ETAP Trial Compares a Nitinol Stent to PTA Alone in Popliteal Treatment

October 24, 2012—The Cardiovascular Research Foundation (CRF) announced that results from the ETAP (Endovascular Treatment of Popliteal Artery–Balloon Angioplasty Versus Primary Stenting) trial were presented by lead investigator Thomas Zeller, MD, at the CRF's TCT 2012: Transcatheter Cardiovascular Therapeutics conference in Miami, Florida. ETAP evaluated a nitinol stent versus balloon angioplasty alone in treating blockages of the popliteal artery.

In the CRF press release, Dr. Zeller commented, “Results from this trial indicate that treatment of popliteal artery obstructive lesions with a nitinol self-expanding stent is safe. Additionally, 1-year primary patency and target lesion revascularization rates (including acute angioplasty failures) were substantially better with the nitinol stent than with balloon angioplasty.”

As summarized in the CRF announcement, the ETAP investigators conducted a prospective, randomized, multicenter trial comparing primary nitinol stent placement to angioplasty alone in patients who had a single, de novo obstructive lesion in the popliteal artery. The trial was composed of 246 patients from nine centers in Europe. Patients were randomly assigned to either a self-expanding nitinol stent (n = 119) or a standard balloon angioplasty procedure (n = 127).

The primary study endpoint was 1-year duplex ultrasound-derived primary patency, defined as freedom from target lesion restenosis without further intervention. Secondary endpoints included target lesion revascularization, secondary patency, changes in Rutherford categories from baseline, and limb salvage rates. X-rays were taken at 1 year and examined for stent fractures.

According to the CRF press release, the mean lesion length was 41.3 mm for the stent group and 43.2 mm for the PTA group. Six patients (2.4%) died during the follow-up period and there were two stent fractures reported at 1 year.

The ETAP investigators found that the 1-year primary patency rate was significantly higher in the stent group than in the PTA group (67.4% vs 44.9%; P < .05). The postprocedure target lesion revascularization rate was lower for the stent group than the PTA group (15.4% vs 21.4%; P = .29). No significant differences between the treatment groups could be observed concerning secondary patency, limb salvage rates, and the clinical course by Rutherford categories. Patients in the stent group also reported more improved walking distances at 1 year than the PTA group, noted the CRF press release.