Platelet Aggregation During the Shift From Clopidogrel to Ticagrelor (SHIFT-OVER)

Antiplatelet therapy with ticagrelor is currently indicated for treatment of patients presenting with acute coronary syndrome. Such therapy is started with the administration of a loading dose in patients which are not yet under treatment with P2Y12 inhibitors (antiplatelet agents). However it is unknown whether a loading dose is needed to maintain a satisfactory inhibition of platelet aggregation in patients who are already treated with a previous generation P2Y12 inhibitor (clopidogrel) during the passage to the newer compound ticagrelor. For this reason aim of the present study is to evaluate the levels of platelet aggregation during the pharmacological shift from clopidogrel to ticagrelor performed with or without a loading starting dose of the newer drug.

• Drug: loading with Ticagrelor
  Patients allocated in the two study arms will receive the same anti platelet treatment, except for the administration of the loading dose, which will be only administered to patients allocated in Group 2
• Drug: no loading with Ticagrelor

  Patients allocated in the two study arms will receive the same anti platelet treatment, except for the administration of the loading dose, which will be only administered to patients allocated in Group 2.

  In other words, patients randomized to this group (group 1) will not receive a loading dose of ticagrelor during the passage from clopidogrel to ticagrelor.

• Group 1 (no loading)
  Patients allocated to this group will not receive a loading dose of ticagrelor. In other words, clopidogrel 75 mg/die will be administered until the day before the pharmacological shift (study start), while ticagrelor 90 mg bis in die will be administered from the day of the pharmacological shift on.
  Intervention: Drug: no loading with Ticagrelor
• Group 2 (loading)
  Patients allocated to this group will receive a loading dose of ticagrelor. In other words, clopidogrel 75 mg/die will be administered until the day before the pharmacological shift (study start). On the very day of the pharmacological shift, patients allocated in Group 2 will receive Ticagrelor 180 mg (loading dose) on the morning and Ticagrelor 90 mg on the evening, while ticagrelor 90 mg bis in die will be administered from the day after the pharmacological shift on.
  Intervention: Drug: loading with Ticagrelor

Inclusion Criteria:

• Acute Coronary Syndrome
• Current dual anti platelet treatment with ASA and Clopidogrel

Exclusion Criteria:

• No coronary revascularization within the previous six months
• Ongoing therapy with ticagrelor, prasugrel or ticlopidine before enrollment
• No treatment with glycoprotein IIb/IIIa inhibitors within the previous 6 days
• Patients which are known to be no responders to Clopidogrel
• Known neoplastic or autoimmune disease
• Liver cirrhosis
• Severe pulmonary disease
• Known disorder of Haemostasis
• Previous Stroke
• Ongoing pregnancy
• Therapy with any inhibitor of P450 Cytochrome until 15 days before enrollment
• Low platelet count or Hb<10 g/dl