Preclinical studies show differences in healing responses to fractured and intact stent implanted in healthy, disease models

CBSET, a non-for-profit preclinical research institute dedicated to biomedical research, education and advancement of medical technologies, announced today that its scientists have published data and analyses ("Fracture in drug-eluting stents increases focal intimal hyperplasia in the atherosclerosed rabbit iliac artery") that "illustrate differences in the dynamic healing responses to fractured and intact stent implanted in healthy and disease rabbit models." The study is published online by Catheterization and Cardiovascular Interventions.

"Despite clinical and autopsy reports of fractures in drug eluting stents (DES), and associated risks including in stent thrombosis and restenosis, it has not been established whether stent fracture is the cause of increased neointimal response," said Claire Conway, Ph.D., first author of the article. "To test the hypothesis that coated drug at stent fracture sites accentuates neointimal response to fractures, our study employed pre-eluted stents as drug-free, yet polymer-coated, controls. The data show that stent fracture increases intimal hyperplasia post-DES implant, with increasing severity in arteries exhibiting more advanced disease."

"The accentuation of stent strut fracture-induced vascular injury by drug-eluted from the stents is intriguing - the proverbial adding salt to the wound," said Elazer Edelman, M.D., Ph.D., chairman and co-founder of CBSET, and senior author of the paper. "Time will tell how our findings for conformal polymer coated stents extend to newer stent designs that employ absorbable coatings or deploy drug microparticles away from the struts." Dr. Edelman is the Director of MIT's Institute of Medical Engineering and the Thomas D. and Virginia W. Cabot Professor of Health Sciences and Technology as well as an attending cardiologist at the Brigham and Women's Hospital. He directs the Harvard-MIT Biomedical Engineering Center (BMEC), dedicated to applying the rigors of the physical sciences to elucidate fundamental biologic processes and mechanisms of disease.

"Partnerships established nearly a decade ago with the Edelman Lab at MIT continue Enhancing Science through Collaborations with FDA," said Brian L. Baker, P.E., Director, Winchester Engineering and Analytical Center at FDA, co-author and signatory of the memorandum of understanding (MOU) between MIT and the FDA during the conduct of this study. "It gives me a great sense of pride to continue to witness advancements from partnerships with MIT contributing to FDA's mission." Baker was named "Federal Engineer of the Year" in 2011, an annual award sponsored by the National Society of Professional Engineers (NSPE) and the Professional Engineers in Government advocacy group of the NSPE.