ABSTRACT
Nishant Agrawal, B.S.
Medical Student
University of Pittsburgh School of Medicine
Sewickley, Pennsylvania, United States
Anticoagulants and antiplatelets are commonly prescribed after deep venous stenting for nonthrombotic (NIVL) and post-thrombotic (PTS) obstruction. Minimal consensus exists on type and duration post-intervention. This study aimed to assess the impact of various antithrombotic regimens after iliofemoral venous stenting.
Methods: Consecutive patients undergoing stenting for NIVL or PTS lesions between 2007 and 2021 at a single institution were identified. A retrospective review of antiplatelets (AP) and anticoagulants (AC) prescribed on discharge, 1-, 6-, and 12- months post-procedure along with demographic and follow-up outcomes data was performed. Primary outcome was 1-year primary patency (PP). Antithrombotic regimens demonstrating significant differences in primary endpoints were further assessed using Cox hazards regression and Kaplan-Meier analysis.
Results:
Of 98 patients (118 limbs) undergoing stenting for PTS or NIVL, 23 (19.5%) patients were discharged on AP alone, 43 (36.4%) on AC alone, 49 (41.5%) on both AP and AC, and 3 (2.4%) without any antithrombotic prophylaxis. Overall PP was 90.6% (87.9% for PTS, 93.3% for NIVL, p=0.313). 1-year PP was significantly higher in patients discharged on AP (with or without AC) compared to patients with no AP (95.8% vs. 82.6%, p =0.016). A trend towards improved 1-year PP was also observed in patients discharged on AP+AC compared to those on AC alone (93.9% vs. 81.6%, p=0.066). 1-year PP was not significantly different in patients discharged on AP+AC compared to those discharged on only AP (p=0.225). AP on discharge was also found to significantly protect against stent reintervention on Cox regression analysis adjusted for hypercoagulable disorder and active smoking status (HR 0.25, 95% CI [0.06-0.89], p=0.044). Figure 1 presents a Kaplan-Meier curve illustrating primary stent patency stratified by AP on discharge (log rank test=.032). AP maintenance at 1-, 6-, and 12-month follow-up was not associated with improved PP at 1 year on uni- or multivariable regression analyses. Lovenox bridge (Lovenox transitioned to oral AC) at discharge did not significantly protect against thirty-day or one-year reintervention in NIVL nor PTS patients.
Conclusions: Initiation of early AP therapy after deep venous stenting for NIVL or PTS is associated with significantly reduced risk of stent failure at 1 year. However, continuing AP after 1-month follow-up did not result in improved patency rates. These data suggest that early AP therapy optimizes antithrombotic management, particularly compared to AC alone. Larger studies focused on thrombotic and non-thrombotic populations are needed to validate these outcomes and establish a post-operative medical management protocol.