A New and Robust Prognostic Biomarker for Mortality Risk Prediction in Dialysis Patients With Coronary Artery Disease: Red Cell Distribution Width-to-Albumin Ratio

Background: Coronary artery disease (CAD) remains a fundamental etiology of morbidity and mortality among patients receiving dialysis, a cohort known to have a particularly poor prognosis. While traditional CAD risk factors, such as hyperlipidemia, hypertension, and diabetes, remain noteworthy, these factors do not fully capture the complexity of the disease in dialysis patients. Therefore, innovative and robust biomarkers that can refine risk stratification and enhance prognostic precision in this vulnerable population are imperative. Hence, this study aimed to evaluate the use of the red cell distribution width-to-albumin ratio (RAR) to predict clinical outcomes, particularly in dialysis patients with CAD. Methods: We analyzed data from a multicenter cohort of 1128 CAD patients on dialysis who were enrolled between January 2015 and June 2021. Patient stratification into tertiles was performed based on RARs. The primary endpoints were all-cause mortality and cardiovascular mortality. The secondary endpoint was the occurrence of major adverse cardiovascular events (MACEs), comprising non-fatal myocardial infarction, non-fatal stroke, and other cardiovascular events. Results: The median follow-up duration was 20.9 months 378 (33.5%) patients experienced all-cause mortality, 261 (19.1%) cardiovascular mortality, and 485 (43.0%) MACEs. In multivariable Cox proportional hazards regression, patients in the highest RAR tertile demonstrated remarkably escalated risks of all-cause mortality (hazard ratio (HR): 1.592, 95% confidence interval (CI): 1.212–2.092), cardiovascular mortality (HR: 1.503, 95% CI: 1.086–2.080), and MACEs (HR: 1.452, 95% CI: 1.141–1.846) compared with those in the lowest tertile. Moreover, restricted cubic spline analysis revealed a linear, dose-dependent association between elevated RAR and an increased risk of these adverse outcomes. The integration of the RAR into existing risk models, specifically the Global Registry of Acute Coronary Events and Gensini scores, noticeably amplified the predictive performance, as demonstrated by notable enhancements in both net reclassification improvement and integrated discrimination improvement. Conclusions: An elevated RAR serves as an independent predictor of poor outcomes in patients with CAD undergoing dialysis. Clinical Trial Registration: This study was registered at ClinicalTrials.gov (Identifier: NCT05841082; https://clinicaltrials.gov/study/NCT05841082).