GRAVITAS Trial finds high dose of clopidogrel does not reduce risk of ischemic events

Nov 19 2010

Accumetrics, Inc., developer and marketer of the VerifyNow® System, today announced that the GRAVITAS (Gauging Responsiveness With A VerifyNow Assay-Impact On Thrombosis And Safety) Trial found that in patients with high residual platelet reactivity, doubling the maintenance dose of clopidogrel did not reduce the risk of further ischemic events after percutaneous coronary intervention (PCI). The study also reported that patients with high residual platelet reactivity, as measured by the VerifyNow P2Y12 test, demonstrated almost twice the risk of ischemic events compared to patients without high residual platelet reactivity. The VerifyNow P2Y12 Test is used to measure the antiplatelet effect of medications such as clopidogrel or prasugrel (Plavix® and Effient®) that reduce platelet reactivity by blocking the platelet P2Y12 receptor.

Matthew J. Price, MD, of the Scripps Translational Science Institute and Scripps Clinic in La Jolla, CA, and Principal Investigator of the GRAVITAS trial, presented the results during the American Heart Association Scientific Sessions Late-Breaking Clinical Trials in Chicago. "The GRAVITAS findings do not support a uniform treatment strategy of high dose clopidogrel in patients with high residual platelet reactivity based upon a single platelet function test after stent implantation. This is important as currently many physicians utilize a strategy of doubling the dose of clopidogrel the morning after the stent procedure," commented Dr. Price. "Alternative therapies or testing a patient multiple times to treat to a specific target of reactivity deserve consideration."

"The GRAVITAS trial provides further evidence of the association between high residual platelet reactivity, sometimes referred to as non-responsiveness, and the occurrence of cardiovascular events. The trial demonstrated a strong trend towards greater risk of ischemic events in non-responders, which is consistent with prior reports," commented Jeffrey R. Dahlen, PhD, Vice President of Clinical and Regulatory Affairs for Accumetrics. "As we further analyze the data, we expect to release additional information that continues to support the value of platelet function testing."

"GRAVITAS continues to position Accumetrics as a diagnostic leader that invests in furthering clinical understanding of individualized treatment for cardiovascular patients," said Timothy I. Still, President and CEO of Accumetrics. "This trial highlights the importance of continually assessing response to antiplatelet therapy as physicians consider various treatment strategies."

The VerifyNow System is the first rapid and easy-to-use point-of-care system for measuring platelet reactivity to multiple antiplatelet agents. The 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. Clopidogrel is an oral antiplatelet agent sold under the brand name Plavix.