Clot-Busting Catheter Procedure for DVT May Reduce Symptoms In Some Patients Interview with:
Suresh Vedantham, M.D
Principal Investigator, ATTRACT Trial
Professor of Radiology & Surgery
Mallinckrodt Institute of Radiology
Washington University School of Medicine What is the background for this study? What are the main findings?

Response:   About 300,000 Americans each year are diagnosed with a blood clot (deep vein thrombosis, DVT) for the first time.  In total, about 600,000 Americans have a DVT each year, as noted in the 2008 Surgeon General’s Call to Action.

Despite the use of standard treatment (blood thinning drugs and compression stockings), about 40% of DVT patients develop a long-term complication called post-thrombotic syndrome (PTS).  PTS impairs patients’ quality of life and typically causes chronic pain and swelling of the leg that occur on a daily basis. In many patients, this leads to major disability the prevents them from walking, working, or conducting normal daily activities. Some patients develop painful open sores on the leg called “venous ulcers”, that are difficult to heal.

Pharmacomechanical catheter-directed thrombolysis (“PCDT”) is a minimally-invasive treatment that removes blood clots through a tiny (2-3 mm) incision using the clot-busting drug tissue plasminogen activator (TPA) along with catheter-based devices that can chew up the clots. The benefits and risks of PCDT have not before been evaluated for DVT treatment in a rigorous study.

     The final results of the ATTRACT Trial, which was primarily sponsored by the National Heart Lung and Blood Institute (NHLBI) of the National Institutes of Health (NIH), are being published in The New England Journal of Medicine.  ATTRACT, the most rigorous study to date of clot-busting treatment for DVT, was a multicenter randomized controlled trial comparing PCDT and standard therapy versus standard therapy alone in 692 patients with above-knee DVT. This landmark study, conducted in 56 U.S. hospitals, was led by Principal Investigator Dr. Suresh Vedantham, Professor of Radiology & Surgery at the Mallinckrodt Institute of Radiology at Washington University in St. Louis, along with outstanding DVT researchers at McMaster University (Hamilton, Ontario [Canada]), the Massachusetts General Hospital (Boston, MA), and the Mid America Heart Institute (Kansas City, MO).  

The primary study result is that for most patients with DVT, the addition of PCDT to standard therapy does not prevent the development of PTS.  Because the use of PCDT involves a small but significant increase in major bleeding complications, it should not be routinely used as first-line DVT treatment.  However, PCDT did reduce the severity of PTS and appeared likely to provide better relief of DVT-related leg pain and swelling.  Further analyses will determine which DVT patients are most likely to experience these benefits.

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Negative Ultrasound Study Can Rule Out Upper Extremity DVT Interview with:
Dott. Michelangelo Sartori

U.O. di Angiologia e Malattie della Coagulazione
Azienda Ospedaliera di Bologna
Policlinico Sant’Orsola Malpighi

Medical Research: What is the background for this study? What are the main findings?

Response: The safety of withholding anticoagulation only on the basis of ultrasound imaging has not been evaluated in patients with suspected (Upper Extremity Deep Vein Thromobsis) UEDVT. The purpose of this management study was to evaluate the failure rate of ultrasound testing for UEDVT diagnosis in outpatients. Our data show that, similarly to the lower extremity, a negative complete ultrasound assessment of the upper extremity can safely exclude DVT. We found a 3-month VTE rate of 0.6% after a negative ultrasound and such figure is not different from the 3-month VTE incidence in management studies for lower limb DVT.  Thus anticoagulant therapy can be withheld for clinically suspected UEDVT after negative ultrasound examination without further testing in the ambulatory office setting.
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