Recent Advancements in Pharmacological Stent Therapy Using Polymeric Materials: Opportunities and Challenges

Percutaneous transvascular coronary angioplasty and stenting is one of the most commonly employed interventional procedures for the treatment of occlusive coronary artery disease. The common long-term complication of this treatment is re-stenosis occuring at the site of the atherosclerotic lesion following stenting. The rate of re-stenosis within 6 months could be as high as 20-30% of patients resulting in increased morbidity and tremendous costs to the health care system. The incidence has been somewhat reduced with the development of drug eluting stents, releasing drugs like paclitaxel, sirolimus, zotarolimus and everolimus with varied sustained release profiles. However the long-term benefits from large studies are still controversial and delayed onset of thrombosis is a major ongoing concern and lifelong anti-platelets therapy has been suggested clinically in patients bearing such pharmacological stents. Drug-eluting polymeric bioresorbable stent is being considered to hold immense promise to effectively address such pertinent complications mainly because of its improved biocompatibility, transient nature of supporting the intervened artery, eliminating local effect and damage of permanent metals, allowing smoother restoration of vasoreactivity and physiologic healing, and higher local drug delivery capacity in comparison to permanent metallic stents. In this article we review the current standpoint of drug eluting metallic stent, which has so long been considered as a major medical innovation in the field of pharmaceutical sciences, and its rapid evolution to pharmacological bioresorbable stent in order to promote proper vascular remodeling and achieve better risk-benefit ratio under diverse clinical challenges.