Current NT-proBNP thresholds may underestimate HF outcome risks in people with high BMI

Current thresholds of N-terminal pro–B-type natriuretic peptide (NT-proBNP) tend to underestimate the risk of adverse heart failure (HF) outcomes among individuals with higher BMI, reveals a study.

The authors evaluated the association between NT-proBNP and clinical outcomes (ie, cardiovascular death or HF hospitalization, cardiovascular death, and all-cause death) in adults with HF and mildly reduced or preserved ejection fraction (HFmrEF/HFpEF) according to BMI as a continuous and categorical variable.

A total of 14,750 participants (mean age 72 years, 50 percent female, mean BMI 30 kg/m2, median NT-proBNP 836 pg/mL) were included. Higher BMI at baseline significantly and nonlinearly correlated with lower NT-proBNP levels.

Over a median follow-up of 2.8 years, each doubling of baseline NT-proBNP resulted in a 40-percent higher covariate-adjusted rate of cardiovascular death or HF hospitalization (HR, 1.40, 95 percent CI, 1.36–1.43; p<0.001). This association, however, seemed “incrementally blunted” with higher baseline BMI (p_interaction=0.008).

NT-proBNP levels in participants without atrial fibrillation were almost threefold lower among those with BMI ≥35 kg/m2 (158 pg/mL) vs <35 kg/m2 (450 pg/mL) for the same absolute risk of cardiovascular death or HF hospitalization (5 events per 100 person-years).

At a contemporary NT-proBNP–based trial eligibility threshold, the absolute risk of cardiovascular death or HF hospitalization ranged from 3.5 per 100 person-years among participants with BMI <30 kg/m2 to 7.3 per 100 person-years among those with BMI ≥40 kg/m2.

“These data question single fixed thresholds and instead suggest that lower NT-proBNP cutoffs may more appropriately risk stratify patients with higher BMI,” the authors said.