Final 12-Month Results From DEFINITIVE LE Study of Directional Atherectomy in PAD Patients Presented at VIVA

October 10, 2012—Covidien (Mansfield, MA) has announced the final 12-month results from the DEFINITIVE LE (Determination of Effectiveness of SilverHawk/TurboHawk Peripheral Plaque Excision Systems for the Treatment of Infrainguinal Vessels/Lower Extremities) study, which were presented at the Vascular InterVentional Advances (VIVA) meeting in Las Vegas. Lawrence A. Garcia, MD, Chief of Interventional Cardiology and Vascular Interventions at St. Elizabeth's Medical Center in Boston, announced the findings during a Late-Breaking Trials session.

The company describes DEFINITIVE LE as the largest peripheral atherectomy study conducted to date with independent physician review of the outcomes. The prospective, multicenter study, which enrolled 800 patients at 47 centers in the US and Europe, comprised two cohorts—those with claudication and those with critical limb ischemia (CLI). A total of 1,022 lesions (up to 20 cm in length) were treated with the Covidien SilverHawk or TurboHawk Plaque Excision device. The study included a broad patient population, with 52% diabetic, 45% female, and 75% claudicants, and a prespecified subanalysis comparing patency outcomes in diabetic and nondiabetic patients.

According to the company, clinical outcomes were improved by 30 days and sustained through 12 months of follow-up; directional atherectomy with the SilverHawk and TurboHawk devices delivered 12-month patency results that were comparable to those reported in stent studies. Among patients with claudication, primary patency was 78% using a peak systolic velocity ratio (PSVR) ≤ 2.4 at 12 months. This rate did not differ between patients with diabetes (77%) and those without diabetes (78%); Covidien notes that these are the first such results to be shown in a prospective, powered analysis. Among CLI patients, 95% were able to avoid a major unplanned amputation of the target limb. The SilverHawk and TurboHawk devices were shown to have a strong safety profile in the study, with low complication rates.

“For the first time, the DEFINITIVE LE study has provided robust evidence within a large and diverse PAD patient population,” said Dr. Garcia via a company press release. “Directional atherectomy, with the SilverHawk and TurboHawk devices, delivers patency results at 12 months posttreatment that are comparable to those reported in stent studies—and with the important advantage of not leaving anything behind in the vessel.”

Prof. Thomas Zeller, MD, Head of the Department of Angiology at Universitäts-Herzzentrum Freiburg-Bad Kronzingen, Bad Krozingen, Germany, noted, “DEFINITIVE LE confirmed equivalent outcomes between diabetics and nondiabetics in terms of patency and persistent clinical improvement up to 12 months after treatment.” He continued, “Because diabetics have more advanced PAD, restenose faster, and are more difficult to treat than nondiabetics, it is critical to preserve future treatment options in this patient population. The confirmation from DEFINITIVE LE of directional atherectomy as a treatment modality that provides strong clinical outcomes in diabetics is a welcome and practice-changing finding.”

DEFINITIVE LE included Steering Committee oversight, adverse event adjudication by an independent physician Clinical Events Committee, and endpoint analyses conducted by two different independent core laboratories—one that analyzed acute angiographic results and another that analyzed duplex ultrasound follow-up.

Dr. Garcia and Prof. Zeller, together with Dr. James McKinsey, Chief of the Division of Vascular Surgery and Endovascular Interventions at New York-Presbyterian Hospital/Columbia University Medical Center, served as Co-Principal Investigators for the DEFINITIVE LE study.

"We are pleased with the long-term results from our groundbreaking DEFINITIVE LE study, which is unique among atherectomy studies conducted to date because of the size of the study and the clinical rigor of execution,” said Mark A. Turco, MD, Chief Medical Officer, Vascular Therapies, Covidien. “We are continuing to invest in the DEFINITIVE clinical program around new innovative treatments as a reflection of our commitment to partnering with medical professionals to deliver the best treatment for patients suffering with PAD.”