Antiplatelet agents maintain arteriovenous fistula and graft function in patients receiving hemodialysis: A nationwide case-control study

Background

In this study, we evaluated the effects of various medications on the patency of vascular access (VA) for hemodialysis.

Methods

We analyzed data from the Longitudinal Health Insurance Database of Taiwan. We adopted a case–control study design within a cohort of patients who had received regular hemodialysis between 2002 and 2012; 34,354 patients with first VA failure were identified, and the duration from VA creation date to the first VA failure date was calculated. We then classified these patients into two groups, namely arteriovenous fistula (AVF, n = 25,933) and arteriovenous graft (AVG, n = 8,421). Each group was further divided into two subgroups, namely short-term (<1 year) and long-term (≥1 year) patency.

Results

The risk factors for early VA failure were age ≥65 years, diabetes mellitus, hyperlipidemia, cerebral vascular disease, congestive heart failure, peripheral artery disease, and sepsis. Male sex, hypertension, cancer, and peptic ulcer were associated with early AVF failure. Antiplatelet therapy increased the AVF and AVG patency times with adjusted odds ratios of 0.748 (95% confidence interval [CI]: 0.703–0.796, p < 0.0001) and 0.810 (95% CI: 0.728–0.901, p = 0.0001), respectively. A significant decrease in the VA failure risk was observed with an increase in the cumulative defined daily dose of antiplatelet agents.

Conclusion

This nationwide study demonstrated that some risk factors were associated with early VA failure and that the use of antiplatelet agents prevented the loss of VA patency in a dose–response manner. Thus, antiplatelet drugs should be routinely administered to high-risk patients receiving dialysis.

Role of antiplatelet therapy in the durability of hemodialysis access

BACKGROUND

Antiplatelet therapy (APT) is often used on anecdotal grounds to improve vascular access patency. The aim of this study was to assess the role of APT in hemodialysis (HD) patients undergoing arteriovenous fistula (AVF) or graft (AVG) placement.

METHODS

All patients in a large HD vascular qualitative initiative database (2011-2017) were included and divided into no antiplatelet therapy (no-APT) vs. any APT [aspirin (ASA) or P2Y12 inhibitors (PI)]. Multivariate [logistic (MLR) and Cox (MCR) regression] analyses were used as appropriate.

RESULTS

A total of 24,847 patients undergoing HD access creation were identified (78% AVF). APT was noted among 49 and 46% of AVG and AVF patients, respectively. In MLR analysis, patients on no-APT vs. APT had a 12-fold increased risk of in-hospital mortality (odds ratio (OR) 11.79, [95% confidence interval 5.30-26.26]) and the risk of developing steal syndrome was higher among patients discharged on APT (OR 1.81, [1.19-2.76]). In patients undergoing AVF, primary patency (PP) was similar between APT and no-APT. However, in patients undergoing AVG, PP rates at 12 months were significantly higher for APT: ASA (47 vs. 41%) and PI (51 vs. 41%) than for no-APT (p = 0.008). At MCR analysis, the loss of PP at 12 months was 13% lower in ASA users (hazard ratio (HR) 0.87, [0.77-0.97], p = 0.02) and 24% lower in PI users (HR 0.76, [0.57-0.99], p = 0.046) compared to no-APT.

CONCLUSION

In a large national database, we showed that antiplatelet therapy was associated with lower in-hospital mortality. Aspirin and P2Y12-inhibitor use among AVG patients demonstrated improved PP rates compared to no antiplatelet therapy. We recommend the use of antiplatelet therapy especially in patients on AVG.

The effect of lowering LDL cholesterol on vascular access patency: post hoc analysis of the Study of Heart and Renal Protection

BACKGROUND AND OBJECTIVES

Reducing LDL cholesterol (LDL-C) with statin-based therapy reduces the risk of major atherosclerotic events among patients with CKD, including dialysis patients, but the effect of lowering LDL-C on vascular access patency is unclear.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Study of Heart and Renal Protection (SHARP) randomized patients with CKD to 20 mg simvastatin plus 10 mg ezetimibe daily versus matching placebo. This study aimed to explore the effects of treatment on vascular access occlusive events, defined as any access revision procedure, access thrombosis, removal of an old dialysis access, or formation of new permanent dialysis access.

RESULTS

Among 2353 SHARP participants who had functioning vascular access at randomization, allocation to simvastatin plus ezetimibe resulted in a 13% proportional reduction in vascular access occlusive events (355 [29.7%] for simvastatin/ezetimibe versus 388 [33.5%] for placebo; risk ratio [RR], 0.87; 95% confidence interval [95% CI], 0.75 to 1.00; P=0.05). There was no evidence that the effects of treatment differed for any of the separate components of this outcome. To test the hypothesis raised by SHARP, comparable analyses were performed using the AURORA (A Study to Evaluate the Use of Rosuvastatin in Subjects on Regular Hemodialysis: An Assessment of Survival and Cardiovascular Events) trial cohort. AURORA did not provide independent confirmation (vascular access occlusive events: 352 [28.9%] for rosuvastatin versus 337 [27.6%] for placebo; RR, 1.06, 95% CI, 0.91 to 1.23; P=0.44). After combining the two trials, the overall effect of reducing LDL-C with a statin-based regimen on vascular access occlusive events was not statistically significant (707 [29.3%] with any LDL-C-lowering therapy versus 725 [30.5%] with placebo; RR, 0.95, 95% CI, 0.85 to 1.05; P=0.29).

CONCLUSIONS

Exploratory analyses from SHARP suggest that lowering LDL-C with statin-based therapy may improve vascular access patency, but there was no evidence of benefit in AURORA. Taken together, the available evidence suggests that any benefits of lowering LDL-C on vascular access patency are likely to be modest.

Basilic vein transposition in the forearm for secondary arteriovenous fistula

Radiocephalic (RC) fistulae remain the first choice access for hemodialysis. The antecubital fossa is recommended as the next site. However, for some patients a basilic vein can be used to create an arteriovenous (av) fistula. We report a series of patients where the forearm basilic vein served as an alternative conduit for secondary procedures. Over an 8-year period, 30 patients who had a failed RC fistula underwent a basilic vein transposition. The immediate results were satisfactory. All fistulas were successfully cannulated. Cumulative patency was 93% after 1 year, 78% after 2 years, and 55% after 3 years. No ischemic or infectious complications were noted during the study period. The use of the forearm basilic vein to create a native av fistula appears to be a good alternative to procedures in the antecubital fossa or upper arm, thus preserving more proximal veins for future use.