Abstract A145: Pre-Hospital Time Matters: Impact of Prehospital Delays on Receipt of IV Thrombolysis and Endovascular Therapy in the Get With The Guidelines-Stroke Registry

Background: Timely prehospital care is the first link in the stroke chain of survival, yet large-scale data on how specific EMS intervals affect acute stroke treatment are limited. We evaluated the association between delays in prehospital care and receipt of IV thrombolysis, endovascular therapy (EVT), and anticoagulation (AC) reversal in a national stroke registry. Methods: This was a retrospective cohort analysis of EMS-transported stroke cases from the American Heart Association Get With The Guidelines-Stroke National Registry (January 1, 2018 to August 31, 2023). Delays in EMS care were defined per guidelines or median values: dispatch to scene arrival (>8 min); scene time (>15 min); scene departure to ED arrival (>15 min); and total prehospital interval (> 40 min). Outcomes included receipt of IV thrombolysis and EVT for patients with acute ischemic stroke (AIS), and AC reversal for patients with hemorrhagic stroke. Logistic regression models with generalized estimating equations (GEE) for intervention-eligible patients controlled for patient demographics, insurance status, past medical history, and hospital characteristics. Race-based interaction terms were tested for effect modification. Results: There were 261,689 AIS patients with last known well ≤4 hours (IV thrombolysis-eligible), 333,527 patients with LKW time ≤24 hours (EVT-eligible), and 13,306 patients with hemorrhagic stroke. Delays in all prehospital intervals significantly reduced the odds of receiving thrombolysis, while delays in scene time, scene departure to ED arrival, and total prehospital interval significantly reduced the odds of EVT; delays were not associated with AC reversal (Figure 1). Longer scene time was associated with longer door-to-needle and door-to-groin times (Figure 2a-b). There was a significant interaction effect by race on the association between prehospital scene time delays and receipt of thrombolysis (p<.001) and EVT (p=.004), with effect sizes varying across racial subgroups (Figure 3). Discussion: Prehospital delays are strongly associated with reduced odds of receiving proven acute ischemic stroke treatments, including thrombolysis and EVT. Targeted strategies to minimize these delays are critical for optimizing stroke care.