Relation of Worsened Renal Function During Hospitalization for Heart Failure to Long-Term Outcomes and Rehospitalization

Worsened renal function (WRF) during heart failure (HF) hospitalization is associated with in-hospital mortality, but there are limited data regarding its relation to long-term outcomes after discharge. The influence of WRF resolution is also unknown. This retrospective study analyzed patients who received care from a large health system and had a primary hospital discharge diagnosis of HF from January 2000 to June 2008. Renal function was estimated from creatinine levels during hospitalization. The first available value was considered baseline. WRF was defined a creatinine increase ≥0.3 mg/dl on any subsequent hospital day compared to baseline. Persistent WRF was defined as having WRF at discharge. Proportional hazards regression, adjusting for baseline renal function and potential confounding factors, was used to assess time to rehospitalization or death. Of 2,465 patients who survived to discharge, 887 (36%) developed WRF. Median follow-up was 2.1 years. In adjusted models, WRF was associated with higher rates of postdischarge death or rehospitalization (hazard ratio [HR] 1.12, 95% confidence interval [CI] 1.02 to 1.22). Of those with WRF, 528 (60%) had persistent WRF, whereas 359 (40%) recovered. Persistent WRF was significantly associated with higher postdischarge event rates (HR 1.14, 95% CI 1.02 to 1.27), whereas transient WRF showed only a nonsignificant trend toward risk (HR 1.09, 95% CI 0.96 to 1.24). In conclusion, in patients surviving hospitalization for HF, WRF was associated with increased long-term mortality and rehospitalization, particularly if renal function did not recover by the time of discharge.