This study aims to evaluate the impact on myocardial reperfusion and residual thrombotic burden of adding Cangrelor -a potent and immediate P2Y12 inhibitor- to ticagrelor in primary PCI patients with high on ticagrelor platelet reactivity compared to standard of care with ticagrelor alone.

Despite the use of potent P2Y12 inhibitor such as ticagrelor, half of the patients presented high platelet reactivity (HPR) at the time of primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI). HPR has been associated with impaired myocardial reperfusion. Myocardial reperfusion, assessed using myocardial blush grade, is a strong prognostic factor associated with infarct size and mortality. Antiplatelet therapy intensification using a potent and immediate P2Y12 inhibitor such as Cangrelor according a point-of-care platelet function test has not been studied in the acute phase of STEMI.

This study aims to evaluate the impact on myocardial reperfusion and residual thrombotic burden of adding Cangrelor to ticagrelor in primary PCI patients with high on ticagrelor platelet reactivity compared to standard of care with ticagrelor alone.

Inclusion Criteria:

• patient admitted for STEMI within 24 hours from symptom onset
• pretreated with ticagrelor, aspirin and enoxaparin (according local protocol)
• successfully treated by primary PCI of a native coronary culprit lesion
• anatomy accessible to optical coherence tomography (OCT or OFDI)

Exclusion Criteria:

• cardiogenic shock
• stent restenosis or thrombosis
• use of glycoprotein IIb/IIIa inhibitors before or during PCI
• known coagulation disease
• high bleeding risk (thrombocytopenia <100,000/dL, surgery <30 days, active bleeding)
• uncontrolled arterial hypertension (>180/110 mmHg)
• history of stroke (ischemic or hemorrhagic) or transient ischemic attack
• known severe renal insufficiency (eGFR <30 ml/min)
• oral anticoagulation