Prognostic value of the urea:creatinine ratio in decompensated heart failure and its relationship with acute kidney damage

Abstract

BackgroundWorsening renal function is associated with an adverse prognosis for patients with acute heart failure (AHF). Urea–creatinine ratio (U:Cr ratio) might be useful for measuring renal function and could help stratify patients with AHF. Material and methodsAn observational and prospective study was conducted to analyze the prognostic value of the U:Cr ratio, measured during the first 24–28h of admission, for patients hospitalised for decompensated heart failure, and its relationship with estimated glomerular filtration rate (eGFR) and acute kidney injury (AKI). ResultsThe study included 204 patients, with a mean age of 79.3 years, and a median eGFR of 55mL/min/1.73m2. In the multivariate analysis, an U:Cr ratio above the median (50) was related to the development of AKI (36.5% vs. 21.9%) and to increased mortality, both overall (OR 2.75) and by HF (OR 3.50) in long term. In combination with eGFR, the U:Cr ratio showed prognostic value in patients with normal eGFR (mortality of 4.4% for an U:Cr ratio≤50 vs. 22% for U:Cr ratio>50; p=0.01), as well as a better predictive capacity for AKI than each of them separately (AUC, 0.718; 95% CI 0.643–0.793; p>0.000). ConclusionsAn U:Cr ratio>50 is a predictor of increased long-term mortality for patients hospitalised for decompensated HF and with normal eGFR. Given the simplicity of this biomarker, its use in clinical practice should be more systematic.