DBP) < 80 mmHg but >70 mmHg in HF patients. Due to reduced coronary perfusion, low DBP has a deleterious impact on cardiovascular outcomes. This present study aimed to assess the relationship between BMI and adjudicated clinical outcomes in HFpEF patients according to the status of DBP. METHODS: We analyzed the data in 1749 HFpEF patients from the Americas of the TOPCAT (Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist) Trial. The population was stratified by DBP (<70 mmHg, and ≥70 mmHg) and BMI strata (normal weight, overweight, and obesity). Cox proportional hazards models and competing-risks regression analysis were performed. RESULTS: At baseline, the median BMI and DBP were 32.9 kg/m(2) (interquartile range 28.0–38.5 kg/m(2)) and 70 mmHg (interquartile range 62–80 mmHg), respectively. In the multivariable analysis, obesity was associated with better survival rates in the total HFpEF population (all-cause death: HR = 0.439, 95% CI 0.256–0.750; and cardiovascular death: HR = 0.378, 95% CI 0.182–0.787). In patients with DBP<70 mmHg, obesity was not significantly associated with reduced risks for all-cause death (HR = 0.531, 95% CI: 0.263–1.704) and cardiovascular death (HR = 0.680, 95% CI: 0.254–1.819). However, multivariate analyses for cardiovascular death (HR = 0.339, 95% CI: 0.117–0.983) and all-cause death (HR = 0.389, 95% CI: 0.156–0.969) were significant in patients with DBP≥70 mmHg. Nevertheless, there were no interactions between DBP and BMI. CONCLUSIONS: The obesity paradox was observed in patients with HFpEF, regardless of DBP strata (<70 mmHg, and ≥70 mmHg).