New 12-month data from the VIRTUS trial demonstrate that patients who were treated with the Vici venous stent system (Boston Scientific) for iliac and femoral vein obstructions exhibited a high rate of patent, or open, target lesions. Primary safety and efficacy results from the trial were presented as a first-time data release at the Leipzig Interventional Course (LINC; 22–25 January, Leipzig, Germany) by principal investigator Mahmood Razavi (St Joseph Heart and Vascular Center, Orange, USA).
The VIRTUS trial evaluated the Vici stent in patients with clinically significant obstructions in the illiofemoral venous outflow tract resulting from post-thrombotic syndrome (PTS) or compressive diseases such as May-Thurner syndrome.
“The primary safety and efficacy endpoints were very successfully met, with very low p-values”, Razavi told the audience at LINC. The trial’s primary effectiveness endpoint saw a primary patency rate of 84% at 12 months, which was greater than the predefined performance goal (PGE) of 72.1% (p<0.0001).
“Nearly all the patients treated with the stent, 98.8%, were free from major adverse events at 30 days post-procedure, thus surpassing the predefined safety performance goal (PGS) of 94%.
The VIRTUS investigational device exemption (IDE) trial, submitted in June of 2018, is a prospective, multicentre, single-arm, nonrandomised study that enrolled 170 patients with chronic disease; 75% (127) of whom were diagnosed as having post-thrombotic lesions and the remaining 25% (43) were diagnosed with non-thrombotic lesions (i.e., May-Thurner syndrome). Venography, Doppler ultrasound and intravascular ultrasound (IVUS) were performed pre- and post-stenting, as well as at 12-month follow-up.
“In treating patients with venous obstruction, the primary goal is to restore and maintain vessel patency to ensure the return of blood flow to the heart,” said Razavi. “In these results, the Vici stent demonstrated excellent performance outcomes in a difficult to-treat patient population, which translates to improvement of long-term symptoms and enhanced quality of life in these patients.”
In terms of clinical severity, Razavi reported a Vascular Clinical Severity Score (VCSS) decrease of 4.4 points at 12 months, with a median VCSS of 10 in 146 patients falling to 5.6 in 132 patients followed up to 12 months. At baseline, 65.8% of patients presented in the category of most severe VCSS of eight or more, which decreased to 33.3% at six months and further fell to 27.3% at one year.
Two adverse events (1.2%; n=169) were seen in the cohort at 30 days, both of which were described as “arterial or venous injury at the tar get vessel segment and/or target lesion location or at the access site requiring surgical or endovascular intervention”. There were no instances of device-related or procedure-related death, major bleeding at target or access site, acute deep vein thrombosis outside target vein segment, clinically significant pulmonary embolism or embolization of the stent at 30 days.
“Physicians who select endovascular treatment options for their patients with venous disease are not only faced with challenging disease states but must also account for the unique anatomical presentation of these deep veins that are subject to chronic obstruction and compression,” said Ian Meredith, executive vice president and global chief medical officer of Boston Scientific, in a company press release.
“The results from the VIRTUS trial demonstrate the importance of having a therapeutic option that is specifically designed for venous application, thus helping patients avoid recurrent pain, swelling and other debilitating aspects of acute and chronic venous disease.”
The stent system was approved for use in Europe and other geographies that recognise CE mark in 2013. In the USA, the stent is an investigational device and is not available for sale. The device was developed by VENITI, which Boston Scientific acquired in August of 2018.