Genetic Test Could Decide If Patients Benefit From Heart Drug Clopidogrel

Genetic testing can help determine whether heart surgery patients benefit from the popular anti-platelet drug clopidogrel, which has been effective for some but carries major risks,

Genetic testing can help determine whether heart surgery patients benefit from the popular anti-platelet drug clopidogrel, which has been effective for some but carries major risks, a study published Tuesday said.

The drug is marketed under the brand name Plavix by Bristol-Meyers Squibb in the United States and Sanofi-Aventis in France.

Coronary Artery Bypass Grafting (CABG) | Coronary Artery Bypass Surgery
Coronary artery bypass grafting (CABG) or heart bypass surgery is an open heart surgery to relieve the blockages of the arteries of the heart. Coronary artery bypass surgery lasts up to 3 to 6 hours.

Clopidogrel, among the most commonly prescribed medications, has been shown to reduce cardiovascular problems in patients undergoing heart procedures like balloon angioplasty or stent placement to open narrowed coronary arteries.

But scientists said there is a great degree of variation in how patients respond to the drug, which can be predicted by a genetic test which measures the presence of a particular enzyme in the blood.

The authors of a study appearing in the Journal of the American Medical Association said that analysis of existing data suggest that the pharmacologic effect of the drug varies based on variations of the gene CYP2C19.

Clopidogrel

This medication is an anti-platelet agent, that is, a drug that inhibits the ability of platelets to clump together as part of a blood clot. This medication is prescribed either alone or with other medications for prevention or treatment of stroke and heart attack (which are usually caused by blood clots) in persons who are at high risk.

"There is a large degree of interindividual variability in the pharmaco-dynamic response to clopidogrel," wrote the authors, researchers with the Harvard Medical School and the Brigham and Women's Medical Center.

The study in the October 27 issue of JAMA analyzed data from previously published studies on the use of clopidogrel, and found that patients who have common genetic variants of a certain gene and who also undergo a coronary stent placement have an increased risk of blood clots or other heart related complication.

Cardiac Catheterization | Coronary Angiogram - Indications Preparation Procedure Risks Test FAQs
Cardiac catheterization is a radiological procedure for both diagnosis and treatment of heart conditions. It involves the insertion of a long thin flexible tube called catheter a vein or an artery to the heart.

"Common genetic variants in the CYP2C19 gene are associated with almost one in three patients not receiving ideal protection from ischemic events when treated with standard doses of clopidogrel for PCI" or percutaneous coronary intervention -- procedures such as the heart stent placement surgery, the authors of the study concluded.

"Given how widely clopidogrel is used to treat patients with cardiovascular disease, determination of the optimal antiplatelet treatment doses or regimens for individual patients is needed to tailor therapy appropriately," they wrote.

Test Your Knowledge on Heart
The heart is a fist-sized organ that pumps blood throughout the body. It is the primary organ of the human circulatory system that helps in circulation of blood throughout the body...

The research compiled nine separate studies involving 9,685 patients (of whom 91.3 percent underwent PCI and 54.5 percent had an acute coronary syndrome, the authors of the study wrote.

Source-AFP