Effectiveness of a Prehospital Wireless 12-Lead Electrocardiogram and Cardiac Catheterization Laboratory Activation for ST-Elevation Myocardial Infarction

Effect of Real-Time Physician Oversight of Prehospital STEMI Diagnosis on ECG-Inappropriate and False Positive Catheterization Laboratory Activation

“…23 Lu et al, on the other hand, did not find a difference in the IA proportion using an ECG-based definition (4% vs 2%), but found a higher FP proportion with emergency physician -initiated compared to EMS-initiated activations (17% vs 11%; p=0.01). 33 The emergency physician-initiated IA proportion was similarly low (5%) in a report by Tanguay et al 35 These last two Canadian studies, 33,35 combined with our prior work 24,25 and the present results, have all reported similarly low IA proportions. Moreover, irrespective of who initiates the CCL activation, ECG-IA has never been associated with a final diagnosis of STEMI, [23][24][25]35 reinforcing the appropriateness of using ECG criteria as the basis for defining IA.…”

“…33 The emergency physician-initiated IA proportion was similarly low (5%) in a report by Tanguay et al 35 These last two Canadian studies, 33,35 combined with our prior work 24,25 and the present results, have all reported similarly low IA proportions. Moreover, irrespective of who initiates the CCL activation, ECG-IA has never been associated with a final diagnosis of STEMI, [23][24][25]35 reinforcing the appropriateness of using ECG criteria as the basis for defining IA. 23,24 Somewhat surprisingly, very little has been published on predictors of IA.…”

“…12 The proportion of IAs reported in the literature is highly variable, ranging from 3% to 36%. 22,[32][33][34][35][36][37] However, this disparity seems largely explained by the inclusion of only cancelled activations on one end of the spectrum to the inclusion of any "unwanted" activation (sometimes termed the "total false positive" proportion; a combination of both IA and FP) on the other, with variable inclusion of relative or social contraindications, such as extreme old age or very poor baseline functional status, in the IA definition. In addition, differences in the design of STEMI referral systems and the extent of training of ECG interpreters and CCL activators 22,36,37 and whether they are supported by automated or other decision aids 38 may also play a role.…”

“…23,24 Somewhat surprisingly, very little has been published on predictors of IA. 22,23,33,35 Lange et al revealed that age, peak troponin, and initial ECG findings were factors discriminating emergent coronary angiography versus cancellation. 39 However, of these, only age and the ECG are knowable at the time of CCL activation and case cancellation and IA are not necessarily synonymous.…”

Continuum of Care for Acute Coronary Syndrome

“…One study found a total positive and inappropriate CCL activation rate of 14%. 11 The authors of the study found that unwanted CCL activations were more likely to occur in men older than 65 years and patients with a history of coronary artery disease.…”