The aim of the present study is to investigate the effects of evolocumab in addition to statin therapy on platelet reactivity in patients with acute coronary syndrome (ACS) while on Ticagrelor and Aspirin treatment.

Ticagrelor is a commercially available antiplatelet adenosine diphosphate (ADP) antagonists. They exert their antiplatelet effects by binding to P2Y12 receptors on the platelet surface. Ticagrelor is used in combination with aspirin to prevent and treat thrombosis in patients with acute coronary syndrome, particularly after stent implantation.

Aspirin has an established role in the treatment of ACS and secondary prevention of ischaemic heart disease. Aspirin inhibits cyclo-oxygenase (COX) enzymes by irreversible acetylation to block platelet aggregation.

Evolocumab is a monoclonal antibody targeting proprotein convertase subtilisin/kexin type 9 (PCSK9). The use of evolocumab significantly reduced the incidence of cardiovascular events compared to statins alone. Whether the reduction in cardiovascular events is due to LDL reduction or other mechanisms is currently unclear.

Inclusion Criteria:

1. Patients were diagnosed as acute coronary disease
2. On therapy with Ticagrelor(90mg bid) and Aspirin(100mg qd), for at least 5 days.
3. Fasting LDL-cholesterol ≥70 mg/dL or a non-high-density lipoprotein cholesterol (HDL-C) of ≥100 mg/dL after ≥4 weeks of optimized stable lipid-lowering therapy with maximally tolerated dose of statin.
4. Have not used Evolocumab in 30 days.

Exclusion Criteria:

1. On treatment with any oral anticoagulant.
2. On treatment with any antiplatelet agent other than Aspirin and Ticagrelor in the past 5 days.
3. Creatinine clearance <30 mL/minute.
4. Known severe hepatic impairment.
5. History of a serious hypersensitivity reaction to evolocumab
6. Hemodynamic instability
7. Pregnant and breastfeeding women.

Patients from the first affiliated hospital of Harbin Medical University.