Research article

Chronic kidney disease increases cardiovascular unfavourable outcomes in outpatients with heart failure

Arise GS Galil , Hélady S Pinheiro , Alfredo Chaoubah , Darcília MN Costa and Marcus G Bastos

NIEPEN - Interdisciplinary Nucleus of Study and Research in Nephrology, Federal University of Juiz de Fora; Center for Control of Hypertension, Diabetes and Obesity, Juiz de Fora, Brasil

author email corresponding author email

BMC Nephrology 2009, 10:31doi:10.1186/1471-2369-10-31

Published:	21 October 2009

Abstract

Background

Chronic heart failure (CHF) has a high morbidity and mortality. Chronic kidney disease (CKD) has consistently been found to be an independent risk factor for unfavorable cardiovascular (CV) outcomes. Early intervention on CKD reduces the progression of CHF, hospitalizations and mortality, yet there are very few studies about CKD as a risk factor in the early stages of CHF. The aims of our study were to assess the prevalence and the prognostic importance of CKD in patients with systolic CHF stages B and C.

Methods

This is a prospective cohort study, dealing with prognostic markers for CV endpoints in patients with systolic CHF (ejection fraction ≤ 45%).

Results

CKD was defined as estimated glomerular filtration rate <60 mL/min/1.73 m² and CV endpoints as death or hospitalization due to CHF, in 12 months follow-up. Eighty three patients were studied, the mean age was 62.7 ± 12 years, and 56.6% were female. CKD was diagnosed in 49.4% of the patients, 33% of patients with CHF stage B and 67% in the stage C. Cardiovascular endpoints were observed in 26.5% of the patients. When the sample was stratified into stages B and C of CHF, the occurrence of CKD was associated with 100% and 64.7%, respectively, of unfavorable CV outcomes. After adjustments for all other prognostic factors at baseline, it was observed that the diagnosis of CKD increased in 3.6 times the possibility of CV outcomes (CI 95% 1.04-12.67, p = 0.04), whereas higher ejection fraction (R = 0.925, IC 95% 0.862-0.942, p = 0.03) and serum sodium (R = 0.807, IC 95% 0.862-0.992, p = 0.03) were protective.

Conclusion

In this cohort of patients with CHF stages B and C, CKD was prevalent and independently associated with increased risk of hospitalization and death secondary to cardiac decompensation, especially in asymptomatic patients.