Zilver Peripheral Stent Proves Durable
The Zilver PTX (Cook Medical, Bloomington, IN) polymer-free paclitaxel-eluting peripheral stent shows near-perfect two-year durability and safety in a nonrandomized study presented at the Society for Cardiovascular Angiography and Interventions (SCAI) 2010 Scientific Sessions in San Diego .
During the late-breaking trial session on May 7, Dr William Gray (Columbia University, New York, NY) presented the two-year results from a 30-site nonrandomized trial of Zilver in patients with symptomatic disease of the above-the-knee femoropopliteal artery with a reference vessel diameter of 4 to 9 mm. The 12-month results were presented at last year's SCAI meeting.
So far, 447 of the patients have reached the 24-month follow-up. The primary end point of the study is survival without amputation or target lesion revascularization (TLR). At one year, 634 out of 725 patients (87%) survived event free, and 367 out 451 (80%) of patients evaluated at the two-year follow-up were event free.
There were no device-related deaths, but there were four procedure-related deaths. One patient required amputation, and 81 patients required reintervention on the target lesion within 24 months of implant.
Each patient was implanted with up to four stents. Of the total 1432 stents implanted in the study, 22 (1.5%) fractured, including 14 type four fractures that caused displacement of segments of the stent.
The results compare favorably with those of other peripheral stents in the literature, Gray said. For example, in patients with lesions 14 cm or shorter, no in-stent restenosis, and moderate to ischemic claudication, the one-year TLR rate with the Protégé EverFlex stent (eV3, Plymouth, MN) was 21% in the 2009 DURABILITY study, but only 6% with Zilver PTX in the current study, Gray showed.
The device has CE Mark approval in Europe, and the company has completed enrollment of 480 patients in a randomized study of the Zilver PTX at 50 sites in the US, Japan, and Germany, comparing the Zilver PTX with peripheral angioplasty, Gray said. Patients in whom angioplasty alone fails are further randomized to Zilver PTX or a bare-metal version of the Zilver platform. The primary end points are 12-month primary patency evaluated by duplex ultrasound and 12-month event-free survival. The patients will be followed for five years.
- Gray, W. Single-arm clinical study of the Zilver PTX drug-eluting peripheral stent: Two-year interim results. Society for Cardiovascular Angiography and Interventions 2010 Scientific Sessions; May 7, 2010; San Diego, CA.