Diversion of ST-elevation myocardial infarction patients for primary angioplasty based on wireless prehospital 12-lead electrocardiographic transmission directly to the cardiologist's handheld computer: a progress report

Abstract

Background: Time to reperfusion is critical for outcome in patients with ST-elevation myocardial infarction (STEMI). In our region, patients are routinely treated by primary percutaneous coronary intervention (pPCI), but rerouting patients from the primary receiving hospital to a catheterization center can cause unacceptable delays that may exceed 1 hour in the emergency department. Wireless transmission of prehospital electrocardiograms (ECGs) to receiving stations in hospitals has been shown to reduce time from symptom onset to reperfusion. However, transmission directly to a cardiologist's handheld digital device has not been investigated.

Aim: To report preliminary data from a larger ongoing trial evaluating prehospital 12-lead ECG transmission to a cardiologist's handheld device in patients with symptoms suggesting an acute coronary syndrome.

Method: Patients suffering acute, nontraumatic chest pain have their prehospital ECG transmitted by wireless technology directly to a cardiologist's handheld device at an invasive hospital, allowing diversion of STEMI cases to rapid pPCI. Transmission failures are documented. Times for symptom onset, 911 alert, ECG recording, hospital arrival, and pPCI are obtained. All time intervals are summarized as median values and are compared with historic controls from the Danish multicenter study, DANAMI-2.

Results: During the first 15 months of the trial, prehospital ECGs were transmitted for 408 chest pain patients with an overall success rate of 93%. Cardiologist receiving the ECGs recommended that 113 patients (28%) be diverted for pPCI. Mean time from symptom onset to 911 alert was 2 hours 16 minutes (range, 1 minute to 23 hours 15 minutes), and the ambulance response interval was 5 minutes (range, 1-25 minutes). The ambulance on-scene time had increased by 7 minutes compared with historic controls (P<.05). Time from ECG recording to hospital arrival was 25 minutes. The total prehospital time was 2 hours 57 minutes. The hospital treatment time was substantially reduced among diverted patients. Hospital arrival to procedure start was 40 minutes, compared with 94 minutes in the DANAMI-2 historic control group (P<.01).

Conclusion: These preliminary data suggest that transmission of prehospital 12-lead ECGs directly to the attending cardiologist using handheld devices is a technologically sound concept without major safety concerns and markedly reducing time to reperfusion in patients with STEMI.