Should Aspirin Be Discontinued Before Coronary Artery Bypass Surgery?

Case 1: Mr B is a 68-year-old retired steel worker who has had Canadian Cardiovascular Class III angina for the last 3 years. He has diabetes, hypertension, and hyperlipidemia, and he stopped smoking ≈5 years ago. His past medical history also includes renal insufficiency secondary to diabetic nephropathy and a mild stroke without permanent neurological deficit. Mr B had a non–ST-elevation myocardial infarction 3 months ago, and a subsequent angiogram showed severe triple-vessel coronary artery disease with preserved left ventricular function. He had been booked for coronary bypass surgery, but he was admitted to the hospital as a result of rest angina that required a nitroglycerin drip and morphine for relief. Because of his continuing rest angina while in the hospital, his cardiac surgeon decided to perform his bypass surgery on a semiurgent basis. Should Mr B continue taking his daily aspirin until the day of surgery, or should it be stopped beforehand? What does the evidence tell us about the effects of preoperative aspirin use?The 2004 American College of Cardiology (ACC) and American Heart Association (AHA) joint guidelines for CABG surgery recommend that aspirin be started within 6 to 48 hours after surgery.1 The 2004 American College of Chest Physicians (ACCP) guideline for antithrombotic therapy in patients with saphenous vein and internal mammary artery bypass grafts recommends that it be started 6 hours after surgery.2 Both guidelines state that preoperative aspirin leads to increased postoperative bleeding; ACC/AHA guidelines recommend that aspirin be discontinued 7 to 10 days before elective surgery.Almost all patients who present for coronary bypass surgery are undergoing chronic daily therapy with aspirin at a dose of 81 to 325 mg. This dose of aspirin improves survival in patients with ischemic heart disease.3 Aspirin has been shown to reduce the risk of …