The writing committee closely delib- erated the exceptions to be included with each measure and, in some cases, determined not to include any exceptions (as in the case of the patient safety measures). During the course of developing the measure set, the writing committee evaluated the potential measures against the ACC/AHA attributes of performance measures (Table 3) to reach consensus on which measures should be advanced for inclusion in the final measure set. After the peer review and public comment period, the writing committee reviewed and discussed the comments received, and further refined the measure set. The writing committee acknowledges that the new measures created in this set will need to be tested and validated over time. By publishing this performance and quality measure set, the writing committee hopes to encourage their widespread and expeditious adoption, as well as facilitate the collection and analysis of data that are needed to continuously assess their relevance over time. In the future, the writing committee members anticipate having data that will allow them to reassess whether any of the mea- sures included in this set should be revised (eg, modified, deleted, or potentially upgraded from a quality measure to a performance measure). 3. AHA/ACC STEMI and NSTEMI Measure Set Performance Measures 3.1. Discussion of Changes to 2008 STEMI and NSTEMI Measure Set After reviewing the existing guidelines, and the 2008 per- formance and quality measure set,2 the writing committee discussed which measures should be revised to reflect the updated science, and worked to identify which guideline rec- ommendations could serve as the basis for new performance or quality measures. The writing committee also reviewed existing measure sets that were publicly available. 