Obesity is associated with elevated invasive filling pressures despite lower natriuretic peptides in patients with preserved ejection fraction
T Murakami, S Ueshima, S Naito, K Kikkawa, Y Horizawa, K Miyoshi, Y Iemura, M Ogata, N Okuda, Y Kawahara, A Tani, T Ando, S Ishihara, H Komiyama, K JujoAbstract
Background
Obesity is highly prevalent in heart failure with preserved ejection fraction (HFpEF). Paradoxically, obese individuals exhibit suppressed circulating natriuretic peptide levels despite a high likelihood of volume overload. Whether excess adiposity independently contributes to elevated invasive filling pressures—beyond natriuretic peptide levels—remains uncertain.
Purpose
To evaluate the association between obesity-related indices and invasively measured filling pressures in patients with preserved ejection fraction.
Methods
This prospective single-centre observational study enrolled consecutive non-dialysis patients who underwent right heart catheterisation for dyspnoea evaluation between November 2025 and February 2026. After excluding patients with left ventricular ejection fraction <40%, 32 patients were included. NT-proBNP and obesity-related indices (body mass index (BMI), waist-to-height ratio (WHtR), HOMA-IR, free fatty acids, and CRP) were measured within 24 hours of catheterisation. Patients were categorised as obese (BMI ≥25 kg/m², n=14) or non-obese (n=18). The primary endpoint was pulmonary capillary wedge pressure (PCWP).
Results
Obese patients had significantly lower NT-proBNP levels compared with non-obese patients (83 [40–361] vs. 248 [150–796] pg/mL, p=0.03), despite numerically higher PCWP (12±5 vs. 9±5 mmHg, p=0.09). PCWP showed a positive correlation with BMI (r=0.46, p=0.01) and WHtR (r=0.46, p=0.02), whereas no significant association was observed with log-transformed NT-proBNP (r=0.04, p=0.81) (Figure). In multivariable linear regression analysis adjusting for age, sex, and log-transformed NT-proBNP, each 1 kg/m² increase in BMI was associated with a 0.46 mmHg increase in PCWP (95% CI 0.13–0.78, p=0.01). In a separate model substituting WHtR for BMI, each 0.1 increment in WHtR was associated with a 2.35 mmHg increase in PCWP (95% CI 0.04–4.65, p=0.05). NT-proBNP was not independently associated with PCWP in either model. For the identification of elevated filling pressures (PCWP ≥15 mmHg), the area under the curve was 0.77 for BMI and 0.88 for WHtR.
Conclusions
In patients with preserved ejection fraction, obesity—particularly central adiposity—is independently associated with elevated invasive filling pressures despite lower natriuretic peptide levels. These findings suggest that reliance on natriuretic peptides alone may underestimate true haemodynamic congestion in obese patients.Figure