CLINICAL TRIAL REVEALS EFFECTIVENESS OF COMMON TREATMENTS FOR DEEP VEIN THROMBOSIS

ORANGE, CALIF. (Dec. 20, 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.

The clinical trial showed that routine use of the procedure did not reduce the chance of developing post-thrombotic syndrome in all patients, but did reduce the severity of post-thrombotic syndrome, easing patients’ long-term symptoms. About 24 percent of people on blood thinners alone experienced moderate to severe pain and swelling, but only 18 percent of people who were treated with blood thinners and clot busters did so.

The procedure also alleviated pain and swelling in the early stages of the disease, when patients are often very uncomfortable.

However, the researchers noted an increase in the number of people who developed major bleeding after undergoing the procedure. While the numbers were small (0.3 percent versus 1.7 percent) and none of the bleeds were fatal, any increase in bleeding is a red flag.

“We are dealing with a very sharp double-edged sword here,” said Vedantham, who also is an interventional radiologist at the university’s Mallinckrodt Institute of Radiology. “None of us was surprised to find that this treatment is riskier than blood-thinning drugs alone. To justify that extra risk, we would have had to show a dramatic improvement in long-term outcomes, and the study didn’t show that. We saw some improvement in disease severity but not enough to justify the risks for most patients.”

While the study showed that most patients should not undergo the procedure, the data hint that the benefits may outweigh the risks in some patients, such as those with large clots.

For now, the procedure should be reserved for use as a second-line treatment for some carefully selected patients, who are experiencing severe limitations of leg function from deep vein thrombosis and who are not responding to blood-thinners, Vedantham added.

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.

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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.

About St. Joseph Hospital
Founded in 1929, St. Joseph Hospital in Orange, California is a nationally recognized, 463-bed, not-for-profit Catholic hospital dedicated to extending the healing ministry of Jesus in the tradition of the Sisters of St. Joseph of Orange. Fully accredited by The Joint Commission and designated as a Magnet hospital for nursing excellence, St. Joseph Hospital’s reputation for clinical excellence and compassionate, family-centered care draws patients from all over the United States. This is one reason why St. Joseph Hospital was named one of the top hospitals in the Los Angeles/Orange County area by U.S. News & World Report. With a highly recognized 1,000-member medical staff and more than 3,100 support staff, St. Joseph Hospital is home to more than 75 specialty programs, including The Center for Cancer Prevention and Treatment, the Heart and Vascular Center and a nationally acclaimed Orthopedics program that has been ranked among the top 50 in the nation by U.S.News & World Report. Equally important is St. Joseph Hospital’s dedication to caring for the medically underserved through health education programs, a free-standing medical and dental clinic, and mobile health vans. St. Joseph Hospital depends on philanthropic support from the community to carry out its mission. These efforts are coordinated through the St. Joseph Hospital Foundation. St. Joseph Hospital is a member of the Irvine-based St. Joseph Hoag Health alliance, an integrated health network of seven hospitals, 26 urgent care centers and an array of programs and services throughout Orange County and the High Desert.

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This release was published on openPR.