Should All Patients With Asymptomatic but Significant (>50%) Left Main Coronary Artery Stenosis Undergo Surgical Revascularization?

Abstract

The incidental detection of asymptomatic but significant (>50%) left main coronary artery disease (LMCAD) has become more frequent with the increased use of coronary angiography for acute myocardial infarction. Most would agree that such LMCAD cannot be ignored. Yet, clarity is somewhat lacking as to the best approach to managing such patients. The long-running debate of the best revascularization method of LMCAD has flared up again. However, medical management also may be a viable option for some of these patients. A 64-year-old nondiabetic man without a history of cardiovascular disease is admitted with an acute inferior ST-elevation myocardial infarction. He undergoes successful primary angioplasty of a dominant right coronary artery. Left ventriculography reveals inferior hypokinesis with an estimated ejection fraction of 45% to 50%. However, the patient also has a smooth mid-to-distal 60% LMCAD without any significant lesions in the left anterior descending or left circumflex artery. A month later, a stress echocardiogram reveals no new wall motion abnormalities. On the basis of this presentation, should he be referred for coronary artery bypass graft (CABG) surgery? The American College of Cardiology/American Heart Association (ACC/AHA) 2002 guidelines for stable angina1 discuss the indications for CABG surgery separately for symptomatic and asymptomatic LMCAD, but the recommendations are the same for both: Revascularization with CABG is a class I recommendation with level of evidence B. (Class I recommendations indicate situations for which evidence or general agreement exists that a given procedure or treatment is beneficial, useful, and effective.) An abbreviated version of these same guidelines was published in 2003.2 These guidelines acknowledged that the evidence behind the recommendation for asymptomatic patients is weak, yet the class IB recommendation was not changed. The ACC/AHA 2004 guidelines for use of CABG surgery also separate symptomatic and asymptomatic LMCAD recommendations and propose that CABG …