May 7, 2010—The Society for Cardiovascular Angiography and Interventions (SCAI) announced the presentation of interim results showing that patients with peripheral artery disease in the superficial femoral artery (SFA) treated with the Zilver PTX paclitaxel-eluting peripheral stent (Cook Medical, Bloomington, IN) maintained clinical improvement at 2 years. William A. Gray, MD, presented the interim results from the Zilver PTX Global Registry at a late-breaking clinical trial session at SCAI’s 33rd annual scientific sessions in San Diego. The prospective, single-arm study is ongoing to evaluate the Zilver PTX for treating peripheral artery disease. Results of a separate pivotal randomized study in a similar cohort of patients are expected to be available later this year.

SCAI stated that this analysis includes 12-month follow-up data from 721 patients and 24-month follow-up data from 447 patients who received the Zilver PTX in the SFA. The registry study was designed to evaluate stent integrity, event-free survival, and freedom from target lesion revascularization.

Of the 787 patients who were enrolled and treated, 24% had restenosis of previously treated lesions, 14% had in-stent restenosis, 38% had total occlusions, and 22% of patients had lesions longer than 15 cm. The mean lesion length was 10 ± 8.2 cm, the mean percent diameter stenosis was 84.6% ± 16.4%, and an average of 2.2 Zilver PTX stents were used per patient.

Dr. Gray reported that at 12 months, the event-free survival rate was 87%, and freedom from target lesion revascularization was 90.5%. X-ray evaluation found a very low rate of stent fractures (1.5% of patients at 12 months). Patients available for 24-month follow-up had an event-free survival rate of 80% and a freedom from target lesion revascularization rate of 83.3%.

According to Dr. Gray, this low rate of target lesion revascularization translated into meaningful clinical improvement for the majority of patients, with both the average walking distance and average walking speed more than doubling after Zilver PTX stent implantation and being sustained to 2 years. In addition, there was a very good safety profile and a very low rate of stent fracture.

“These interim data suggest this device is safe and efficacious for the treatment of SFA lesions," commented Dr. Gray. “Previous attempts to demonstrate drug-eluting stent effectiveness using sirolimus or its analogues have fallen short, but the use of a paclitaxel-coated, nonpolymeric stent appears to have improved the outcomes for patients who received this study stent.”

Click here to read an in-depth discussion by principal investigators Michael D. Dake, MD, Gary M. Ansel, MD, and Anthony O. Ragheb, MD, on the study design and previous results with the Zilver PTX stent, originally published in the March 2010 issue of Endovascular Today (2010;9:52–57).