Clinical significance of prehospital 12-lead electrocardiography in patients with ST-segment elevation myocardial infarction presenting with syncope: from a multicenter observational registry (K-ACTIVE study).

Patients with acute myocardial infarction (AMI) presenting with syncope have poor clinical outcomes partly due to a delay in the diagnosis. Although the impact of prehospital 12-lead electrocardiography (PHECG) on the reduction of first medical contact (FMC)-to-device time and subsequent adverse clinical events in patients with AMI has been demonstrated, the impact of PHECG for the patients presenting with syncope remains to be elucidated. This study aimed to explore the impact of PHECG on 30-day mortality in patients with ST-segment elevation myocardial infarction (STEMI) presenting with syncope. From a cohort of multi-center registry [Kanagawa-ACuTe cardIoVascular rEgistry (K-ACTIVE)], a total of 90 consecutive patients with STEMI presenting with syncope were included. The 30-day mortality were compared between patients with PHECG (PHECG group, n = 25) and those without PHECG (non-PHECG group, n = 65). There was no significant difference in the baseline clinical characteristics between the 2 groups. FMC-to-device time was significantly shorter in the PHECG group than in the non-PHECG group (122 [86, 128] vs. 131 [102, 153] min, p = 0.03) due to the shorter door-to-device time. Thirty-day mortality was significantly lower in the PHECG group than in the non-PHECG group (16.0 vs. 44.6%, p = 0.03). In conclusion, PHECG was associated with shorter FMC-to-device time and lower 30-day mortality in patients with STEMI presenting with syncope.