Final 12-Month DEFINITIVE LE Results Announced
Global 800-patient study shows directional atherectomy to be "highly effective" in patients with claudication and critical limb ischemia.
October 11, 2012—Final 12-month data from DEFINITIVE LE (Determination of Effectiveness of SilverHawk/TurboHawk Peripheral Plaque Excision Systems for the Treatment of Infrainguinal Vessels/Lower Extremities) were presented by Co-Principal Investigator Lawrence A. Garcia, MD, on Wednesday afternoon at the Vascular InterVentional Advances 2012 meeting in Las Vegas.
DEFINITIVE LE is the largest independently adjudicated peripheral atherectomy study performed to date. It was designed to prospectively evaluate intermediate and long-term effectiveness of stand-alone endovascular treatment with the catheter-based SilverHawk/TurboHawk plaque excision systems (Covidien, Mansfield, MA) of peripheral arterial disease (PAD) in the femoropopliteal and tibial-peroneal arteries. The global, multicenter study included patients with claudication or critical limb ischemia (CLI). Patency and device and procedural success were assessed by independent duplex and angiographic core laboratories. DEFINITIVE LE also included a prespecified noninferiority analysis comparing 12-month patency of diabetic to nondiabetic claudicants.
"For the first time, the DEFINITIVE LE study has provided robust evidence within a large and diverse PAD patient population," said Dr. Garcia, who is Chief of Interventional Cardiology and Vascular Interventions at St. Elizabeth's Medical Center in Boston. "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."
A total of 800 subjects with 1,022 target lesions < 20 cm were enrolled at 47 centers in the United States and Europe. The mean age of subjects was 70.1 years; 54.6% were male; and 25% had CLI. The most common preexisting risk factors were hypertension (92%), hyperlipidemia (83.6%), and diabetes (52.3%). Mean lesion length was 7.4 cm across all vessel beds, with the mean lesion length in the superficial femoral artery being 8.3 cm, popliteal 5.8 cm, and infrapopliteal segments 5.8 cm.
Dr. Garcia reported that time-to-event analyses including the primary endpoints were conducted using Kaplan-Meier methods. Primary patency at 365 days in claudicants was 82% by duplex using a peak systolic velocity ratio (PSVR) < 3.5 and 78% using a PSVR < 2.4 across all vascular beds. The primary patency (PSVR < 2.4) in the superficial femoral artery was 74%, popliteal 74%, and tibial 84%, for all comers. One-year primary patency (PSVR < 2.4) in diabetic claudicants (80%) was noninferior to that of nondiabetic claudicants (83%), indicating that diabetic subjects did as well as nondiabetic subjects when treated with directional atherectomy.
"DEFINITIVE LE confirmed equivalent outcomes between diabetics and nondiabetics in terms of patency and persistent clinical improvement up to 12 months after treatment," said Prof. Thomas Zeller, MD, Head of the Department of Angiology at Universitäts-Herzzentrum Freiburg-Bad Kronzingen, Bad Krozingen, Germany. "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."
For CLI patients, freedom from major unplanned amputation of the target limb at 12 months was 95%. Dr. Garcia reported that the results from this large, rigorously analyzed data set demonstrate that directional atherectomy is a highly effective treatment option for patients with femoropopliteal and tibial-peroneal PAD presenting with claudication or CLI.
Dr. Garcia and Prof. Zeller, together with James McKinsey, MD, 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.
Stay tuned for more late-breaking trial updates from VIVA 2012.