Prognostic value of lung ultrasonography and bioimpedance spectroscopy in patients with heart failure and reduced ejection fraction

Abstract

Introduction: Chronic heart failure (HF) represents a major global public health problem, and despite significant advances in diagnosis and management over the past two decades, HF patients still have a poor prognosis. The aim of the study was to evaluate the relationship between lung congestion, as assessed by lung ultrasonography (LUS), bioimpedance spectroscopy, body fluid compartments, and echocardiographic parameters, and to determine the effect of these associations on all-cause mortality in HF patients.<br /> Material and methods: Eligible patients with a left ventricular ejection fraction (LVEF) below 45% were identified via daily echocardiography assessments. Lung ultrasonography was performed with patients in the supine position, for a total of 28 sites per complete examination. The extracellular water (ECW) was determined using a BIS device.<br /> Results: Our study included 122 patients (67.2% males) with a mean age of 67.2 years. In the multivariable linear regression analysis, including all the univariable predictors of lung congestion, only New York Heart Association (NYHA) class, ECW, estimated glomerular filtration rate (eGFR), and LVEF levels maintained an independent association with the number of B-lines. During the follow-up, 33 patients died. In multivariable Cox analysis, a B-line number of at least 15 remained significantly associated with all-cause mortality, independently of age, sex, diabetes, LVEF, estimated glomerular filtration rate, C-reactive protein, N-terminal pro-brain natriuretic peptide, or ECW values (adjusted HR = 3.84, 95% CI: 1.12-13.09).<br /> Conclusions: We show for the first time in HF patients that pulmonary congestion, as assessed by LUS, is associated with the severity of NYHA class, LVEF, eGFR, and ECW, and it identifies those at increased risk of death.