Prognostic implication of lung ultrasound in heart failure: a pooled analysis of international cohorts

Lung ultrasound (LUS) is often used to assess congestion in heart failure (HF). In this study, we assessed the prognostic role of LUS in patients with HF at admission and hospital discharge, and in an outpatient setting, and explored whether clinical factors [age, sex, left ventricular ejection fraction (LVEF), and atrial fibrillation] impact the prognostic value of LUS findings. Further, we assessed the incremental prognostic value of LUS on top of the following two clinical risk scores: (i) the atrial fibrillation, haemoglobin, elderly, abnormal renal parameters, diabetes mellitus (AHEAD) and (ii) the Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) clinical risk scores.

We pooled data on patients hospitalized for HF or followed up in outpatient clinics from international cohorts. We enrolled 1947 patients at admission (n = 578), discharge (n = 389), and in outpatient clinics (n = 980). The total LUS B-line count was calculated for the eight-zone scanning protocol. The primary outcome was a composite of rehospitalization for HF and all-cause death. Compared with those in the lower tertiles of B lines, patients in the highest tertiles were older, more likely to have signs of HF and had higher N-terminal pro b-type natriuretic peptide (NT-proBNP) levels. A higher number of B lines was associated with increased risk of primary outcome at discharge [Tertile 3 vs. Tertile 1: adjusted hazard ratio (HR): 5.74 (3.26-10.12), P < 0.0001] and in outpatients [Tertile 3 vs. Tertile 1: adjusted HR: 2.66 (1.08-6.54), P = 0.033]. Age and LVEF did not influence the prognostic capacity of LUS in different clinical settings. Adding B-line count to the MAGGIC and AHEAD scores improved net reclassification significantly in all three clinical settings.

A higher number of B lines in patients with HF was associated with an increased risk of morbidity and mortality, regardless of the clinical setting.