Maturation of an arteriovenous fistulas (AVF) fails to occur for 20–60% of patients who have one created for haemodialysis access, and there is a need for better interventions to raise these rates. So say the authors of new research published in the Clinical Journal of the American Society of Nephrology (CJASN), led by Jia Hwei Ng (Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Great Neck, USA), who contend that simpler, standardised criteria for defining maturation could lead to improved outcomes and interventions.
Ng et al utilised data from the Hemodialysis Fistula Maturation (HFM) study, a multicentre, prospective study, the follow-up of which with 602 patients was completed in 2014. The authors explain that they “determined sensitivities, specificities, positive and negative predictive values of multiple candidate maturation criteria using the HFM study maturation criteria as a reference”. Cox proportional hazards models were also used to evaluate the relationship between fistula survival and maturation “across the maturation criteria”.
From the study’s 602 participating patients, 535 were selected for inclusion in Ng and colleagues’ research. They detail that the median age of the patients was 57 years, as well as that 70% were male and 45% Black. A variety of criteria and time frames for measurement included three, four, five, six, or nine months. According to these, the authors note, sensitivities ranged from 57–100%, specificities ranged from 85–100%, positive predictive values ranged from 88–100%, and negative predictive values ranged from 65–100%.
The area under the curve (AUC) for six-month (0.90–0.97 for unassisted maturation and 0.89–0.95 for overall maturation) and nine-month timeframes “were similar” for all criteria, the authors say. Successful unassisted maturation was associated with “reduced risks of fistula abandonment”, Ng et al add, “with hazard ratios (HRs) ranging from 0.10–0.40 depending on the criterion and time frame”. They also note that there was no significant effect on performance characteristics when the criteria were simplified in other ways or when dialysis adequacy indicators were removed entirely.
Ng and colleagues conclude simply: similar outcomes can be achieved in fistula maturation with simpler criteria for defining that maturation than those used in the HFM study outcome measurements. Simplified criteria, they say, may also be “less burdensome to ascertain” than existing measures.
