Rationale: Dual antiplatelet therapy, consisting of aspirin and a P2Y12-inhibitor, reduces the risk of stent-related and non-stent-related ischemic events after percutaneous coronary intervention (PCI). However, this therapy is also associated with a higher risk of bleeding. Given the advances in stent technology and pharmacology, it may be possible to treat patients undergoing PCI with low dose prasugrel as single antiplatelet therapy, regardless of medical history, age or body weight.

Objective: Assess the feasibility and safety of a single antiplatelet strategy with a reduced dose of prasugrel 5 mg after PCI in acute and chronic coronary syndrome patients (ACS and CCS).

Study design: Open-label, single-centre, randomized controlled trial.

Study population: Patients undergoing successful PCI due to acute or chronic coronary syndrome.

Intervention: A once-daily reduced dose of 5 mg prasugrel for 6 months in CCS patients and for 12 months in ACS patients, preceded by a loading dose of 60 mg prasugrel after PCI, administered without concomitant use of aspirin.

Main study parameters/endpoints: The primary endpoint is Net Adverse Clinical Events (NACE), a composite of all-cause death, myocardial infarction, definite stent thrombosis, ischemic stroke, clinically relevant non-major bleeding or major bleeding defined as Bleeding Academic Research Consortium type 2, 3 or 5.

Inclusion Criteria:

• Acute Coronary Syndrome
• Chronic Coronary Syndrome
• Successful PCI

Exclusion Criteria:

• Known allergy or contraindication for prasugrel, including Active pathological bleeding Severe liver disease (defined as Child Pugh class C)
• Current indication for oral anticoagulant therapy (OAC)
• Indication for ongoing DAPT (e.g. PCI ≤ 6 months for CCS or ACS ≤ 12 months)
• Pregnancy or breast-feeding women
• Participation in another trial with an investigational drug or device
• Recent or ongoing use of CYP2B6 substrates with a narrow therapeutic window (e.g. cyclophosphamide, efavirenz)