Onset-to-device time of patients who arrive at off-hours: Importance of prehospital management and public awareness for patients with ST-segment elevation myocardial infarction.

AIM: The influence of the time of arrival at the hospital on the door-to-device (DTD) time has been investigated; however, the influence on the onset-to-device (OTD) time is unclear in ST-segment elevation myocardial infarction (STEMI) patients. The aim of this study was to investigate the relationship between the time of arrival at the hospital and the OTD time in STEMI patients.

METHODS: We evaluated 377 STEMI patients who underwent primary percutaneous coronary intervention (pPCI) between January 2008 and December 2014.

RESULTS: During the study period, 222 patients arrived at our hospital between 9 AM and 9 PM (on-hours group) and 155 patients arrived between 9 PM and 9 AM (off-hours group). The DTD time was longer in the off-hours group than in the on-hours group (50.4 vs 39.3 minutes; P<.001), while the OTD time was longer in the on-hours group than in the off-hours group (285.7 vs 184.5 minutes, P<.001). The 30-day mortality and peak creatinine kinase levels were similar between the groups. Transfer from a non-pPCI-capable facility to our hospital was more common in the on-hours group than in the off-hours group (49.1% vs 15.5%, P<.001). The OTD time was shorter in patients who directly visited our hospital than in those who were transferred (172.9 vs 338.5 minutes, P<.001).

CONCLUSIONS: The OTD time might be markedly longer in STEMI patients who arrive at the hospital during on-hours than in those who arrive at the hospital during off-hours because of the underuse of emergency medical services at STEMI onset.