SP593REGIONAL DIFFERENCES IN ARTERIOVENOUS FISTULA FAILURE OBSERVED IN THE FAVOURED TRIAL

Abstract

INTRODUCTION AND AIMS: Arteriovenous fistulae (AVF) are the preferred haemodialysis access but are vulnerable to early failure (20‐50%). Regional variation in early AVF failure might identify additional determinants of AVF failure and inform best practice. The aim of this study was to determine whether there were regional differences in AVF failure (Malaysia versus Australia and New Zealand [ANZ]) by analysing data from the omega‐3 fatty acids (Fish oils) and Aspirin in Vascular access OUtcomes in REnal Disease (FAVOURED) trial. METHODS: AVF failure, defined as a composite of AVF thrombosis and/or abandonment and/or cannulation failure by 12 months post access creation, was compared for a subset of participants from ANZ (n=209) and Malaysia (n=144). The risk ratio (RR) for region was determined for the composite outcome and its components by log binomial regression: without adjustment; adjusted for known covariates of AVF failure (age, gender, diabetes, cardiovascular disease, AVF site, smoking, and BMI); and adjusted for propensity scores (PS) derived from known covariates of AVF failure plus heart rate, blood pressure, calcium channel blocker and aspirin use, haemoglobin, albumin, and dialysis at baseline. RESULTS: The 353 participants had a mean age of 55 years, 64% were male and 52% diabetic. Overall 47% of AVF failed. AVF failure was significantly lower in Malaysia compared to ANZ (54/144 [38%] versus 113/209 [54%], p=0.003, unadjusted RR 0.69, 95% confidence interval [CI] 0.54‐0.89; covariate adjusted RR 0.71, 95% CI 0.53‐0.96, p=0.023, PS adjusted RR 0.68, 95% CI 0.47‐0.98, p=0.037). This difference in AVF failure was driven by a lower risk of cannulation failure: 42/144 (29%) versus 98/209 (47%); unadjusted RR 0.62, 95% CI 0.46‐0.83, p=0.001; covariate adjusted RR 0.63, 95% CI 0.44‐0.91, p=0.008; PS adjusted RR 0.57, 95% CI 0.36‐0.90, p=0.015. There was no significant regional variation in AVF thrombosis (25/144 [17%] versus 42/209 [20%], p=0.52) and abandonment (36/144 [25%] versus 49/209 [23%], p=0.74). CONCLUSIONS: There was significant regional variation in AVF failure principally due to a lower risk of cannulation failure in Malaysia. Differences in clinical practice patterns, including patient selection, surgical and/or cannulation techniques, likely contributed to these findings and warrant further investigation.