Ultrasound lung comets for the differential diagnosis of acute cardiogenic dyspnoea: A comparison with natriuretic peptides

Background: Acute dyspnoea as a presenting symptom is a frequent diagnostic challenge for physicians. The main differential diagnosis is between dyspnoea of cardiac and non-cardiac origin. Natriuretic peptides have been shown to be useful in this setting. Ultrasound lung comets (ULCs) are a simple, echographic method which can be used to assess pulmonary congestion. Aim: To evaluate the accuracy of ULCs for predicting dyspnoea of cardiac origin compared to natriuretic peptides. Methods: We evaluated 149 patients admitted with acute dyspnoea. Chest sonography and NT-proBNP assessments were performed a maximum of 4 h apart and independently analyzed. ULCs were evaluated via cardiac probes placed on the anterior and lateral chest. Two independent physicians, blinded to ULCs and NT-proBNP findings, reviewed all the medical records to establish the aetiologic diagnosis of dyspnoea. Results: Cardiogenic dyspnoea was confirmed in 122 patients and ruled-out in 27 patients. The number of ULCs was significantly correlated to NT-proBNP values (r=.69, p<.0001). Receiver operating characteristic analysis, showed an area under the curve of .893 for ULCs and .978 (p=.001) for NT-proBNP, in predicting the cardiac origin of dyspnoea. Conclusions: In patients admitted with acute dyspnoea, pulmonary congestion, sonographically imaged as ULCs, is significantly correlated to NT-proBNP values. The accuracy of ULCs in predicting the cardiac origin of dyspnoea is high.