Large-scale clinical trial showed that routine use of clot procedure did not reduce the chance of developing post-thrombotic syndrome in all patients
ORANGE, CALIF. (Dec. 15, 2017) – Not all patients with blood clots in their legs – a condition known as deep vein thrombosis (DVT) – need to receive powerful clot-busting drugs, according to results of a large-scale, multicenter clinical trial.
The study showed that clearing the clot with drugs and specialized devices could reduce the likelihood of long-term complications of DVT in some but not all patients.
“What we know now is that we can spare many patients the need to undergo a risky and costly treatment,” said Principal Investigator Suresh Vedantham, MD, a professor of radiology and of surgery at Washington University School of Medicine in St. Louis.
The findings were published Dec. 7 in The New England Journal of Medicine.
Between 300,000 and 600,000 people a year in the United States are diagnosed with a first episode of deep vein thrombosis and, despite standard treatment with blood thinners, roughly half will develop post-thrombotic syndrome, a condition leading to leg pain, pressure, swelling and difficulty walking. There is no treatment to prevent the potentially debilitating complication. However, small studies had suggested that a procedure that delivers clot-busting drugs directly into the clot may reduce the chance the syndrome will develop. The procedure is currently used as a second-line treatment to alleviate pain and swelling in people who do not improve on blood thinners.
The Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis (ATTRACT) study – a randomized controlled trial primarily funded by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH) – was designed to determine whether performing the procedure as part of initial treatment for patients when they are first diagnosed with deep vein thrombosis would reduce the number of people who later develop the syndrome. In 2008, then-Acting Surgeon General Steven K. Galson, MD, issued a national call to action on deep vein thrombosis and specifically called for research into the benefits and risks of removing clots.
“The clinical research in deep vein thrombosis and post-thrombotic syndrome is very important to the clinical community and of interest to the National Heart, Lung, and Blood Institute,” said Andrei Kindzelski, MD, PhD, the NHLBI program officer for the ATTRACT trial. “This landmark study, conducted at 56 clinical sites, demonstrated in an unbiased manner no benefits of catheter-directed thrombolysis as a first-line deep vein thrombosis treatment, enabling patients to avoid an unnecessary medical procedure. At the same time, ATTRACT identified a potential future research need in more targeted use of catheter-directed thrombolysis in specific patient groups.”
The study involved 692 patients, randomly assigned to receive blood thinners alone or blood thinners and the procedure. Each patient was followed for two years.
St. Joseph Hospital’s Heart and Vascular Services program was one of the participating sites and a major contributor to the study. Site Principal Investigators were Interventional Radiologist Mahmood Razavi, MD, who also acted as a study steering committee member and James Pierog, MD, medical director of Emergency Services.
Dr. Razavi, the principal investigator with St. Joseph Hospital’s Heart and Vascular Services program added, “This is why recent advances in clearing the blood clot from veins without the use of more risky clot-busting medications such as that used in this study are a substantial contribution to the care of patients with DVT.” One such device is now in common use at St. Joseph Hospital to treat patients with DVT.
The ATTRACT study was led by researchers at Washington University; McMaster University in Ontario, Canada; Massachusetts General Hospital in Boston; and St. Luke’s Mid-America Heart Institute in Kansas City, Mo.
Vedantham S, Goldhaber SZ, Julian J, Kahn SR, Jaff MR, Cohen DJ, Magnuson E, Razavi MK, Comerota AJ, Gornik HL, Murphy TP, Lewis L, Duncan JR, Nieters P, Derfler MC, Filion M, Gu C-S, Kee S, Schneider J, Saad N, Blinder M, Moll S, Sacks D, Lin J, Rundback J, Garcia M, Razdan R VanderWoude E, Marques V, Kearon C and the ATTRACT Trial Investigators. Pharmacomechanical Catheter-Directed Thrombolysis for Deep-Vein Thrombosis. The New England Journal of Medicine. Dec. 7, 2017.
The ATTRACT Trial was supported by the National Heart, Lung and Blood Institute of the National Institutes of Health (NIH), grant numbers U01-088476 and U01-088118; Washington University’s Center for Translational Therapies in Thrombosis, grant number U54-HL112303; Washington University’s Institute of Clinical & Translational Sciences, which is supported by the National Center for the Advancement of Translational Sciences, grant number UL1-TR00044810; Boston Scientific; and Covidien (now Medtronic). Study drug and funding were provided by Genentech (a Roche Company). Compression stockings were donated by BSN Medical.