Final Five Unpublished Late-Breaking Clinical Trial Results Announced at VIVA19


VIVA Physicians, a not-for-profit organization dedicated to advancing the field of vascular medicine and intervention through education and research, announces the final round of 21 highly anticipated late-breaking clinical trial results at VIVA19 hosted at Wynn Las Vegas.

Below are highlights of this afternoon’s five late-breaking clinical trial presentations.

IN.PACT AV Access 6-Month Lesion Outcomes
Presenter: Robert Lookstein, MD, MHCDL

Robert Lookstein, MD
Interventional Radiology
Mount Sinai Medical Center
New York, New York

The IN.PACT AV Access randomized trial is an independently adjudicated, prospective, global, multicenter, single-blinded study evaluating the safety and effectiveness of the IN.PACT AV Access drug-coated balloon (DCB; Medtronic) compared to percutaneous transluminal angioplasty (PTA) for the treatment of 330 patients with obstructive lesions (de novo or restenotic) of the native arteriovenous dialysis fistulae (AVF) in the upper extremity.

The primary effectiveness endpoint was the target lesion primary patency rate, defined as freedom from clinically driven target lesion revascularization (CD-TLR) or access circuit thrombosis measured through 6 months (210 days) postprocedure. The primary safety endpoint was defined as the serious adverse event rate involving the AV access circuit through 30 days postprocedure.

As reported at CIRSE 2019, both endpoints were met. Target lesion primary patency was 81.4% in the DCB group compared to 59% in the PTA group (P < .001); there was a 56% reduction in the total number of reinterventions required to maintain patency. Twelve-month all-cause mortality was 90.6% in the DCB group compared to 90.4% in the PTA group.

Distribution of lesion location, AVF type, and lesion type among patients in the DCB and PTA groups was similar (P = .310, P = .918, and P = .905, respectively). Six-month primary patency of restenotic lesions was 78.9% in the DCB group compared to 52.4% in the PTA group (difference, 26.5%). Primary patency of radiocephalic fistulas was 81.7% in the DCB group compared to 60% in the PTA group (difference, 21.7%). Primary patency of brachiocephalic fistulas was 80.8% in the DCB group compared to 57.4% in the PTA group (difference, 23.4%). Primary patency of anastomotic lesions was 84.6% in the DCB group compared to 50.0% in the PTA group (difference, 34.6%). Primary patency of cephalic arch lesions was 84.0% in the DCB group compared to 50.0% in the PTA group (difference, 34.0%).

Lateral Subdermic Plexus Insufficiency: A New Paradigm Shift With Restless Leg Syndrome
Presenter: Swar Shah, MD

Restless leg syndrome (RLS) and nighttime leg cramping/Charley horses are common symptoms, but their etiologies have always been poorly understood. Over the years, we have noticed that many patients with chronic superficial venous insufficiency/varicose veins have had presenting symptoms of RLS and nighttime leg cramping/Charley horses. It was also noted that many of these patients presented with abnormal reflux of the lateral subdermic venous plexus (LSP) and superficial veins on the lateral thigh and calf typically not evaluated in most settings. It was hypothesized that there is an association between these leg symptoms and this poorly understood LSP.

A total of 510 patients were evaluated for a correlation between RLS/nighttime leg cramping with reflux in the LSP. In patients with either symptom, 83% and 89%, respectively, had an abnormal LSP on ultrasound. Of patients with both symptoms, 91% had an abnormal LSP on ultrasound. A total of 242 symptomatic patients underwent ultrasound-guided foam sclerotherapy of the LSP and up to 92% were symptom-free at 1 year.

The LSP appears to play a key role in RLS and nighttime cramping and should be added to the comprehensive venous ultrasound, especially for patients presenting with these symptoms. Furthermore, treatment for this is simple, cheap, and effective and can be life-changing for many of these patients.

Early Outcomes From the ClotTriever (CLOUT) Registry
Presenter: David Dexter, MD

David J. Dexter, M.D
Vascular Surgeon
Sentara Medical Group
Norfolk, VA

The ClotTriever Outcomes (CLOUT) Registry is evaluating real-world patient outcomes following treatment of acute and non-acute lower extremity proximal deep vein thrombosis (DVT) with the ClotTriever system (Inari Medical), a mechanical thrombectomy system 510(k) cleared for the nonsurgical removal of soft thrombi and emboli from peripheral blood vessels.

The CLOUT Registry is enrolling 500 patients with lower extremity DVT involving the femoral vein, iliac vein, and/or inferior vena cava at up to 50 sites. Thrombus age is not capped, including acute, subacute, and chronic clot. Patients with vena cava filters and venous stents are excluded. Baseline demographics, comorbidities, eligibility for thrombolytic treatment, and DVT-specific baseline characteristics are collected prior to the ClotTriever procedure. Patient outcomes are collected at hospital discharge following thrombectomy and at 30 days, 6 months, 1 year, and 2 years postprocedure.

