Abstract 10953: Physician Accuracy in Interpreting Potential ST-Segment Elevation Myocardial Infarction Electrocardiograms in the Absence of Clinical Context
Background: There is increasing focus on pre-hospital diagnosis of ST elevation myocardial infarction (STEMI) from ECGs transmitted electronically, often in the absence of context. However, the diagnostic accuracy of potential STEMI ECGs in the absence of context is not known, nor is it known how it changes with physician specialty or experience.
Methods: 101 general cardiologists, interventional cardiologists, and emergency medicine physicians with various levels of experience were asked to review a random sample of 36 de-identified ECGs, representing 10% of all potential STEMI diagnoses made at 2 UC San Francisco hospitals in the prior 30 months. Per ECG, participants were asked “Based on this ECG, is there a blocked coronary artery causing a STEMI?” All 36 patients had undergone coronary angiography; STEMI was confirmed in 69% by culprit lesion. Physician responses were analyzed using logistic regression accounting for repeated measures.
Results: Among 101 study participants, the overall sensitivity for true culprit lesion was only 66% and the specificity was 79% (Table). Analyzed by specialty, emergency physicians were no worse at, identifying true STEMIs than general cardiologists (OR 0.95, 95%CI 0.69-1.3, p = 0.75) or interventional cardiologists (OR 1.15, 95%CI 0.75-1.7, p = 0.51). Analyzed by experience, attending physicians had a 26% greater odds of accurate diagnosis compared to trainees (OR 1.26, 95%CI 1.05-1.52, p = 0.02). Per decade of experience since medical school, the odds of accurate interpretation increased by 10% (OR 1.10, 95%CI 1.01-1.19, p = 0.03).
Conclusions: ECGs concerning for STEMI interpreted without context have insufficiently low sensitivity and specificity irrespective of the reader's specialty. Diagnostic accuracy improves significantly, though modestly, with experience. Utilization of precious cath lab resources for STEMI management requires caution when based on ECGs alone, given their low diagnostic accuracy.
- © 2011 by American Heart Association, Inc.