Acetyl Salicylic Elimination Trial JAPAN: The ASET JAPAN Pilot Study

The ASET Japan Pilot study is a multicenter, single arm, open-label trial of single antiplatelet therapy with prasugrel for patients undergoing successful and optimal Percutaneous Coronary Intervention (PCI) for Chronic Coronary Syndrome (CCS) and Non-ST elevation Acute coronary syndrome (NSTE-ACS). The enrollment consists of two phases: i) 200 patients presenting with CCS; ii) 200 patients presenting with NSTE-ACS. The patients will be loaded with standard dual antiplatelet therapy according to local practice (usually aspirin 81 to 330 mg and clopidogrel 300 mg or prasugrel 20 mg or ticagrelor 180 mg, unless patient is on long-term therapy) prior to the PCI procedure. After PCI, if the results are considered to be satisfactory by the operator based on clinical (e.g. clinical status, ECG, etc.), angiographic and/or findings from intracoronary imaging, only then patients will be enrolled in the study and loaded with prasugrel 20 mg if the patients have not loaded prasugrel prior to PCI or have not taken a maintenance dose of prasugrel before the index PCI. Patients continued with prasugrel only (3.75 mg once a day) for three months in CCS patients and for 12 months in NSTE-ACS patients. Aspirin, clopidogrel, and ticagrelor will be discontinued just after the index procedure. i. CCS patients (phase 1): At the 3-months follow-up visit, prasugrel monotherapy will be replaced by aspirin monotherapy or dual-antiplatelet therapy according to local standard of care. Clinical follow-up with office visit will be performed at 3 months and telephone contacts at 1, and 4 months (final follow-up). ii. NSTE-ACS patients (phase 2): At the 12-months follow-up visit, prasugrel monotherapy will be replaced by aspirin monotherapy for an observational period of 1 month, followed by antiplatelet treatment according to local practice. Clinical follow-up with office visit will be performed at 1 and 12 months and telephone contacts at 3, 6, 9 and 13 months (final follow-up). All events will be adjudicated by an independent clinical events committee (CEC). An independent Data Safety and Monitoring Board (DSMB) will monitor the individual and collective safety of the patients in the study during enrolment of CCS patients and up to 3 months follow-up of CCS patients, and during enrollment of NSTE-ACS patients and up to 12 months follow-up of NSTE-ACS patients (timepoint for primary endpoint).