Prevalence and prognostic impact of clinical obesity in heart failure with preserved ejection fraction: a prospective cohort study

Obesity contributes to heart failure with preserved ejection fraction (HFpEF), but body mass index (BMI) inadequately reflects excess adiposity and clinical consequences, especially in Asians where BMI tends to be lower despite prevalent central adiposity. The Lancet Diabetes & Endocrinology Commission defined clinical obesity as a chronic disease with excess adiposity and obesity-related organ dysfunction. This study aims to evaluate its prevalence and prognostic impact in a HFpEF registry cohort. This single-center, prospective cohort study enrolled 426 hospitalized Chinese HFpEF patients from November 2020 to July 2024. Because all participants had established HFpEF, which is considered as an obesity-related organ dysfunction in the framework, clinical obesity classification within this cohort was determined by confirmation of excess adiposity (assessed via BMI, waist circumference, waist-to-hip ratio and body fat percentage measured by bioelectrical impedance). The primary endpoint was a composite of worsening heart failure (WHF) or cardiovascular death. Clinical obesity was prevalent in 74.9% of patients, far exceeding BMI-defined obesity (BMI ≥ 28 kg/m 2 , 15.0%) and clinical obesity was common even among patients with normal BMI. Over a median 907-day follow-up, patients with clinical obesity experienced higher composite endpoint incidence rates (35.24 vs 15.82 per 100 person-years). Clinical obesity correlated with an increased risk of the composite endpoint [adjusted Hazard Ratio (aHR) 2.04; 95% CI 1.42–2.95] and WHF (aHR 2.24; 95% CI 1.51–3.31), whereas BMI-defined obesity showed no significant prognostic value. A Cox regression model incorporating age, atrial fibrillation, and clinical obesity improved 1- and 2-year risk discrimination comparing to the published HFpEF-ABA score and yielded significant net reclassification improvement and integrated discrimination improvement at 1, 2, and 3 years. (all p < 0.05). Clinical obesity is highly prevalent in Chinese HFpEF patients and identifies individuals at significantly higher risk for heart failure-related events. This framework provides superior prognostic value beyond conventional BMI, helping refine risk stratification in HFpEF.