One-year survival and renal function recovery of acute kidney injury patients with chronic heart failure.

OBJECTIVE

To describe and analyze the clinical characteristics of acute kidney injury (AKI) patients with preexisting chronic heart failure (CHF) and to identify the prognostic factors of the 1-year outcome.

METHODS

A total of 120 patients with preexisting CHF who developed AKI between January 2005 and December 2010 were enrolled. CHF was diagnosed according to the European Society of Cardiology guidelines, and AKI was diagnosed using the RIFLE criteria. Clinical characteristics were recorded, and nonrecovery from kidney dysfunction as well as mortality were analyzed.

RESULTS

The median age of the patients was 70 years, and 58.33% were male. 60% of the patients had an advanced AKI stage ('failure') and 90% were classified as NYHA class III/IV. The 1-year mortality rate was 35%. 25.83% of the patients progressed to end-stage renal disease after 1 year. Hypertension, anemia, coronary atherosclerotic heart disease and chronic kidney disease were common comorbidities. Multiple organ dysfunction syndrome (MODS; OR, 35.950; 95% CI, 4.972-259.952), arrhythmia (OR, 13.461; 95% CI, 2.379-76.161), anemia (OR, 6.176; 95% CI, 1.172-32.544) and RIFLE category (OR, 5.353; 95% CI, 1.436-19.952) were identified as risk factors of 1-year mortality. For 1-year nonrecovery from kidney dysfunction, MODS (OR, 8.884; 95% CI, 2.535-31.135) and acute heart failure (OR, 3.281; 95% CI, 1.026-10.491) were independent risk factors.

CONCLUSION

AKI patients with preexisting CHF were mainly elderly patients who had an advanced AKI stage and NYHA classification. Their 1-year mortality and nonrecovery from kidney dysfunction rates were high. Identifying risk factors may help to improve their outcome.