Inhospital mortality of patients with left ventricle dysfunction admitted with acute decompensated heart failure: the role of renal function during hospitalization

Background

Heart failure is a high morbidity and mortality condition with a growing number of hospitalizations due to decompensation. Understanding the parameters associated with higher mortality in acute decompensated heart failure (ADHF) may result in better therapeutic strategies. Registries in ADHF developed mortality risk scores; however, national data are scarce.

Objective

To determine the parameters related to inhospital mortality in patients admitted with ADHF to a high-complexity Brazilian private hospital.

Methods

From January 2006 to December 2007 clinical parameters associated with inhospital mortality were analysed for 386 patients admitted with ADHF. The inclusion criteria consisted of patients with left ventricle ejection fraction ≤ 45%.

Results

Univariable analysis of patients who died during hospitalization demonstrated older age (82 vs 74 years, P = 0.0001) and at admission: lower systolic arterial pressure (116 vs 130 mmHg, P = 0.0174), reduced pulse pressure (46 vs 53 mmHg, P = 0.0403), higher urea (95 vs 70 mg/dl, P = 0.0069) and creatinine levels (2 vs 1.5 mg/dl, P = 0.0157). During hospitalization, higher urea and creatinine levels were consequently higher differentially compared with admission (urea delta: 65 vs 16 mg/dl, P < 0.0001 and creatinine delta: 1 vs 0.3 mg/dl, P < 0.0001) and also demonstrated a relation to mortality. There was statistical significance related to higher BNP (1,600 vs 950, P = 0.0235), inhospital length of stay (31 vs 10 days, P < 0.0001) and the use of an intra-aortic balloon pump (P = 0.0295). The multivariable logistic regression analysis demonstrated that the independent parameters related to inhospital mortality included older age (P = 0.02) and higher inhospital urea (P = 0.02) and creatinine (P = 0.02) levels.

Conclusion

ADHF registries raise the renal function as an important mortality admission risk factor. Nevertheless in this cohort, worsening renal function during hospitalization was an independent mortality predictor. In this context, renal function preservation must be attempted as a mortality reduction strategy in the setting of ADHF patients.