Trial to Test Value of Genetic Tests for Heart Disease

(James. J. Caras, National Science Foundation)

The Stanford University Medical Center in California has begun a clinical trial to determine if giving patients genetic information about their risk of coronary artery disease will help motivate them to reduce that risk by changing their behavior. The study, just underway, is expected to be completed in December 2012.

The trial will test the hypothesis that patients at risk for coronary artery disease, when informed of their genetic predisposition of the disease, make changes their lifestyles and eating habits, and more closely follow prescribed drug regimens, compared with members of a control group. Coronary artery disease, also called coronary heart disease, is a narrowing of the small blood vessels that supply blood and oxygen to the heart, and is the leading cause of death in the United States.

Stanford medical faculty member Joshua Knowles, who heads the study, says the trial can help resolve the uncertainty over the value of genetic tests, since there is not enough information to advocate for such testing. At this point, says Knowles, genetic tests are no better at predicting someone’s risk of coronary disease than old-fashioned diagnostic methods, such as looking at family history and measuring such factors as age, weight, blood pressure, cholesterol levels, and diabetes status.

The Stanford team is recruiting 100 adult patients at medium to high risk for coronary disease. All enrolled patients in the trial will undergo testing for dozens of genetic markers unequivocally associated with increased susceptibility to the disease. However, only half of the participants, selected at random, will be given the results of their tests.

Participants will be expected to make three visits to Stanford Hospital during the trial, to evaluate their medical histories and undergo a physical exam. They also will receive standard care, including laboratory tests for lipids and a calculation of their risk of the disease based on traditional prediction models.

Therapy will be based on current clinical guidelines and may include recommendations related to diet, exercise and lifestyle, as well as prescribed medication.

The researchers will gauge whether patients who received genetic-test results — compared to the control group who did not receive the genetic test information — experienced improved outcomes by looking for decreases in their bad cholesterol, blood pressure, and weight, as well as whether their diet and clinical attendance improved. At the end of the trial, the control group participants will be given their genetic test results.

Read more: Consumers Want, Will Pay for Predictive Health Tests

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