NEW YORK (Reuters Health) – For patients with high platelet reactivity after percutaneous coronary intervention, treatment with a high-dose clopidogrel regimen does not improve outcomes compared with standard therapy, according to a report in the Journal of the American Medical Association for March 16.

The findings come from the GRAVITAS trial. The authors note that patients with high on-treatment platelet reactivity while receiving clopidogrel are at increased risk of cardiovascular events after PCI. The trial investigated whether such patients, identified with the VerifyNow point-of-care platelet function assay, would fare better with a high daily dose of clopidogrel compared with the standard dose.

The trial involved 2214 patients at 83 centers in North America who underwent PCI with a drug-eluting stent and had high-on-treatment platelet reactivity 12-24 hours after the procedure. They were randomized to high-dose clopidogrel (600-mg initial dose, 150 mg daily thereafter) or standard-dose clopidogrel (no additional loading dose, 75 mg daily) for 6 months.

The primary end point of death from cardiovascular causes, nonfatal MI, or stent thrombosis, occurred in 25 patients in both arms of the study, report Dr. Matthew J. Price with the Scripps Clinic in La Jolla, California, and colleagues.

The outcome was identical despite a reduced rate of high platelet reactivity at 30 days with high-dose clopidogrel (40%) compared with standard-dose clopidogrel (62%), according to the report.

On the upside, bleeding rates were no worse with the high-dose treatment than with standard dosing.