by Suresh Vedantham, MD

The ATTRACT (Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis) Study, which may define the future of DVT treatment, is now OPEN to patient enrollment! This study will determine if new clot-busting treatments for patients with large blood clots of the leg (deep vein thrombosis or DVT) can prevent long-term disability. Despite the use of standard blood-thinning drugs, 25-50% of DVT patients will develop the Post-Thrombotic Syndrome (PTS), a long-term condition that typically causes daily pain, heaviness, fatigue, and swelling of the leg. Because these symptoms are aggravated by standing or walking, affected patients are often forced to alter their daily activities to include periods of rest or leg elevation in order to avoid severe pain and swelling. In the more severe cases, PTS can lead to an inability to walk without pain, inability to hold a steady job or perform household duties, changes in leg skin color and texture, and/or open sores (leg ulcers). As a result, PTS has been shown to significantly reduce quality of life (QOL) in DVT patients. Indeed, PTS has been shown to be the leading determinant of long-term health-related QOL in DVT patients.

Preliminary studies suggest that patients who have their blood clots removed using new clot-busting treatments may be less likely to develop PTS. However, because these procedures are somewhat more invasive and costly up front, doctors do not agree on when to use them. The ATTRACT Trial is being performed to answer this important question. Says Dr. Suresh Vedantham, an interventional radiologist from Washington University in St. Louis who is the study’s Principal Investigator, “This study could define a new standard of care for DVT treatment. Since 1960, physicians have focused almost exclusively upon preventing pulmonary embolism in patients with DVT using blood-thinning drugs. Long-term consequences of DVT such as post-thrombotic syndrome have been largely neglected by physicians, but in actuality have a major negative impact upon patients’ lives. If the ATTRACT Trial is positive, it will create a major shift in the paradigm for initial DVT treatment by spurring physicians to also remove the clot that has already formed in order to reduce long-term patient disability.”

The ATTRACT Trial was built as a truly multidisciplinary endeavor that recruits the skills of leading DVT researchers from interventional radiology, cardiovascular medicine, vascular surgery, pulmonary medicine, hematology, epidemiology, health economics, and biostatistics. The trial’s most senior leadership includes a proceduralist (Dr. Vedantham), a non-proceduralist medical physician (Dr. Samuel Z. Goldhaber, Professor of Medicine at Harvard Medical School), and a clinical trials methodologist with specialized experience with trials of DVT (Dr. Clive Kearon, Professor of Medicine at McMaster University in Hamilton, Ontario (Canada)). Its Clinical Coordinating Center is based at the Mallinckrodt Institute of Radiology at Washington University in St. Louis, and its Data Coordinating Center is based at the renowned Ontario Clinical Oncology Group at McMaster University in Hamilton, Ontario (Canada). Core labs for ultrasound and economic assessment are located at VasCore at the Massachusetts General Hospital in Boston, MA and the St. Luke’s Mid America heart Institute in Kansas City, MO, respectively. The Society of Interventional Radiology (SIR) Foundation played a major role in the trial’s development and continues to collaborate with the investigator team. The SIR Foundation, the American Venous Forum, and the American College of Phlebology have all endorsed the study. The ATTRACT investigator network includes over 250 researchers from a broad variety of disciplines, including the ones noted above.

On June 28, 2009, the ATTRACT Investigator Meeting was honored by the presence of Dr. James M. Galloway, Assistant U.S. Surgeon General. In his keynote address, Dr. Galloway highlighted the study’s relevance to U.S. public health, telling the attendees that “The Surgeon General is passionate for the ATTRACT Trial to go forward.” The ATTRACT Trial was officially opened to subject accrual on November 16, 2009 and has enrolled 20 patients to date. Of the 60 U.S. Clinical Centers in the ATTRACT research network, 28 are now fully activated and many more will become activated during the next 1-2 months. Investigators who are interested in participating in the study should contact the study team as soon as possible. Physicians who see patients with proximal DVT should contact the ATTRACT study team to determine if their patients can be referred to a local ATTRACT Trial Clinical Center.

The ATTRACT Trial is primarily sponsored by the National Heart Lung and BloodInstitute, part of the National Institutes of Health, under grants U01-HL088?76 andU01-HL088018. Additional support is being provided by BSN Medical (maker othe elastic compression stockings that are being used in study patients), Covidien– Bacchus Vascular (manufacturer of the Trellis Peripheral Infusion System which isbeing featured in the study), Genentech (manufacturer of the Study Drug Activase®or tissue-plasminogen activator), and Medrad Interventional – Possis (manufacturerof the AngioJet device which is also featured in the study).

For more information, please visit the ATTRACT Study website at www.attract.wustl.edu.

Dr. Suresh Vedantham is a practicing interventional radiologist and an Associate Professor of Radiology & Surgery at the Mallinckrodt Institute of Radiology at the Washington University School of Medicine in St. Louis, MO.