The benefits of drug-eluting stents in the treatment of coronary artery disease

The advent of coronary stents has been a landmark development in the treatment of coronary artery disease with percutaneous coronary intervention. Initial percutaneous treatment using balloon angioplasty alone had limited clinical efficacy due to immediate vascular elastic recoil and dissection, in addition to late negative vascular remodeling and neointimal hyperplasia. With the introduction of coronary stents, initially bare-metal stents (BMS), the problems of dissection and negative remodeling due to injury in addition to vascular elastic recoil were eliminated; however, neointimal hyperplasia remained an ongoing obstacle in the long-term efficacy of stents. Neointimal hyperplasia resulted in in-stent restenosis in 20%–30% of cases after intervention with BMS, which led to high rates of target lesion revascularization. Subsequently, drug-eluting stents (DES) were introduced, which had the added advantage of releasing an anti-proliferative drug from the stent to reduce the neointimal proliferation, thus resulting in the reduction of the rates of in-stent restenosis. Although the first-generation DES had significantly improved outcomes over its predecessor, the BMS, several challenges including stent thrombosis and delayed endothelialization of the stent remained. The second-generation DES have been significantly improved over their first-generation predecessors in regard to efficacy and safety, ie, improved long-term outcomes and significant reductions in stent thrombosis. The duration of dual antiplatelet therapy after DES has also been studied extensively in multiple large trials. A newer generation of stents, including those with bioresorbable polymers, polymer-free, and fully bioresorbable scaffolds is still in the early stages of development. Lastly, the ongoing heated comparison in multiple trials regarding the use of coronary stents vs coronary artery bypass surgery for the treatment of complex/multi-vessel coronary disease continues to evolve.