Low NT‐proBNP levels in overweight and obese patients do not rule out a diagnosis of heart failure with preserved ejection fraction

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome that presents clinicians with a diagnostic challenge. The use of natriuretic peptides to exclude a diagnosis of HFpEF has been proposed. We sought to compare HFpEF patients with N‐terminal pro‐brain natriuretic peptide (NT‐proBNP) level above and below the proposed cut‐off. METHODS: Stable patients (n = 30) with left ventricular (LV) ejection fraction ≥ 50% were eligible if they had a diagnosis of HF according to the European Society of Cardiology diagnostic criteria. Characteristics of patients with NT‐proBNP below (≤125 pg/mL) and above (>125 pg/mL) the diagnostic criterion were compared. RESULTS: There were 19 (66%) women with median age 54 years. Half were African American (16, 53%), and most were obese. There were no significant differences in clinical characteristics or medication use between groups. LV end‐diastolic volume index was greater in high NT‐proBNP patients (P = 0.03). Left atrial volume index, E/e′ ratio, and E/e′ ratio at peak exercise were not significantly different between NT‐proBNP groups. Peak oxygen consumption (VO(2)), VO(2) at ventilatory threshold, and ventilatory efficiency measures were impaired in all patients and were not significantly different between high and low NT‐proBNP patients. CONCLUSIONS: NT‐proBNP was below the proposed diagnostic cut‐off point of 125 pg/mL in half of this obese study cohort. Cardiac diastolic dysfunction and cardiorespiratory fitness were not significantly different between high and low NT‐proBNP patients. These data indicate that excluding the diagnosis of HFpEF based solely on NT‐proBNP levels should be discouraged.