DVT Thrombolysis Does Not Prevent Long-Term Complications

A new study suggests that pharmacomechanical catheter-directed thrombolysis does not lower the risk of post-thrombotic syndrome in patients with acute proximal deep-vein thrombosis (DVT).

Researchers at McMaster University (Hamilton, ON, Canada), Washington University School of Medicine (WUSTL; St. Louis, MO, USA), and other institutions conducted a study that randomly assigned 692 acute proximal DVT patients to either anticoagulation alone or anticoagulation plus pharmacomechanical thrombolysis, delivered via catheter-mediated or device-mediated intrathrombus delivery of recombinant tissue plasminogen activator (tPA), combined with thrombus aspiration or maceration. The primary outcome was development of post-thrombotic syndrome.

The results revealed that after six to 24 months of follow-up, there was no significant between-group difference in the percentage of patients with the post-thrombotic syndrome. Pharmacomechanical thrombolysis led to five times more major bleeding events within 10 days, but no significant difference in recurrent DVT was seen over the 24-month follow-up period. Moderate-to-severe post-thrombotic syndrome occurred in 18% of patients in the pharmacomechanical thrombolysis group, versus 24% of those in the control group. Improvement in quality of life from baseline to 24 months did not differ significantly between treatment groups. The study was published on December 7, 2017, in the New England Journal of Medicine (NEJM).

“We are dealing with a very sharp double-edged sword here. 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,” said lead author professor Suresh Vedantham, MD, of WUSTL. “What we know now is that we can spare most patients the need to undergo a risky and costly treatment. The findings are also interesting because there is the suggestion that at least some patients may have benefited.”

About 300K- 600K people a year in the United States alone are diagnosed with DVT, and despite standard treatment with blood thinners, roughly half will develop post-thrombotic syndrome, which results from damaged venous valves that become leaky and allow fluid to pool around the ankles. Symptoms include chronic leg pain, swelling, redness, and eventually ulcers. There is no treatment to prevent the potentially debilitating complication.

Related Links:
McMaster University
Washington University School of Medicine