Procedural and acute data from 50 patients across 12 sites and 30-day follow-up data of 37 patients were assessed. 98% of patients were treated in a single session with a median thrombectomy time of 38.0 minutes. Thrombus removal of ≥ 75% via core lab–assessed Marder scores was achieved in 76.5% of treated limbs, including those with chronic disease. There was one (2%) major adverse event, neither procedure nor DVT related: a death 23 days postprocedure due to sepsis and renal failure in a metastatic lung cancer patient. No bleeding complications and one (2%) access site hematoma was reported. At 30-day follow-up, the number of patients with postthrombotic syndrome (PTS) as well as moderate or severe PTS had significantly decreased (P < .01). Additionally, quality of life scores, including Villalta, revised Venous Clinical Severity Score, EQ-5D, and Numeric Pain Rating Scale, showed statistically significant improvement at 30 days. Further registry enrollment and analysis will provide insight for future definitive studies for the treatment of DVT.

Indigo Aspiration System for Acute Pulmonary Embolism
Presenter: Akhilesh K. Sista, MD

Akhilesh K. Sista, MD
NYU Langone Health
Vascular & Interventional Radiology
New York, NY

EXTRACT-PE is a prospective, single-arm, multicenter trial designed to evaluate the safety and efficacy of mechanical aspiration thrombectomy using the Indigo aspiration system (Penumbra, Inc.) in patients with acute pulmonary embolism (PE). The trial enrolled 119 patients at 22 U.S. sites. Inclusion criteria were symptomatic acute PE ≤ 14 days, systolic blood pressure ≥ 90 mm Hg, right ventricular (RV)/left ventricular (LV) diameter ratio > 0.9, and age ≥ 18 years. A key exclusion criterion was tissue plasminogen activator administration within 14 days of baseline CTA.

The primary efficacy endpoint was the reduction in RV/LV ratio from baseline to 48 hours as assessed by CTA. The primary safety endpoint was the rate of major adverse events, a composite of device-related death, major bleeding, and device-related serious adverse events (including clinical deterioration, pulmonary vascular injury, and cardiac injury) within 48 hours.

Mechanical aspiration thrombectomy was performed using an 8-F aspiration catheter (CAT8, Penumbra, Inc.) and a Penumbra pump. Median procedure time was 66 minutes, and median time from study device insertion to removal was 37 minutes.

Mean pretreatment RV/LV ratio was 1.47 and was 1.04 at 48 hours postprocedure. Mean reduction in RV/LV ratio was 0.43 (95% confidence interval, 0.38–0.47; P < .0001), corresponding to a 27.3% reduction. Two (1.7%) patients experienced three major adverse events. Rates of cardiac injury, pulmonary vascular injury, clinical deterioration, major bleeding, and device-related death at 48 hours were 0%, 1.7%, 1.7%, 1.7%, and 0.8%, respectively. Rates of any-cause mortality, device-related serious adverse events, and symptomatic PE recurrence within 30 days were 2.5%, 1.7%, and 0%, respectively. Thrombolytic drugs were not used in 98.3% of patients.

Based on the study findings, mechanical aspiration thrombectomy with the Indigo aspiration system is associated with a significant reduction in the RV/LV ratio and a low rate of major adverse events. The Indigo aspiration system met its prespecified safety and efficacy endpoints in the treatment of acute PE.

1-Year Results of the DISAPEAR Registry
Presenter: Steven Kum, MD

Steven Kum, MD Vascular Surgery
Changi General Hospital Singapore,

The Absorb bioresorbable vascular scaffold (BVS; Abbott Vascular) has demonstrated favorable short- and medium-term results in below-the-knee vessels in patients with chronic limb-threatening ischemia (CLTI) or claudication. The DISAPEAR registry aimed to evaluate the safety and effectiveness of the Absorb BVS in an Asian cohort exclusively with CLTI.

A retrospective analysis was performed in patients with Rutherford class 4 to 6 CLTI with de novo infrapopliteal lesions with angiographic stenosis > 50% who were treated with Absorb BVS between August 2012 and June 2017 at Changi General Hospital, Singapore. Assessments included technical success, primary patency (duplex ultrasound peak systolic velocity ratio < 2.0), freedom from clinically driven target lesion revascularization (CD-TLR), amputation-free survival, limb salvage, and wound healing at 6 and 12 months after the index intervention.

Forty-one patients (41 limbs) with 53 lesions were treated with 69 scaffolds during the study period. About 90% of the patients had diabetes, 59% had ischemic heart disease, 12% had dialysis-dependent renal failure, and 93% had Rutherford category 5/6 ischemia with tissue loss.

Technical success was achieved in all patients. The mean lesion length was 22.7 ± 17.2 mm. Twenty-four percent of lesions were classified as severely calcified according to the PARC classification. The primary patency rates at 6 and 12 months were 95% and 86%, respectively. The corresponding rates of freedom from CD-TLR were 98% and 93%. Freedom from major amputation was 98% at both time points and amputation-free survival was 93% and 85% at 6 months and 1 year after the index procedure. Complete wound healing occurred in 79.5% of patients with Rutherford 5 and 6 ischemia by the end of 12 months after the index procedure. There were no deaths within 30 days of the index intervention.

The Absorb BVS demonstrated good patency and clinical outcomes in patients with CLTI and complex infrapopliteal disease and comorbidities such as diabetes and renal failure. Future prospective controlled studies can further help corroborate the significance of these findings.

Cardiology Magazine