Prognostic value of lung ultrasound in acute heart failure

Abstract

Introduction

Clinical congestion rather than low cardiac output, is the most frequent cause in patients hospitalized for heart failure and accounts for high rates of death. Persisting symptoms and signs of congestion at discharge or amongst out-patients are strong predictors of an adverse outcome. Lung ultrasound (LUS) has emerged as a simple, non-invasive and semi-quantitative tool for the detection and the assessment of pulmonary congestion.

Objective

Assess the prognostic importance of pulmonary congestion detected with LUS on short-term adverse events and to describe the dynamic changes of LUS findings.

Method

In a bi-centric prospective observational study, we included consecutive patients hospitalized for acute heart failure. Each patient underwent a thorough clinical examination, a biological evaluation, a chest X-ray, LUS and echocardiography. The operators performing LUS were blinded to clinical data and examined 8 thoracic zones .The main clinical outcomes were a composite of urgent visit, HF hospitalization for acute decompensation of HF or cardiac death.

Results

A total of 116 individuals were included (median, 69 years of age; 53% men; mean ejection fraction 40%) The mean number of B-lines at discharge was 6.6 ± 3.3. During a mean follow-up of 6 months, we detected 72 events: 52 patients were admitted due to severe HF symptoms and 20 patients died from cardiac cause. By multivariate analysis, ≥ 3 B-lines Bilaterally (11.024 HR, 95% CI 5.542–21.926, P < 0.001) was retained as a predictor for the risk of the combined endpoint at 180-day follow-up. The number of B-lines significantly decreased from 31.9 ± 12.7 when patients were admitted at the hospital to 6.6 ± 3.1 when discharged from it (P = 0).

Conclusion

A simplified 8-Zone LUS method is useful to assess severity and monitor the resolution of lung congestion. Patients with persistent pulmonary congestion at discharge assessed by LUS have worse prognosis.