Highest Obesity Category Associated With Largest Decrease in N‐Terminal Pro‐B‐Type Natriuretic Peptide in Patients Hospitalized With Heart Failure With Preserved Ejection Fraction

Background Heart failure with preserved ejection fraction ( HF p EF ) constitutes half of hospitalized heart failure cases and is commonly associated with obesity. The role of natriuretic peptide levels in hospitalized obese patients with HF p EF , however, is not well defined. We sought to evaluate change in NT ‐pro BNP (N‐terminal pro‐B‐type natriuretic peptide) levels by obesity category and related clinical outcomes in patients with HF p EF hospitalized for acute heart failure. Methods and Results A total of 89 patients with HF p EF hospitalized with acute decompensated heart failure were stratified into 3 obesity categories: nonobese ( body mass index [BMI] <30.0 kg/m 2 , 19%), obese ( BMI 30.0–39.9 kg/m 2 , 29%), and severely obese ( BMI ≥40.0 kg/m 2 , 52%), and compared for percent change in NT ‐pro BNP during hospitalization and clinical outcomes. Clinical characteristics were compared between patients with normal NT ‐pro BNP (≤125 pg/ mL ) and elevated NT ‐pro BNP . Admission NT ‐pro BNP was inversely related to BMI category (nonobese, 2607 pg/ mL [interquartile range, IQR: 2112–5703]; obese, 1725 pg/ mL [IQR: 889–3900]; and severely obese, 770.5 pg/ mL [IQR: 128–1268]; P <0.01). Severely obese patients had the largest percent change in NT ‐pro BNP with diuresis (−64.8% [95% CI, −85.4 to −38.9] versus obese −40.4% [95% CI, −74.3 to −12.0] versus nonobese −46.9% [95% CI, −57.8 to −37.4]; P =0.03). Nonobese and obese patients had significantly worse 1‐year survival compared with severely obese patients (63% versus 76% versus 95%, respectively; P <0.01). Patients with normal NT ‐pro BNP (13%) were younger, with higher BMI , less atrial fibrillation, and less structural heart disease than those with elevated NT ‐proBNP. Conclusions In hospitalized patients with HF p EF , NT ‐pro BNP was inversely related to BMI with the largest decrease in NT ‐pro BNP seen in the highest obesity category. These findings have implications for the role of NT ‐pro BNP in the diagnosis and assessment of treatment response in obese patients with HF p EF .