ISET: Combination treatment for DVT appears efficacious

The results of a Phase II trial exploring the efficacy of combination treatment in dissolving deep venous thromboli (DVT) suggest that the procedure resolves DVT so quickly that treatment may someday be handled on an outpatient basis, Robert A. Lookstein, MD, told Cardiovascular Business. He presented the results Jan. 21 at the International Symposium on Endovascular Therapy (ISET) in Miami Beach, Fla.

Traditional treatment for DVT involves administration of blood thinners, and recently catheter-based treatments that destroy the clot mechanically have been introduced with positive results. Combination treatment uses the AngioJet (Medrad, Pittsburgh) device, as do standard catheter-based treatments, but adds the application of clot-dissolving medication directly to the clot through the catheter. Once the medication has weakened the clot, saline jets break it up and the debris is extracted, just as in conventional catheter-based treatments.

The PEARL (PEripheral Use of AngioJet Rheolytic Thrombectomy with a Variety of Catheter Lengths) registry, enrolled 371 patients at 35 centers. Most of the operators (86 percent) used combination therapy to treat the patients’ DVT. Lysis was achieved in 95 percent of treated vessels, and most patients remained free of rethrombosis (94 percent at three months, 86 percent at six months and 81 percent at 12 months).

The adverse event rate was 2.2 percent, Lookstein said, most of which were bleeding events. He said that this trial‘s bleeding complication rate is comparable to the rate found in traditional DVT treatment.

Treatment time was less than 24 hours in 76 percent of cases, and less than six hours in 36 percent of cases. “In contrast, the mean treatment time for CaVenT (Catheter-directed Venous Thrombolysis in acute iliofemoral vein thrombosis) trial was 57.6 hours, and for the Venous Registry, it was 48 hours,” he noted.

Lookstein, of the vascular and interventional radiology department at Mt. Sinai Medical Center in New York City, was enthusiastic about the possibilities combination treatment presents. “This is a transformational technology that will revolutionize the way we treat DVT. It opens the door to treatment for many people who are not candidates for traditional therapies or who cannot be immobile for extended periods,” he said.

Lookstein's presentation at ISET was based on approximately eight months of follow-up. He and his team plan to continue to follow the enrolled patients for another 12 months.

Acknowledging the small sample size in the study, Lookstein explained that a large, prospective randomized trial comparing optimal medical therapy to combination therapy is currently 50 percent enrolled. Results of this trial are expected in 2016 or 2017.

The PEARL Registry is sponsored by Bayer HealthCare, the parent company of Medrad.