Impact of Antithrombotic Therapy on Thrombotic and Bleeding Complications after Elective Endovascular Repair of Abdominal Aortic Aneurysms

Purpose: To investigate the influence of antithrombotic therapy on occurrence of thrombotic and bleeding complications after endovascular aneurysm repair (EVAR). Methods: In this retrospective single-center cohort study, patients who underwent elective endovascular aneurysm repair for abdominal aortic aneurysm were categorized into three antithrombotic groups: single antiplatelet therapy (SAPT), anticoagulants, or dual antiplatelet therapy (DAPT). Outcome measures were the incidence of major adverse cardiovascular events (MACE), prosthetic limb occlusions, and bleeding complications during follow-up. Results: Among 616 patients (SAPT: n = 450, anticoagulants: n = 84, and DAPT: n = 82), Kaplan–Meier analysis showed no significant difference (log-rank p = 0.37) in incidence of MACE between patients receiving SAPT (20.9%), anticoagulants (25.0%), and DAPT (14.6%) during a median follow-up of almost 4 years. In multivariable Cox regression analysis, only age (HR = 1.03; 95% CI 1.01–1.06, p = 0.01) and American Society of Anesthesiologists (ASA) classification (HR = 1.46; 95% CI 1.12–1.91; p = 0.01) were significant predictors for MACE. Prosthetic limb occlusion was observed in 38 patients during a median follow-up of 4 years; incidence between patients receiving SAPT (5.8%), anticoagulants (10.7%), and DAPT (3.7%) was not significantly different (log-rank p = 0.08). Age (HR = 0.96; 95% CI 0.92–1.00; p = 0.03) and use of anticoagulants (HR = 3.79, 95% CI 1.46–9.83; p < 0.01) were significant predictors for prosthetic limb occlusion. Bleeding complications occurred in 73 patients during median follow-up of almost 4 years, without significant difference (log rank p = 0.06) in incidence between patients receiving SAPT (10.7%), anticoagulants (19.0%), and DAPT (11.0%). ASA classification (HR = 1.74; 95% CI 1.23–2.46; p < 0.01) was a significant predictor for bleeding complications. Conclusion: Use of anticoagulants after EVAR appears to be associated with a higher risk of prosthetic limb occlusion compared to the use of single or dual antiplatelet therapy.