An international perspective on the time to treatment for acute myocardial infarction

Purpose: To compare delay and circumstances of decisions to seek care in patients with acute myocardial infarction (AMI) in the United States (US), England, Australia, South Korea, and Japan. Design: Comparative prospective design. Methods: Patients diagnosed with AMI (N=913) were interviewed within 72 hours of hospital admission for confirmed AMI using the Response to Symptoms Questionnaire. Delay times were calculated from review of emergency room records and patients' interviews. Analysis of variance was used to test differences in delay time among countries. Findings: Median delay ranged from 2.5 hours in England to 6.4 hours in Australia, with the three Pacific Rim countries reporting median delay times > 4 hours. The majority of patients experienced initial symptoms at home (range: 56% in Japan to 73% in the US) with the most common witness being a family member (32% in South Korea to 48% in England). Ambulance use was widely divergent with the highest use in England (85%) and the lowest use in the US (42%). Conclusions: In all countries, median delay was too long to obtain maximum benefit from AMI therapies, particularly thrombolysis. Education and counseling of patients and families to reduce prehospital delay in AMI episodes might be more effective if the various factors influencing patients' first responses to symptoms are considered, as well as differences in health care systems.