October 5, 2021

Four More Late-Breaking Clinical Trials Announced at VIVA21

LAS VEGAS, Oct. 5, 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 second 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.

KNOCOUT PE: Retrospective and Prospective International EKoSoNic Registry of the Treatment and Clinical Outcomes of Patients With Pulmonary Embolism
Presented by Keith M. Sterling, MD

The KNOCOUT PE registry was designed to understand the changing protocols used with ultrasound-facilitated, catheter-direct-ed thrombolysis as standard of care in the treatment of acute pulmonary embolism (PE) and associated patient outcomes after publication of the OPTALYSE PE study. The OPTALYSE PE study demonstrated that the EkoSonic endovascular system (EKOS; Boston Scientific Corporation) is effective in the treatment of acute intermediate-risk PE using lower thrombolytic doses and shorter duration of infusion.

This study involved 83 international sites and enrolled 489 and 991 patients in prospective and retrospective cohorts, respectively. This report highlights results from the prospective registry. Patients with acute intermediate–high-risk or high-risk PE and treated with EKOS acoustic pulse thrombolysis were enrolled between March 2018 and June 2020. The mean recombinant tissue plasminogen activator (rtPA) infusion duration was 10.4 hours, and the mean total rtPA dose was 17.9 mg, with 32.4% of patients receiving ≤ 12 mg of rtPA. The mean percent reduction in right ventricular/left ventricular (RV/LV) ratio from baseline to postprocedure was 22.6%. This statistically significant reduction in RV/LV was maintained over time. There was a significant improvement in quality of life, with a 41.1% reduction in PEmb-QoL (Pulmonary Embolism Quality of Life Questionnaire) score by 3 months postprocedure. Major bleeding events within 30 days of the procedure, as defined by the International Society on Thrombosis and Haemostasis bleeding scale, occurred in 2.5% (12/489) of patients in the prospective cohort. No intracerebral hemorrhagic events were reported.

Results from this prospective multicenter registry reflect contemporary practice and demonstrate the performance of EKOS in the management of acute PE, with lower total rtPA dose and shorter infusion duration, marked clinical improvement in RV/LV ratio, low rates of major hemorrhagic complications with no intracerebral hemorrhagic events, and improvement in PE-specific quality of life.

A Prospective Multicenter Trial of Pharmacomechanical Catheter-Directed Thrombolysis With the Bashir Endovascular Catheter for Intermediate-Risk Acute Pulmonary Embolism: Interim Analysis of the RESCUE Study
Presented by Akhilesh Sista, MD

This study evaluated the preliminary efficacy and safety of Activase (Genentech) infused via a novel pharmacomechanical catheter-directed therapy (PM-CDT) device (the Bashir endovascular catheter [BEC]) for the treatment of intermediate-risk acute pulmonary embolism (PE). We present the results of our prespecified interim analysis of this National Heart, Lung, and Blood Institute–sponsored study.

In this study, up to 125 adult patients with symptoms of acute PE and CT evidence of right ventricular (RV) dysfunction and dilatation are being enrolled at 20 sites in the United States. A total of 7 mg of Activase is delivered through the BEC into each pulmonary artery (2-mg pulse spray plus 1-mg/hr infusion) over 5 hours. The primary efficacy endpoint is the core laboratory–assessed change in CTA-derived RV/left ventricular (LV) diameter ratio at 48 hours, and the primary safety endpoint is major device- or drug-related adverse events, including major bleeding, at 72 hours.

From August 2020 to the present, 81 patients have been enrolled. The first 61 evaluable patients were aged 58.2 ± 11 years, 76.9% were male, 92.3% had bilateral PE, and 90.3% had elevated bio-markers plus RV dilatation. The median procedure time was 52 minutes, and the average hospital length of stay was 3.0 ± 1.4 days. The primary efficacy endpoint of RV/LV ratio reduction at 48 hours was 0.52 (32.1% reduction; 95% CI, 0.42-0.62; P < .0001). None of the patients had any major device- or drug-related adverse events. The major bleeding rate was 0%. Thrombus burden, as measured by the refined modified Miller index, was reduced from a baseline of 23.4 ± 4.2 to 14.9 ± 4.8 (36.3% reduction; P < .0001). PM-CDT using the BEC appears to be efficacious and safe at this interim analysis.

