The aim of this study is to determine whether early administration of aspirin in acute ischemic stroke patients treated with systemic thrombolysis is safe and can improve outcomes due to decreasing the number of early rethromboses.

According to the current guidelines (European Stroke Organisation, 2009; American Heart Association-American Stroke Association, 2013) on the systemic thrombolysis in ischemic stroke patients it is recommended (class C) to start antithrombotic therapy (including antiplatelets and anticoagulants) when 24 hours go after alteplase (rtPA, recombinant tissue plasminogen activator) administration. Meanwhile rtPA has wery short lifetime in blood (T1/2 4-6 minutes). Some retrospective studies have found that early administration of antithrombotics (8-16 hours) after systemic thrombolysis can improve functional outcome and does not increase the risk of haemorrhage.

The investigators suggest a controlled prospective trial to recognise risks and benefits of early administration of aspirin (in 12 hours) after rtPA therapy in patients with acute ischemic stroke.

Inclusion Criteria:

• acute ischemic stroke patients treated with rtPA
• mRS score before current stroke <4
• NIHSS score after rtPA treatment <25

Exclusion Criteria:

• contraindications for treatment with aspirin
• contraindications fot iodinated radiocontrast agents administration
• intracranial haemorrhage after rtPA treatment