Factors Associated With Prehospital Delay Among Patients With Acute Myocardial Infarction in the Era of Percutaneous Coronary Intervention ― Insights From the OACIS Registry ―

BACKGROUND: The Japan Circulation Society launched the STOP-MI campaign in 2014, focusing on immediate hospital arrival for acute myocardial infarction (AMI) treatment. This study aimed to determine the factors influencing longer prehospital time among patients with AMI in Japan. METHODS AND RESULTS: This study analyzed a total of 4,625 AMI patients enrolled in the Osaka Acute Coronary Insufficiency Study registry from 1998 to 2014. The prehospital time delay was defined as the time interval from the onset of initial symptoms to hospital arrival time ≥2 h. Among eligible patients, 2,927 (63.3%) had a prehospital time ≥2 h. In multivariable analyses, age 65-79 years (adjusted odds ratio [AOR] 1.19, 95% confidence interval [CI] 1.02-1.39), age ≥80 years (AOR 1.42, 95% CI 1.13-1.79), diabetes mellitus (AOR 1.33, 95% CI 1.16-1.52), and onset time of 0:00-5:59 h (AOR 1.63, 95% CI 1.37-1.95) were positively associated with prehospital time ≥2 h, whereas smoking (AOR 0.78, 95% CI 0.68-0.90) and ambulance use (AOR 0.37, 95% CI 0.32-0.43) were negatively associated with prehospital time ≥2 h. CONCLUSIONS: Older age, diabetes mellitus, and nighttime onset were associated with prehospital time delay for AMI patients, whereas smoking and ambulance use were associated with no prehospital time delay. Healthcare providers and patients could help reduce the time to get to a medical facility by being aware of these findings.