Abstract
BACKGROUND: Pulmonary congestion detected by lung ultrasound (LUS) has emerged as a valuable prognostic marker in acute heart failure (AHF). This systematic review and meta-analysis aimed to evaluate the prognostic significance of residual B-lines identified by LUS before hospital discharge. METHODS: A comprehensive literature search of PubMed, Cochrane Library, ScienceDirect, and ClinicalTrials.gov was conducted up to October 4, 2024. Studies assessing the association between residual B-lines and adverse clinical outcomes in hospitalized AHF patients were included, while studies involving ambulatory assessments were excluded. The primary outcome was a composite of all-cause mortality and heart failure (HF) rehospitalization. Secondary outcomes included all-cause mortality and HF rehospitalization individually. Pooled hazard ratios (HRs) with 95 % confidence intervals (CIs) were calculated. RESULTS: Fifteen studies were included. Residual B-lines were significantly associated with an increased risk of composite outcomes (HR: 2.32; 95 % CI: 1.91-2.82), all-cause mortality (HR: 3.01; 95 % CI: 1.91-4.73), and HF readmission or cardiovascular events (HR: 4.01; 95 % CI: 2.22-7.24). Risk increased with greater B-line burden. Prognostic impact was stronger in short-term follow-up (<6 months; HR: 3.57) than in longer-term follow-up (≥6 months; HR: 1.96). CONCLUSIONS: Residual pulmonary congestion assessed by LUS at discharge is a strong independent predictor of adverse outcomes and may guide therapy decisions in AHF management.