VIVA 2011: Long-Term RESILIENT Data for Nitinol Stenting in the SFA

October 18, 2011—Barry Katzen, MD, presented late-breaking long-term clinical trial results from RESILIENT at the VIVA 2011: Vascular Interventional Advances meeting in Las Vegas, Nevada. RESILIENT is a study of a self-expanding nitinol stent (LifeStent, Bard Peripheral Vascular, Tempe, AZ) for the treatment of moderate-length peripheral arterial disease in the superficial femoral artery (SFA) and/or proximal popliteal artery. Dr. Katzen summarized long-term outcomes out to 3 years.

The purpose of the RESILIENT study was to evaluate outcomes after percutaneous transluminal angioplasty (PTA) compared to a primary stenting strategy in a controlled randomized trial. The background of the study is that PTA has been shown to be effective for focal SFA lesions (< 4 cm), but an analysis of published results of PTA alone for longer lesions (mean, 8.7 cm) revealed a primary patency rate of 33% at 1 year.

According to Dr. Katzen, 206 patients with intermittent claudication (Rutherford categories 1–3) and obstructive lesions of the SFA and/or proximal popliteal artery (stenoses > 50%; up to 150 mm in length) were randomized at 24 centers in the United States and Europe for treatment with either a LifeStent after predilation or with PTA alone. The primary outcome measure was the rate of target lesion revascularization (TLR) at 12 months. Various secondary parameters (eg, clinical success, quality of life, and major adverse clinical events) were followed out to 36 months postprocedure. Freedom from TLR was used as a long-term clinical benefit measure. In addition, x-rays were completed out to 18 months and assessed by an independent core laboratory for evidence of stent fractures.

Dr. Katzen reported that 12-month freedom from TLR (Kaplan-Meier estimate using Greenwood's formula) was 87.3% for the stent group compared to 45.1% for the angioplasty group (P < .0001). This statistical difference between groups was maintained throughout the course of the study, with freedom from TLR at 3 years for the stent group of 75.5% compared to 41.8% for the angioplasty group (P < .0001). Three-year clinical success was also significantly higher in the stent group than in the angioplasty group (63.2% vs 17.9%; P < .0001), and there was no difference in freedom from major adverse clinical events between the stent and angioplasty groups (75.2% vs 75.2%; P = .98). At 18 months, stent fractures were identified in 4.1% of stents.

The RESILIENT investigators concluded that this randomized trial demonstrates that the benefits documented at 1 year from primary use of the LifeStent self-expanding nitinol stent over angioplasty for moderate-length lesions in the SFA and/or proximal popliteal artery are durable and provide significantly improved long-term outcomes at 3 years compared to balloon angioplasty alone.