Leg-Artery Stent Shows Benefits In Interim RESILIENT Results

By Mitchel L. Zoler 

HOLLYWOOD, FLA. -- A stent designed for use in leg arteries led to substantially better outcomes than did balloon angioplasty alone in an interim analysis of 6-month and 1-year follow-up data from the stent's pivotal trial.

Treatment with this stent has so far produced no safety issues, and the stent had a low fracture rate, Dr. Barry T. Katzen said at the 19th International Symposium in Endovascular Therapy.

The study, at 24 centers in the United States plus 1 center in Leipzig, Germany, and 1 in Vienna, finished enrolling its 226th and final patient last August. Enrolled patients had a clinically significant stenosis in a native superficial femoral artery (SFA) and/or a proximal popliteal artery that was 3 cm above the knee joint and 1 cm below the origin of the profunda femoris artery. The target vessel reference diameter had to be greater than 4.0 mm and less than 6.5 mm by visual estimate. The total length of all treated lesions in one patient had to be less than 150 mm. Enrolled patients also needed to have angiographic evidence of at least one run-off vessel to the foot. Patients could have either new lesions or lesions in previously treated segments not yet stented.

The primary end point of the Randomized Study Comparing the Edwards Self-Expanding LifeStent vs. Angioplasty-Alone in Lesions Involving the SFA and/or Proximal Popliteal Artery (RESILIENT) is the need for target-lesion or target-vessel revascularization after 6 months. The primary safety end point is death at 30 days after treatment. The protocol allowed bailout stenting in the angioplasty patients for major dissections or occlusive complications.

Including 20 patients who were enrolled in a pilot phase, the study involved 172 patients who received stent treatment and 74 treated with angioplasty only in a 2:1 randomization scheme. Data collected at the 6-month follow-up, which were available for 42 patients treated with angioplasty and 89 treated with a stent (58% of the total study group), showed a reintervention rate of 44% in the angioplasty group and 5% in patients who received a stent, said Dr. Katzen, medical director of the Baptist Cardiac and Vascular Institute in Miami.

Twelve-month follow-up data were available for 31 patients in the angioplasty group and 61 patients who received a stent. A year after treatment, reinterventions were needed by 56% of the angioplasty patients, compared with 19% of patients who received a stent.

The study is testing the LifeStent, a self-expanding, nitinol stent (without any drug coating) made by Edwards Lifesciences LLC. Dr. Katzen is a consultant to the company. The stent's wires are woven in a helical structure that allows high flexibility, with bending up to 180 degrees, without kinking.

No patient in either group was dead 30 days after treatment. The only complication after 30 days was one case of significant, distant embolization in an angioplasty patient. The stented patients who were followed for 12 months received a total of 136 stents, of which 5 fractured (4%).