Consistent aspirin use associated with improved arteriovenous fistula survival among incident hemodialysis patients in the dialysis outcomes and practice patterns study

Abstract

Background and objectives: The relationship between aspirin use and arteriovenous fistula (AVF) survival has been lacking. The aim of this study was to evaluate the association between AVF survival and aspirin use.

Design, setting, participants, & measurements: Data on 2815 incident hemodialysis patients (on dialysis <or= 30 d) using an AVF at enrollment into the Dialysis Outcomes and Practice Patterns Study between 1996 and 2004 were analyzed. Cox regression was used to examine the association between aspirin use and the risk of final AVF failure, first AVF failure, and a gastrointestinal bleeding event. Aspirin use was determined at baseline and one year later. Patients using aspirin at baseline and one year later were considered consistent aspirin users. All models accounted for facility clustering effects and were adjusted for age, race, gender, body mass index, prior permanent access failure, prior placement of a catheter, 10 comorbid conditions, laboratory data, and other medications, and stratified by regions.

Results: Consistent aspirin use was significantly related to a lower risk of final AVF failure. Facility-level analysis, which may reduce confounding by indication, also showed a nearly significant trend of reduced risk of final AVF failure with greater prevalence of consistent aspirin use within dialysis facilities (P for trend = 0.07). The occurrence of a new gastrointestinal bleeding event during the study period was not associated with aspirin use.

Conclusions: These results suggest that consistent aspirin use may be beneficial for AVF survival among incident hemodialysis patients.

Figure 1.

Percentage of aspirin use at baseline by region. Based on a point prevalent cross section at study entry of HD patients on dialysis ≤ 30 d participating in DOPPS: n = 707 in North America, n = 1590 in Europe/Australia and New Zealand, n = 518 in Japan, and n = 2815 in total.

Figure 2.

Distribution of percent consistent facility aspirin use. The percent of patients in a facility taking aspirin consistently for a year was determined using the medication information at both baseline and one year later (n = 260 facilities). *Restricting to facilities having at least 5 patients with aspirin prescription information at both baseline and one year later.

Figure 3.

Adjusted hazard ratio (AHR) of final AVF failure by percent consistent facility aspirin use. AHR for final AVF failure by percent consistent facility aspirin use based on a multivariate analysis. Results are provided for percent consistent facility aspirin use as a continuous variable or as categories of percent consistent aspirin use. The multivariate analysis was adjusted for age, race, gender, body mass index, 10 comorbid conditions, prior permanent VA failure, prior placement of catheter, laboratory data (hemoglobin, serum albumin, serum creatinine), medications (warfarin, other antiplatelet agent, angiotensin converting enzyme inhibitor, angiotensin receptor blocker, calcium channel blocker, statin), accounted for facility clustering effects, and was stratified by region (n = 1082). *Restricting to facilities having at least 5 patients with aspirin prescription information at both baseline and one year later. **The 80th percentile of consistent facility aspirin use was 40% of facility patients taking aspirin consistently for 1 yr.