DANCE Trial's Atherectomy Cohort Evaluated at 12 Months

September 21, 2016—Chris Owens, MD, presented the DANCE study during the third Late-Breaking Trials session at VIVA 16, the 14th annual Vascular InterVentional Advances meeting, which is sponsored by VIVA Physicians, Inc. and held September 18–22, 2016 at the Wynn Las Vegas in Las Vegas, Nevada.

The DANCE trial is a 281-patient, multicenter, single-arm trial examining the local microinfusion delivery of dexamethasone into the adventitial and perivascular tissues via the Bullfrog device (Mercator MedSystems, Inc.) to safely reduce restenosis rates in patients with atherosclerotic obstructive lesions of the superficial femoral and/or popliteal arteries.

Dr. Owens explained that two revascularization treatment options were evaluated with dexamethasone use: atherectomy and percutaneous transluminal angioplasty. The primary efficacy endpoint is primary patency (lack of target lesion revascularization and duplex ultrasound peak systolic velocity ratio ≤ 2.4) at 12 months.

He noted that the adventitia is an ideal drug reservoir for treating cardiovascular diseases that are subject to barotrauma and, thus, inflammation. Local delivery of the generic anti-inflammatory steroid dexamethasone at a dose of 1.6 mg per centimeter along the target lesion length is intended to block the injury-related vessel inflammation associated with revascularization, thereby reducing restenosis. By placing the drug through the media and outside the external elastic lamina, the onset of the restenosis cascade can be treated without the uncertainty of whether a sufficient amount of the drug has migrated from the intima outward through calcification or heavy plaque burden.

As presented by Dr. Owens at VIVA 16, the DANCE trial enrolled 157 patients who received primary atherectomy revascularization and 124 patients who received PTA without atherectomy. Enrollment demographics showed a higher proportion of critical limb ischemia (Rutherford class 4), complex lesions (TASC II B), and severe calcification than published drug-coated balloon studies. After revascularization, hemodynamic, clinical, and duplex ultrasound assessments were performed at 4 weeks and 6, 12, and 18 months. 

The atherectomy group has completed 1-year follow-up, and the intent-to-treat population had a 1-year primary patency rate of 79.5% by Kaplan-Meier. The per-protocol population (for the purpose of matching eligibility to published drug-coated balloon trials) had a Kaplan-Meier primary patency rate of 83.8% at 365 days and 80.2% at 395 days, reported Dr. Owens at VIVA 16.