The intersection of obesity and acute heart failure: Cardiac structure and function and congestion across BMI categories.

Background: Overweight/obesity are important risk factors for heart failure (HF), however, the pathophysiologic consequences of obesity in patients with acute HF (AHF) are incompletely understood.

Methods: We examined cardiac structure and function, and congestion-related markers in adults hospitalized for AHF across 3 body mass index (BMI) groups: 18.5-24.9 kg/m2 (normal weight), 25-29.9 kg/m2 (overweight), ≥30 kg/m2 (obese), and based on left ventricular ejection fraction (LVEF) >40% (HF with mildly reduced/preserved EF (HFmrEF/HFpEF)) vs. ≤40% (HF with reduced EF (HFrEF)). Echocardiography, 4-zone lung ultrasound, and patient-reported symptoms were assessed at baseline, and 6-month outcomes (HF hospitalizations and all-cause death) were collected.

Results: Among 354 participants (median age 75, 59% men), 36% were normal weight, 29% overweight and 35% obese. Higher BMI was associated with younger age, more comorbidities, a higher proportion of prior HF, and worse patient-reported symptoms. Patients with HFmrEF/HFpEF were older, more likely female, had a higher BMI and higher proportions of hypertension and atrial fibrillation. Both patients with HFmrEF/HFpEF and HFrEF had greater biventricular volumes/area and LV mass, similar degrees of elevated LV filling pressure and lower degrees of pulmonary congestion with higher BMI. The risk of the composite outcome was similar across BMI groups both in the overall cohort and when stratified by LVEF.

Conclusions: Among patients with AHF, those with overweight/obesity had greater biventricular volumes/area and LV mass, similar sonographic evidence of hemodynamic congestion and less pulmonary congestion than those with normal weight. The risk of 6-month HF hospitalization or death was similar across BMI groups.