Role of pulmonary ultrasonography in diagnosis of acute heart failure

Background

One of the most prevalent causes of emergency room visits is acute dyspnea. Several etiologies, including cardiac, pulmonary, metabolic, psychogenic etc… may be involved. Acute heart failure (AHF) is among the most common causes. This study aims to evaluate, in patients presenting with acute dyspnea to the emergency departement (ED), the accuracy of a diagnostic approach combining Lung ultrasonography (LUS) and clinical assessment as compared to the traditional AHF diagnostic work-up.

Methods

This is a bi-centric cross-sectional observational study, conducted at the Emergency and Cardiology Department of both the Hedi Chaker Hospital in Sfax and the Habib Thameur Hospital in Tunis for the period extending from 01/07/2022 to 30/09/2023. The diagnostic performance of pulmonary ultrasonography was studied and the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were compared with those of clinical examination, chest X-Ray, NT-pro -BNP and the Transthoracic echocardiography (TTE) which was the reference exam.

Results

The most common cause of acute dyspnea is acute heart failure (79.3 %). LUS had a sensitivity of 94,2 % in diagnosing AHF and a specificity of 77,5 %. Its PPV and NPV were respectively 92 % and 81 %. The area under curbe (AUC) of B-Lines required for the diagnosis of interstitial pulmonary syndrome was excellent (92 %). There was a moderate significant positive correlation between the number of B-Lines and NT-Pro-BNP levels r = 0.51, P < 0.001. Also, there was a very strong significant positive relationship between the pulmonary congestion assessed by LUS and Left atrium - pressure r = 0.788, P < 0.001

Conclusion

LUS is an excellent test both to confirm and exclude the diagnosis of AHF in patients consulting the emergency room for acute dyspnea and therefore deserves to be performed systematically.