The study funding was dropped with no patients enrolled

African Americans with coronary artery disease who have been prescribed clopidogrel (also known as Plavix), an antiplatelet drug will be enrolled. The purpose of this study is to help identify why African Americans are at an increased risk of having a major heart attack or stroke after a common procedure to open up blocked arteries with stents. The knowledge to be gained from this study includes:

1. A better understanding of the metabolism of the antiplatelet drug, clopidogrel, and abnormal platelet function in African Americans; this understanding may provide a basis for potential future therapy
2. A better understanding of challenges to taking clopidogrel as prescribed by a doctor and opinions about a genetic test related to this medicine.

Inclusion Criteria:

1. 18 years of age or older
2. Sex: Male and Female
3. Race: Self-identified as African American
4. History of percutaneous coronary intervention in the past 12 months
5. Currently taking aspirin and clopidogrel for at least one month and up to one year
6. English speaking

Exclusion Criteria:

1. Use of nonsteroidal anti-inflammatory drugs
2. Pregnancy will be excluded in women of child-bearing potential using urine pregnancy test

Participant population will be recruited from routine care clinic/physician visits