The addition of pharmacomechanical catheter-directed thrombolysis to anticoagulation did not lower the risk for post-thrombotic syndrome in patients with acute proximal deep vein thrombosis, but led to a higher risk for major bleeding, according to data published in The New England Journal of Medicine.
“Despite the use of anticoagulant therapy, the post-thrombotic syndrome develops within 2 years in approximately half of patients with proximal deep vein thrombosis,” Suresh Vedantham, MD, from the Washington University School of Medicine in St. Louis, and colleagues wrote. “The post-thrombotic syndrome commonly causes chronic limb pain and swelling and can progress to cause major disability, leg ulcers and impaired quality of life.”
According to the researchers, previous small randomized trials have suggested that the removal of acute thrombus may preserve venous function and prevent post-thrombotic syndrome.
To determine whether pharmacomechanical catheter-directed thrombolysis removes thrombus, Vedantham and colleagues enrolled 692 patients with acute proximal deep vein thrombosis into a phase 3, multicenter, randomized, open-label, assessor-masked, controlled clinical trial.
Participants were randomly assigned to a control group of anticoagulation alone or anticoagulation plus pharmacomechanical thrombolysis.
The primary outcome of the trial was development of post-thrombotic syndrome between 6 and 24 months of follow-up.
The results of the study showed no significant difference in the percentage of patients with post-thrombotic syndrome between 6 and 24 months (47% in the pharmacomechanical thrombolysis group and 48% in the control group; RR = 0.96; 95% CI, 0.82-1.11).
Patients who were assigned to pharmacomechanical thrombolysis had higher rates of major bleeding events within 10 days, but had no significant difference in recurrent venous thromboembolism after 24 months.
Eighteen percent of participants in the pharmacomechanical group had moderate to severe post-thrombotic syndrome vs. 24% in the control group (RR = 0.73; 95% CI, 0.54-0.98).
There were lower severity scores for post-thrombotic syndrome observed in those in the pharmacomechanical thrombolysis group at 6, 12, 18 and 24 months, but QOL improvement was not significantly different between the two groups.
“In this trial, pharmacomechanical thrombolysis did not prevent the post-thrombotic syndrome in patients with acute proximal deep vein thrombosis; this finding persisted in per-protocol analyses and was consistent across all prespecified subgroups,” the researchers wrote. “In the pharmacomechanical thrombolysis group, there were more early major bleeds than in the control group, but less major bleeding ... occurred in association with the procedure than in past studies of thrombolysis for deep vein thrombosis.” – by Dave Quaile
Disclosure: Vedantham reports he receives grant support from Cook Medical and Volcano.