Lung Ultrasound Offers Fast and Reliable Exclusion of Heart Failure in the Emergency Department: A Prospective Diagnostic Study

<b>Background/Objectives</b>: Acute dyspnea is a common and urgent presentation in the emergency department, with acute heart failure (AHF) as one of its leading causes. Rapid differentiation between AHF and other etiologies is essential. <b>Methods</b>: This study aimed to evaluate the diagnostic accuracy of lung ultrasound (LUS) and compare it to chest X-ray (CXR) and NT-proBNP accuracy in patients with acute dyspnea, and to assess the potential of LUS for fast bedside diagnosis. This prospective study included 242 adult patients presenting with acute dyspnea of ≤3 days' duration. All underwent NT-proBNP testing, CXR, and LUS according to a standardized protocol. The final diagnosis was established by experienced clinicians using all available clinical, laboratory, and imaging data, blinded to the LUS results. Diagnostic performance measures of LUS, CXR, and NT-proBNP were evaluated, and examination times of LUS and CXR were compared. <b>Results</b>: LUS achieved the highest sensitivity (95.3%) and negative predictive value (90.8%) for AHF, outperforming NT-proBNP (87.5%, 74.2%) and CXR (84.4%, 79.0%). CXR showed the highest specificity (65.8%) and positive predictive value (73.5%), while LUS specificity was moderate (51.8%). The LUS results were available significantly faster (median 10.0 min) than CXR (median 62.5 min). <b>Conclusions</b>: LUS demonstrated diagnostic accuracy comparable to CXR and NT-proBNP, with superior sensitivity, negative predictive value, and shorter time to results. These findings support its use as a rapid, non-invasive, first-line tool for excluding AHF in acute dyspnea patients.