Changes in the Heart Sounds Between Discharge and Initial Follow-Up and Subsequent Cardiac Events in Patients with Acute Decompensated Heart Failure.

Background: Cardiac acoustic biomarkers (CABs) measured by acoustic cardiography support the diagnosis or monitoring of worsening heart failure (HF). Our previous observational study suggested that temporal changes in CABs in patients with acute decompensated HF may reflect changes in cardiac function during hospitalization and between discharge and the first follow-up visit. This study aimed to assess whether changes in CABs between discharge and the first follow-up visit in such patients are associated with cardiac events over a 1-year follow-up period. Methods: This study was a follow-up to our previous observational study. CABs assessed at discharge and the first clinic visit following discharge were examined. The incidence of cardiac events, defined as the composite of death and rehospitalization due to worsening HF following the first clinic visit, was investigated. Results: Among 60 patients enrolled in our previous study, 47 who had CAB data at discharge and their first clinic visit were monitored for 1 year. During a median follow-up period of 351 days, 17 of these 47 patients experienced cardiac events, including 4 deaths and 13 rehospitalizations. The cumulative event-free survival rate was significantly poorer in patients whose change in third heart sound (ΔS3) strength was ≥ 0.1 than in those whose ΔS3 strength was < 0.1. Multivariate Cox regression models indicated that the ΔS3 strength increase was significantly associated with increased risk of cardiac events. Conclusions: An increase in S3 as assessed using the CAB device between discharge and the first clinic visit may be a predictor of subsequent cardiac events in patients initially hospitalized for acute decompensated HF.