The pre-hospital 12-lead electrocardiogram is associated with longer delay and worse outcomes in patients presenting to emergency medical services with acute stroke: a linked cohort study.

Objectives: To investigate the association between pre-hospital 12-lead electrocardiogram (PHECG) use in patients presenting to emergency medical services (EMS) with acute stroke, and clinical outcomes and system delays. Methods: Multi-centre linked cohort study. Patients with verified acute stroke admitted to hospital via EMS were identified through routinely collected hospital data and linked to EMS clinical records via EMS unique identifiers. Ordinal and logistic regression analyses were undertaken to analyse the relationship between having a PHECG and modified Rankin Scale (mRS); hospital mortality; pre-hospital time intervals; door-to-scan and door-to-needle times; and rates of thrombolysis. Results: Of 1161 eligible patients admitted between 29 December 2013 and 30 January 2017, PHECG was performed in 558 (48%). PHECG was associated with an increase in mRS (adjusted odds ratio [aOR] 1.30, 95% confidence interval [CI] 1.01-1.66, p = 0.04) and hospital mortality (aOR 1.83, 95% CI 1.26-2.67, p = 0.002). There was no association between PHECG and administration of thrombolytic treatment (aOR 1.06, 95% CI 0.75-1.52, p = 0.73). Patients who had PHECG recorded spent longer under the care of EMS (median 49 vs 43 minutes, p = 0.006). No difference in times to receiving brain scan (median 28 with PHECG vs 29 minutes no PHECG, p = 0.32) or thrombolysis (median 46 vs 48 minutes, p = 0.37) were observed. Conclusion: The PHECG was associated with worse outcomes and longer delays in patients with acute ischaemic stroke.