AUTHOR=Guo Linjuan , Liu Xiao , Yu Peng , Zhu Wengen 

TITLE=The “Obesity Paradox” in Patients With HFpEF With or Without Comorbid Atrial Fibrillation

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=Volume 8 - 2021

YEAR=2022

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2021.743327

DOI=10.3389/fcvm.2021.743327

ISSN=2297-055X

ABSTRACT=ABSTRACT
Background: Overweight and mildly obese individuals have a lower risk of death than their normal-weight counterparts; this phenomenon is termed "obesity paradox". Whether this "obesity paradox" exists in patients with heart failure (HF) or can be modified by comorbidities is still controversial. Our current study aimed to determine the association of body mass index (BMI) with outcomes in heart failure with preserved ejection fraction (HFpEF) patients with or without coexisting atrial fibrillation (AF). 
Methods: Patients with HFpEF from the Americas in the TOPCAT trial were categorized into three groups: normal weight (18.5–24.9 kg/m2), overweight (25.0–29.9 kg/m2), and obesity (≥30 kg/m2). Cox proportional-hazards models were used to calculate the adjusted hazard ratios (HRs) and confidence intervals (CIs). 
Results:We identified 1,749 HFpEF patients, 42.1% of which had baseline AF. In the total HFpEF population, both overweight (HR=0.59, 95%CI: 0.42-0.83) and obesity (HR=0.49, 95%CI: 0.35-0.69) were associated with a reduced risk of all-cause death. Among HFpEF patients without AF, overweight (HR=0.51, 95% CI: 0.27-0.95) and obesity (HR=0.64, 95%CI: 0.43-0.98) were associated with a lower risk of all-cause death. In those with AF, obesity (HR=0.62, 95%CI: 0.40-0.95) but not overweight (HR=0.81, 95%CI: 0.54-1.21) was associated with a decreased risk of all-cause death.   
Conclusions: The "obesity paradox" assessed by BMI exists in patients with HFpEF regardless of comorbid AF.