Rapid cardiothoracic ultrasound protocol for diagnosis of acute heart failure in the emergency department.

Abstract

The aim of this study was to evaluate the performance of a rapid cardiothoracic ultrasound protocol (CaTUS), combining echocardiographically derived E/e' and lung ultrasound (LUS), for diagnosing acute heart failure (AHF) in patients with undifferentiated dyspnea in an emergency department (ED). We enrolled 100 patients with undifferentiated dyspnea from a tertiary care ED, who all had CaTUS done immediately upon arrival in the ED. CaTUS was positive for AHF with an E/e' > 15 and congestion, that is bilateral B-lines or bilateral pleural fluid, on LUS. In addition, an inferior vena cava index was also recorded to analyze whether including a central venous pressure estimate would add diagnostic benefit to the CaTUS protocol. All 100 patients had a brain natriuretic peptide (BNP) sample withdrawn, and 96 patients underwent chest radiography in the ED, which was analyzed later by a blinded radiologist. The reference diagnosis of AHF consisted of either a BNP of more than 400 ng/l or a BNP of less than 100 ng/l in combination with congestion on chest radiography and structural heart disease on conventional echocardiography.CaTUS had a sensitivity of 100% (95% confidence interval: 91.4-100%), a specificity of 95.8% (95% confidence interval: 84.6-99.3%), and an area under the curve of 0.979 for diagnosing AHF (P<0.001). The diagnostic accuracy of CaTUS was higher than of either E/e' or LUS alone. Adding the inferior vena cava index to CaTUS did not improve diagnostic accuracy. CaTUS seemed helpful also for differential diagnostics of dyspnea, mainly regarding pneumonias and pulmonary embolisms. CaTUS, combining E/e' and LUS, provided excellent accuracy for diagnosing AHF.