Influence of renal dysfunction on inhospital morbidity and mortality of patients with decompensated heart failure

Background

Renal dysfunction (RD) is a clinical condition associated with worse inhospital prognosis for patients admitted due to decompensated heart failure (DHF).

Objectives

To evaluate the impact of RD in patients admitted due to DHF, and its relationship with clinical features and laboratory data, length of stay (LOS), and inhospital complications and mortality.

Methods

From January 2003 to December 2004, we studied a cohort of 137 patients admitted to the coronary care unit due to DHF (79.6% NYHA class IV). The mean age was 76.5 ± 11.08 years, 54% male, 29.9% diabetes mellitus, 74.5% systemic hypertension, 64% ischemic cardiomyopathy and the mean LOS was 14.2 ± 34.6 days. RD was defined as an estimated (Cockcroft) creatinine clearance less than 60 ml/min on admission. Baseline demographics, laboratory findings, LOS and complications (cardiac arrhythmias, hemorrhage, need of blood transfusions, hemodynamic instability and infections) and mortality rates were compared. The Mann–Whitney test (laboratory findings and LOS), the Student t test (age) and Pearson's chi-square test (other variables) were used.

Results

A total of 73.4% of the patients with DHF were considered to have RD. They were older (79.7 ± 9.5 vs 67.1 ± 10.4 years, P < 0.0001), with paradoxically less diabetes (18.1% vs 55.9%, P < 0.0001). On admission, B-type natriuretic peptide (P = 0.021), D-dimer (P = 0.024), hematocrit (36.2 ± 5.6% vs 38.2 ± 4.4%, P = 0.029) and hemoglobin (12.1 ± 1.89 vs 12.9 ± 2.08 g/dl, P = 0.057) were smaller. The need for blood transfusion (21.2% vs 5.9%, P = 0.041), and a significant increase of LOS was observed in the RD group (16.3 ± 41.2 vs 8.4 ± 5.7 days, P = 0.013), and higher inhospital mortality (9.57% vs 5.88%, P = not significant) was observed in the RD group.

Conclusions

RD is highly prevalent in patients admitted due to severe heart failure, with a clinical impact on blood transfusion, length of stay, and determining a trend to higher mortality.