Fourth and Final Round of Late-Breaking Clinical Trials Announced at VIVA21

LAS VEGAS, Oct. 6, 2021 /PRNewswire/ -- The VIVA Foundation, a not-for-profit organization dedicated to advancing the field of vascular medicine and intervention through education and research, announces the fourth round of highly anticipated late-breaking clinical trial results at VIVA21 hosted at Wynn Las Vegas.

VIVA (Vascular InterVentional Advances) is an annual vascular education symposium that brings together a global, multispecialty faculty to present a variety of talks and live case presentations from clinical centers around the world. Attendees include an audience of interventional cardiologists, interventional radiologists, vascular surgeons, and endovascular medicine specialists.

Below are highlights of this afternoon's 4 late-breaking clinical trial presentations.

2-Year PROMISE I Results With the LimFlow Deep Vein Arterialization System
Presented by Daniel Clair, MD

The PROMISE I trial represents the evaluation of a purpose-built system (LimFlow system, LimFlow SA) for creating deep vein arterialization to treat patients with severe, unreconstructable chronic limb-threatening ischemia (CLTI). Thirty-two patients were enrolled at seven United States sites from 2017 to 2019, with primary endpoints including a composite endpoint of amputation-free survival, overall survival, and freedom from amputation. The study included confirmation of no option for revascularization through an independent review board consisting of vascular specialists and represents the initial experience with this technique in the United States. There was a very high incidence of diabetes (69%) and hypertension (88%) in the group overall, and nearly one-third of patients had renal insufficiency.

There was one technical failure, for a technical success rate of 97%. Amputation-free survival was 74%, 70%, and 59% at 6, 12, and 24 months, respectively. Importantly, there were no amputations in any patient after day 75, and there were no limb-related mortality events. Freedom from amputation in this incredibly high-risk patient group was 77% out to 2 years. At 2 years, 85% of wounds were completely healed, and 92% of patients were either healed or healing.

Significant lessons have been learned in this initial experience, including the benefit of gaining initial venous access in the foot, maintaining current arterial inflow in the foot until the deep vein arterialization matures, and the critical management of these foot wounds. Improvements in arteriovenous crossing and stent graft deployment ease and precision are highlighted with technology improvements in the system, and these enhancements will all be included in the PROMISE II trial, a global, multicenter registry to assess the outcome of deep vein arterialization in the "no-option" CLTI patient population.

MIMICS-3D: Claudicants and CLTI Patients Treated With BioMimics 3D Have Similar Patency at 2 Years
Presented by Sahil A. Parikh, MD

BioMimics 3D (Veryan Medical) is a nitinol stent designed to provide optimal radial support, flexibility, durability, and delivery accuracy for femoropopliteal intervention. The addition of a unique three-dimensional (3D) helical centerline provides the advantages of biomechanical compatibility and swirling blood flow to elevate wall shear stress to limit intimal hyperplasia. MIMICS-3D is a European registry investigating the outcomes of BioMimics 3D treatment in patients with longer, more complex lesions than previously studied.

MIMICS-3D enrolled 507 patients treated with BioMimics 3D at 23 sites: 76% were claudicants (Rutherford class 1-3) and 24% had chronic limb-threatening ischemia (CLTI; Rutherford class 4-6).  Of these, 34% and 47% were diabetic and 7% and 13% had renal insufficiency, respectively. Respective mean lesion length was 126.3 ± 92.9 mm and 130.2 ± 92.7 mm, and 54% and 64% of lesions were occluded. An independent clinical events committee adjudicated major adverse events (MAEs), including death and potential device-related events.

The primary safety endpoint, a composite of freedom from MAE comprising death, major index limb amputation, or clinically driven target lesion revascularization (CD-TLR) through 30 days, was 99% for claudicants and 97% for CLTI patients. The primary outcome measure for effectiveness (freedom from CD-TLR through 12 months) at 1 and 2 years was 92% and 85% for claudicants and 85% and 77% for CLTI. Kaplan-Meier freedom from loss of primary patency (peak systolic velocity ratio ≤ 2.4) at 1 and 2 years (days 365 and 730) was 89% and 80% for claudicants and 81% and 72% for CLTI, respectively. There was no statistical difference in patency between the two groups through 2 years, although there was a slight trend toward a worse outcome in patients with CLTI.

This subgroup analysis shows that the benefits of swirling flow previously established in claudicants are also relevant for CLTI patients. These are compelling data that support the use of BioMimics 3D to manage patients with CLTI. Three-year follow-up continues.

