We aim to optimize the radiological selection and the transfer model in patients with a 6-24h stroke for a fairer and broader access to a reperfusion treatment. The specific objectives are:

1. To confirm that the selection of patients for reperfusion therapies in the late window is safe by applying the same clinical and imaging criteria recommended by clinical guidelines for the early window treatment selection.
2. To evaluate the performance of non-contrast CT by applying immediate post-processing software for the selection of patients for reperfusion treatment in the late window.
3. To analyze the prehospital and arrival variables at the primary stroke center to generate decision trees that optimize the transfer decision in patients with activation of the stroke code in >6h from the onset of symptoms.

METHODOLOGY: Study based on a mandatory, prospective, multicenter registry (CICAT registry) consisting of two phases

1. retrospective analysis with a detailed evaluation of the images of the included patients and generation of "machine learning" models that accurately predict the probability of receiving reperfusion treatment in the late window.
2. validation of the models in a prospective study. Clinical, radiological and transport variables will be studied.

Response variables: rate of patients receiving reperfusion treatment in the late window, functional prognosis at 90 days, hemorrhagic transformation, and mortality.

• SUBSTUDY 1. OPTIMIZATION OF IMAGING SELECTION METHODS FOR SELECTING STROKE PATIENTS FOR REPERFUSION TREATMENT IN THE EXTENDED WINDOW.

  - Inclusion criteria: Consecutive patients registered in the CICAT registry between the years 2019 and 2021 with a stroke who meet the following criteria

  1. Age older than 18 years,
  2. Diagnosis of acute cerebral infarction,
  3. More than six hours of evolution or uncertain chronology of symptoms,
  4. Absence of disability prior to stroke (modified Rankin score 0-2),
  5. NIHSS score>5,
  6. Neuroimaging study including at least one non-contrast cranial CT scan within 60 minutes of arrival at the hospital center.

• SUBSTUDY 2. OPTIMIZATION OF CIRCUITS AND TRANSFER MODEL IN PATIENTS WITH STROKE IN THE EXTENDED WINDOW OF TREATMENT.

  • Inclusion criteria: Selection of consecutive, prospective patients to be included in the CICAT registry between January 2023 and March 2024 with stroke meeting the following criteria:

    1. Age over 18 years,
    2. Suspicion of acute cerebral infarction,
    3. More than six hours of evolution or uncertain chronology of symptoms,
    4. absence of pre-stroke disability (modified Rankin score 0-2),
    5. NIHSS score greater than 5.

Consecutive patients with stroke suspiction in Catalonia included in the CICAT registry