Abstract 10350: “Appropriateness” of Emergency Department Triage of Presumed ST Elevation Myocardial Infarction Patients for Primary Coronary Intervention: Factors Contributing to False Activation
Introduction: The onus of initiating timely reperfusion therapy for ST elevation myocardial infarction (STEMI) is reliant on the emergency department (ED) physician interpretation of electrocardiographic (ECG) presence of ST elevation (STE) or left bundle branch block (LBBB). ECG misinterpretation or ECG patterns of “STEMI-mimetics” could be considered “inappropriate” or “appropriate” false activation (FA) of STEMI care processes respectively and carries diverse perceptions of appropriateness of ED care.
Methods: We retrospectively defined: a) the frequency, b) clinical variables and c) ECG patterns of FA among 1178 consecutive presumed STEMI pts undergoing cardiac cath for primary intervention (PCI) presenting directly to 3 tertiary PCI-capable or transferred from 24 non-PCI capable (STEMI-referral) hospitals between 1/2005–;12/2009. FA was defined as: coronary stenosis ≤ 50% not requiring PCI. ECG's were blindly reviewed for presence/absence of STE (≥ 1 mm in ≥ 2 contiguous leads) or LBBB. FA-defined pts were categorized as: a) STEMI-mimetic (alternative cause of STE or LBBB present) or b) True FA (no-STE or LBBB).
Results: Of 1178 pts, 196 (16.6%) were defined FA. FA frequency increased over 5 yrs (2005: 10.9%, 2006: 12.6%, 2007: 18.2%, 2008: 19.3%, 2009: 19.8%; p for trend=0.025) and more commonly in the STEMI-referral (137/660;20.8%) compared to tertiary facilities (59/522;11.3%, p<0.001).
Among the FA group, 110 (56%) were defined as STEMI-mimetic and 86 (44%) as True FA, with acute injury pattern (23%), early repolarization (20%), LV aneurysm (19%) and LBBB (16%) as most common STEMI-mimetic ECG findings.
Conclusions: In STEMI care, FA's are not infrequent and were observed to increase over time, possibly reflecting the urgency for timely PCI encumbered on ED care. FA is more frequent among pts with prior coronary disease, LBBB and in lower volume ED's. Importantly, the majority of FA (56%) reflects “appropriate” (STEMI-mimetic) ED STEMI activation.
- © 2010 by American Heart Association, Inc.