PB0450 - Does Iliac Vein Stenting Reduce the Severity of Post-Thrombotic Syndrome? Progress on an Ongoing Multicenter Randomized Controlled Trial

Background: Patients with post-thrombotic syndrome (PTS) experience activity-limiting lower extremity pain, swelling and impaired quality of life (QOL). Endovascular stent placement can re-establish iliac vein outflow, but its risk-benefit ratio has not been rigorously evaluated.

Aims: Describe the progress and challenges of a pivotal ongoing randomized trial that is evaluating iliac vein stent placement for the treatment of PTS, and elucidate opportunities for hematology physicians to contribute to the study’s successful completion.

Methods: The Chronic Venous Thrombosis: Relief with Adjunctive Catheter-Directed Therapy (C-TRACT) Trial is sponsored by the National Heart Lung and Blood Institute (NHLBI), part of the National Institutes of Health (NIH). The study is a Phase III, multicenter, randomized, open-label, assessor-blinded, parallel two-arm, controlled clinical trial. 374 patients with moderate-or-severe PTS and documented iliac vein obstruction are being randomized to receive endovascular stent therapy (EVT) + standard PTS therapy versus standard PTS therapy alone. The study will evaluate if EVT reduces PTS severity, assessed with the Venous Clinical Severity Scale (VCSS), at 6 months to a greater degree than standard care alone. Secondary outcomes assessed over 24 months include QOL, venous ulcer healing, safety, valvular reflux, and cost-effectiveness.

Results: Between July 2018 and January 2023, the C-TRACT Trial enrolled 159 patients. At the time of enrollment, 50% of patients had a normal common femoral vein and 13% had an open ulcer. In response to the coronavirus pandemic, the protocol was updated to encourage remote visits after 6 months, with use of the remotely-administered Patient-Reported Villalta Scale. Active measures are being taken to promote enrollment across the clinical center network.

Conclusion(s): The C-TRACT Trial will determine if EVT should be routinely used to reduce PTS severity in patients with moderate-to-severe PTS.