We sought to demonstrate the safety and performance of the actinomycin D-coated Multilink-Tetra stent(Guidant Corp., Santa Clara, California) in the treatment of patients with single de novo native coronary esions. Drug-eluting stents (DES) releasing sirolimus or paclitaxel dramatically reduce restenosis. The anti-proliferative drug, actinomycinD,which is highly effective in reducing neointimal proliferation in preclinical studies, was selected for clinical evaluation. The multi-center, single-blind, three-arm ACT inomycin-eluting stent Improves Outcomes by reducing Neointimal hyperplasia(ACTION) trial randomized 360 patients to receive a DES(2.5 or 10 μg/cm2 of actinomycin D) or metallic stent(MS). The primary end points were major adverse cardiac events(MACE) at 30 days, diameter stenosis by angiography, tissue effects, and neointimal volume by intravascular ultrasound(IVUS) at six months. When early monitoring revealed an increased rate of repeat revascularization, the protocol was amended to allow for additional follow-up for DES patients. Angiographic control of MS patients was no longer mandatory. The biased selection of DES patients undergoing IVUS follow-up invalidated the interpretation of the IVUS findings. The in-stent late lumen loss and that at the proximal and distal edges were higher in both DES groups than in the MS group and resulted in higher six-month and one-year MACE (34.8%and 43.1%vs. 13.5%), driven exclusively by target vessel revascularization without excess death or myocardial infarction. The results of the ACTION trial indicate that all anti-proliferative drugs will not uniformly show a drug class effect in the prevention of restenosis. We sought to demonstrate the safety and performance of the actinomycin D-coated Multilink-Tetra stent (Guidant Corp., Santa Clara, California) in the treatment of patients with single de novo native coronary esions. Drug-eluting stents (DES) releasing sirolimus The anti-proliferative drug, actinomycin D, which is highly effective in reducing neointimal proliferation in preclinical studies, was selected for clinical evaluation. The multi-center, single-blind, three-arm ACT inomycin-eluting stent improves Outcomes by reducing Neointimal hyperplasia (ACTION) trial randomized 360 patients to receive a DES (2.5 or 10 μg / cm2 of actinomycin D) or metallic stent (MS). The primary end points were major adverse cardiac events (MACE) at 30 days, diameter stenosis by angiography, tissue effects, and neointimal volume by intravascular ultrasound (IVUS) at six months. When early monitoring revealed an increased rate of repeat revascularization, the protocol was amended to allow for additional follow-up for DES patients. The biased selection of DES patients undergoing IVUS follow-up invalidated the interpretation of the IVUS findings. The in-stent late lumen loss and that at the proximal and distal edges were higher in both DES groups than in the MS group and resulted in higher six-month and one-year MACE (34.8% and 43.1% vs. 13.5%), driven exclusively by target vessel revascularization without excess death or myocardial infarction. The results of the ACTION trial indicate that all anti-proliferative drugs will not uniformly show a drug class effect in the prevention of restenosis.