Body Mass Index and B-Lines on Lung Ultrasonography in Chronic and Acute Heart Failure
Philip Brainin, Brian Claggett, Eldrin F. Lewis, Kristin Dwyer, Allison A. Merz, Montane B Silverman, Varsha Swamy, Tor Biering‐Sørensen, Jose Rivero, Susan Cheng, John J.V. McMurray, Scott D. Solomon, Elke Platz
Abstract
AIMS: Increased body mass index (BMI) is common in heart failure (HF) patients and is associated with lower levels of N-terminal pro-brain natriuretic peptide (NT-proBNP). We evaluated the influence of BMI on lung ultrasonography (LUS) findings indicative of pulmonary congestion (i.e. B-lines) in patients with chronic and acute HF (AHF). METHODS AND RESULTS: , mean ejection fraction 42%) undergoing echocardiography and LUS in eight chest zones. B-lines and chest wall thickness (skin to pleura) on ultrasound were quantified offline and blinded to clinical findings. NT-proBNP was available in AHF patients (n = 167). In chronic HF, B-line number decreased by 18% per 5 unit increase in BMI [95% confidence interval (CI) -35% to +5%, P = 0.11]. In AHF, the number of B-lines decreased by 12% per 5 unit increase in BMI (95% CI -19% to -5%, P = 0.001), whereas NT-proBNP concentration decreased by 28% per 5 unit increase in BMI (95% CI -40% to -16%, P < 0.001). For AHF, B-line number declined to a lesser degree than NT-proBNP concentration with increasing BMI (P = 0.020), and >6 B-lines were observed in half of AHF patients with severe obesity. There was an inverse relationship between B-line number and chest wall thickness, and this association varied by chest region. CONCLUSIONS: Despite an inverse relationship between B-lines and BMI, B-lines declined to a lesser degree than NT-proBNP with increasing BMI. These data suggest that LUS may be useful in patients with HF despite obesity.