Abstract 3192: Obesity and Its Relationship to Adverse Cardiovascular Outcomes in Older Patients With Heart Failure and Preserved Ejection Fraction in the I-PRESERVE Trial
Background: Obesity is a major independent risk factor for development of heart failure (HF) in patients with reduced left ventricular ejection fraction (LVEF), but paradoxically high BMI appears to be protective of adverse outcomes in such patients. The majority of elderly patients with HF have preserved LVEF (HFPEF), and BMI increases with age even in the absence of HF. However, there is relatively little information regarding obesity and its effect on outcomes in elderly patients with HFPEF.
Methods: Demographic and clinical characteristics and cardiovascular (CV) outcomes were assessed in the 4,109 patients (mean age 72 years) in the completed I-PRESERVE trial who were sorted to 5 BMI groups used by WHO and the CHARM trial: <23.5; 23.5–26.49; 26.5–30.99; 31–34.99; ≥35.
Results: Most patients (71%) were overweight or obese (BMI ≥26.5); 21% were normal weight, and 8 % were underweight (BMI<22.5). Patients with increased BMI were older, more often female, and had more hypertensive etiology and diabetes, and slightly higher EF, but lower prevalence of EKG abnormalities anemia, and ischemic etiology, lower pro-NT brain natriuretic peptide (BNP), and no difference in renal function or NYHA class. Adverse outcomes, including the primary composite outcome, all-cause mortality, and CV death or HF hospitalization, were lowest in the mildly overweight group (BMI 26.5–30.99) which was used as the reference (Hazard Ratio=1.0). Hazard ratio (HR) for the primary outcome was similar in mild obesity (BMI 31–34.99; HR 1.04; p=0.64), mildly increased in severe obesity (BMI >35; HR 1.16; p=0.058) and in normal weight (BMI 23.5–26.49; HR 1.18; p=0.02) and greatest in underweight patients (BMI <23.5; HR 1.65; p<0.0001). The pattern of relationships between BMI and HR was similar for other adverse outcomes and remained even after adjusting for age and gender, or for these plus 16 other key risk variables, including BNP.
Conclusions: In elderly HFPEF patients, obesity is highly prevalent and is accompanied by multiple differences in key clinical and demographic characteristics. There is a reverse J-shaped relationship between BMI and adverse outcomes, and this effect remains even after accounting for multiple key prognostic variables that differ by BMI subgroup, including BNP.