Abstract WP037: Reperfusion Therapy for Acute Ischemic Stroke in California in the Endovascular Thrombectomy Era: A Seven-Year Retrospective Analysis (2015-21)

Introduction: Since 2015, the indications for endovascular thrombectomy (EVT) and the number of certified stroke hospitals have expanded dramatically. However, the effects of this expansion on reperfusion rates among acute ischemic stroke (AIS) patients are not well described. Methods: We conducted a retrospective cross-sectional analysis of statewide, all-payer data between 2015-2021 using patient-level discharge data from the California Department of Health Care Access and Information. We identified encounters with a primary diagnosis of AIS and assessed treatment with intravenous thrombolysis (IVT) and EVT. We calculated the proportion of patients treated with reperfusion therapy and discharged from a certified stroke center hospital and an EVT-capable (performing at least 2 EVT in given year) hospital by year. Results: Among 309,118 AIS patients, 47,664 (15.4%) received reperfusion therapy. Over time, there was a 5.5% increase in the proportion of AIS patients treated with reperfusion therapy from 11.5% (n=5,126) in 2015 to 17.0% (n=7,414) in 2021 (Figure 1). EVT use more than doubled, from 3.1% (n=1,385) in 2015 to 6.8% (n= 2938) in 2021, while IVT use increased more modestly from 9.5% (n=4,225) to 11.7% (Figure 1). Most patients (90.4%) were discharged from a certified stroke center hospital, and the proportion discharged from an EVT-capable hospital increased from 42.1% in 2015 to 57.8% in 2021 (Figure 2). Conclusions: The overall increase in reperfusion therapy has been significant in the modern endovascular era of care, with a more than 50% increase in treatment with EVT in the first seven years. This trend may be related, in part, to the high proportion of AIS patients in California receiving care from a certified stroke center hospital, including more than half from an EVT-capable hospitals by 2021.