NEW YORK (Reuters Health) - Among medically treated patients with acute coronary syndrome (ACS), prior clopidogrel therapy appears to be associated with more cardiovascular events, researchers have found.
As Dr. Chee Tang Chin told Reuters Health by email, "We found that among patients who were admitted for an acute coronary syndrome and did not undergo coronary revascularization, those patients who were already taking clopidogrel were at a higher risk for a subsequent
cardiovascular event, as compared to patients not taking clopidogrel on admission."
The study, a prespecified subanalysis of the TRILOGY ACS trial, was published online March 30 in Heart.
Of almost 9,000 patients, 73% first received clopidogrel in-hospital within 72 hours of presentation and daily until randomization to clopidogrel versus prasugrel (plus aspirin). The remaining 27% were taking clopidogrel prior to admission and continued daily clopidogrel therapy until the date of randomization.
Over 30 months, those with prior clopidogrel use had a significantly higher frequency of cardiovascular death, MI and stroke (20.8% vs. 18.3%, p=0.002). There was no significant difference in the frequency of bleeding events.
Dr. Chin pointed out that in the prior users, "This excess risk was largely accounted for by the higher burden of high-risk co-morbidities among this group, such as diabetes and prior
cardiovascular disease. However, consistent with the overall TRILOGY-ACS results, the use of a more potent antiplatelet agent such as prasugrel did not modify this risk."
"These results," Dr. Chin concluded, "are important as they imply that among ACS patients treated only medically, strategies beyond platelet inhibition need to be considered for further optimizing outcomes."