萝莉社

Blood thinning medications prevent cells in the body called platelets from sticking together that would lead to a clot and subsequent heart attacks. Dual blood thinning therapy with aspirin and clopidogrel is considered the standard when a stent is placed not in the setting of a heart attack. However, some clinical and genetic characteristics are associated with lower likelihood of adequate response to clopidogrel, increasing the risk of heart attacks and other complications. Ticagrelor (Brilinta®) is a blood-thinning medication which is more potent than clopidogrel and provides better protection than clopidogrel in subjects receiving a stent in the setting of a heart attack. Ticagrelor at a lower dose (60 mg twice a day) is also beneficial in subjects considered at high risk.

However, there are no studies which have compared these two at the same time: low-dose ticagrelor versus clopidogrel in subjects considered to be at high risk after stent due to genetic and clinical factors.

Therefore, the purpose of this study is to compare the effects of ticagrelor and clopidogrel on how platelets stick together in subjects considered to be at high risk after stent due to genetic and clinical factors.

Inclusion criteria:

1. Males or females of age ≥ 18 years old
2. Stable CAD, defined as troponin-negative patients undergoing elective PCI or patients more than 12 months following an acute coronary syndrome.
3. On treatment with low-dose aspirin (81mg od) and clopidogrel for at least 24 hours
4. Available CYP2C19 genetic test
5. ABCD-GENE score (³10)
6. Able to provide written informed consent

* Troponin negative will be defined as hs-cTn below the URL for the laboratory (Male < 22 ng/L; Female < 14 ng/L) or modestly positive hs-cTn (Male: 22-99 ng/L; Female: 14-99 ng/L) flat or decreasing from hour 0 to 3.

† If troponin is unknown before coronary angiography and no clinical signs of acute coronary syndrome is present, a troponin will not be collected as this is line with standard practice.

Exclusion criteria:

1. Acute coronary syndrome in the previous 12 months;
2. On treatment with prasugrel or ticagrelor;
3. Documented hypersensitivity to clopidogrel;
4. Use of an intravenous antiplatelet therapy (i.e., cangrelor or GPI) in the prior 24 hours;
5. Concomitant therapy with strong CYP3A4 inhibitors or CYP3A4 substrates;
6. Use of oral anticoagulant therapy;
7. History of previous intracerebral bleed at any time;
8. Active pathological bleeding;
9. Documented hypersensitivity to ticagrelor;
10. Increased risk of bradycardic events (e.g., known sick sinus syndrome, second or third degree AV block or previous documented syncope suspected to be due to bradycardia) unless treated with a pacemaker;
11. Known severe liver disease;
12. Known platelet count <80x106/mL;
13. Known hemoglobin <9 g/dL;
14. Women of child-bearing potential (i.e., those who are not chemically or surgically sterilized or who are not post-menopause) who are not willing to use a medically accepted method of contraception that is considered reliable in the judgment of the investigator OR who have a positive pregnancy test at enrollment or randomization OR women who are breast-feeding.
15. Inability to provide written informed consent.