New interventional radiology treatment used to burst leg blood clots
ATTRACT—the first U.S. trial of a catheter-based treatment for deep vein thrombosis (DVT)—has commenced, designed to evaluate the use of clot-dissolving drugs in combination with clot removal devices to prevent post-thrombotic syndrome (PTS) in patients with DVT.

About 25 to 50 percent of DVT patients develop PTS when treated with blood thinners alone. However, the researchers said that blood thinners alone do not dissolve the existing clot. Preliminary studies have shown that interventional clot-busting treatments can, unlike standard DVT therapy, remove clots and have strong potential to prevent PTS.

The outcomes of the multicenter trial—funded with more than $10 million from the National Institutes of Health's National Heart, Lung and Blood Institute (NHLBI)—are likely to change the way DVT is treated in the United States, the authors wrote.

“The ATTRACT trial could fundamentally shift the 50-year-old DVT treatment paradigm to one that includes interventional clot removal as an essential element of standard DVT care," said interventional radiologist Suresh Vedantham, MD, an associate professor at the Washington University School of Medicine in St. Louis, who will lead the trial.

ATTRACT (Acute Venous Thrombosis: Thrombus Removal With Adjunctive Catheter-Directed Thrombolysis) is a randomized trial designed to “determine if the newest clot-busting treatment, pharmacomechanical catheter-directed thrombolysis (PCDT), prevents post-thrombotic syndrome in patients with DVT,” said Vedantham.

PCDT combines the use of a clot-dissolving drug with a catheter-mounted miniature clot removal device, allowing an interventional radiologist to break up the clot and remove it from the vein, restoring blood flow.

“Established PTS is a lifelong, irreversible condition for which there are no consistently effective treatments. Its prevention is extremely important; however, physicians have historically neglected the prevention of PTS,” said Vedantham. "The groundbreaking combination of clot-busting drugs with innovative device technology—pioneered by interventional radiologists—now enables clot removal in a safer and more efficient manner, often in a single procedure session.”

The Society of Interventional Radiology Foundation (SIR) Foundation has been a partner in developing the ATTRACT trial, helping to coordinate the site selection process and partnering with the ATTRACT research team to conduct the trial, according to Vedantham.

The ATTRACT trial will begin later this year to assess the presence and severity of PTS, quality of life, relief of pain and swelling, safety and costs. At least 28 U.S. clinical centers will enroll 692 patients and monitor their health for two years, Vedantham said.