There is conflicting evidence in the literature suggesting that the use of proton pump inhibitors (PPIs), and/or some statins can interfere with clopidogrel antiplatelet effect and result in adverse cardiovascular outcomes in patients treated with coronary artery stents and dual antiplatelet therapy.

The primary aim of the study is to determine the effect of various currently used PPI on platelet aggregation in patients undergoing percutaneous coronary intervention (PCI) and treated with dual antiplatelet therapy.

The secondary aim of the study is to evaluate how statins and 2C19*2 polymorphism modulate the effect of PPI on clopidogrel efficacy.

Inclusion Criteria:

• Subject must be 18 years of age or older
• Bare metal stent implantation
• Discharged with dual antiplatelet therapy for at least 60 days
• Written informed consent

Exclusion Criteria:

• Patients who do not consent to participate in the study
• Premenopausal women not using contraceptive methods or without a negative pregnancy test in the past week
• Patients treated or planned to be treated with oral anticoagulants
• Present treatment with or clear indication for treatment with a PPI or H2 antagonists
• Allergy or intolerance to study medications including ranitidine, Proton pump inhibitors, atorvastatin, rosuvastatin, aspirin and/or clopidogrel
• Patient treated with a strong CYP2C19 interacting drug
• History of a bleeding diathesis, or evidence of active abnormal bleeding within 30 days before enrollment
• History of intracranial hemorrhage or intracranial surgery in the last 3 months
• History of gastro-intestinal ulcers in the last 3 months
• Any serious illness or any condition that the investigator feels would influence the impact of this therapy on the subject
• Known platelet count < 100000/mm3 at time of enrollment or within 24 hours prior to enrollment