The Society of Thoracic Surgeons Practice Guideline Series: Aspirin and other antiplatelet agents during operative coronary revascularization (Executive summary)

Multiple well-done studies indicate that aspirin prolongs event-free survival after myocardial infarction (MI) [1, 2]. One consequence of the widespread use of aspirin is that a majority of patients (at least 60% to 70%) who need operative coronary artery revascularization (CABG) have taken aspirin within 24 hours of operation [3]. Aspirin, and many other NSAIDS, limit platelet function by interfering with secondary platelet aggregation. Among the many actions of NSAIDS, aspirin is known to limit prostaglandin production by platelets (Table 1). One important clinical consequence of the various cellular effects of aspirin is to limit vein graft occlusion after operative coronary artery revascularization [4]. Several randomized clinical trials suggest that aspirin administered before operative coronary revascularization using cardiopulmonary bypass causes increased postoperative bleeding and blood transfusion (Table 2). This leads to the so-called "aspirin paradox." On the one hand, aspirin is beneficial (improving post-MI survival and improving graft patency), but on the other, aspirin has detrimental effects in patients who require on-pump CABG. A similar dilemma exists for many antiplatelet drugs and other beneficial agents that alter operative hemostasis. Our goal in developing these guidelines is to provide specific recommendations for managing antiplatelet medications, especially aspirin, in patients who require operative intervention. A great deal of information exists regarding the effects of aspirin in patients having operative coronary revascularization using cardiopulmonary bypass (on-pump CABG or CABG) while much less information is available concerning the effects of aspirin in patients having off-pump CABG (OPCABG). Hence almost all of the guidelines described below apply to patients having on-pump CABG. When information was available concerning patients having OPCABG, an attempt was made to include this information in the guidelines.