Preoperative high-sensitivity C-reactive protein-to-albumin ratio predicts arteriovenous fistula failure in hemodialysis patients: a retrospective cohort study with landmark analysis.

BACKGROUND: The arteriovenous fistula (AVF) is the preferred vascular access for hemodialysis, yet up to 50% of AVFs fail within the first year due to stenosis or thrombosis. The high-sensitivity C-reactive protein to albumin ratio (HRR) integrates inflammation and nutritional status, but its association with AVF failure has not been systematically evaluated. METHODS: This retrospective cohort study included 279 patients who underwent first-time AVF creation. HRR was calculated as hsCRP (mg/L) divided by albumin (g/L). The primary outcome was AVF failure (stenosis ≥50% or thrombosis requiring intervention). Multivariate Cox regression adjusted for age, sex, BMI, diabetes, hypertension, smoking, and vessel diameter. Model performance was assessed using time-dependent ROC, calibration curve, and decision curve analysis (DCA). RESULTS: During a median follow-up of 50 months, 141 patients (50.5%) developed AVF failure.In multivariate analysis, higher HRR was independently associated with increased AVF failure risk (HR per unit increase = 1.65, 95% CI: 1.33-2.05, P < 0.001), independent of vessel diameter (HR = 0.21, 95% CI: 0.08-0.57, P = 0.002). A landmark analysis stratified at 24 months demonstrated that the predictive effect of HRR was directionally consistent across early (HR = 1.60, 95% CI: 1.27-2.02) and late (HR = 1.47, 95% CI: 0.66-3.29) follow-up periods (P for interaction = 0.766), although the late-phase estimate was imprecise due to the reduced sample size. The model demonstrated moderate discrimination at 24 months (AUC = 0.608, 95% CI: 0.519-0.701) and good calibration. DCA confirmed that incorporating HRR provided positive net clinical benefit across clinically relevant threshold probabilities. The proportional hazards assumption was satisfied (global P = 0.97). Sensitivity analysis using multiple imputation yielded consistent results. CONCLUSIONS: Preoperative HRR is an independent predictor of AVF failure. Although the model demonstrated weak to moderate discrimination (24-month AUC = 0.608), decision curve analysis confirmed a positive net clinical benefit, supporting its potential utility in preoperative risk stratification. This simple, widely available laboratory-based marker may assist clinicians in identifying high-risk patients and individualizing surveillance intensity, though external validation is warranted.