Association of congestion with worsening renal function in acute decompensated heart failure according to age

Acute decompensated heart failure (ADHF) is a frequent cause of hospitalization for patients with heart disease, and ADHF patients are at high risk of heart failure (HF) re-hospitalization. Residual congestion at discharge is also a strong predictor of poor outcomes and re-hospitalization for ADHF patients. However, the impact of residual congestion at discharge on worsening renal function (WRF) in both high-aged and older patients remains uncertain because previous studies of WRF in ADHF patients were conducted for older patients. We therefore designed and conducted a retrospective, population-based study using the Kobe University Heart Failure Registry in Awaji Medical Center (KUNIUMI) Registry to investigate the association of residual congestion at discharge with WRF in ADHF patients according to age.

We studied 966 hospitalized ADHF patients with a mean age of 80.2 ± 11.4 years from among 1971 listed in the KUNIUMI Registry. WRF was defined as an increase of ≥0.3 mg/dL in the serum creatinine level during the hospital stay compared with the value on admission. The primary endpoint was defined as cardiovascular death or HF re-hospitalization after discharge over a mean follow-up period of 2.0 ± 0.1 years. The primary endpoint was recorded for 369 patients (38.2%). As expected, patients with both WRF and residual congestion at discharge had significantly less favourable outcomes compared with those without one of them, and patients without either of these two characteristics had the most favourable outcomes, whereas those with residual congestion and with WRF had the least favourable outcomes. Moreover, WRF was significantly associated with worse outcomes for high-aged patients ≥80 years old, but not for those <80 years old if decongested. Multivariable Cox regression analysis showed that both residual congestion at discharge and WRF were the independent predictors of outcomes for high-aged patients, but residual congestion at discharge, not WRF, was the independent predictor of outcomes for older patients.

Association of residual congestion at discharge with WRF for hospitalized ADHF patients can differ according to age. Our findings showed the importance of WRF and residual congestion at discharge for high-aged ADHF patients and of aggressive diuresis to alleviate congestion for older ADHF patients for better management of such patients in a rapidly ageing society.