[Acute kidney injury in hospitalized patients with decompensated heart failure]

Acute kidney injury (AKI) occurs frequently in critical patients, but its clinical relevance has not been determined in decompensated heart failure (DHF).

To study the occurrence and prognostic value of AKI in patients with DHF and to compare the clinical and laboratory characteristics and in-hospital mortality with those without AKI.

Prospective study of 85 patients hospitalized in intensive care unit (ICU) with DHF from March 2010 to February 2011. Diagnosis of heart failure (HF) was established using the Boston criteria (scale > 8) and additional tests, and AKI was defined using the AKIN classification. Patients data with and without AKI were compared using Student's t-test, chi-squared statistic and multiple logistic regression, considering statistically significant p < 0.05.

Most patients were male (55%), valvular disease was the main etiology of HF (42.4%), and inadequate medication was the main cause of decompensation (22.4%). AKI occurred in 76.5% of patients (4.7% stage 1, 32.9% stage 2 and 38.8% stage 3). Patients were more anemic (p = 0.01) and had over 60 years (p = 0.02) in the AKI-group when compared to control. All patients with chronic kidney failure developed AKI. The duration of ICU stay was longer for the AKI group (group AKI 8.8 ± 6.6 days; group non-AKI 4 ± 1.4 days, p < 0.01). In-hospital mortality rate was higher in patients with AKI (p = 0.04), especially in stage 3 (p < 0.01). The duration of ICU stay was an independent predictor of AKI (p = 0.02). Only AKI was considered as independent predictor of mortality in this group (p = 0,05).

AKI is frequent in DHF, especially in advanced stages, in the elderly and patients with chronic kidney disease, and was associated with longer hospitalization and higher mortality rate.