Impact of a Maturing Fistula or Graft on Dialysis Patient Outcomes

Background: Catheter (CVC) access is used by ~80% of patients who initiate hemodialysis (HD), but some of these patients also have a fistula (AVF) or graft (AVG) which is not yet ready for use (CVC-Plus). We evaluated patient survival after day 90 and transplant waitlisting for the CVC-Plus group, compared to patients using AVF/G and CVC-only. Methods: All adult patients enrolled in the US Renal Data System with first-time, incident HD with primary Medicare between 2014-2017 were considered, if still receiving chronic dialysis on day 90. Propensity-matched samples were constructed to balance the characteristics between patients with each type of initial vascular access, including: age, sex, race, BMI, albumin, hemoglobin, eGFR, kidney diagnosis, pre-dialysis nephrology/dietary care, and comorbid conditions. Patient survival was evaluated with Cox regression. Transplant waitlist appearance was evaluated by logistic regression. CVC-plus was the reference group for all models. Results: Among 236,775 subjects, 58% had CVC-only, 19% had CVC-Plus, and 23% had AVF/G. Median follow up was 34 (IQR: 14-50) months. Mean age was 69.6 years and 44% were female. There were 160,264 deaths (68%) during the study period. Waitlisting occurred for 15% of AVF/G, 9% of CVC-Plus, and 7% of CVC-only. Compared to CVC-Plus, CVC-only was associated with increased death (HR: 1.19, 95%CI=1.17-1.21), and AVF/G was associated with decreased death (HR: 0.86, 95%CI=0.84-0.87), p<0.001 for both. Compared to CVC-Plus, the odds of being waitlisted were higher in patients with AVF/AVG (OR: 1.56, (95%CI=1.49-1.62), and lower in patients with CVC-only (OR: 0.84, (95%CI=0.80-0.88), p<0.001 for both. Conclusion: Initiating HD with an unready AVF/G is associated with better survival and more opportunity for transplant waitlisting, compared to having CVC as sole access – but functioning AVF/G are associated with the best outcomes. These associations are robust to extensive propensity matching. Working diligently to secure vascular access is worthwhile, especially as the need for dialysis approaches.. Funding: Other NIH Support - NIDDK awards: U2CDK129917, d TL1DK132769