Antiplatelet agents such as aspirin have been used for many years for the treatment of ischaemic heart disease. More recently, newer drugs such as clopidogrel have been used as single antiplatelet treatment or in conjunction with other antiplatelet drugs to reduce platelet aggregation and therefore lessen the risk of myocardial infarction before and after the insertion of coronary artery stents.^1–3 Clopidogrel is a thienopyridine derivative with a structure and mechanism of action that is distinct from other clinically available antiplatelet agents. Its primary effect appears to be inhibition of ADP induced platelet aggregation without directly affecting arachidonic acid metabolism.⁴

Intermittently patients present for coronary angiography but after imaging it is apparent that operative intervention is required instead of angioplasty despite the continuing use of clopidogrel. These patients may be at increased risk of complications from haemorrhage. In addition, patients with peripheral vascular disease who are being treated with clopidogrel and are potentially at high risk of postoperative adverse events may be referred for cardiac surgery.

Intuitive complications of such potent antiplatelets, such as postoperative haemorrhage, have potentially serious side effects, especially in patients undergoing coronary surgery. Multiple transfusions after cardiac surgery are associated with significant morbidity, mortality, and transmission of viral diseases.^5,6 Several studies have investigated the effect of clopidogrel and postoperative bleeding in patients undergoing cardiac surgery and report varying results.^7,8 No meta-analyses have been done to …