Clinical Evaluation of the BioMimics 3D Stent: the MIMICS Study
Veryan has completed a multicentre, prospective, randomised (2:1) control trial, with a 24-month follow-up in subjects undergoing femoropopliteal intervention; the Mimics Study. After a 10 patient phase I lead-in, the Mimics study enrolled 76 patients in the phase II randomised portion; 50 patients received the BioMimics 3D stent and 26 patients received a straight Nitinol control stent. C.R. Bard’s LifeStent® was the most commonly used stent in the control arm (placed in 24/26 control cases). A core lab provided independent review and analysis of imaging data.
There were no significant differences in demographics and risk factors between the two cohorts. Baseline data on the treated lesion(s) in both cohorts showed that moderate to severe levels of calcification or total occlusions were each present in 44% of the BioMimics 3D subjects and 46% of the control subjects, indicative of a challenging population. Mean lesion length (MLL) for the BioMimics 3D stent-treated subjects was 66 mm with a mean stented segment length of 99 mm. Angiographic and X-ray imaging with clinical follow-up assessments show that, particularly in this challenging patient cohort, the femoropopliteal artery adapts safely to the curvature imparted by the BioMimics 3D stent (see image right) and that the curvature of the stented vascular segment is maintained over time.
No major adverse events occurred within 30 days from the index procedure and no clinically driven target lesion revascularisation occurred in the BioMimics 3D arm within 6 months.
Full two-year data from the Mimics study presented at the VIVA Symposium in Las Vegas on 4th November 2014 by Mimics Principal Investigator Professor Thomas Zeller confirm that BioMimics 3D provides a significant improvement in long-term patency compared to a straight Nitinol control stent in patients undergoing femoropopliteal artery intervention.
There are two key findings; firstly, the Kaplan Meier (KM) survival analysis of freedom from loss of primary patency at two years was 72% for BioMimics 3D subjects vs. 55.0% for the control group: a significant difference by log rank test (P=0.0497).
24 Month Kaplan Meier Estimate of Survival From Loss of Patency.
Secondly, there was no increase in the clinically driven target lesion revascularisation (CDTLR) rate in the BioMimics arm between 12 and 24 months (9% at both time-points) compared to a 3-fold increase (8% at 12 months and 24% at 24 months) in the control arm.
24 Months Kaplan Meier Estimate of Survival From CDTLR.
The data indicate a correlation between primary patency and stent curvature. BioMimics 3D stented segments showed significantly greater curvature (P= 0.02) compared with the control, providing improved blood flow and elevated wall shear, which may explain the longer term patency protective effect seen with BioMimics 3D. No stent fractures were detected by the independent core lab.
The article entitled Helical Centerline Stent Improves patency: Two-Year Results From the Randomized mimics Trial, authored by Professor Thomas Zeller MD, Professor Peter Gaines MD, Gary Ansel, MD and Professor Colin Caro was published in Circulation: Cardivascular Interventions on May 20, 2016. To access the article, click here.