Influence of the Proton Pump Inhibitor Omeprazole on the Anti-Platelet of P2Y12 Antagonists in Subjects With Coronary and Peripheral Artery Disease

Inclusion Criteria: * Adults between 18 and 75 years of age * Known or documented history of CAD or PAD prior to enrollment (a diagnosis of CAD may be based upon a positive stress test, prior documented acute coronary event, or angiographic demonstration of CAD; a diagnosis of PAD may be based upon an ankle-brachial index less than 0.9, or angiographic demonstration of PAD) * Have not had thienopyridine therapy for at least 15 days before the study * Have not had treatment with a PPI for at least 15 days before the study * Are taking aspirin (75 to 325 mg/day) for at least one week prior to randomization Exclusion Criteria: * Have New York Heart association (NYHA) Class III and IV congestive heart failure * Have any form of coronary revascularization (PCI or coronary artery bypass grafting \[CABG\]) planned to occur during the study * Have undergone PCI or CABG within 30 days of entry to the study * Have received a drug eluting endovascular stents in the past year * Have any of the following: 1. Prior history of hemorrhagic stroke or transient ischemic attack (TIA) 2. Intracranial neoplasm, arteriovenous malformation, or aneurysm 3. A body weight less than 60 kg * Have prior history of GI ulcer disease or bleeding * Have symptoms of dyspepsia or gastroesophageal reflux disease * Have active internal bleeding or history of bleeding diathesis * Have clinical findings, in the judgment of the investigator, associated with an increased risk of bleeding * Have an International Normalized Ratio (INR) known to be \>1.5 at the time of evaluation * Have a platelet count of \<100,000/mm3 at the time of screening, if known * Have anemia (hemoglobin \[Hgb\] \<10 gm/dL) at the time of screening, if known * Are receiving or will receive oral anticoagulation or other antiplatelet therapy (other than aspirin) that cannot be safely discontinued for the duration of the study * Are receiving daily treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) that cannot be discontinued or require daily treatment with NSAIDs during the study. * Are receiving corticosteroid therapy