Current perspectives of biodegradable drug-eluting stents for improved safety

The introduction of the drug-eluting stent (DES) proved to be an important step forward in reducing the rates of restenosis and target lesion revascularization after percutaneous coronary intervention (PCI). However, the rapid implementation of DES in standard practice and the expansion of the indications for PCI to high-risk patients and complex lesions also introduced a new problem. DES in-stent restenosis (ISR) occurs in 3 ∼ 20% of patients, depending on the patient, lesion characteristics and the DES type. The initial commercially available DES used a stainless steel platform coated with a permanent polymer to provide a controlled release of an anti-restenotic drug. The platform, polymer and drug are all targets for improvement. More advanced metallic and fully biodegradable stent platforms are currently under investigation. The permanent polymer coating, a likely contributor to adverse events, is being superseded by biocompatible and bioabsorbable alternatives. New drugs and drug combinations are also a research goal, as interventional cardiologists and the industry strive towards a safer anti-restenotic DES. This paper reviews the benefits, risks, and current status of biodegradable drug-eluting stents.