Impact of Residual B-lines at Discharge on Outcome of Heart Failure Patients（IMP-OUTCOME)

Background：Discharged heart failure (HF) patients might still have lung congestion (PC) expressed by residual lung ultrasound B-lines (LU-BL). Detection efficacy for PC is suboptimal with widely used imaging modalities, like x-ray or echocardiography, while lung ultrasound (LU) can sufficiently detect PC by visualizing LU-BL. In this trial, we sought to evaluate the impact of residual LU-BL at discharge and other clinical indexes on rehospitalization due to HF and all-cause mortality (composite primary outcome) up to 1 year post discharge in HF patients. The impact of intensive HF therapy post discharge on outcome up to 1 year after discharge will also be investigated for discharged HF patients with evidence of PC.Aim: IMP-OUTCOME is a prospective, single-center, observational cohort study, which is designed to investigate whether residual LU-BL at discharge is one of the independent determinants of poor outcome in discharged HF patients and if intensive HF therapy (adding SGLT2 inhibitor and more frequent follow up including LU-BL assessment) post discharge could improve the outcome of discharged HF patients with residual LU-BL up to 1 year after discharge.Methods and results: After receiving the standardized treatment of HF according to current guidelines, 233 discharged HF patients will be grouped into < 3 LU-BL and ≥ 3 LU-BL groups according to LU measurement within 48 hours before discharge. Patients in the ≥ 3 LU-BL group will be further divided into the conventional HF therapy group and the intensive HF therapy group at 1:1 ratio. Intensive HF therapy group will be treated with an SGLT2 inhibitor, if not contraindicated, beyond other HF medications and monitored by HF nurses and cardiologists at 1-month interval by clinical visit. Patient-relates basic clinical data including sex, age, blood chemistry, imaging examination, drug utilization, and so on will be obtained and analyzed. Following discharge from the hospital, patients in the LU-BL<3 group and conventional HF therapy group will be followed up at 1 month, 3 months, 6 months, post discharge by clinical visit or telephone call, by clinical visit at 12 months post discharge. LU-BL will be assessed monthly post discharge in the intensive HF therapy group, and at 12 months post discharge for patients in the conventional HF therapy group and LU-BL<3 group. Echocardiography examination will be performed for all patients at 12 months post discharge. The primary endpoint is the composite of re-hospitalization for worsening HF and all-cause death during follow-up. Secondary endpoints include the change in the Duke Activity Status Index (DASI), NT-pro BNP value and 6-min walk distance at each follow up, EF and number of LU-BL at 12 months post discharge. Conclusion: This trial will explore the potential impact of residual B-lines on the outcome of discharged HF patients and the impact of intensive HF management on the outcome of discharged HF patients with residual LU-BL up to 1 year after discharge.Trial Registration ClinicalTrials.gov; NCT05035459. Registration date, 2021/09/02, “prospectively registered”.