Updates in Acute Ischaemic Stroke Management

The hyperacute management of stroke generally refers to treatment in the first 24 hours of onset of symptoms and focuses on minimising brain injury. This includes time critical reperfusion therapies: intravenous thrombolysis (IVT) as well as endovascular clot retrieval (ECR) for stroke due to large vessel occlusion (LVO).

Dr Darshan Ghia, neurologist, Karrinyup
Pre-hospital triage

Selected hospital emergency departments administer the hyperacute therapies. Patients with LVO benefit from direct transportation to an intervention centre, while non-LVO stroke patients need rapid IVT in the nearest stroke centre. Numerous prehospital stroke scales have been developed to identify stroke patients with LVO in the prehospital setting based on their clinical symptoms.

In Perth, hospitals variably can administer both IVT and ECR 24/7, IVT 24/7 and ECR during the daytime, IVT 24/7 or neither hyperacute therapy.  A strategy covering such heterogeneity while avoiding the double handling of a stroke patient is challenging. Based on a previous Perth observational study, St John Ambulance staff will apply the FAST (Face Arm Speech Time) criteria to identify stroke in the community if it presents within eight hours. 

If positive, then RACE (Rapid Arterial oCclusion Evaluation) score is applied. This is a simple tool that can accurately assess stroke severity and identify patients with acute stroke with LVO in a prehospital setting. The ambulance services have an algorithm allowing them to take the patient to the appropriate hospital based on the time of the onset, above scales, time of the day and the day of the week. 

Any patient presenting to the primary practice within the first 24 hours of the onset of stroke symptoms or time-last-well warrants calling an ambulance.

Intravenous thrombolysis

For patients with potentially disabling ischaemic stroke within 4.5 hours of onset who meet specific eligibility criteria, intravenous thrombolysis with alteplase should be administered as early as possible after stroke onset. Screening for the strict eligibility criteria will be done by the stroke team. 

For patients with potentially disabling ischaemic stroke without LVO who meet specific clinical and brain imaging eligibility criteria, tenecteplase may be used as an alternative to alteplase within 4.5 hours of onset.

In patients with potentially disabling ischaemic stroke meeting perfusion mismatch criteria or MRI FLAIR-diffusion mismatch criteria in addition to standard clinical criteria, IVT can be administered beyond the standard 4.5 hours based on the updated stroke guidelines.

Endovascular clot retrieval

For patients with ischaemic stroke caused by a large vessel occlusion in the internal carotid artery, proximal middle cerebral artery (M1 segment), or with tandem occlusion of both the cervical carotid and intracranial large arteries, ECR should be undertaken when the procedure can be commenced within six hours of stroke onset. 

ECR should be undertaken when the procedure can be commenced between 6-24 hours after they were last known to be well if clinical and CT perfusion or MRI features indicate the presence of salvageable brain tissue.

Eligible stroke patients should receive IVT while concurrently arranging ECR, with neither treatment delaying the other. In selected stroke patients with occlusion of the basilar artery, ECR should be undertaken. For patients with ischaemic stroke caused by occlusion in the M2 segment of the middle cerebral artery, ECR may be considered.   

Antithrombotic treatment 

Aspirin plus clopidogrel (dual antiplatelet) should be commenced within 24 hours and used in the short term (first three weeks) in patients with minor ischaemic stroke or high-risk TIA to prevent stroke recurrence. Treatment should commence with a loading dose of 300mg aspirin and 300-600mg clopidogrel followed by 100-150mg aspirin and 75mg clopidogrel daily for a total of 21 days and a single antiplatelet agent thereafter.

Most cryptogenic strokes are likely embolic. This understanding is captured by a related concept, termed embolic stroke of undetermined source (ESUS), defined as a nonlacunar brain infarct without proximal arterial stenosis or cardioembolic sources. 

Subclinical and paroxysmal AF is associated with an increased risk of embolic events including ESUS. Consider long-term cardiac monitoring for AF detection in patients selected by stroke physicians after appropriate stroke work-up. Initiate direct oral anticoagulants (DOACs) in preference to warfarin for patients with non-valvular atrial fibrillation and adequate renal function.

In patients under 60 with ischaemic stroke, where patent foramen ovale is considered the likely cause of stroke (after exclusion of other aetiologies by stroke physician), percutaneous closure of the PFO is recommended.

Key messages
  • In patients experiencing signs of stroke call the ambulance for immediate transfer to hospital and potential hyperacute treatment
  • Administer dual antiplatelet therapy in all patients with high-risk TIA and minor ischaemic stroke after ruling out bleeding on neuroimaging.

– References available on request
Author competing interests – nil