Impact of anticoagulation/antiplatelet therapy on femoropopliteal bypass graft outcomes

Background: Anticoagulant and antiplatelet (AC/AP) medications have been reported to improve bypass graft patency, however, the optimal AC/AP strategy remains unclear in the heterogenous peripheral artery disease population. Methods: A multi-institutional retrospective review utilizing the Research Patient Data Registry database from 1995 to 2020 was performed for all patients who underwent femoropopliteal bypass procedures. Electronic medical records were used to obtain demographic information, comorbidities, smoking status, operative details (bypass target), postoperative AC/AP medications, post-operative complications, and long-term outcomes and were reviewed for the cohort. Cox proportional hazards model was used to determine independent risk factors for major adverse limb events (MALE) after bypass. MALE was defined as reintervention for patency or major amputation of index limb (above- or below-knee amputation). Results: A total of 1421 patients underwent femoropopliteal bypass between 1995 and 2020 throughout five institutions included in this study. Complete data were available for 1292 of the 1421 patients (90.9%). The indications for bypass included intermittent claudication (21.4%), rest pain (30.3%), tissue loss (33.5%), and nonatherosclerotic disease (14.8%). Distal bypass targets comprised above-knee (38.6%) and below-knee (61.4%) popliteal arteries. Patients were divided into six groups based on postoperative AC/AP use including none (n = 57 [4.4%]), monoantiplatelet therapy (n = 587 [45.4%]), dual AP therapy (n = 214 [16.6%]), AC alone (n = 73 [5.7%]), AC thorn monoantiplatelet therapy (n = 319 [24.7%]), and AC thorn dual AP therapy (n = 42 [3.3%]). Postoperative bleeding complications were low for both hematoma (3.7%) and pseudoaneurysm (0.7%). There was no difference in bleeding complications across AC/AP groups (hematoma, P = .61; pseudoaneurysm, P = .31). After adjusting for patient factors, below-knee bypass target (hazard ratio [HR], 1.25; 95% confidence interval [CI], 1.04-1.52; P = .019) and bypass for tissue loss (HR, 1.40; 95% CI, 1.04-1.88; P = .028) were independent predictors for MALE. Great saphenous vein conduit trended toward protection for MALE, compared with prosthetic grafts (HR, 0.84; 95% CI, 0.70-1.01; P = .06). No AC/AP regimen was associated with of MALE, even stratifying by above-knee and below-knee bypass cohorts. The median follow-up period was 2 years. Conclusions: Among patients undergoing femoropopliteal bypass grafting, no combination of AC or AP medications was associated with improved graft patency; however, a below-knee target and tissue loss were associated with adverse limb events. AC and AP regimen may be individualized after bypass with regard to other concomitant medical comorbidities.