Prasugrel may reduce cardiovascular events among patients managed medically after an angiogram for acute coronary syndrome

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 platelet inhibitor is beneficial in patients with unstable angina (UA) or non-ST segment elevation myocardial infarction (NSTEMI). Because a substantial fraction of these patients do not undergo revascularization after angiography, their optimal DAPT strategy is unknown.

The TRILOGY ACS trial compared prasugrel with aspirin versus clopidogrel with aspirin in the primary cohort of 7,243 UA/NSTEMI patients less than 75 years old who were medically managed without revascularization and had at least one high-risk criterion. The primary results of this study, presented at the European Society of Cardiology earlier this year, did not show any benefit for prasugrel with aspirin versus clopidogrel.

Patients were enrolled in 52 countries from June 2008 through September 2011 with median follow-up of 17 months. Those who weighed more than 60 kg were treated with a 10 mg maintenance dose of prasugrel versus 75 mg of clopidogrel; patients less than 60 kg received 5 mg of prasugrel.

Angiography was not required for enrollment, but if performed, evidence of coronary disease had to be demonstrated (at least one lesion > 30 percent stenosis or prior percutaneous coronary intervention/ coronary artery bypass graft surgery). Approximately 43% of the patients had angiography performed and coronary anatomy determined before being triaged to medical therapy.  

Overall, in the TRILOGY ACS Trial, prasugrel did not reduce cardiovascular events among patients managed medically for ACS.

However, when treated with prasugrel compared to clopidogrel, patients who were triaged to medical therapy in the trial following angiography tended to have:

• Lower rates of the combined endpoint of cardiovascular disease/heart attack/stroke
• Lower rates of heart attack, stroke alone, and recurrent ischemic events
• Higher rates of bleeding

"Though hypothesis-generating, these results are consistent with previous trials and suggest that when angiography is performed and coronary disease is confirmed, the benefits and risks of intensive antiplatelet therapy exist whether medical therapy or percutaneous coronary intervention is elected," said Stephen D. Wiviott, MD. Dr. Wiviott is a senior investigator with the TIMI Study Group, associate physician, Cardiovascular Division at Brigham and Women's Hospital, and associate professor of Medicine at Harvard Medical School.

The results of the TRILOGY ACS Angiographic Cohort trial will be presented on October 24 in Miami, Florida.