A September 4, 2013 release from the European Society of Cardiology congress held in Amsterdam describes data from the ARCTIC-GENE study illustrating that genotyping for metabolic polymorphisms provides no improvement in clopidogrel therapy outcomes. You can read more in this linked Heart.com article.
Category: Antiplatelet Therapy
George substituted for Dave McGlasson and presented, “Monitoring the New Antithrombotics: Whatever Happened to the PT and PTT?“ on Wednesday, April 3, 10 AM; and “Antiplatelet Therapy, Do Aspirin and Plavix Work?” on Thursday, April 3, 2:30–2:30 PM at the Great Plains Regional Laboratory Expo in Omaha Nebraska. His presentation handouts, in PDF, appear on our Audio Modules page. Thanks to all who participated in these presentations, and please feel free to post any follow-up questions or comments to George through this web site.
This is a February 18 follow-up from the individual whom I responded to in a January 30 post entitled Clopidogrel Efficacy. I had collaborated with Prof. Bernadette Rodak of Indiana University on the original email to the questioner. Here is the comment (with identification removed):
This question arrived last week in the American Society for Clinical Laboratory Science Consumer Forum: “I would like to know the differences between platelet aggregation testing and pharmacogenetic testing of CYP2C19 for clopidogrel. In 2010, the FDA issued a black box warning for clopidogrel in persons who are CYP2C19 poor metabolizers. I am very interested in what the results for both tests reveal and when these tests would be appropriate. Thank you.”
Attached to the December 28 post, “Platelet Function Testing and the Bleeding Time” with the AC Ivy story was the question, “Is the Accumetrics VerifyNow aggregometer useful for screening patients for inherited platelet function disorders?” Yes, I consider the VerifyNow assay effective in screening for platelet function defects, like storage pool disorder or platelet secretion disorder (aspirin-like syndrome), however I find no reference to this function on the Accumetrics web site, which highlights only their FDA-cleared assays for aspirin, clopidogrel, and glycoprotein IIb/IIIa inhibitor efficacy. Consequently, I have placed an inquiry with the company’s technical service department and will post their answer when it arrives.
I received this truncated communication on July 16 from Michael Suter with no follow-up, but I post it regardless, as Accumetrics’ decision to change their P2Y12 cartridge report seems to be a concern for many:
“We monitor Plavix therapy using the VerifyNow P2Y12 assay kit. Accumetrics is in the process of discontinuing the reporting of percent inhibition, leaving the PRU value as the only reported result. There is good documentation of the cutoff for effective therapy…” (message ends)
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