Title: The evaluation of helicopter emergency medical services with a physician for acute myocardial infarction in Japan: Registry-Based study of prognosis and time reduction

Abstract

Introduction: The aim of this study is to compare the prognosis and time reduction between helicopter emergency medical service with physician (HEMS) and ground emergency medical services (GEMS) in acute myocardial infarction (AMI) cases. Methods: This is a registry-based study of Japan Helicopter Emergency Medical Service registry from April 1, 2015, to March 31, 2018. Results: A total of 605 cases of AMI were registered in the HEMS group, while 794 cases in the GEMS group. In the cases of non-cardiopulmonary arrest (CPA), the prognosis between HEMS and GEMS did not differ significantly. Regarding the road distance, for ranges of 20-40km and >40 km, the times from the call to the angiography room were significantly shorter in the HEMS than in the GEMS (median 91 vs. 97 minutes, p=0.036, 101 vs. 132 minutes, p=0.002, respectively). In cases of CPA, HEMS had a higher rate of return of spontaneous circulation (ROSC) than GEMS (55.3% vs. 36.8%, p=0.038), but HEMS had a lower prognosis than GEMS (22.9% vs. 38.9%, p=0.036). Conclusion: The present study suggested that HEMS had an advantage in reducing the time to angiography in AMI cases of non-CPA. In cases of CPA, HEMS increased ROSC without improving the prognosis.