Mechanisms of in-hospital acute ischemic stroke and their relevance to prognosis: A retrospective analysis

In-hospital stroke (IHS) is common and has a poor prognosis. Limited data were about the mechanisms of IHS, posing a challenge in taking measures to prevent stroke during hospitalization. This study aims to investigate the mechanisms of IHS and their relevance to prognosis.Patients with in-hospital acute ischemic stroke at Peking Union Medical College Hospital from June 2012 to April 2022 were consecutively enrolled. The Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification of stroke and detailed mechanisms were evaluated by two experienced neurologists. Functional outcome at discharge was evaluated.A total of 204 IHS patients were included, with a median age of 64 (IQR 52-72) and 61.8% male. The most common mechanism was embolism (57.8%), followed by hypoperfusion (42.2%), hypercoagulation (36.3%), small vessel mechanism (19.1%), discontinuation of antithrombotic drugs (13.2%), and iatrogenic injury (9.8%). Iatrogenic injury (P = 0.001), hypoperfusion (P = 0.006), embolism (P = 0.03), and discontinuation of antithrombotic drugs (P = 0.004) were more common in perioperative stroke compared to non-perioperative stroke. Median NIHSS improvement (2 vs 1, P = 0.002) and median mRS improvement (1 vs 0.5, P = 0.02) at discharge were higher in perioperative patients. Advanced age and higher NIHSS at onset were significantly associated with a poorer prognosis, whereas embolism mechanism was associated with a better prognosis.The etiologies and mechanisms of IHS are complex. Perioperative and non-perioperative IHS have different mechanisms and prognostic features. Determining the causes and mechanisms of IHS will help to identify the population at risk and prevent stroke appropriately during hospitalization.