The likelihood that re- vascularization might decrease angina and improve a patient s quality of life should be considered when a patient deems his or her quality of life unsatisfactory despite a conscientious program of evidence-based medical therapy. Fihn et al Stable Ischemic Heart Disease: Full Text e387 The most commonly used nomenclature for defining cor- onary anatomy is that which was developed for CASS367 and further modified by the BARI study group.368 This scheme is based on the assumption that there are 3 major coronary arteries: the LAD, the circumflex, and the right coronary artery, with a right-dominant, left-dominant, or codominant circulation. The extent of disease is defined as 1-vessel, 2-vessel, 3-vessel, or left main disease, with a significant stenosis $70% diameter reduction. Left main disease, how- ever, also has been defined as a stenosis $50%. Despite being recognized as the traditional gold standard for clinical assessment of coronary atherosclerosis, coronary angiography is not without limitations. First, the technical quality of angiograms in many settings can make accurate interpretation difficult or impossible. In a random sample of .300 coronary angiograms performed in New York State during the 1990s, 4% were of unacceptable quality, and 48% exhibited technical deficiencies that could interfere with accurate interpretation.369 Although more modern techniques and equipment likely have eliminated some of these deficien- cies, few studies have addressed this issue, particularly in patients who present technical challenges, such as those who are obese. Second, problems also exist with interobserver reliability. These investigators also found only 70% overall agreement among readers with regard to the severity of stenosis, and this was reduced to 51% when restricted to coronary vessels rated as having some stenosis by any reader. 