5-Year VenaSeal Outcomes for Symptomatic Saphenous Incompetence: Is This the Clear Choice?
Presented by Morwan Bahi, MBChB

Chronic venous insufficiency is common in modern practice and a cause of significant morbidity, including skin and soft tissue infections, bleeding, ulceration, and pain. This was previously managed with venous stripping, which is a painful procedure with high recurrence rates. Thermal and laser ablation of incompetent saphenous veins has also been trialed. The VenaSeal (Medtronic) cyanoacrylate ablation method is relatively new. This presentation reports 5-year outcomes for treatment of incompetent saphenous veins with VenaSeal in a single center.

We conducted a retrospective, observational, single-center study detailing out-comes for all patients with symptomatic lower limb chronic venous insufficiency treated with saphenous vein closure with cyanoacrylate ablation (VenaSeal) between January 1, 2016, and December 31, 2020. All patients were postoperatively reviewed at 6 weeks, and outcomes were recorded.

We identified 235 patients matching our study criteria. The average age was 60.5 years, with slight male predominance (55.8%). The majority of patients were New Zealand European (63.8%), followed by Maori and Pacific (31.0%). The most common indication was venous ulceration (57.9%). Other indications included superficial thrombophlebitis, recurrent cellulitis, varicose vein bleeding, and deep vein thrombosis (DVT). Fifty percent underwent bilateral treatment. Only one saphenous vein (greater saphenous vein or small saphenous vein) required treatment in 88% of patients. The most common postprocedure symptom was phlebitis in 49 (21%) patients, which is an expected part of recovery. Excluding phlebitis, only 33 complications were noted, all relatively minor. We reported 15 cases of residual varicose veins, nine saphenous nerve neuropraxia cases, six cases of wound cellulitis, and three DVTs.

VIVO Clinical Study of the Zilver Vena Venous Stent in the Treatment of Symptomatic Iliofemoral Venous Outflow Obstruction: 3-Year Outcomes
Presented by Paul Gagne, MD

We present the 3-year outcomes for the VIVO clinical study, which assessed the safety and effectiveness of the Zilver Vena venous stent (Cook Medical) in the treatment of symptomatic iliofemoral venous outflow obstruction.

Patients with symptomatic obstruction of one iliofemoral venous segment were enrolled (ie, CEAP [clinical, etiology, anatomy, pathophysiology] clinical classification ≥ 3 or Venous Clinical Severity Score [VCSS] pain score ≥ 2). Follow-up through 3 years included measures of patency, reintervention, clinical outcomes (measured by VCSS, vascular duplex scan [VDS], CEAP “C”, and Chronic Venous Insufficiency Questionnaire [CIVIQ]), and device integrity measures of fracture and migration.

The VIVO study enrolled 243 patients (70% female; mean age, 53 ± 15 years; 67.5% with current or past deep vein thrombosis). The 30-day primary safety endpoint and 12-month primary effectiveness endpoint were met, exceeding the corresponding performance goals (P < .0001), and improvement in clinical outcome measures was demonstrated at 12 months (P < .0001). Follow-up through 3 years is complete, and results observed at 12 months were maintained. Specifically, 3-year outcomes include high rates of patency by ultrasound (90.3% ± 2.2%), freedom from clinically driven reinterventions (92.6% ± 2.0%), and freedom from reinterventions (82.9% ± 2.6%). Clinical improvement, as measured by VCSS, VDS, CEAP “C”, and CIVIQ, was sustained through 3 years (P < .0001). Importantly, there were no core laboratory–reported stent fractures, and only one core laboratory–reported migration (adjudicated as technique-related due to device undersizing) through 3 years.

In conclusion, the 3-year results of the VIVO clinical study support the continued safety and effectiveness of the Zilver Vena venous stent.

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/.