Acute kidney injury and outcomes in acute decompensated heart failure: evaluation of the RIFLE criteria in an acutely ill heart failure population

Aims The clinical course including the outcome of acute decompensated heart failure (ADHF) correlates with renal dysfunction, but the evaluation of renal function has not yet been standardized. We therefore investigated the relationship between the prognosis of ADHF and acute kidney injury (AKI) evaluated using the risk, injury, failure, loss, end stage (RIFLE) criteria. Methods and results This study assessed 376 consecutive patients with ADHF admitted to the intensive care unit (ICU) (mean age 71.6 years; 238 male). The underlying aetiology was ischaemic heart disease, hypertensive heart disease, cardiomyopathy, valvular diseases, and 'other' in 124, 70, 60, 107, and 15 patients, respectively. We defined AKI according to the RIFLE criteria, and the most severe RIFLE classifications during hospitalization were adopted to assess patient outcomes. The in-hospital mortality was significantly higher among patients with AKI (29 of 275; 10.5%) than in those without AKI (1 of 101; 1.0%, P = 0.0010). Both ICU and hospital stays were longer for patients with AKI (8.8 +/- 15.4 vs. 48.6 +/- 47.6 days), than for patients without (5.0 +/- 2.8 vs. 25.7 +/- 16.8 days, P < 0.05 and P < 0.001). Conclusion Acute kidney injury evaluated by the RIFLE criteria was associated with a poorer outcome for patients with ADHF.