Covidien Reports 12-Mo. DEFINITIVE AR Results: Show Higher Technical Success

Covidien plc (NYSE: COV) today announced 12-month results of the DEFINITIVE ARstudy, the first randomized study designed to identify the clinical benefitsof plaque removal using directional atherectomy followed by drug coatedballoon. The results were presented by Professor Thomas Zeller of theUniversitaets-Herzzentrum, Bad Krozingen, Germany at the VascularInterventional Advances (VIVA) 2014 conference in Las Vegas, Nev.DEFINITIVE AR results demonstrated higher technical success and lowerincidence of vessel injuries known as flow-limiting dissections. Additionally,the study suggests the combination of directional atherectomy andanti-restenosis therapy with drug coated balloons (known as DAART) improvespatency in long and severely calcified lesions. Longer lesions have lowerpatency across all current treatments, and presence of calcification mayprohibit drug uptake and lead to less durability and loss of patency. Patencyis the ability for the treated artery to remain open. (Click here for asummary of research findings.)“DEFINITIVE AR was designed as a hypothesis-generating study to detect trendsin treatment differences between patients who were treated with DAART andpatients who were treated with drug-coated balloons (DCB) alone. While the useof DCBs to treat peripheral artery disease has demonstrated reducedrestenosis, there have been limited clinical studies evaluating theeffectiveness of DCBs in complex disease,” said Professor Zeller. “The resultssuggest DAART may address an unmet clinical need in difficult to treat long orseverely calcified lesions.”Duplex Ultrasound primary patency rates for the long (≥10 cm) lesion subsetat 12 months were 96.8 percent in patients treated with DAART compared to 85.9percent in patients treated with DCB alone. Primary patency rates at 12 monthsin severely calcified lesions, per core lab assessment, were 70.4 percent inDAART patients compared to 62.5 percent in DCB alone patients.“Lumen gain, or the amount of plaque removed from the artery with directionalatherectomy prior to DCB treatment, may also be a critical factor incontributing to the long-term clinical success of DAART therapy,” saidProfessor Gunnar Tepe, Klinikum Rosenheim, Germany. “This data suggests whenthe optimal amount of plaque is removed, that is <30 percent residualstenosis, the patency rate is improved.”Results showed 94.1 percent primary angiographic patency for DAART when moreplaque was removed with directional atherectomy (less than 30 percent residualstenosis was achieved) compared to 68.8 percent patency when less plaque wasremoved (more than 30 percent residual stenosis) prior to treatment with theDCB. Directional atherectomy is unique as it allows for the largest amount ofluminal gain while maintaining vessel integrity.The primary endpoint of the study was defined as the percent stenosis(narrowing of the vessel), at one year per Angiographic Core Lab assessment.At 12 months, the percent stenosis in the randomized groups was 33.6 ± 17.7for the DAART arm compared to 36.4 ± 17.6 for the DCB arm. These results wereobservational as the study was not powered to detect differences between thegroups.“This small but rigorous pilot study suggests an added benefit for DAART overDCB in challenging lesions,” said Dr. Mark Turco, chief medical officer,Vascular Therapies, Covidien. “Further investigation in larger, prospective,statistically-powered randomized trials is warranted to confirm the positivetrends observed in DEFINITIVE AR and to evaluate a possible economic advantageto a DAART strategy. Covidien continues to invest in the DEFINITIVE AR study,and patients will be followed out to 24 months to assess the durability of theresults.”