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Mr. P. is a 67-year-old, retired engineer who has had Canadian Cardiovascular Society class III angina for the past 3 months and symptomatic intermittent claudication for the past 12 months. His medical history shows no previous cardiovascular interventions, but he does have a number of vascular risk factors, including smoking, hypertension, and diabetes. Coronary angiography showed blockages in three vessels, with involvement of the left anterior descending coronary artery; his ejection fraction is 45%, and chest radiography showed a possible calcified ascending aorta. Mr. P. was referred to Dr. S. for consideration of coronary artery bypass graft surgery (CABG). After discussion of Mr. P.’s health goals and priorities and of the risks and benefits associated with CABG, Dr. S. and Mr. P. agree that surgery is the best treatment option for Mr. P. Mr. P., however, has an additional question: He has looked up some information on CABG procedures, as well as questioning friends and family members who have undergone revascularization procedures themselves or who work in medicine and has learned that CABG can be performed in more than one way, specifically, on pump (which uses cardiopulmonary bypass to enable surgeons to work on a still heart that has been arrested temporarily) versus off pump (which is performed on a beating heart). He wants to know if he is a candidate for both types of surgery, and, if so, what the risks and benefits of each type are and which is likely to offer him the best outcome. Dr. S. only performs on-pump CABG, and although he knows some of his colleagues strongly believe in the superiority of the off-pump procedure, he is not familiar enough with it to provide Mr. P. with the answers he is looking for. Because Mr. P.’s surgery is not immediately urgent, Dr. S. suggests that they schedule another appointment in a few days, giving him the opportunity to review the relevant literature regarding the two techniques.
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More than 1 million patients worldwide undergo isolated CABG each year. In Asia, the majority (>60%) of these procedures are performed off pump (i.e., beating-heart surgery), but in the Western world, more than 80% of CABG procedures are performed on pump (i.e., with cardiopulmonary bypass). Off-pump CABG is relatively cheaper and is thought to reduce the risk of some adverse complications (i.e., postoperative atrial fibrillation, pulmonary complications, infection, and stroke) associated with conventional on-pump CABG. Drawbacks associated with this technique are the reduced graft patency and completeness of revascularization. To date, more than 200 studies have investigated the efficacy (randomized controlled trials [RCTs]) and effectiveness (observational studies) of off-pump CABG compared with on-pump CABG in terms of short- and long-term mortality. Study results are inconsistent and conflicting and leave the question regarding the best treatment option unanswered. In such situations, reviewing the primary research literature is unlikely to be of great help to physicians who find themselves in ...