Cardiac stenting and catheterization patients at the University of Maryland Medical Center (UMMC) and Baltimore VA Medical Center are now undergoing genetic tests to better shape their post-treatment options and decisions.The patients are being tested for variations in the CYP2C19 gene, which can lead to different rates of metabolization of clopidogrel, a widely used anti-clotting drug marketed as Plavix. It is suspected that as many as a quarter of the U.S. population has a gene variant that makes them react differently to standard dosages of Plavix. “Knowing a patient’s genotype is helping us to make more informed decisions for our patients,” said Mark R.Vesely, M.D., a cardiologist who practices at both hospitals and also teaches at the University of Maryland’s School of Medicine. “A combination of aspirin and clopidogrel is the routine choice of medications many physicians will prescribe for their stent patients. But patients who are likely to have a poor or moderate response may be better protected by other medications or possibly a higher dose of clopidogrel. It comes down to what is best for each patient.” The CYP2C19 test ranges in price from about $200 to $500. It is being offered free to the UMMC and VA patients as part of a National Institutes of Health initiative analyzing the efficacy of genetic testing programs. “We plan to share lessons learned . . . to develop best practices for implementation of pharmacogenetics in everyday clinical practice. We are putting together a toolbox that will be useful to other institutions,” said Alan R. Shuldiner, M.D., associate dean for personalized medicine and director of the personalized and genomic medicine project at the UM medical school. There has been some controversy regarding the medical efficacy of the CYP2C19 test. Shuldiner was lead author of a 2009 study published in the Journal of the American Medical Association that linked variations in the gene to reduced effectiveness in the use of Plavix—research that led to the Food and Drug Administration issuing an advisory. However, the American Heart Association and American College of Cardiology have said there isn’t enough evidence to support genotyping.