How to Predict and Prevent 30-Day Heart Failure Readmission

Background Readmissions for heart failure (HF) are a major burden. We aimed to assess whether the extent of improvement in pulmonary fluid content (∆PC) during HF-hospitalization evaluated by lung impedance (LI), or indirectly by other clinical and laboratory parameters, predicts readmissions.

Methods The present study is based on predefined secondary analysis of the IMPEDANCE-HF extended trial comprising 266 HF patients at NYHA class II-IV and LVEF≤35% randomized to LI-guided or conventional therapy during long-term follow-up.

Results LI-guided patients were followed for 58±36 months and the control patients for 46±34 months (p<0.01) accounting for 253 and 478 HF hospitalizations, respectively (p<0.01). LI, NT-proBNP, weight, radiological score, NYHA class, lung rales, leg edema or jugular venous pressure were measured at admission and discharge on each hospitalization in both groups with the difference defined as DPC. Average LI-assessed DPC was 12.1% vs. 9.2% and time to HF-readmission was 659 vs. 306 days in the LI-guided and control groups, respectively (p<0.01). LI-based DPC predicted 30 and 90-day HF readmission better than DPC assessed by the other variables (p<0.01). The readmission rate for HF was lower if DPC> median compared with DPC≤ median for all parameters evaluated in both study groups with the most pronounced difference predicted by LI (p<0.01). Net reclassification Improvement analysis showed that adding LI to the traditional clinical and laboratory parameters improved the predictive power significantly.

Conclusion The extent of DPC improvement, primarily the LI-based, during HF-hospitalization, and study group allocation strongly predicted readmission and event-free survival time.