In accordance with direction from the Task Force and feedback from readers, in this iteration of the guideline, the text has been shortened, with an emphasis on summary Levine et al 2011 ACCF/AHA/SCAI PCI Guideline e579 statements rather than detailed discussion of numerous indi- vidual trials. Online supplemental evidence and summary tables have been created to document the studies and data considered for new or changed guideline recommendations. 2. CAD Revascularization Recommendations and text in this section are the result of extensive collaborative discussions between the PCI and CABG writing committees, as well as key members of the SIHD and UA/NSTEMI writing committees. Certain issues, such as older versus more contemporary studies, primary analyses versus subgroup analyses, and prospective versus post hoc analyses, have been carefully weighed in designating COR and LOE; they are addressed in the appropriate corre- sponding text. The goals of revascularization for patients with CAD are to 1) improve survival and/or 2) relieve symptoms. Revascularization recommendations in this section are predominantly based on studies of patients with symptomatic SIHD and should be interpreted in this context. As discussed later in this section, recommendations on the type of revas- cularization are, in general, applicable to patients with UA/ NSTEMI. In some cases (eg, unprotected left main CAD), specific recommendations are made for patients with UA/ NSTEMI or STEMI. Historically, most studies of revascularization have been based on and reported according to angiographic criteria. Most studies have defined a significant stenosis as 70% diameter narrowing; therefore, for revascularization decisions and recommendations in this section, a significant stenosis has been defined as 70% diameter narrowing ( 50% for left main CAD). Physiological criteria, such as an assessment of fractional flow reserve (FFR), has been used in deciding when revascularization is indicated. 