INSIGHT: Evaluation of the Pantheris OCT-Imaging Atherectomy System in Treatment of In-Stent Restenosis Occlusions in Lower Extremity Arteries
Presented by Jon George, MD

The INSIGHT trial is a multicenter, prospective, single-arm trial conducted at 17 institutions to evaluate the safety and effectiveness of the Pantheris OCT-imaging atherectomy system (Avinger) to reduce in-stent restenosis (ISR) in vascular stents placed in lower extremity arteries. A total of 97 patients presenting with stent stenosis > 70% were enrolled, with 85 having completed a 6-month follow-up clinic visit and 78 completing the 1-year visit. The patients had a mean age of 74 years, mean weight of 85.6 kg, and mean height of 165 cm; were equally male/female; and were predominantly Caucasian (78%). Most had a history of smoking and were being treated for hypertension, coronary artery disease, and diabetes at the time of enrollment. The ISR occlusions had a mean length of 13 cm, none to mild calcification, and a mean stenosis of 85% prior to the procedure. As assigned by the clinical events committee, 97% of patients were free of major adverse events within 30 days postprocedure, and the freedom from target lesion revascularization was 93% at 6 months postprocedure and 89% after 1 year. The ankle-brachial index measures improved by 36% and 39% between baseline and 30 days and 6 months, respectively. Patients experienced a 71% improvement (reduction) in Rutherford class by 6 months, with 77% of patients either Rutherford class 0 or 1. As adjudicated by a central core lab, stent stenosis was reduced by 82% after treatment.

The data collected in the INSIGHT trial document a substantial reduction of ISR stenosis, with few adverse events related to use of the Pantheris catheter and measured clinical benefit.

Amplifi Treatment Prior to AVF Creation
Presented by Surendra Shenoy, MD, PhD

Arteriovenous fistula (AVF) eligibility and successful maturation are dependent on initial vein diameter and blood flow. The Amplifi vein dilation system (Artio Medical, Inc.) is a small, wearable blood pump system that dilates arm veins prior to AVF creation. It is designed to improve AVF eligibility, reduce maturation failure, reduce time to maturation, and prolong primary and secondary patency. A prospective, nonrandomized, single-arm, open-label, first-in-human clinical study in five patients with end-stage renal disease was conducted at Sanatorio Italiano, Asunción, Paraguay, commencing Q4 2020.

During Amplifi system implantation, the inflow catheter was tunneled, inserted percutaneously into an internal jugular vein, and advanced under fluoroscopy to the right atrium. The outflow catheter was inserted into the forearm cephalic vein after surgical exposure. The catheters and controller were connected to the blood pump, and treatment was initiated. 

Patients remained in hospital through-out the treatment period (mean, 8.6 days). Amplifi system blood flow was measured continuously, and contrast venography was performed periodically to measure vein diameter. Pump speed was increased during treatment to maintain wall shear stress of approximately 4 Pa in the treated veins. After treatment, an AVF was created with a treated vein, and an ultrasound examination was performed 1 day, 2 weeks, and 6 weeks after AVF creation. Two radiocephalic and three brachiocephalic AVFs were created. In two patients, a dilated median ante-cubital vein was incorporated into the brachiocephalic AVF. 

Amplifi system treatment resulted in 105%, 110%, and 85% increases in the diameter of the forearm cephalic, upper arm cephalic, and upper arm basilic veins, respectively.

AVFs created with Amplifi-treated dilated veins matured quickly, with outflow vein diameters and flow rates increasing to 7.0 mm and 1,100 mL/min, respectively, over the 6-week maturation period. There were no device- or procedure-related serious adverse events. The Amplifi vein dilation system uniformly dilated the outflow veins, increasing patient eligibility for AVF and resulting in early maturation. There were no adverse events.

About the VIVA Foundation
The VIVA Foundation, a not-for-profit organization dedicated to advancing the field of vascular medicine and intervention through education and research, strives to be the premier educator in the field. Our team of specialists in vascular medicine, interventional cardiology, interventional radiology, and vascular surgery is driven by the passion to advance the field and improve patient outcomes. Educational events presented by the  have a distinct spirit of collegiality attained by synergizing collective talents to promote awareness and innovative therapeutic options for vascular disease worldwide. To learn more about the VIVA Foundation, visit https://thevivafoundation.org/.

SOURCE The VIVA Foundation