 The follow up period will be up to 2 years. During the follow up period, treatment with aspirin or clopidogrel will be given as needed and platelet function will be assessed after any change in the antiplatelets therapy. Patients who are being treated with aspirin, will continue to take the medication with no dose change unless they will have acute cardiovascular event or active bleeding. Patients will be treated with antihypertensive therapy, erythropoietin, calcium, vitamin D and other medications as needed. 