Different impact of chronic kidney disease in older patients with heart failure according to frailty

Background

Chronic kidney disease (CKD) and frailty are often present in older patients with heart failure (HF). Our aim was to evaluate the association of CKD and frailty in one-year mortality in a cohort of older (≥75 years) outpatients with HF

Methods

Our data come from the FRAGIC study (“impacto de la FRAGilidad y otros síndromes Geriátricos en el manejo clínico y pronóstico del paciente anciano ambulatorio con Insuficiencia Cardíaca"), a multicenter prospective registry conducted in 16 cardiology services in Spain which included ≥75 years outpatients with HF. Renal function was assessed according to CKD-EPI formula. A comprehensive geriatric assessment was performed and frailty was identified according to visual mobility scale (frail if VMS≥2). Survival rates were analyzed by Cox regression model.

Results

We included 499 patients, mean age 81.4 ± 4.3 years, 38 % women. Mean estimated glomerular filtration rate (eGFR) was 52.1 ± 17.5 ml/min/1.72 m². Patients were classified in normal renal function (eGFR≥60 ml/min/1.72m², 182 patients, 36 %), moderately impaired (eGFR 30–59 ml/min/1.72m², 261 patients, 52.7 %) and severely impaired (eGFR<30 ml/min/1.72m², 56 patients, 11.3 %). Patients with severe CKD were older, more often female, and presented a worse clinical profile, with higher comorbidity burden and frailty. After a median follow up of 371 days, 58 patients (11.6 %) died. Mortality was higher in patients with worse renal function (8.8 %, 11 % and 21 % according to renal function subgroups, respectively, p = 0.036) and frailty in the univariate analysis. However, only frailty, according to VMS, but not severe renal dysfunction, was independently associated with one year mortality.

Conclusions

Most HF patients≥75 years have renal dysfunction. CKD is a marker of worse prognosis in elderly patients with chronic HF, but it does not independently associate one-year mortality in the presence of frailty.