Abstract Body: Introduction: Education campaigns have previously successfully informed the public regarding stroke symptoms and the need for urgent evaluation of suspected stroke. However, not all patients with strokes requiring intervention present to the hospital by ambulance, which would usually be the fastest means by which to reach a hospital. The aims of this study were to characterize the cohort of patients with an acute ischemic stroke that require reperfusion therapy who present to an emergency department without engaging ambulance services.

Methods: A multicentre statewide retrospective cohort study was conducted involving all acute ischemic stroke admissions in South Australia from January 1, 2018, to January 1, 2024. Data were analyzed for all patients who received reperfusion therapy (either thrombolysis or endovascular thrombectomy) and presented directly to hospital (interhospital transfers and remote retrievals were excluded) via either ambulance or a non-ambulance (walk-in or driven by other) method.

Results: Of the 1,497 individuals who presented directly to hospital and 66.1% received thrombolysis and 53.6% received endovascular thrombectomy, 60/1,497 (4.0%) presented without an ambulance (10 cases per year in a state with a population of 1.8 million). Those who received reperfusion therapy after presenting without an ambulance were more likely to be male (75.0% vs 56.0%, P < 0.001) and younger (median 65.4 vs 75.5 years, P < 0.001) than other patients who received reperfusion. Those who presented without an ambulance had longer door-to-scan (median 24 vs 34 minutes, P < 0.001) and door-to-needle times (median 63 minutes vs 70 minutes, P = 0.18).

Conclusion: Reperfusion-eligible stroke patients not utilising ambulance services are more likely to be young and male. Patients receiving reperfusion therapy after presenting without an ambulance are uncommon, but such cases demonstrate the ongoing need for educating specific patient populations about the importance of identifying new stroke symptoms and seeking urgent evaluation and hospital transport. Further research is needed to elucidate the underlying causes, and design education strategies to reinforce the need to urgent emergency service contact.