Prognostic significance of blood urea nitrogen/creatinine ratio in chronic HFpEF

BACKGROUND: The prognostic significance of blood urea nitrogen (BUN)/creatinine ratio specifically in chronic heart failure with preserved ejection fraction (HFpEF) patients remained unclear. We aimed to evaluate the association of BUN/creatinine ratio (baseline level and visit-to-visit variation) with the risk of adverse clinical outcomes among patients with chronic HFpEF. METHODS AND RESULTS: This is a secondary analysis of the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) trial. Of the enrolled 3445 participants in the TOPCAT trial, associations between BUN/creatinine and clinical outcomes were examined in a subset of 1521 (baseline measurements level) and 1453 (visit-to-visit variation) participants. A multivariable Cox proportional hazard model was used to assess the prognostic significance of BUN/creatinine ratio and BUN/creatinine ratio variation for the prespecified clinical outcomes. A higher BUN/creatinine ratio was associated with a higher risk of all-cause mortality (hazard ratio [HR] = 1.52, 95%CI, 1.21-1.91; p < .001) as well as cardiovascular disease mortality (HR = 1.83, 95%CI, 1.35-2.49; p < .001) in the fully adjusted model. Greater visit-to-visit variability in BUN/creatinine ratio tended to be independently associated with a higher risk of heart failure hospitalization and primary endpoint (p < .001 for both outcomes). Furthermore, those findings were consistent across participants stratified by the presence of chronic kidney disease at baseline. CONCLUSIONS: Higher BUN/creatinine ratio and greater BUN/creatinine ratio variability are independently associated with adverse outcomes in HFpEF participants in the TOPCAT trial.