Post-exercise lung ultrasound enhances detection of residual congestion before discharge in patients with acute decompensated heart failure
A Donizeti Rodrigues Dias, F H Valicelli, D M Tanaka, H T Moreira, F Marques, S C Hermann, F S Coneglian, A Schmidt, M V SimoesAbstract
Introduction
The detection of congestion before hospital discharge in patients with acutely decompensated heart failure (ADHF) is associated with higher risk of post-discharge events. We tested the use of lung ultrasound (LUS) immediately after submaximal exertion through a 6-minute walk test (6MWT) to enhance the detection of subclinical residual congestion in the pre-discharge evaluation (PD) in patients hospitalized for ADHF.
Methods
We prospectively investigated 100 consecutive patients hospitalized for ADHF, of whom 71 (71%) were able to perform the 6MWT at PD and constituted the study population. The mean age was 54.8 ± 12.8 years, 59% male, with a median left ventricular ejection fraction (LVEF) of 23% (19.0-28.0), and a mean hospital stay of 11.1 ± 5.8 days. At PD, patients were assessed by using LUS with scanning of 8 lung zones to detect B-lines (BL). LUS at rest was considered positive for congestion if ≥1 lung zone showed ≥3 BL and post-exercise (immediately after 6MWT) LUS was positive if ≥1 additional lung field showed ≥3 BL. During the 90 day period after hospital discharge (vulnerable phase), we monitored the occurrence of heart failure events, encompassing ambulatory intravenous furosemide use (IVF) and rehospitalization for ADHF (RH-ADHF), and all-cause mortality.
Results
The performance of the 6MWT was not associated with complications, and the mean walked distance was 366.0 ± 104.7 m, with 26.8% of patients walking less than 300 m. Rest-LUS detected congestion in 21 (30%) patients, while additional 11 patients (15.7%) were identified as positive after exertion. Twenty patients (28.2%) had adverse outcomes during the vulnerable phase: 10 (14%) needed IVF, 9 (12.7%) had RH-ADHF, and 4 (5.6%) deaths. In univariate Cox regression analysis assessing associations with clinical outcomes, positive rest-LUS presented no significant association with heart failure events of IVF and/or RH-ADHF, with HR = 0.78 (95% CI:0.49 - 1.26, p = 0,679; while positive post-exertion LUS showed significant association (HR = 6.36 (95% CI: 1.57-25.75, p = 0.009). None of the variables presented significant association with all-cause mortality.
Conclusion
The use of LUS immeadiately after the 6MWT enhances the detection of subclinical congestion in a significant proportion of pre-discharge ADHF patients, identifying those at higher risk of heart failure events during the vulnerable phase.