Kohei Wakabayashi, Rajbabu Pakala, Michael Mahmoudi, Takuya Watanabe, Hiroyoshi Mori, Yoshitaka Iso and Hiroshi Suzuki
As compared with bare metal stents (BMS), Drug-eluting stents (DES) have dramatically reduced the incidence of target lesion revascularization and neointimal formation. There are, however, potential toxic effects of DES upon arterial tissue. Previous pathological studies have indicated that durable polymers and the drug itself play critical role in delayed endothelialization, persistent inflammation, hypersensitivity, apoptosis, necrosis, and positive remodeling leading to adverse cardiovascular events. To address these issues, new generation DES, biodegradable polymers, polymer-free and fully bioabsorbable scaffolds are currently in evolution. This review summarized the clinical trials that have assessed the feasibility and efficacy of new generation DES. A number of pivotal trials have also demonstrated the non-inferiority of biodegradable polymer or polymer-free DES to durable polymer DES in terms of clinical outcomes and angiographic in-stent late loss, although long-term follow-up data remain sparse. Fully absorbable DES has also provided promising results in selected populations and requires sufficiently powered randomized studies to assess their safety and efficacy.