Modifying a patient’s dosage of the antiplatelet drug clopidogrel (Plavix®) for six months depending on the patient’s level of platelet reactivity did not result in combined lower rates of nonfatal heart attack, stent thrombosis (clot) and cardiovascular death in patients who had a procedure such as balloon angioplasty and received a drug-releasing coronary stent, according to the results of the study released in the March 16 issue of the Journal of the American Medical Association (JAMA).
First presented at the American Heart Association’s Annual Scientific Sessions in November 2010, the Gauging Responsiveness with A VerifyNow assay—Impact on Thrombosis And Safety (GRAVITAS) results refute a “one-size fits all” strategy of uniformly doubling the dose of clopidogrel 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.
“The GRAVITAS findings do not support a uniform treatment strategy for patients with high on-treatment platelet reactivity,” said Matthew J. Price, MD, of Scripps Health and Scripps Translational Science Institute 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.”
Scripps physicians Eric Topol, MD, Paul Teirstein, MD, and Curtiss Stinis, MD, are co-authors. The full article is available at: link