Recovery of worsening renal function after acute heart failure

Background

Worsening renal function (WRF) is common during hospitalization for acute decompensated heart failure (ADHF). WRF has been variably associated with outcomes, with prior studies reporting conflicting results. Such heterogeneity likely reflects the dynamic nature of cardiorenal interactions, whereby transient creatinine increases may arise from effective decongestion or initiation of guideline-directed medical therapy rather than from irreversible kidney injury.

Purpose

In patients with WRF during a hospitalization for ADHF, we aimed to evaluate the rate of WRF recovery after discharge, predictors of persistent WRF and its prognostic significance.

Methods

In a cohort of patients hospitalized for ADHF, creatinine was measured at admission, daily during hospitalization, and at 12 months after discharge. WRF was defined as a creatinine increase ≥0.3 mg/dL. Only patients who developed WRF during the index hospitalization were included. At the 12-month follow-up, WRF was classified as recovered if creatinine differed by <0.3 mg/dL compared with the admission value, and persistent when the difference remained ≥0.3 mg/dL. Predictors of WRF persistence were assessed by multivariable logistic regression analysis. Multivariable Cox regressions were performed for outcome analyses. The primary endpoint was 5-year all-cause mortality after the 12-month creatinine reassessment.

Results

Of 2,020 patients hospitalized for ADHF, 331 patients (16%) experienced WRF. Of them, 38 patients died before the 12-months revaluation, and 3 were lost to follow-up. The remaining 290 patients represented the study population. At 12 months, 157 patients (54%) had recovered WRF and 133 (46%) had persistent WRF.

Older age (OR=1.037 per 1 year increase, p=0.016), elevated natriuretic peptide levels (OR=1.822, p=0.043), and right ventricular dysfunction during hospitalization (OR=1.861, p=0.044) were independent predictors of persistent WRF.

At 5-year follow-up after the 12-month assessment, recovered WRF – compared with persistent WRF – was strongly associated with a lower risk of mortality (adjusted HR=0.229, p<0.001) and of mortality or rehospitalization for ADHF (HR=0.295, p<0.001). The association between WRF recovery and improved survival was independent of prior chronic kidney disease, of baseline creatinine and of age; conversely, recovered WRF seemed more strongly associated with lower mortality in male sex (p-int=0.034).

Conclusions

WRF is frequent during hospitalization for ADHF, but reversible in more than half of cases during the first year. The recovery of renal function is associated with a strong reduction in mortality and morbidity risk. These findings support a careful assessment of the trajectory of renal function after discharge in patient who experience in-hospital WRF. Further studies with deeper assessment of the multiple domains of renal injury might provide a clearer picture of the different subtypes of WRF and their prognostic implications.For image description, please refer to the figure legend and surrounding text.For image description, please refer to the figure legend and surrounding text.