Lung ultrasound in outpatients with heart failure: the wet-to-dry HF study

In ambulatory patients with chronic heart failure (HF), congestion and decongestion assessment may be challenging. The aim of this study is to assess the value of lung ultrasound (LUS) in outpatients with HF in characterizing decompensation and recompensation, and in outcomes prediction.

Heart failure outpatients attended to establish HF decompensation were included. LUS was blindly performed at baseline (LUS1) and at clinical recompensation (LUS2). B-lines were counted in eight scanned areas. Diagnosis of no HF decompensation vs. right-sided, left-sided, or global HF decompensation, and patients' management were performed by physicians blinded to LUS1. Outcome was the composite of all-cause death or HF-related hospitalization. Two hundred and thirty-three suspicions of HF decompensation were included in 187 patients (71.4 ± 11.3 years, 66.8% men). Mean B-line (LUS1) was 17.6 ± 11.2 vs. 3.7 ± 4.5 for episodes with and without HF decompensation, respectively (P < 0.001). Global HF decompensation showed the highest number of B-lines (20.6 ± 11), followed by left-sided (19.7 ± 11.6) and right-sided (13.5 ± 9.8). B-lines declined to 6.9 ± 6.7 (LUS2) (P < 0.001 vs. LUS1) after treatment, within a mean time of 24.2 ± 23.7 days [median 13.5 days (interquartile range 6-40)]. B-lines were significantly associated with the composite endpoint at 30 days (hazard ratio [HR] 1.04 [95% confidence interval 1.01-1.07], P = 0.02), but not at 60 (P = 0.22) or 180 days (P = 0.54). In multivariable analysis, B-line number remained as an independent predictor of the composite endpoint at 30 days, [HR 1.04 (1.01-1.07), P = 0.014], with a 4% increase risk per B-line added. B-lines correlated significantly with CA125 (R = 0.30, P = 0.001).

Lung ultrasound supports the diagnostic work-up of congestion and decongestion in chronic HF outpatients and identifies patients at high risk of short-term events.