A Look Into C-TRACT: The Chronic Venous Thrombosis: Relief with Adjunctive Catheter-Directed Therapy Clinical Trial

When patients develop a blood clot (deep vein thrombosis or “DVT”), it is important for them to receive anticoagulant medications to prevent clots from moving to the lungs (which can be fatal), extending within the vein, or returning at a later date. 

However, even with anticoagulant treatment, about half of patients with DVT wind up with long-term leg problems.  This complication, called “post-thrombotic syndrome” or “PTS”, typically causes patients to experience daily leg pain, swelling, heaviness, and fatigue.  Some patients with PTS develop permanent skin changes on their leg, and some experience skin breakdown with open sores (“ulcers”) that are often slow to heal. People with severe PTS can have difficulty completing normal daily activities or working, and experience poor quality of life.  Unfortunately, there currently exists no consistently effective, evidence-based treatment.  Common approaches use compression therapy (usually stockings) or medications, but these methods usually do not provide enough relief to patients with PTS of moderate or greater severity.

 In recent years, imaging-guided, catheter-based treatments have been used to try to reduce symptom severity in selected patients with PTS.  This can involve placement of metallic stents to re-open large veins that are blocked by old clots, or catheter-based procedures to eliminate valve reflux (backwards blood flow) in the surface veins of the leg. Early experiences suggest that these methods may be helpful for at least some patients.  However, they have never been carefully studied in well-designed clinical trials, so doctors do not know if the benefits are worth the risks and inconveniences for most patients. 

The Chronic Venous Thrombosis: Relief with Adjunctive Catheter-Directed Therapy (C-TRACT) Clinical Trial is an ongoing, multicenter randomized clinical trial that is evaluating the ability of catheter-based procedures (known as “endovascular therapy” or “EVT”) to reduce PTS severity and improve quality of life in patients with moderate-to-severe PTS.  The study is sponsored by the National Heart Lung and Blood Institute (part of the National Institutes of Health) and is led by Dr. Suresh Vedantham at the Washington University School of Medicine in St. Louis, MO, in partnership with other leading doctors.  

In this study, all patients who choose to participate receive close monitoring and optimal standard PTS care that includes medications, compression therapy, and (if they need it) quality venous ulcer care.  Half of the patients are randomly assigned to also undergo EVT procedures.  All patients are followed for 2 years to see which treatment strategy (EVT or No-EVT) is most effective in reducing PTS severity, improving quality of life, and healing venous ulcers.  

Participation in the C-TRACT study enables patients to learn about their condition and receive state-of-the-art PTS treatment with close monitoring, and to create new knowledge that will help providers improve care for future patients. Providers are encouraged to download the C-TRACT Referral App, which enables quick referral of potential study patients. Interested physicians can also apply to serve as site investigators. For more information, please visit https://bloodclotstudy.wustl.eduor contact the C-TRACT Clinical Trial Manager, Angela Oliver at 1-866-974-CLOT (2568) or CTRACT@wustl.edu.