New drug-eluting stent concepts.

Drug-eluting stents (DES) have revolutionized interventional cardiology. The first bare-metal stents successfully prevented abrupt artery closure and reduced the likelihood of clinical restenosis compared with balloon angioplasty. They were, however, limited by the frequent occurrence of restenosis owing to smooth muscle proliferation, and resultant neointimal hyperplasia and target lesion revascularization. By coating stents with drugs that target smooth muscle cell proliferation, it has been possible to considerably attenuate in-stent restenosis. This innovative technology still has shortcomings, however, and novel approaches are needed to improve the safety and efficacy of DES. The main components that determine the performance of a stent are the stent backbone, active drug, polymer and delivery system, and each of these factors need to be examined to optimize DES platforms. Improvements include the use of new coating technologies, bioabsorbable stents, non-drug-based stent coatings, and tailored lesion therapy. Efforts to develop this technology further will greatly enhance the outcome for patients with coronary artery disease.