Triple Versus Dual Antiplatelet Therapy After ABT578-Eluting Stent

Use of drug-eluting stent (DES) has reduced the incidence of restenosis rate and the need for repeat revascularization compared to using bare metal stents. DES implantation also significantly reduced the angiographic restenosis in patients with long coronary lesions.However, although the use of DES has decreased the effect of lesion length on restenosis, the restenosis after DES implantation of long coronary lesions remain at a higher risk of restenosis.

Cilostazol, a phosphodiesterase III inhibitor, has been known to reduce smooth muscle proliferation and intimal hyperplasia after endothelial injury and restenosis after balloon angioplasty and bare-metal stent (BMS) implantation when compared with aspirin and clopidogrel or ticlopidine. Recently, the impact of 6-month cilostazol treatment in addition to aspirin and clopidogrel on neointimal hyperplasia after sirolimus-(SES) or paclitaxel-eluting stent (PES) implantation for long-coronary lesions has been evaluated in our institution. It reported that cilostazol treatment achieved primary end point (in-stent late loss) and reduced need of target lesion revascularization without significant adverse drug-side effects with open-label design, which suggest that 6-month treatment of cilostazol effectively inhibits the neointimal hyperplasia after DES implantation and can be safely applied to the patients or lesions with higher risk of restenosis such as diabetes and long lesions.However, our study was done in unblinded manner and might underestimate the angiographic results due to relatively short-term follow-up angiographic follow-up(6-month.

Recently commercially available new-DES, zotarolimus-eluting stent (ZES) demonstrated significant reduction of restenosis and cardiac events during 9-month. However, it has not been tested that 8-month treatment of cilostazol also effectively inhibits the neointimal hyperplasia after ZES implantation in patients with long coronary lesions. Therefore, to evaluate whether the cilostazol reduce neointimal hyperplasia after ZES implantation, the investigators performed double-blind, randomized, multicenter, prospective study compared triple antiplatelet therapy (aspirin plus clopidogrel plus cilostazol) and dual antiplatelet therapy (aspirin plus clopidogrel) for 8 months in patients with long coronary lesion treated with ZES.

Inclusion criteria

• Clinical 1) Patients with angina and documented ischemia or patients with documented silent ischemia 2) Patients who are eligible for intracoronary stenting 3) Age >18 years, <75 ages
• Angiographic 1) De novo lesion 2) Percent diameter stenosis ≥50% 3) Reference vessel size >2.5 mm by visual estimation 4) Lesion length >25 mm by visual estimation that is required for long Endeavor stent implantation (planned total stent length >30mm)

Exclusion criteria

• History of bleeding diathesis or coagulopathy
• Pregnant
• Known hypersensitivity or contra-indication to contrast agent, heparin, sirolimus and paclitaxel
• Limited life-expectancy (less than 1 year) due to combined serious disease
• ST-elevation acute myocardial infarction
• Characteristics of lesion 1) Left main disease 2) In-stent restenosis 3) Graft vessels
• Hematological disease (Neutropenia <3000/mm3, Thrombocytopenia <100,000/mm3)
• Hepatic dysfunction, liver enzyme (ALT and AST) elevation >3 times normal
• Renal dysfunction, creatinine >2.0mg/dL
• Contraindication to aspirin, clopidogrel or cilostazol
• planned bifurcation stenting