Abstract TP215: Clinical Factors Influencing Time to Emergency Department Stroke Response Activation in Patients Presenting Without EMS Pre-Notification

Background: Rapid stroke response upon ED arrival is critical for reperfusion therapy. AHA Target Stroke Phase III guidelines recommend stroke team activation <5 minutes to achieve <30 minutes door-to-needle (DTN). Patients presenting to the ED without EMS pre-notification remain susceptible to critical delays in care. We investigated clinical factors associated with delayed stroke response activation times among such stroke patients receiving time-sensitive acute treatment. Methods: Retrospective study of AIS thrombolytic/thrombectomy patients arriving without pre-notification by EMS (2017-2025, n=95) at a Comprehensive Stroke Center. Primary outcome was stroke team notification <5 minutes. Predictors included demographics, NIHSS severity, arrival mode (EMS vs. walk-in), and anterior vs. posterior circulation territory. Discharge outcome was noted, with “good outcome” being discharge to home or acute inpatient rehabilitation. Results: Among 95 patients, 37.9% had stroke team notification time <5 minutes. NIHSS score was the strongest predictor of timely response (Chi-square=6.829, p<0.05). Moderate-severe (NIHSS≥16) strokes had faster response times than minor strokes (61.1% vs. 23.3%, OR=5.16). Mean NIHSS was higher in <5 minute response group (11.3 vs. 7.3, p<0.05). Anterior circulation strokes showed faster response times than posterior circulation (39.2% vs. 15.4%, OR=3.55, p≥0.05). All PCA strokes (n=5) experienced delays. Interaction analysis revealed young patients with moderate-severe strokes achieved optimal response (83.3%). Timely response was associated with higher rates of good discharge outcomes compared to those of delayed response (80.6% vs 74.6%, OR=1.41) though not statistically significant (Chi-square=0.449, p≥0.05). Stratified analysis revealed greatest benefit in mild strokes (NIHSS 5-15) where timely response was associated with 23.4% improvement in good outcomes (88.9% vs 65.5%). Conclusions: Patients arriving to the ED without EMS pre-notification experienced faster stroke response times when presenting with higher NIHSS scores indicative of anterior circulation stroke. All PCA strokes experienced relative delays. Timely response was correlated with the greatest clinical benefit in mild strokes, though average response times were faster for this group. These findings suggest the importance of early stroke response activation especially among patients presenting with mild stroke, as they may benefit the most from early activation.