Prognostic value of residual pulmonary congestion at discharge assessed by lung ultrasound imaging in heart failure

Abstract

Aims Residual pulmonary congestion at discharge is associated with poor prognosis in heart failure (HF), but its quantification through physical examination is challenging. Ultrasound imaging of lung comets (B-lines) could improve congestion evaluation. The aim of this study was to assess the short-term prognostic value of B-lines after discharge from HF hospitalisation compared with other indices of haemodynamic congestion (BNP, E/e', and inferior vena cava diameter) or clinical status (NYHA class). Methods and results Sixty consecutive HF inpatients underwent clinical examination, echocardiography, and lung ultrasound at discharge, independently of, and in addition to routine management by the attending physicians. The median B-line count was 8.5 (5-34). Three-month event-free survival for the primary endpoint (all-cause death or HF hospitalisation) was 27 ± 10% in patients with ≥30 B-lines and 88 ± 5% in those with <30 B-lines (P < 0.0001). In a multivariable model, ≥30 B-lines significantly predicted the combined endpoint (hazard ratio 5.66, 95% confidence interval 1.74-18.39, P = 0.04), along with NYHA ≥III and inferior vena cava diameter, while other indirect measures of congestion (BNP and E/e' ≥15) were not retained in the model; furthermore ≥30 B-lines independently also predicted the secondary outcomes (HF hospitalisation and death). Importantly, B-line addition to NYHA class and BNP was associated with improved risk classification (integrated discrimination improvement 15%, P = 0.02; continuous net reclassification improvement 65%, P = 0.03). Conclusion Residual pulmonary congestion at discharge, as assessed by a B-line count ≥30, is a strong predictor of outcome. Lung ultrasonography may represent a useful tool to identify and monitor congestion and optimize therapy during and/or after hospitalisation for HF, which should be further validated in multicentre studies.