Most of our denominator fallouts are patients who did not have a STEMI.  They presented to the ED with ST-elevation.  An initial diagnosis of STEMI is used to activate the Cath Lab.  The Cath Lab clears them of having a STEMI without need for PCI.  No further intervention is needed.  Because the initial diagnosis of STEMI is used to activate the team, this will be documented in the Emergency Physician's active problem list.  This rule-out diagnosis will likely appear on the DC Summary.  Either way, STEMI will be coded on the final billing that drives this measure.  Because no interventions were needed for a STEMI, this will be a denominator fallout.  Given this scenario, this measure can never be one that we would choose to report to CMS.  Our STEMI program tracks its own numbers and are they are stellar.  Surely, we are not the only facility for whom this measure does not work.  It would work if time to Cath Lab replaced time to PCI intervention.  What do other Coding departments do when diagnoses are documented in the record by providers and then ruled out?