Should clopidogrel be stopped prior to urgent cardiac surgery?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether clopidogrel should be stopped prior to urgent cardiac surgery. Altogether 143 papers were identified using the below mentioned search and all major international guidelines were included. Fourteen presented the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group, relevant outcomes and weaknesses were tabulated. We conclude that there are two issues to address when considering this topic. Firstly, whether recent clopidogrel administration causes an increase in blood loss during cardiac surgery, and secondly, whether there is a risk to the patient of withholding clopidogrel and delaying surgery. In answer to the first issue, a meta-analysis of 11 cohort studies and also many additional papers have clearly shown recent clopidogrel administration within 5-7 days of surgery is associated with an increased chest drainage of 30-100%, an increase in blood product usage, and a 2-5 times increase in the need for re-exploration. In answer to the second issue, data from the major trials that provide the basis for the current era of clopidogrel therapy also suggest that witholding clopidogrel prior to a revascularization procedure is associated with a 1% increase in the risk of myocardial infarction. Despite this small increased risk, The American College of Cardiology recommend witholding clopidogrel for 5-7 days when clinically feasible.