We have having patients included in the measure denominator that are seen in ED for a previous STEMI within 4 weeks after initial occurence. . per the 2024 CD-10-CM Official Guidelines for Coding and Reporting, Page 52. " For encounters occurring while the myocardial infarction is equal to, or less than, four weeks old, including transfers to another acute setting or a post-acute setting, and the myocardial infarction meets the definition for “other diagnoses” (see Section III, Reporting Additional Diagnoses), codes from category I21 may continue to be reported."

Our validation is finding many patients whose STEMI was not 'present on admission' to ED. We believe this conflict between coding rules and measure methodology is causing unreliable performance rate calculations.