Clinical characteristics and one-year mortality according to admission renal function in patients with a first acute heart failure hospitalization

Abstract

Introduction and objectives: Chronic kidney disease is related to poor outcomes in patients with heart failure (HF). Few studies have assessed whether renal function influences one-year mortality risk in patients admitted for the first time for acute HF.

Methods: We reviewed the medical records of all patients aged >50 years admitted within a two-year period for a first episode of decompensated HF. The sample was divided according to the patients' estimated glomerular filtration rate (eGFR) on admission into three groups (eGFR >60, 30-60 and <30 ml/min/1.73 m²). Index admission and one-year all-cause mortality rates were compared between groups using Cox regression analysis.

Results: A total of 985 patients were included in the study, mean age 78.4±9 years, and with mean admission eGFR of 60.5±26 ml/min/1.73 m². Of these, 516 (52.3%) patients had eGFR <60 ml/min/1.73 m². One-year all-cause mortality was 25.4%, with a significant association between worse eGFR category and mortality (p<0.0001). Cox regression analysis assessing eGFR as a categorical variable confirmed this association (HR 1.378; p=0.030), together with older age (HR 1.066; p<0.001), previous diagnosis of hypertension (HR 0.527; p<0.001), and both lower systolic blood pressure (HR 0.993; p=0.009) and higher serum potassium on admission (HR 1.471; p <0.001).

Conclusions: Renal impairment is common in HF patients, even at the time of first admission. In this group of HF patients the presence of renal impairment was associated with higher mid-term (one-year) mortality risk.

Keywords: Chronic kidney disease; Doença renal crónica; Heart failure; Hospitalization; Hospitalização; Insuficiência cardíaca; Mortalidade; Mortality; Readmission; Readmissão.