The Journal of the American Medical Association has published the results of a retrospective observational study that aimed to assess the rate of death and acute myocardial infarction after stopping clopidogrel in patients with acute coronary syndrome (ACS). Pulse Magazine has reported this study.
The study reviewed data for 3,137 patients with ACS discharged from 127 American hospitals between October 2003 and March 2005. The main outcome was the rate of all-cause mortality or acute myocardial infarction (AMI) after stopping treatment with clopidogrel.
The results were analysed for those patients who were medically treated and those who underwent percutaneous coronary intervention (PCI) separately. Average treatment duration was 302 days (SD 151 days) in medically treated patients and 278 days (SD 169 days) in PCI-treated patients.
Death or AMI occurred in 17.1% of the medically treated patients with 60.8% of these events happening within 90 days of stopping clopidogrel. The same outcome occurred in 7.9% of the PCI-treated patients with 58.9% occurring within the first 90 days.
It has already been suggested that treatment with clopidogrel should be extended, tapered gradually or bridged with alternative antiplatelet therapies. However, the study did not identify reasons for treatment cessation with clopidogrel and examined all-cause mortality rather than cardiovascular mortality and the data may therefore contain some inherent and unexplained bias.
The authors of the study conclude that, "additional studies are needed to confirm the clustering of events" and "to identify strategies to reduce early events after clopidogrel cessation".