Acute Coronary Syndrome
Cloud-Based Prehospital Electrocardiography May Save More ST-Segment-Elevation Myocardial Infarction Patients in Regional Medical Systems
2022 Volume 86 Issue 10 Pages 1488-1489
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2022 Volume 86 Issue 10 Pages 1488-1489
In a cardiovascular emergency, survival and other clinical outcomes are sharply affected by the medical care and time lapse from onset. Above all, ST-segment-elevation myocardial infarction (STEMI) is the most prominent time-sensitive situation in which clinical outcomes substantially depend upon reduction of the total ischemic time to achieve survival and prevention of future heart failure. Therefore, the solution should aim to shorten the overall onset-to-reperfusion time for all STEMI patients, which requires minimizing patient delays, system delays and in-facility delays. To date, the door-to-balloon time (DTBT) has been the remarkable and amenable target of time reduction as the hospital performance component of PCI-capable institutes (PCIIs). A variety of attempts were made, and shortening of DTBT has been continuously achieved in Japan as well as in the USA. Besides the many efforts made inside the PCIIs, prehospital systems of care using electrocardiography (ECG) have emerged as another big target of reduction in total ischemic time. In the USA, this important issue has been solved in nationwide initiatives.1 The American Heart Association’s (AHA) “Mission: Lifeline” programs have established a successful model of formal STEMI “systems of care” using prehospital ECG for the past 15 years. The initiative includes prehospital activation of the cardiac catheterization laboratory followed by emergency department bypass for STEMI patients by improving the communication using prehospital ECG and process flows between the emergency management system (EMS), emergency physicians, cardiologists, and other hospital staff in both referral and receiving hospitals.2,3 Consequently, it aims to reduce not only the DTBT but also in-hospital deaths over time.4
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In Japan also, a study using a multicenter registry in Kanagawa prefecture recently reported that prehospital 12-lead ECG transmission at the first medical contact significantly reduced both DTBT and mortality.5
However, there remains the problem of “appropriate” transport of STEMI patients to PCIIs in time. For example, not a few STEMI patients whose mode of onset and symptoms are atypical tend to be transported to non-PCI hospitals, resulting in critical delay to receiving timely primary PCI (pPCI). In fact, in contrast to direct transfer of STEMI patients, a number of studies, including the CREDO-Kyoto AMI registry,6 have shown that inter-facility transfer was associated with significantly worse long-term clinical outcomes for patients with STEMI undergoing pPCI. To avoid treatment delay caused by inter-facility transfer for pPCI and to increase the rate of direct admission by ambulance, prehospital diagnosis of STEMI and direct admission to PCII by ambulance should be pursued. According to the recent report of the AHA: Mission Lifeline program Accelerator-2, only 13% of inter-facility transfer patients were treated with pPCI within 90 min of arrival at non-PCI hospitals.4 It was reported in North Carolina, USA, that using prehospital ECG to bypass geographically closer hospitals without pPCI capability was associated with shorter total ischemic times and 3-fold greater likelihood of achieving the guideline target of <90 min from first medical contact to PCI.7 Thus, another target of improving EMS includes avoiding inter-facility transfer for STEMI patients who would have been transported directly to a PCII if only prehospital ECG had been available.7 Therefore, it should be another innovative target of the total EMS performance for all potential beneficiary STEMI patients within an entire regional area to be directly transport to a PCII.
In this issue of the Journal, Kawano and the colleagues report their prefectural regional-scale observational study demonstrating the effect of cloud-based prehospital 12-lead ECG (C-ECG) on regional EMS in terms of optimal transportation of ACS patients,8 following a previous report revealing C-ECG’s efficacy in reducing in-facility DTBT in Oita Prefecture (Figure).9 C-ECG is characterized by the ability for multiple medical personnel to share accurate 12-lead ECGs instantaneously from remote locations, allowing them to diagnose STEMI and determine the proper destination for timely reperfusion therapy. Less educational and training cost for EMS personnel is required to establish the prehospital ECG environment than the conventional way for paramedics to be able to report the diagnosis of ECGs. The overall results of the trial showed the significantly higher prevalence of cardiovascular disease in the regional core hospital (RCH)-PCII group than in the PCII-RCH group in their regional medical system domain equipped with C-ECG. Moreover, they compared the diagnosis and incidence of PCI <24 h cases among 4 groups defined by the 2 targets of prehospital ECG by 2 destinations of patient transportation. Of note, the rate of PCI <24 h cases was significantly more common in the PCII-PCII and RCH-PCII groups than in the other two groups with not so different time courses.
Regional medical system equipped with cloud ECG (C-ECG). In Oita Prefecture, the C-ECGs were used in 24 hospitals and 52 ambulances of 14 fire departments across the whole prefecture as of 2022. Patients were appropriately directed to PCI-capable institute or regional core hospital, according to the prehospital ECG.
Having a prehospital C-ECG system seemed to assist in rationally deciding the destination of patients with suspected ACS to a PCII, indicating that in Oita Prefecture most patients in need of PCI were properly transferred to PCII irrespective of the primary target hospitals with or without PCI capability.
This study demonstrated for the first time that a C-ECG system might be an innovative solution for the optimization of regional EMS consisting of multiple ambulances, PCIIs and RCHs in terms of appropriate transport to PCIIs. Furthermore, in the presence of limited regional EMS resources such as ambulances, institutes, and cardiologists, a reduction in unnecessary ambulance transfer should also optimize the EMS capacity.
Based on these results, C-ECG presents not only a versatile solution to improving the performance of regional EMS, but may also provide a clinical basis and future direction for further optimizing of EMS for cardiovascular diseases.
To achieve a better prognosis for STEMI patients, the prehospital field emerges as an unexplored and expectant target for innovation. C-ECG is a strong candidate for a good solution. Further research and development of EMS by means of information and communication technology will be required for innovation to establish better EMS for STEMI.
H.F. has served as a consultant for Mehergen Group Holdings, Inc., and received speaker’s honoraria from Novartis Pharma and Otsuka Pharmaceutical Co. Ltd.
