Members of the writing committee volunteered their time for this effort. Meetings of the writing committee were confiden- tial and attended only by writing committee members and staff from the ACC, AHA, and the Society for Cardiovascular Angiography and Interventions who served as a collaborator on this project. 2.1. Literature Review In developing the updated STEMI/NSTEMI measure set, the writing committee reviewed evidence-based guidelines and statements that would potentially impact the construct of the measures. The practice guidelines and statements that most directly contributed to the development of these measures are summarized in Table 2. 2.2. Definition and Selection of Measures The writing committee reviewed recent clinical practice guidelines and other clinical guidance documents (Table 2). The writing committee also examined available information on disparities in care to address which new measures might be appropriate as performance versus quality measures for this measure set update. To this effect, an extensive environ- mental scan of the published literature was performed. In a large retrospective analysis of STEMI patients transferred to primary percutaneous coronary intervention (PCI) centers in the ACTION-Get With The Guidelines registry (2007-2010), only 11% had timely door-in-door-out time 30 minutes.20 In another cohort of STEMI patients transferred from non PCI- capable hospitals to STEMI receiving centers (2008-2012), timely primary PCI ( 120 minutes) was achieved in 65% of Another report showed that only 41% of patients were referred to cardiac rehabilitation after AMI.22,23 These reports highlight but a few examples of the persistent disparities in care. Importantly, it appears guideline-directed care can greatly reduce a large proportion of disparities previ- ously noted in women.24,25 All measures were designed to assess quality of care experienced by individuals who have STEMI or NSTEMI in the inpatient setting. 