Balloon expandable coronary stent materials: a systematic review focused on clinical success

Abstract

Balloon expandable coronary stenting has revolutionized the field of interventional cardiology as a potential, minimally invasive modality for treating coronary artery disease. Even though stenting is successful compared to angioplasty (that leaves no stent in place), still there are many associated clinical complications. Bare metal stents are associated with in-stent restenosis caused mostly by neointimal hyperplasia, whereas success of drug-eluting stents comes at the expense of late-stent thrombosis and neoatherosclerosis. Even though innovative and promising, clinical trials with bioabsorbable stents reported thrombosis and a rapid pace of degradation without performing scaffolding action in several instances. It should be noted that a vast majority of these stents are based on a metallic platform which still holds the potential to mitigate major cardiovascular events and reduced economic burden to patients, alongside continuous improvement in stent technology and antiplatelet regimes. Hence, a systematic review was conducted following PRISMA guidelines to assess the clinically relevant material properties for a metallic stent material. From a materials perspective, the major causes identified for clinical failure of stents are inferior mechanical properties and blood-material interaction-related complications at the stent surface. In addition to these, the stent material should possess increased radiopacity for improved visibility and lower magnetic susceptibility values for artefact reduction. Moreover, the review provides an overview of future scope of percutaneous coronary interventional strategy. Most importantly, this review highlights the need for an interdisciplinary approach by clinicians, biomaterial scientists, and interventional cardiologists to collaborate in mitigating the impediments associated with cardiovascular stents for alleviating sufferings of millions of people worldwide.

Is There an Advantage of Ultrathin-Strut Drug-Eluting Stents over Second- and Third-Generation Drug-Eluting Stents?

“…A modern stent contains four primary characteristics: its metallic platform, its strut thickness, its polymer coating thickness, and its polymer type [20]. The physical features of the stent platform play an essential role in deliverability and restenosis limitation.…”

Electrochemical and in vitro biological behaviors of a Ti-Mo-Fe alloy specifically designed for stent applications

“…However, the Ti alloys already available on the market do not meet the mechanical requirements for balloon-expandable stent applications. Indeed, the main drawbacks for the present group of alloys are their disadvantageous strength-ductility trade-off and low work hardening rate [ 7 , 12 ]. In the past ten years, several β-type Ti alloys combining different plastic deformation mechanisms have been developed [13] .…”

Drug-Eluting, Bioresorbable Cardiovascular Stents─Challenges and Perspectives

“…However, typically these coatings have no capacity to carry drugs. 11 Consequently, treatments were developed involving the implantation of drugeluting coronary stents. These devices incorporated antiproliferative drugs on the surface of the stents.…”

“…Biocompatible coatings are mostly composed of inorganic materials, including silver, gold, or carbon, and have as a principal function an increase in stent biocompatibility, serving as a barrier to ion release by metallic stents. However, typically these coatings have no capacity to carry drugs . Consequently, treatments were developed involving the implantation of drug-eluting coronary stents.…”