Abstract WP98: Utilization Of Perfusion Imaging For Acute Ischemic Stroke: Secular Trends And Effects On Outcomes Of Endovascular Treatment

Introduction: Perfusion imaging (PI) could guide decision-making for endovascular treatment (EVT) of acute ischemic stroke (AIS). However, PI was underused even in the US before the pivotal EVT trials proved its usefulness in 2018. This study aimed to describe the secular trends of PI utilization and investigate the effectiveness of PI-based EVT in real-world practice. Methods: Using a prospective multicenter (n=17) stroke registry in South Korea, we identified patients with AIS who presented within 24 hours from onset between 2011 and 2021. The study period was divided into 3 epochs: 2011-2014, 2015-2017, and 2018-2021. The study population was divided into the early (arrival within 6 hours) and late window (6-24 hours) groups. Results: A total of 51,650 patients (15,654 patients in 2011-2014, 14,432 patients in 2015-2017, and 21,564 patients in 2018-2021) were analyzed. Utilization of PI decreased in the overall population and early window group ( P trend <0.001); 43.3% and 54.1% in 2011-2014, 40.1% and 44.1% in 2015-2017, and 38.4% and 40.2% in 2018-2021, respectively; but increased in the late window group ( P trend <0.001); 31.3% in 2011-2014, 35.7% in 2015-2017, and 36.5% in 2018-2021. Of 10,872 patients with anterior large-vessel occlusion (aLVO), the EVT rate was not different between patients with and without PI (48.7% vs. 46.6%, P =0.08) in the early window but higher in those with PI than without PI in the late window (29.8% vs. 18.7%, P <0.001). The EVT outcome (3-month mRS 0-2) was not different between patients with and without PI in the early window (44.1% vs. 41.8%, P =0.21) and late window (38.4% vs. 39.2%, P =0.81). Propensity score analysis and instrumental variable analysis with PI rate per center as an instrument will be performed to adjust imbalances between patients with and without PI. Conclusion: Between 2011 and 2021 in South Korea, PI utilization has decreased in patients arriving within 6 hours from onset but has increased in those arriving between 6 and 24 hours. Among patients with aLVO, PI likely increased the EVT rate in the late window but did not in the early window. PI utilization did not seem to affect the EVT outcomes, but in-depth analysis is required.