LAUSR

The advent of mechanical thrombectomy (MT) in 2015 drastically changed the treatment of acute stroke. The corresponding guidelines were revised in 2019 to broaden the scope of MT within 24 hours of symptom onset. In previous studies, MT have improved the prognoses of patients in real-world clinical settings. Using nationwide representative data, this study aimed to evaluate the national trends in clinical outcomes of patients treated with endovascular therapy (ET) in South Korea. From the Korean National Health Insurance Service database, we extracted the claims data of patients aged >45 years who were hospitalized due to cerebral infarction (International Classification of Diseases, 10th revision, code: I63) and underwent ET (based on the registered procedure codes) between 2007 and 2017. We categorized the analysis period as follows: the “non-advanced MT period (January 2008 to December 2010),” when stent retrievers were rarely used; “transitional period (January 2011 to July 2014),” when stent retrievers were used off-label and were not reimbursed; and the “MT period (August 2014 to December 2016),” when the insurance claims data verified the frequency of stent retriever use. We categorized the status of discharge to home as a good outcome and statuses of cerebral hemorrhage, disability, and death as poor outcomes. SAS version 9.4 (SAS Institute Inc., Cary, NC, USA) was used to perform statistical analysis. Methods are provided in detail in the Supplementary methods. This study was approved by the Institutional Review Board of the National Health Insurance Service Ilsan Hospital (NHIMC 2019-01-006). Between 2008 and 2016, a total of 12,501 patients with acute ischemic stroke were treated with ET. In 2015, ET was administered at a higher rate than that in the previous year. During the study period, the annual rate of discharge to home significantly increased, whereas the rates of cerebral hemorrhage, disability, and death significantly decreased (P<0.0001) (Figure 1). The rate of home discharge was 35.8% in 2008 and 43.8% in 2016. The 3-month mortality rate was 27.2% in 2008 and 19.7% in 2016. The ratio of patients receiving surgery for National Trends in Clinical Outcomes of Endovascular Therapy for Ischemic Stroke in South Korea between 2008 and 2016