Optimizing vessel healing following drug eluting stent implantation with biodegradable polymer DES

The introduction of coronary drug eluting stents (DES) more than 10 years ago drastically decreased the occurrence of restenosis, compared with first generation bare metal stents (BMS). However, the optimism created by the first studies was soon shadowed by the demonstration of higher rates of late and very late stent thrombosis (ST). The research performed in this phenomenon highlighted the causative role played by incomplete stent strut coverage, hypersensitivity reactions caused by the drug eluting polymer, and neoatherosclerosis, all markers of an inadequate vascular response to DES implantation. Over the following years, new development in stent and eluting polymer technologies have been incorporated in second generation DES to optimize the process of vessel healing and, thus, to avoid these complications. Furthermore, it is envisaged that adequate vessel healing would be followed by less dependence on double antiplatelet, a limiting aspect for DES use in different clinical scenarios. In this review, we focused on the use of biodegradable eluting polymers to increase DES safety, revisiting the rationale for its use and the synergic action with other changes in stent technology aimed to optimize vessel healing after DES implantation.