NEW YORK (Reuters Health) – Giving elderly patients with acute MI a clopidogrel loading dose of 300 mg or more rather than a lower conventional dose doesn’t increase the risk of serious bleeding. On the other hand, the higher dose does not appear to increase survival.
Those findings, from a French study, are reported in the American Journal of Cardiology online July 4 by Dr. Etienne Puymirat, with Hopital Europeen Georges Pompidou, Paris, and University Paris Descartes, and colleagues.
The authors note that data are lacking on the efficacy and safety of a loading dose of clopidogrel for elderly MI patients. They therefore examined data from a nationwide registry on more than 3000 MI patients admitted to the ICU within 48 hours of symptom onset, and identified 791 patient 75 years of age and older (mean age 81 years) given a known dose of clopidogrel.
Within this cohort, 466 patients (59%) received an loading dose of at least 300 mg clopidogrel (ranging from 300 mg in the majority up to 900 mg in one patient), and 325 patients (41%) were given a conventional dose (75 mg in most cases but up to 225 mg in some patients).
The rate of major bleeding was not significantly different in patients who received a clopidogrel loading dose (3.2%) than in those given a conventional dose (3.7%: p=0.72). Similarly, there was no significant difference in the need for blood transfusions in the two groups at 5.4% vs 6.2%, respectively (p=0.64) ), according to the report.
On logistic regression analysis, the team found that giving a loading dose rather than a conventional dose of clopidogrel did not affect mortality at 30 days (odds ratio 1.15; p=0.63) or at 12 months (hazard ratio 1.00; p=0.98). Survival free of stroke or repeat MI was also not significantly different (HR 0.92; p=0.61).
“The present data, gathered from a nationwide ‘real-world’ registry of patients admitted for AMI, indicate that in an elderly population the use of a clopidogrel loading dose at the acute stage of MI is not associated with an increase in major bleeding or a significant independent effect on mortality or hard events at 1 year,” Dr. Puymirat and colleagues conclude.
That said, they add, “Large-scale randomized trials are still needed to identify the optimal loading dose of clopidogrel for elderly patients admitted for acute MI.”
Comparison of Efficacy and Safety of a Standard Versus a Loading Dose of Clopidogrel for Acute Myocardial Infarction in Patients ?75 Years of Age (from the FAST-MI Registry)
Am J Cardiol 2011.