Comparing the Impact of DOACs and Warfarin on Below-the-Knee Autologous Vein Bypass Patency in Peripheral Artery Disease: A Retrospective Cohort Study with 2-Year Follow-Up.

Background: Peripheral artery disease (PAD) affects over 200 million individuals globally, leading to significant morbidity and mortality. For patients with complex lesions of the superficial femoral artery requiring revascularization, autologous vein bypass surgery remains a viable treatment option. Postoperative anticoagulation is critical for maintaining graft patency, but the optimal choice between direct oral anticoagulants (DOACs) and warfarin remains uncertain. Objectives: This study aims to evaluate the patency of below-the-knee autologous vein bypasses in PAD patients receiving either DOACs or warfarin over a two-year period. Methods: A retrospective cohort study was conducted at a tertiary care hospital in Berlin, Germany, including patients who underwent femoropopliteal or femorocrural bypass surgery between 2017 and 2022. Patients were divided into two groups based on postoperative anticoagulation therapy: DOACs or warfarin. The primary outcome was graft patency at 24 months. Results: Out of 192 patients, after applying exclusion criteria, 36 were analyzed. The mean bypass patency was longer in the warfarin group (18.3 months) compared to the DOAC group (14.3 months). However, the log-rank test p-value (0.524) suggests that this difference is not statistically significant. Given the log-rank test's limitations in accounting for confounders, a multivariable Cox regression was performed, including age, sex, comorbidities, bypass type and antiplatelet use. The model (Omnibus p = 0.93) showed no statistically significant effect for any variable. Conclusions: DOACs appear to be a viable alternative to warfarin in maintaining graft patency in below-the-knee autologous vein bypasses for PAD patients. The lack of a need for regular INR monitoring with DOACs may offer a practical advantage in clinical settings.