Is personalized medicine cost-effective? University of Alabama at Birmingham researcher Nita Limdi, Pharm.D., Ph.D., and her colleagues across the United States have answered that question for one medical treatment.

Patients experiencing a heart attack have sharply diminished blood flow in coronary arteries, with a high risk of heart failure or death. Coronary angioplasty, a procedure to open narrowed or blocked arteries in the heart, and percutaneous coronary intervention, known as PCI or stenting, can restore blood flow to minimize damage to the heart. These procedures reduce the risk of subsequent major adverse cardiovascular events, or MACE, which include heart attacks, strokes or death.

After stenting, all patients are treated with two antiplatelet agents for up to one year. Which combination of antiplatelets is best? The answer comes through pharmacogenomics, says Limdi, a professor in the UAB Department of Neurology and associate director of UAB’s Hugh Kaul Precision Medicine Institute.

Pharmacogenomics combines pharmacology, the study of drug action, with genetics, the study of gene function, to choose the best medication according to each patient’s personal genetic makeup. This is also called precision medicine — tailored medical treatment for each individual patient.

The most commonly used antiplatelet combination after PCI is aspirin and clopidogrel, which is trademarked as Plavix. Clopidogrel is converted to its active form by an enzyme called CYP2C19. However, patients respond to clopidogrel differently based on their genetic makeup.

More than 30 percent of people have loss-of-function variants in the CYP2C19 gene that decrease the effectiveness of clopidogrel. The FDA warns that these patients may not get the full benefit of clopidogrel, which would increase the risk of MACE. So the FDA advises doctors to consider a different treatment such as prasugrel or ticagrelor, trademarked as Effient and Brillinta, to replace clopidogrel.