ACC indicates American College of Cardiology; AHA, American Heart Association; AMA-PCPI, American Medical Association Physician Consortium for Performance Improvement; NCQA, National Committee for Quality Assurance; PCI, percutaneous coronary intervention; and SCAI, Society for Cardiovascular Angiography and Interventions. Any writing committee member who develops new RWI during his or her tenure on the writing committee is required to notify staff in writing. These statements are reviewed peri- odically by the Task Force and by members of the writing committee. Author and peer reviewer RWI relevant to the doc- ument are included in the appendices: Please see Appendix A for relevant writing committee RWI and Appendix B for relevant peer reviewer RWI. Additionally, to ensure complete transparency, the writing committee members' comprehensive disclosure information, including RWI not relevant to the pres- ent document, is available online at http://circ.ahajournals. DC1. Disclosure information for the Task Force is also avail- able online at http://www.cardiosource.org/ACC/About-ACC/ Who-We-Are/Leadership/Guidelines-and-Documents-Task- Forces.aspx. The work of the writing committee was supported exclu- sively by the ACC, the AHA, and the AMA, without commer- cial support. Members of the writing committee volunteered their time for this effort. Meetings of the writing committee were confidential and attended only by committee members and staff from theACC,AHA, SCAI,AMA-PCPI, and NCQA. The development of performance measurement systems involves identification of a set of measures targeting a specific patient population observed over a particular time period. To achieve this goal, the ACC/AHA Task Force on Performance Measures has outlined a set of mandatory sequential steps.1 The following sections outline how these steps were applied by the present writing committee. 2.1. 