CHD is the leading cause of death in the United States. Anti-platelet agents lessen platelet aggregation and are used commonly to prevent recurrent CHD events. Two of the most common anti-platelet agents are aspirin and clopidogrel. However, up to 25% to 30% of people do not respond to these medications. Evidence indicates that treatment response may be related to genetics. The purpose of this study is to determine specific gene variants that predict response to aspirin and clopidogrel therapy.~This study is part of a larger group of studies called the Pharmacogenomics Research Network (PGRN). Participants will include the Old Order Amish of Lancaster, Pennsylvania. They are well suited for genetic studies because they are a homogenous, closed, founder population. Participants will receive 300 mg of clopidogrel on the first day, then 75 mg of clopidogrel per day for the next 6 days. On the last day of clopidogrel treatment, participants will take a single dose of 324 mg aspirin. Participants will undergo platelet function tests before and after clopidogrel alone, and then again after taking clopidogrel plus aspirin. Using the gene variation profiles across the genome, researchers will analyze which genes correspond to treatment response.
One of the most common ways for preventing coronary heart disease (CHD) is to take aspirin or clopidogrel. However, studies have shown that not all people respond to these medications. The variance in treatment response may be linked to genetics. This study will examine the effects of aspirin and clopidogrel in a population whose genes are well known in order to determine the role that genes play in treatment responses.