Degree of Improvement in Pulmonary Congestion during Hospitalization for Heart Failure as Measured by Lung Impedance Predicts Readmission Rate

Background Readmission of patients discharged following hospitalization for heart failure (HF) is a medically and financially concern.

Aim to assess the hypothesis that the extent of improvement in pulmonary congestion during hospitalization for HF as evaluated by lung impedance (LI) can predict readmission rate.

Methods and results Study population included 256 patients with HF and LVEF ≤35% in NYHA class II-IV randomized to conventional or LI-guided therapy. Baseline LI was calculated and used to derive ∆LIR reflecting the degree of pulmonary congestion. The difference between ∆LIR at admission and at discharge, the pulmonary congestion difference (∆PC), was used to assess improvement during hospitalization. Readmission rate and time to readmissions by ∆PC quartiles were evaluated. Mean follow-up was 55± 31months in the monitored and 44±28 months in the control group (p<0.001) accounting for 212 vs. 382 HF hospitalizations, respectively (p<0.001). There were 28 and 51 HF-related and all-cause deaths in the monitored group and 47 and 67 deaths in the control group, respectively (p<.0.01). The 1-,3-,12- and 24-month rate of readmission due to HF, and HF-related and all-cause mortality were lower in the higher ∆PC quartiles compared to lower quartile in both study groups (p<0.01 for both). LI-guided treatment resulted in lower re-hospitalization rate (p<0.01). The 12-month readmission rate of study population was 100%, 99%, 93% and 33% by ∆PC quartile (p<0.01).

Conclusion the extent of ∆PC improvement during HF hospitalization measured by lung impedance strongly predicts readmission rates and event free survival times for HF hospitalization, and HF-related and all-cause mortality