Catheterization laboratory activations and time intervals for patients with pre-hospital ECGs.

Objective: The use of pre-hospital ECGs (PH-ECG) reduces time to reperfusion for patients with ST-segment elevation myocardial infarction (STEMI). The feasibility of reperfusion therapy within 60 minutes for hospitals with 24/7 PCI capability has been questioned, and current guidelines have set time targets to 90 minutes. Our primary objective was to investigate the proportion of false-positive catheterization laboratory activations by PH-ECG. Our secondary objective was to describe the time intervals from first medical contact to reperfusion and to establish the proportion of patients receiving reperfusion within 60 minutes.

Design: A retrospective cohort study among 4298 patients for whom a PH-ECG was transmitted to the investigating hospital, mainly due to chest pain, during 2013 were included.

Results: Among patients with PH-ECGs, 139 (3.2%) patients had a STEMI. There were 115 pre-hospital catheterization laboratory activations among which 16% (95% confidence interval 10-23) were false-positive for STEMI. The median total time from emergency call to arterial puncture was 76 minutes. The target of PCI within 60 minutes was met in 83% of the cases. The time from EMS arrival to PH-ECG was 20 minutes for female patients and 13 minutes for male patients (p < .001), and only 16% had a PH-ECG within 10 minutes from Emergency Medical Service arrival.

Conclusion: The rate of false-positive catheterization laboratory activations based on pre-hospital ECGs was low and the target of PCI within 60 minutes is achievable for a majority of patients. Efforts should be made to reduce the time from ambulance arrival to PH-ECG transmission, especially for female patients.