Abstract Body (Do not enter title and authors here): Introduction: There is no established consensus on the optimal antithrombotic regimen following peripheral vascular intervention (PVI), although the most recent AHA guidelines recommend dual antiplatelet therapy (DAPT) and dual pathway inhibition (DPI). This study aims to evaluate post-procedural prescribing patterns of single antiplatelet therapy (SAPT), DAPT, and DPI following lower extremity PVI.

Hypothesis: Despite current guideline recommendations, dual pathway inhibition (DPI) remains underutilized following lower extremity PVI, with postoperative antithrombotic selection primarily reflecting preoperative therapy rather than clinical escalation.

Methods: Patients undergoing lower extremity PVI between March 2024 and April 2025 were identified in the Vascular Quality Initiative (VQI) registry. To focus specifically on antiplatelet treatment patterns, patients on full-dose preoperative anticoagulation were excluded. Discharge antithrombotic regimens were categorized as SAPT, DAPT, or DPI. Descriptive statistics were used to summarize regimen distribution and medication transition patterns.

Results: A total of 46,012 patients underwent lower extremity PVI during this period. At discharge, the most common antithrombotic regimen was DAPT, prescribed in 65.3% of patients, followed by SAPT in 25.2% and DPI in 6.4%. Patients discharged on DPI had similar demographic and comorbidity profiles to those on SAPT and DAPT. Among those on preoperative DPI, 82.8% remained on DPI following PVI. Among patients on preoperative DAPT, 91.4% remained on DAPT postoperatively. Among patients on preoperative SAPT, 39% remained on SAPT at discharge. Of patients not on any preoperative antithrombotic therapy, 48% were discharged on DAPT and 33% on SAPT. Transition patterns showed that 56% of patients on SAPT were escalated to DAPT and 3.4% to DPI, while 2.5% of preoperative DAPT patients were escalated to DPI (Table 1).

Conclusion: DAPT remains the dominant discharge antithrombotic regimen following lower extremity PVI, while DPI is infrequently used. Postoperative therapy closely mirrors preoperative use, reflecting limited escalation to intensified strategies. These findings underscore the need for implementing procedure-specific antithrombotic guidelines.