Risks of arteriovenous fistula failure in hemodialysis patients older than 75 years.

BACKGROUND: Arteriovenous fistula (AVF) failure remains a major clinical problem in older patients undergoing hemodialysis. However, the relative contributions of risk factors and their time-dependent effects remain unclear. METHODS: We retrospectively analyzed 303 patients aged ≥ 75 years in whom AVFs were created. Cox proportional hazards models were used to identify the independent predictors of AVF failure within 1 year. Relative importance was assessed using the likelihood ratio chi-square statistic, and time-dependent effects were evaluated using Schoenfeld residuals. RESULTS: AVF failure within 1 year occurred in 30 patients (9.9%), including 10 patients who experienced early failure. Malnutrition, prolonged surgical time, and arterial calcification were identified as independent predictors. Each factor contributed comparably, accounting for approximately one-third of the model contribution. The effect of surgical time was attenuated after approximately 6 months. CONCLUSIONS: AVF failure in older patients is multifactorial, with comparable contributions from vascular, nutritional, and procedural factors.