Abstract 109: Impact of Hospital Readmission Site on Outcomes in Acute Ischemic Stroke Patients Undergoing Mechanical Thrombectomy: A Nationwide Analysis

Introduction Mechanical thrombectomy (MT) significantly improves outcomes in patients with acute ischemic stroke due to large vessel occlusion. While MT has been widely adopted, there is limited understanding of how the site of hospital readmission after MT influences patient outcomes. Specifically, it remains unclear whether readmission to the original hospital where MT was performed (the “index hospital”) offers advantages over readmission to a different hospital (“non‐index hospital”). Addressing this gap is crucial for optimizing post‐MT care and improving long‐term outcomes for stroke patients. Method We conducted a retrospective cohort analysis using data from the Nationwide Readmissions Database, focusing on acute ischemic stroke patients who underwent MT between 2016 and 2019. Multivariable Cox regression and Fine and Gray competing risks models were used to assess the impact of readmission site on patient outcomes, including mortality and the likelihood of discharge to home. Interaction and subgroup analyses were performed to explore the influence of previous discharge status, readmission hospital size and MT volume, and readmission diagnosis on these outcomes. Result The analysis included 18,330 patients readmitted within 90 days post‐MT, with 63.7% readmitted to index hospitals and 36.3% to non‐index hospitals. Readmission to the index hospital was not significantly associated with reduced mortality (HR = 1.05, 95% CI 0.86‐1.29, p = 0.619) but was linked to a higher likelihood of discharge to home (Subdistributed HR = 1.26, 95% CI 1.16‐1.36, p < 0.001). The effect of index hospital readmission on home discharge was significantly influenced by the MT volume of the readmission hospital (p = 0.023 for interaction). Subgroup analysis indicated that patients readmitted with cerebrovascular disease diagnoses had a non‐significant likelihood of home discharge when readmitted to the index hospital (SHR = 1.24, 95% CI 0.98‐1.58, p = 0.774), and those with infectious disease diagnoses also did not experience a significantly improved likelihood of home discharge (SHR = 0.95, 95% CI 0.66‐1.37, p = 0.130). Conclusion This nationwide analysis suggests that for acute ischemic stroke patients treated with MT, readmission to non‐index hospitals within 90 days is associated with less favorable outcomes, particularly for those readmitted with non‐cerebrovascular and non‐infectious conditions. These findings highlight the need for targeted strategies to address the disparities in outcomes related to readmission site, potentially informing future improvements in post‐MT care pathways. Further research is warranted to better understand the underlying causes of these disparities and to enhance continuity of care for this vulnerable patient population.