Designing Better Cardiovascular Stent Materials: A Learning Curve

Cardiovascular stents are life‐saving devices and one of the top ten medical breakthroughs of the 21st century. Decades of research and clinical trials have taught us about the effects of material (metal or polymer), design (geometry, strut thickness, and the number of connectors), and drug‐elution on vasculature mechanics, hemocompatibility, biocompatibility, and patient health. Recently developed novel bioresorbable stents are intended to overcome common issues of chronic inflammation, in‐stent restenosis, and stent thrombosis associated with permanent stents, but there is still much to learn. Increased knowledge and advanced methods in material processing have led to new stent formulations aimed at improving the performance of their predecessors but often comes with potential tradeoffs. This review aims to discuss the advantages and disadvantages of stent material interactions with the host within five areas of contrasting characteristics, such as 1) metal or polymer, 2) bioresorbable or permanent, 3) drug elution or no drug elution, 4) bare or surface‐modified, and 5) self‐expanding or balloon‐expanding perspectives, as they relate to pre‐clinical and clinical outcomes and concludes with directions for future studies. As materials processing and knowledge increase, newer stents are developed to meet the needs of patient health. A contrast of these materials shows bare‐metal stents suffer from restenosis, DES suffer from strut protrusion/malapposition, bioresorbable materials can suffer from weak mechanical properties, surface‐functionalization may risk late complications from permanent caging, and self‐expanding stents are not suitable for heavily calcified plaques.