Double-Dose Clopidogrel (Plavix) Does Not Reduce Heart Attack or Stent Thrombosis for Angioplasty Patients with High Platelet Reactivity, Scripps Translational Science Institute Study
Published: Mar 17, 2011
First presented at the American Heart Association's Annual Scientific Sessions in November 2010, the results refute a "one-size fits all" strategy of uniformly doubling the dose of clopidogrel (Plavix®) over six months for patients with high on-treatment platelet reactivity (low response) after taking a standard dose of the commonly prescribed antiplatelet drug.
While there was a modest reduction in platelet reactivity in GRAVITAS patients receiving a 6-month double dose of Plavix compared to the standard dose, it was not sufficient to impact overall outcomes, leading the authors to suggest that more potent platelet inhibition may have been beneficial.
Further, and consistent with numerous previous studies, the trial demonstrated an association between high on-treatment platelet reactivity and the occurrence of adverse cardiac events such as death, heart attack and stent thrombosis.
"The GRAVITAS findings do not support a uniform treatment strategy for patients with high on-treatment platelet reactivity," said Matthew J. Price, MD, of the Scripps Translational Science Institute and Scripps Clinic in La Jolla, CA, lead author of the article and Principal Investigator of the GRAVITAS trial. "Rather than prescribing a fixed, higher dose of clopidogrel based on a single post-PCI platelet function test, we need to consider alternative treatment strategies that incorporate platelet function testing, such as using more potent antiplatelet agents or repeated testing to a specific target of reactivity."
The article reports that 41% of patients in the GRAVITAS trial had high on-treatment platelet reactivity after receiving Plavix®. This is consistent with previous studies that show that up to 1 in 3 patients may not be responding adequately to their antiplatelet therapy. Numerous factors are associated with low platelet response, including pre-existing health conditions such as diabetes, interference from other medications, non compliance and genetics.
"GRAVITAS underscores the need to develop more individualized treatment strategies for cardiovascular patients," said Timothy I. Still, President and CEO of Accumetrics. "As more antiplatelet treatment options become available, the VerifyNow System continues to help clinicians better assess a patient's response to therapy."
The VerifyNow System is widely used in various clinical settings where antiplatelet medications are prescribed to reduce the occurrence of future thrombotic events such as heart attack and stroke.
(1) Price MJ, Berger PB, Teirstein PS, et al. Standard- vs High-Dose Clopidogrel Based on Platelet Function Testing After Percutaneous Coronary Intervention. JAMA.2011;3051097-1105.
Accumetrics is committed to advancing medical understanding of platelet function and enhancing quality of care for patients receiving antiplatelet therapies by providing industry-leading and widely accessible diagnostic tests for rapid platelet function assessment.
Accumetrics' VerifyNow System is the first rapid and easy-to-use platform to help physicians determine an individual's response to multiple antiplatelet agents. Addressing every major antiplatelet drug, including FDA-cleared products for aspirin, P2Y12 inhibitors (e.g. prasugrel (Effient®) and clopidogrel (Plavix®)), and GP IIb/IIIa inhibitors (e.g. ReoPro® and Integrilin®), the VerifyNow System provides valuable information to help physicians make informed treatment decisions. For more information about the Company and its products, visit www.accumetrics.com.
The Accumetrics logo and VerifyNow are registered trademarks of Accumetrics, Inc. ReoPro is a registered trademark of Centocor, Inc. Integrilin is a registered trademark of Millennium Pharmaceuticals. Plavix is a registered trademark of sanofi-aventis. Effient is a registered trademark of Eli Lilly and Company.
Timothy I. Still
President and CEO Accumetrics
SOURCE Accumetrics, Inc.