There is growing evidence that standard dual antiplatelet therapy with acetylsalicylic acid (ASA) and clopidogrel is not as effective in the setting of therapeutic hypothermia after cardiac arrest as in normothermic patients. The reasons for this are probably slower gastrointestinal motility, absorption and liver metabolism required for clopidogrel to take action. Since ticagrelor has faster intestinal absorption and no need for liver metabolism we expect its effect to be good even in patients with therapeutic hypothermia after cardiac arrest. Patients treated with therapeutic hypothermia after cardiac arrest and percutaneous coronary intervention will be randomised into two groups. One will be treated with ASA and clopidogrel and the other with ASA and ticagrelor. Blood samples will be collected before and 2, 4, 12, 22 and 48 hours after P2Y12 inhibitor administration. Platelet function will be measured by VerifyNow P2Y12 assay and by Multiplate ADPTest. Differences between the groups will be analysed.

Hypothesis: Antiplatelet therapy with ticagrelor is more effective than therapy with clopidogrel in the comatose survivors of cardiac arrest treated with therapeutic hypothermia and percutaneous coronary intervention (PCI).

Inclusion Criteria:

• Female and male over 18 years old
• Unconscious survivors of cardiac arrest treated with therapeutic hypothermia
• Acute coronary syndrome (NSTEMI or STEMI) as a reason of cardiac arrest
• PCI with stent implantation
• Provision of informed consent prior to any study specific procedures is impossible because subjects are unconscious at the moment of inclusion

Exclusion Criteria:

• Use of any P2Y12 inhibitors in last 10 days
• Use of prasugrel before and 48 hours after loading dose of P2Y12 inhibitor
• Use of eptifibatide before and 48 hours after loading dose of P2Y12 inhibitor
• Thrombocytopenia (<50*109/L)
• Allergic reaction to acetylsalicylic acid, clopidogrel or ticagrelor
• Ticagrelor contraindications: previous intracranial bleeding, active pathological bleeding, moderate to severe hepatic impairment, heart rate < 40/min at presentation
• Suspected or confirmed pregnancy
• Use of bivalirudin before and 48 hours after loading dose of P2Y12 inhibitor

From the date of randomization until hospital discharge or death during hospitalization.

Did not address effectiveness of prasugrel. Not powered to address stent thrombosis or bleeding.