Authors: Kristina Shkirkova; Michelle Connor; Krista Lamorie-Foote; Arati Patel; Qinghai Liu; Li Ding; Nerses Sanossain; Frank Attenello; William Mack (Los Angeles, CA)

Introduction: Stroke systems of care typically employ a spoke-and-hub model, with few centers performing mechanical thrombectomy (MT) compared to a large number of stroke-receiving centers. This system design offers high-level, centralized treatment to a large number of patients, and relies on suitable postoperative care for at local/ regional hospitals. Methods: This study leveraged a population-based, national sample of stroke patients undergoing MT from the National Readmissions Database from 2010 to 2014. Descriptive and dichotomized analyses were performed to determine patient and hospital level factors that influenced 90-day readmissions to index and non-index hospitals. Regression models were used to assess for differences in mortality, complications, subsequent readmissions, and failure to rescue between patients readmitted to index and non-index hospitals. Results: During the study period, 2111 stroke patients were treated with MT, of whom 534 (25.3%) were readmitted within 90 days. The most frequent reasons for readmission were: septicemia (5.93%), atrial fibrillation (4.78%), and cerebral artery occlusion with infarct (4.78%). Among readmitted patients, 387 (74%) were readmitted to index hospital and 136 (26%) to non-index hospital. On multivariable logistic regression analysis, non-index hospital readmission was not independently associated with mortality (p=0.22), major complications (p=0.07), neurological complications (p=0.38), second readmission (p=0.82), or failure to rescue (p=0.5). Conclusion: Approximately one-fourth of stroke patients treated with mechanical thrombectomy were readmitted within 90 days, one quarter of whom were readmitted to non-index hospitals. Readmission to non-index hospital was not associated with mortality or increased complication rates. In a spoke-and-hub treatment model it is important that follow up care for a specialized procedure can be performed effectively at a vast number of non-index hospitals that cover a large geographic area.