Accuracy of Several Lung Ultrasound Methods for the Diagnosis of Acute Heart Failure in the ED: A Multicenter Prospective Study

Abstract

Early appropriate diagnosis of acute heart failure (AHF) is recommended by international guidelines. This study assessed the value of several lung ultrasound (LUS) strategies for identifying AHF in the ED. This prospective study, conducted in four EDs, included patients with diagnostic uncertainty based on initial clinical judgment. A clinical diagnosis score for AHF (Brest score) was quantified, followed by an extensive LUS examination performed according to the 4-point (BLUE protocol) and 6-, 8-, and 28-point methods. The primary outcome was AHF discharge diagnosis adjudicated by two senior physicians blinded to LUS measurements. The C-index was used to quantify discrimination. Among the 117 included patients, AHF (n= 69) was identified in 27.4%, 56.2%, 54.8%, and 76.7%of patients with the 4-point (two bilateral positive points), 6-point, 8-point (≥ 1 bilateral positive point), and 28-point (B-line count≥ 30) methods, respectively. The C-index (95%CI) of the Brest score was 72.8 (65.3-80.3), whereas the C-index of the 4-, 6-, 8-, and 28-point methods were 63.7 (58.5-68.8), 72.4 (65.0-79.8), 74.0 (67.1-80.9), and 72.4 (63.9-80.9). The highest increase in the C-index on top of the BREST score was observed with the 8-point method in the whole population (6.9; 95%CI, 1.6-12.2; P= .010) and in the population with an intermediate Brest score, followed by the 6-point method. In patients with diagnostic uncertainty, the 6-point/8-point LUS method (using the 1 bilateral positive point threshold) improves AHF diagnosis accuracy on top of the BREST score. ClinicalTrials.gov; No.: NCT03194243; URL: www.clinicaltrials.gov.