It is therefore the ultimate responsibility of the physician performing the PCI and of the physician s insti- tution to accurately document key features. 5.2. Appropriate Indication for Elective PCI There has been considerable discussion among the writing committee members about this performance measure in the context of the recently published AUC for coronary revascularization (11), which include assessments of both coronary artery bypass surgery and PCI, and the well- documented variation (25) in practice of PCI across the United States (11,12). Furthermore, prior attempts to construct performance measures have not relied heavily on AUC, so this represents one of the more innovative and unexplored aspects of this performance measure set. The writing committee therefore approached the creation of this measure cautiously to maximize its value to users without leading to unintended consequences that could be harmful to patients. Several key aspects of this measure deserve to be high- lighted. To optimize our opportunity to improve care, we focused on elective PCIs that occur in nonacute settings, inasmuch as analyses of PCIs performed in acute settings have shown that the vast majority of these procedures are classi ed as appropriate according to AUC (19). In addi- tion, even though we aimed to harmonize the document with recently published guidelines and AUC, this perfor- mance measure is not completely superimposable on their de nitions for 2 reasons. First, it is acknowledged that the AUC cannot possibly include every conceivable patient presentation of appropriateness. The AUC are created via a modi ed Delphi approach, in which experts reach consensus after being presented with speci c clinical sce- narios that focus on coronary anatomy, symptoms, current medical therapy, and noninvasive studies. Thus, subtle differences between the AUC and guidelines do exist, particularly for PCI. 