Point-of-Care Test Permits Tailoring of Antiplatelet Therapy

Platelet reactivity was assessed 1 week later with the VerifyNow P2Y12 assay (Accumetrics), and patients were defined as having high reactivity if their result exceeded 234 platelet reactive units. Additionally, *2 carrier status was assessed among patients in the standard therapy group at that time.

Trial results showed that *2 carriers were significantly less likely to have high platelet reactivity at 1 week if they received point-of-care testing plus prasugrel therapy than if they received standard clopidogrel therapy (0% vs. 30.4%).

Additional analyses showed that relative to the conventional laboratory genetic test, the rapid point-of-care test had 100% sensitivity and 99.4% specificity for identifying *2 carriers.

"There was no difference in clinical events between the two arms," Dr. So reported; however "there was a numerical increase in bleeding among patients on the rapid genotyping arm, compared to the standard therapy arm."

He acknowledged the numerous genetic influences on clopidogrel response and their interaction, and noted that the rapid point-of-care testing device is being improved in this regard. "There is a second study now of the three-SNP [single-nucleotide polymorphism] device, so we will be able to look at multiple SNPs at the same time in the future," he said.

Dr. So reported that he receives grant or research support from Spartan and is a consultant to, speaker for, or receives honoraria from Daiichi-Sankyo/Eli Lilly. Dr. Gurbel reported that he is a consultant to, speaker for, or receives honoraria from Merck/Schering Plough, Portola Pharmaceuticals, Bayer/Pozen, AstraZeneca, and Daiichi-Sankyo/Eli Lilly.