Current patterns of P2Y12 receptor inhibitor use provide an excellent opportunity to test the impact of copayment reduction on clinician choice of medication, patient adherence, and clinical outcomes. The ARTEMIS trial is a practical multicenter, cluster- randomized clinical trial that will assess the impact of copayment reduction by equalizing the copayment of clopidogrel and ticagrelor. ARTEMIS will assess prescribing patterns, patient medication adherence, and clinical outcomes up to one year. We hypothesize that reducing out--of--pocket cost for P2Y12 receptor inhibitor will lead to improved adherence. Additionally, copayment reduction of both generic and brand antiplatelet agents may lead to a reduction in MACE risk. This is in part due to greater adherence to an evidence--based secondary prevention medication. Additionally the reduction in MACE may reflect greater selection of a more potent antiplatelet agent that has been shown to reduce MACE in randomized clinical trials, as provider choice of antiplatelet therapy will be primarily driven by risk- benefit assessment rather than the cost burden to the patient.

ARTEMIS is a prospective, cluster-randomized clinical trial that will evaluate whether patient copayment elimination significantly influences antiplatelet therapy selection and long-term adherence, as well as patient outcomes and overall cost of care after acute myocardial infarction. Approximately 11,000 patients with ST-elevation myocardial infarction (STEMI) or non-STEMI (NSTEMI) will be enrolled at the approximately 300 hospitals in this study. Study sites selected for ARTEMIS will be geographically diverse, and will represent a diversity of hospital types and capabilities (e.g., teaching hospital, community hospital, etc). After institutional review board (IRB) approval of the study, each hospital will be randomized into either the intervention arm or the control arm. Hospitals randomized to the intervention arm will have the opportunity to offer enrolled patients either clopidogrel (generic P2Y12 receptor inhibitor option) or ticagrelor (brand P2Y12 receptor inhibitor option) without patient contribution to copayment in the next 12 months after the index MI discharge. Hospitals in the control arm will provide care per usual clinical routine. Notably, for both intervention and control arms, all patient management decisions (including the choice of antiplatelet therapy) are completely at the discretion of the care providers. Duration of antiplatelet therapy will also be at the discretion of care providers. All enrolled patients will be followed up to 15 months after index MI discharge to collect data on longitudinal treatment patterns and outcomes. Primary and secondary endpoints will be assessed at 12 months. An additional three months of follow up will assess for antiplatelet persistence and clinical events after discontinuation of the copayment intervention. Centralized follow-up will be conducted every 3 months via telephone or web-based contact.

Inclusion Criteria:

Patients are eligible to be included in the study if they meet all of the following criteria:

• are ≥ 18 years of age
• have been diagnosed with STEMI or NSTEMI during the index hospitalization
• be treated with a P2Y12 receptor inhibitor at the time of enrollment
• have U.S. based health insurance coverage with prescription drug benefit
• have been fully informed and are able to provide written consent for longitudinal follow-up

Exclusion Criteria:

Patients are excluded if they meet any of the following criteria:

• have a history of prior intracranial hemorrhage
• have any contraindications to P2Y12 receptor inhibitor therapy at discharge
• involvement in another research study that specifies the type and duration of P2Y12 receptor inhibitor use within the next 12 months.
• have a life expectancy of less than one year
• have plans to move outside the US in the next year

Registry Site shall submit to the Committee for its review a copy of any proposed publication resulting from the Registry at least thirty (30) days prior to the date of submission for publication or at least fifteen (15) days prior to submission for an abstract, and if no response is received within sixty (60) days of the date submitted to Sponsor, it will be conclusively presumed that the publication may proceed without delay.