Lung ultrasound and diuretic therapy in chronic heart failure: a randomised trial

Background: Lung congestion is frequent in heart failure (HF) and is associated with symptoms and poor prognosis. Lung ultrasound (LUS) identification of B-lines may help refining congestion assessment on top of usual care. Three small trials comparing LUS-guided therapy to usual care in HF suggested that LUS-guided therapy could reduce urgent HF visits. However, to our knowledge, the usefulness of LUS in influencing loop diuretic dose adjustment in ambulatory chronic HF has not been studied.

Aims: To study whether to show or not LUS results to the HF assistant physician would change loop diuretic adjustments in "stable" chronic ambulatory HF patients.

Methods: Prospective randomised single-blinded trial comparing two strategies: (1) open 8-zone LUS with B-line results available to clinicians, or (2) blind LUS. The primary outcome was change in loop diuretic dose (up- or down-titration).

Results: A total of 139 patients entered the trial, 70 were randomised to blind LUS and 69 to open LUS. The median (percentile_25-75) age was 72 (63-82) years, 82 (62%) were men, and the median LVEF was 39 (31-51) %. Randomisation groups were well balanced. Furosemide dose changes (up- and down-titration) were more frequent among patients in whom LUS results were open to the assistant physician: 13 (18.6%) in blind LUS vs. 22 (31.9%) in open LUS, OR 2.55, 95%CI 1.07-6.06. Furosemide dose changes (up- and down-titration) were more frequent and correlated significantly with the number of B-lines when LUS results were open (Rho = 0.30, P = 0.014), but not when LUS results were blinded (Rho = 0.19, P = 0.13). Compared to blind LUS, when LUS results were open, clinicians were more likely to up-titrate furosemide dose if the result "presence of pulmonary congestion" was identified and more likely to decrease furosemide dose in the case of an "absence of pulmonary congestion" result. The risk of HF events or cardiovascular death did not differ by randomisation group: 8 (11.4%) in blind LUS vs. 8 (11.6%) in open LUS.

Conclusions: Showing the results of LUS B-lines to assistant physicians allowed more frequent loop diuretic changes (both up- and down-titration), which suggests that LUS may be used to tailor diuretic therapy to each patient congestion status.