Evolutionary Perspective of Drug Eluting Stents: From Thick Polymer to Polymer-Free Approach

The introduction of drug-eluting stents (DES) has remarkably altered the management of coronary artery disease by efficiently reducing the risk of restenosis after percutaneous coronary intervention (PCI). Early-generation DES were thick and had durable polymer coatings to deliver anti-proliferative agents directed against neointimal hyperplasia; however, these designs were associated with serious complications of delayed endothelial healing, chronic inflammation, and increased risk of late stent thrombosis, thereby warranting further advancement in stent technology. This review will focus on the progressive evolution of DES technologies, from thick polymer systems to thinner bioresorbable or polymer-free coatings. It will attempt to examine how these innovations have tried to overcome some of the limitations of their predecessors and what implications these developments might have for improving clinical outcomes in interventional cardiology. With the advancement in DES design came thinner strut platforms, polymers with better biocompatibility or resorbability, and polymer-free drug delivery strategies. The newer designs have shown better-endothelialization rates and, thus, reduced adverse events like late-stent thrombosis. Next-generation DES have been shown to be safe and effective in clinical trials, although further research is required to better optimize release kinetics, mechanical integrity, and long-term vascular compatibility. The evolution of DES has been driven by the desire to maximize their safety and efficacy through innovations in materials and delivery systems. A bioadaptive polymer, nanotechnology, and personalized medicine approaches may be harnessed in combination in the future to further mitigate complications and truly personalize therapy. The evolving design phase will require strong direction from ongoing research and long-term clinical studies.