Thank you for your inquiry regarding CMS996v5, Appropriate Treatment for ST-Segment Elevation Myocardial Infarction (STEMI) Patients in the Emergency Department (ED). The measure’s initial population includes all emergency department (ED) encounters for patients 18 years and older at the start of the encounter with a diagnosis of STEMI during the ED encounter that ends during the measurement period (aside from those meeting measure denominator exclusions or exceptions). As such, the measure does not capture a STEMI that presents outside of an ED encounter, such as a subsequent inpatient encounter, as this is not the measure’s intent. It is however the measure’s intent to include ED encounters in the denominator of patients with a STEMI diagnosis who have an ongoing ED encounter, such as those boarding or being evaluated in the ED. In terms of the first example described in the inquiry, if the STEMI presented during the inpatient encounter after the patient was discharged from the ED, it should not be included in the measure denominator. To indicate that an ED encounter has ended, we recommend proper documentation of both the ED discharge time and the ED discharge disposition. We also recommend appropriate documentation of STEMI diagnosis onset and abatement times so that STEMIs occurring outside of the ED encounter are not captured by the measure. A measure flow chart for the 2025 (CMS996v5) implementation is located on the eCQI Resource Center. The following diagram assists in visualizing the measure calculation: https://ecqi.healthit.gov/sites/default/files/ecqm/measures/CMS996v5-eCQMFlow.pdf In relation to the inquiry’s second example, this patient would be captured in the measure denominator and would not meet numerator criteria if the time from ED arrival to PCI deployment time was more than 90 minutes. The measure does not currently use the timing of EKGs or time to cardiac catheterization lab in its numerator definitions. This decision was based on clinical expert input and measure testing results indicating that EKG timing in EHR documentation was unreliable. Additionally, the measure does not currently exclude cases where the STEMI develops during the ED encounter. The issue you have raised regarding the STEMI onset timing has previously been brought to the measure developer’s attention. The measure developer will consider refinements in a future Annual Update.

Patients are populating in the IPP/Denominator as an Inpatient STEMI or as a STEMI that occurs as an ED Hold or a STEMI that occurs while being evaluated in the ED. The STEMI does not occur on or prior to arrival and therefore fails as we use the time of arrival to PCI intervention for the measure.