In the previous trial, 1-month dual antiplatelet therapy (DAPT) followed by clopidogrel monotherapy provided a net clinical benefit for the cardiovascular and bleeding events over 12-month DAPT with aspirin and clopidogrel after cobalt-chromium everolimus-eluting stent (CoCr-EES) implantation. However, even with very short DAPT, the rate of bleeding at 1-year remained very high in other trials that enrolled the patients with high bleeding risk (HBR). Notably, the risk of bleeding in patients with high bleeding risk (HBR) was particularly high within 1-month after percutaneous coronary intervention (PCI) in previous chort data, when DAPT is implemented even in very short DAPT regimen. More recently, in another trial, prasugrel monotherapy without aspirin immediately after successful stent implantation was associated with no stent thrombosis in selected patients with low risk stable coronary artery disease. Aspirin-free strategy might be particularly beneficial in reducing bleeding in HBR patients. Patients with acute coronary syndrome (ACS) are also reported to be associated with higher risk for bleeding.~Therefore, we have planned a study to compare the cardiovascular and bleeding events at 1-month after PCI using CoCr-EES between no DAPT strategy and 1-month DAPT strategy in patients with HBR or ACS.
The purpose of this study is to explore the benefit of the prasugrel monotherapy without aspirin as compared with the 1-month dual therapy with aspirin and prasugrel in terms of reducing bleeding events after percutaneous coroanry intervention (PCI) using cobalt-chromium everolimus-eluting stents (CoCr-EES, XienceTM) in patients with high bleeding risk or under the acute coronary syndrome patients.