Right heart failure as a source of B-lines at lung ultrasound: prevalence and functional correlates

Abstract

Abstract Background Lung ultrasound is part of the standard transthoracic examination and B-lines provide an index of extravascular lung water allowing to measure pulmonary congestion in left heart failure. However, pulmonary congestion can also appear as a consequence of right heart failure and it has been assumed that depends on the increase in central venous pressure increasing the resistance to lymphatic drainage. Aim of this study was to assess the prevalence of lung B-lines in a clinical model of pure right heart failure due to idiopathic pulmonary arterial hypertension (PAH) and its correlation with haemodynamic parameters. Methods All patients referred for suspicion of pulmonary hypertension in a single tertiary centre from January 2020 to December 2022 underwent a complete diagnostic work-up including echocardiography, lung ultrasound and right heart catheterization. The diagnosis of PAH was made following the current international recommendations. Pulmonary congestion was identified by lung ultrasound B-lines using an 8-site scan. Results The study enrolled 102 patients with PAH. Patients’ characteristics are shown in Table 1. The median lung B-lines were 3 [IQR: 1-5]. Results of univariate and multivariate analysis of B-lines predictors are shown in Table 1. Right atrial pressure (RAP), tricuspid annular plane excursion (TAPSE)/ Systolic pulmonary pressure (sPAP) ratio and pro hormone brain natriuretic peptide (proBNP) were independent predictors of B lines. Conclusion RAP, TAPSE/sPAP and proBNP were independent predictors of B lines in PAH patients according to the pathophysiological hypothesis that B-lines depends on the increase in central venous pressure increasing the resistance to lymphatic drainage.Table 1