Background: There is no quality metric for emergency physicians' diagnostic time for acute coronary occlusion. Objective We sought to quantify diagnostic time associated with automated interpretation, classic ST-elevation myocardial infarction (STEMI) criteria, STEMI-equivalents, and subtle occlusions, using electrocardiogram (ECG)-to-activation of catheterization laboratory time. 

Methods: This multicenter retrospective study reviewed all code STEMI patients from the emergency department (ED) with confirmed culprit lesions from January 2016 to December 2018. We measured door-to-ECG (DTE) time and ECG-to-activation (ETA) time. We examined the first ED ECGs to determine whether automated interpretation labeled STEMI, and they met classic STEMI criteria, STEMI-equivalents, or rules for subtle occlusion. ECG analysis was performed by two emergency physicians blinded to clinical scenario, automated interpretation, and angiographic outcome. 

Results: There were 177 code STEMIs with culprit lesions, with a median DTE time of 9.0 min and a median ETA time of 16.0 min. Automated interpretation labeled 55.4% of first ECGs STEMI (ETA 6.5 min) and 44.6% not STEMI (ETA 66 min, p < 0.0001). Of first ECGs, 63.8% met classic STEMI criteria (ETA 8.0 min), 8.5% had STEMI-equivalents (ETA 32.0 min, p = 0.0026), 16.4% had subtle occlusions (ETA 89.0 min, p = 0.045), and 11.3% had no diagnostic sign of occlusion (ETA 68.0 min, p = 0.20). 

Conclusions: STEMI criteria missed more than one-third of occlusions on first ECG, but most had STEMI-equivalents or rules for subtle occlusion. ETA time can serve as a quality metric for emergency physicians to promote new ECG insights and assess quality improvement initiatives.

Authors: Jesse T.T. McLaren, Monika Kapoor, Soojin L. Yi, Lucas B. Chartier