The aim of this study is to evaluate the impact of a standardized alarming system on treatment times and workflow in stroke patients with interhospital transfer for mechanical thrombectomy (MT). The main questions it aims to answer are:

• Is the implementation of a standardized alarming system associated with shorter transfer and treatment times?
• Is the implementation of a standardized alarming system associated with a better adherence on existing standard operating procedures for interhospital transfer? We will analyze data from our existing thrombectomy registry comparing time periods before and after introduction of the MT alarming system.

Inclusion Criteria:

• age >= 18 years
• diagnosis of acute ischemic stroke
• indication for mechanical thrombectomy
• admission to one of 7 participating primary stroke centers within in the catchment area of the referral center

Exclusion Criteria:

• unclear indication for mechanical thrombectomy (patients admitted for perfusion imaging before decision for or against a MT)

Acute ischemic stroke patients admitted to one of 7 nonurban primary stroke centers with subsequent interhospital transfer to a referral center for mechanical thrombectomy in Southeast Bavaria, Germany.

No plan to make IPD available to other researchers.