Gene Variant Associated with Diminished Effects of Clopidogrel in PCI Patients After One Year


April 9, 2009

April 9, 2009 - According to research presented last week at ACC, patients with the CYP2C19*2 genotype had more ischemic events in the one year following percutaneous coronary intervention (PCI).

A study was undertaken to link patients’ non-responsiveness to clopidogrel to the genetic variability of the Cytochrome P450 gene, or CYP2C19. The relation of the CYP2C19*2 variant to platelet function was measured through ADP-induced platelet aggregation and one-year cardiovascular outcomes in 227 patients using clopidogrel following traditional post-PCI procedures used to treat coronary heart disease. It was determined that those patients with the CYP2C19*2 genotype did in fact have more ischemic events in the one year following PCI.

The CYP2C19*2 variant is present in about 30 percent of the general U.S. population.

“This knowledge may enable physicians for the first time to improve individual antiplatelet management by a diagnostic approach utilizing platelet function or genetic testing,” said Paul A. Gurbel, M.D., lead author from the University of Maryland School of Medicine in Baltimore, Maryland. Patients with high platelet reactivity already on clopidogrel therapy may be offered alternative P2Y12 inhibitors that are either not prodrugs or a thienopyridine not highly dependent on CYP2C19 for metabolic activation. Alternatively, prior to institution of clopidogrel therapy, genetic testing may also lead to more selective use of these alternative agents.”

Dr. Gurbel presented the study “Influence of CYP2C19 Polymorphism on Antiplatelet Effects of Clopidogrel and Long-Term Recurrent Ischemic Event Occurrence” during the ACC in Orlando, FL.

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