VIVA 2009 Late-Breaking Trials Highlight Advances in PAD Treatments

November 10, 2009 – The latest data from seven studies focused on the treatment of peripheral arterial disease (PAD) were presented in the late-breaking trials session of the Vascular Interventional Advances (VIVA) 2009 annual meeting, which took place on Oct. 19 to 23 in Las Vegas.

COBEST
Patrice Mwipatayi, M.D., FCS (SA), FRACS, presented preliminary 18-month results for the Covered Versus Balloon Expandable Stent Trial (COBEST) study. COBEST is a prospective, multicenter, randomized, controlled trial that compares the Advanta V12 polytetrafluoroethylene-covered stent (Atrium Medical Corp.) to bare-metal stents (BMS) in patients with iliac occlusive disease. The data showed a statistically significant difference in restenosis and freedom from occlusion rates when using the Advanta V12 versus a BMS.

The study enrolled 123 patients (167 limbs). At 18 months, there were 69 limbs in the V12 group and 63 limbs in the BMS group. The results showed that 95.4 percent of patients in the V12 group had less than 50 percent binary restenosis (duplex scan) compared to 82.2 percent in the BMS group. The investigators found that there was a significant difference showing superiority of the V12 stent compared to BMS for TASC C and D lesions, whereas in TASC B lesions the V12 and BMS patency rates were similar.

FlexStent System in the SFA
William A. Gray, M.D., presented interim six-month clinical results on the safety and efficacy of the FlexStent femoropopliteal self-expanding stent system (Flexible Stenting Solutions Inc.) in the superficial femoral artery in a first-in-man study conducted in Auckland, New Zealand (n=15) and a supplementary study conducted in Leipzig, Germany (n=20).

The angiographic results showed that periprocedural lesion success (restenosis less than 30 percent) was 100 percent in both groups. The 30-day safety endpoints showed zero adverse events. The interim six-month efficacy endpoints demonstrated 100 percent freedom from major adverse cardiovascular events and no fractures. In the pooled data set, there was a 92.3 percent patency rate with an 86.6 mm average lesion length. Among the secondary endpoints, average treadmill, ankle brachial index and Rutherford scores improved.

ARMOUR
L. Nelson Hopkins, M.D., presented results from the prospective, multicenter ARMOUR (Proximal Protection with the Mo.Ma Device During Carotid Stenting) trial showing that use of the Mo.Ma Ultra proximal protection device (Invatec Inc.) for cerebral protection during carotid artery stenting in high-surgical-risk patients with any FDA-approved carotid stent is safe and effective.

The results showed a 30-day major adverse cardiac and cerebrovascular events (MACCE) rates of 2.7 percent for intention-to-treat (ITT) patients and 2.3 percent overall. There were no myocardial infarctions. There was a 0.9 percent death rate for ITT patients and 0.8 percent overall. The stroke rates were 2.3 percent for ITT patients and 1.9 percent overall. The MACCE rates were 1.5 percent for both groups. In the ITT patients, 16.4 percent had site-reported serious adverse events. There were no unanticipated adverse device effects. At 30 days, the restenosis rate was 1.6 percent, and the target lesion revascularization rate was 0 percent. The Mo.Ma device success rate was 98.2 percent. The technical success rate was 94.6 percent, and the procedural success rate was 93.2 percent.

Symplicity HTN-1
Krishna Rocha-Singh, M.D., presented results from the Symplicity HTN-1 study showing that catheter-based renal denervation yields significant and sustained reductions in blood pressure in patients with multidrug-resistant hypertension. The Symplicity HTN-1 study, sponsored by Ardian Inc. was a pilot evaluation of the safety and blood pressure–lowering efficacy of percutaneous renal sympathetic denervation in patients with resistant hypertension. Twenty patients were enrolled, 15 of which had qualifying anatomy.

The results (93 percent responder rate) showed average decreases in blood pressure of -28/-10, -24/-8, and -30/-13 mm Hg at one, three and six months, respectively. Four patients had their medications reduced (by an average of three medications), and no patients had their medications increased.

VIBRANT
Gary M. Ansel, M.D., presented one-year interim results from the multicenter, real-world Viabahn Versus Bare-Nitinol Stent (VIBRANT) study showing that the Gore Viabahn endoprosthesis in the treatment of long-lesion (8 cm) superficial femoral artery occlusive disease is clinically safe and effective.

The outcomes of the Viabahn group versus the control group, respectively, include technical success (97 vs. 97 percent); primary patency (53 vs. 58 percent); freedom from target lesion revascularization (73 vs. 69 percent); assisted primary patency (84 vs. 91 percent); and secondary patency (93 vs. 98 percent). Device occlusion was reported in nine patients in the Viabahn group compared to six patients in the bare-nitinol stent group. Focal-edge stenosis comprised 87 percent of failures in the Viabahn group whereas in-stent stenosis comprised 93 percent of bare-nitinol stent failures. There was one stent fracture in the 47 Gore Viabahn patients compared to 16 stent fractures in the 52 bare-nitinol stent patients (2 vs. 30.8 percent).

VIVA I: Xcell
Krishna J. Rocha-Singh, M.D., also presented six-month clinical results from the VIVA I: Xcell trial that demonstrated the feasibility of the Xpert nitinol stent (Abbott Vascular) for below-the-knee primary stenting in patients with critical limb ischemia. The data show that revascularization via percutaneous transluminal angioplasty plus nitinol stenting is promising with limb salvage rates that are similar to surgery with lower early morbidity and mortality.

At six-month follow-up in 115 patients, there were 36 (31.3 percent) target lesion revascularizations, of which 21 (18.3 percent) were symptomatic. There were seven (6.1 percent) major amputations, six (5.2 percent) deaths, four (3.5 percent) target vessel revascularizations, and one (0.9 percent) access-site complication requiring transfusion. For 127 analyzable wounds, 68 (53.5 percent) were 100 percent healed, 43 (33.9 percent) had significant decreased wound area, and 16 (12.6 percent) had increased wound area. A secondary analysis of complete wound healing showed significant trends including that 68 of 127 wounds (53.5 percent; in 44 of 77 patients) were 100 percent healed at six months.

PATRIOT
James D. Joye, DO, presented findings from the Peripheral Approach to Recanalization in Occluded Totals (PATRIOT) pivotal trial of the Crosser catheter from FlowCardia Inc. to mediate chronic total occlusion (CTO) recanalization. The data showed the device to be a safe and valuable tool for crossing CTOs in the lower extremities.

Primary efficacy endpoints demonstrated that 84 percent of the guidewire-resistant CTOs were successfully recanalized with the Crosser catheter. Regarding the primary safety endpoint, there were no clinical perforations related to the Crosser. Another endpoint was freedom from limb loss, clinical perforation, and repeat revascularization through 30 days in 80 of 85 patients (94.1 percent). The Crosser catheter safely traversed 84 percent of guidewire resistant CTOs without any clinical perforations. There was an 81 percent efficacy in lesions 15 cm. The average lesion length was 12 cm, and average activation time was 126 seconds.

VPI is a multidisciplinary group of independent physicians who are nationally known experts in the diagnosis and management of all peripheral vascular diseases, and who are joined together to advance education in vascular medicine and support research and innovative treatment options. In 2002, the group of 10 specialists in vascular medicine, vascular surgery, interventional cardiology and interventional radiology, organized VIVA: The National Education Course for Endovascular Interventions, an annual educational symposium held in Las Vegas that provides a highly interactive educational forum.

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