Rationale & objective: Vascular access type (arteriovenous fistula [AVF] vs arteriovenous graft [AVG] vs central venous catheter [CVC]) associates with clinical outcomes in patients with end-stage kidney disease undergoing hemodialysis. Whether a similar association exists with outcomes after kidney transplantation is unknown. We hypothesized that AVGs would associate with worse outcomes, perhaps owing to persistent subclinical inflammation.
Study design: Retrospective cohort study.
Setting & participants: Using US registry data merged with electronic health records of a large dialysis organization (2006-2011), we selected patients receiving a first-ever kidney transplant after undergoing more than 30 days of hemodialysis.
Exposure: Hemodialysis access used during the patient’s last pretransplantation hemodialysis session.
Outcomes: Patients were followed up from kidney transplantation for all-cause mortality, kidney allograft loss from any cause, and allograft loss not from death.
Analytical approach: Time-to-event analysis including Kaplan-Meier plots and Cox proportional hazards regression estimated cause-specific HRs and 95% CIs.
Results: Among 9,291 patients who underwent kidney transplantation between 2006 and 2011, a total of 65.3% used an AVF, 20.4% used an AVG, and 14.3% used a CVC for hemodialysis before transplantation. Multivariable regression models adjusted for demographic variables, comorbid conditions, transplant characteristics, and laboratory parameters identified no independent associations between vascular access type and all-cause mortality (HRAVG, 1.13 [95% CI, 0.97-1.33]; HRCVC, 1.00 [95% CI, 0.83-1.21]). Similarly, AVG and CVC use were not independently associated with all-cause allograft loss compared with AVF use (HRAVG, 1.13 [95% CI, 1.00-1.28]; HRCVC, 1.12 [95% CI, 0.96-1.29]). CVC use was associated with 30% higher risk for allograft loss from causes other than death compared with AVF use (HRCVC, 1.30 [95% CI, 1.06-1.57]), but AVGs were not (HRAVG, 1.17 [95% CI, 0.98-1.39]).
Limitations: Nonrandomized exposure leading to potential residual confounding.
Conclusions: No association was found for AVG use before kidney transplantation with mortality, all-cause allograft loss, and allograft loss from all causes other than death, compared with AVF use. The association of CVC use with allograft loss from causes other than death requires further investigation.
Reference:Airy M, Lenihan CR, Ding VY, et al. Association Between Type of Vascular Access Used in Hemodialysis Patients and Subsequent Kidney Transplant Outcomes. Kidney Med. 2019;1(6):383-390. Published 2019 Oct 25. doi:10.1016/j.xkme.2019.08.005