Impact of transport pathways on the time from symptom onset of ST-segment elevation myocardial infarction to door of coronary intervention facility.

BACKGROUND

Reducing total ischemic time is important in achieving better outcome in ST-segment elevation myocardial infarction (STEMI). Although the onset-to-door (OTD) time accounts for a large portion of the total ischemic time, factors affecting prolongation of the OTD time are not established.

PURPOSE

The purpose of this study was to determine the impact of transport pathways on OTD time in patients with STEMI.

METHODS AND SUBJECTS

We retrospectively studied 416 STEMI patients who were divided into 4 groups according to their transport pathways; Group 1 (n = 41): self-transportation to percutaneous coronary intervention (PCI) facility; Group 2 (n = 215): emergency medical service (EMS) transportation to PCI facility; Group 3 (n = 103): self-transportation to non-PCI facility; and Group 4 (n = 57): EMS transportation to non-PCI facility. OTD time was compared among the 4 groups.

ESSENTIAL RESULTS

Median OTD time for all groups combined was 113 (63-228.8)min [Group 1, 145 (70-256.5); Group 2, 71 (49-108); Group 3, 260 (142-433); and Group 4, 184 (130-256)min]. OTD time for EMS users (Groups 2 and 4) was 138 min shorter than non-EMS users (Groups 1 and 3). Inter-hospital transportation (Groups 3 and 4) prolonged OTD by a median of 132 min compared with direct transportation to PCI facility (Groups 1 and 2). Older age, history of myocardial infarction, prior PCI, shock at onset, high Killip classification, and high GRACE Risk Score were significantly more frequent in EMS users.

PRINCIPAL CONCLUSIONS

Self-transportation without EMS and inter-hospital transportation were significant factors causing prolongation of the OTD time. Approximately 35% of STEMI patients did not use EMS and 21% of patients were transported to non-PCI facilities even though they called EMS. Awareness in the community as well as among medical professionals to reduce total ischemic time of STEMI is necessary; this involves educating the general public and EMS crews.