Arteriovenous fistula placement in the elderly: when is the optimal time?

Arteriovenous fistula (AVF) is the preferred vascular access for hemodialysis (HD). However, many AVFs fail before starting dialysis. To assess the optimal time for AVF placement in the elderly, we linked data from the US Renal Data System with Medicare claims data to identify 17,511 patients ≥67 years old on incident HD who started dialysis between January 1, 2005, and December 31, 2008, with an AVF placed as the first predialysis access. AVF success was defined as dialysis initiation using the AVF, with time between AVF placement and dialysis start as our primary variable of interest. The mean age was 76.1±6.0 years, and 58.3% of subjects were men. Overall, 54.9% of subjects initiated dialysis using an AVF, and 45.1% of subjects used a catheter or graft. The success rate increased as time from AVF creation to HD initiation increased from 1-3 months (odds ratio [OR], 0.49; 95% confidence interval [95% CI], 0.44 to 0.53) to 3-6 months (OR, 0.93; 95% CI, 0.85 to 1.02) to 6-9 months (OR, 0.99; 95% CI, 0.88 to 1.11) but stabilized after that time. Furthermore, the number of interventional access procedures increased over time starting at 1-3 months, with a mean of 0.64 procedures/patient for AVFs created 6-9 months predialysis compared with 0.72 for AVFs created >12 months predialysis (P<0.001). Although limited by the observational nature of this study, our results suggest that placing an AVF >6-9 months predialysis in the elderly may not associate with a better AVF success rate.