What is the appropriate urgent workup and secondary‑prevention strategy for a patient with recurrent transient ischemic attacks?

Management of Recurrent Transient Ischemic Attacks

Patients with recurrent TIAs require immediate emergency department evaluation with brain and vascular imaging completed within 24 hours, as the risk of major stroke reaches 36% within 7 days for high-risk patients, but this risk can be reduced by up to 80% with urgent specialist assessment and treatment initiation. 1

Immediate Triage and Risk Stratification

Very High Risk (Symptoms within 48 hours)

Patients presenting within 48 hours with unilateral weakness (face, arm, or leg) or speech disturbance/aphasia are at highest risk and require: 1

• Immediate transfer to an emergency department with advanced stroke capabilities (on-site brain imaging and access to acute stroke treatments) 1
• This population has a 3-6% stroke risk within 1-4 weeks and up to 24% may have concurrent stroke on MRI 2

High Risk (48 hours to 2 weeks)

Patients presenting between 48 hours and 2 weeks with motor weakness or speech disturbance need comprehensive evaluation by stroke specialists within 24 hours of first healthcare contact 1

Urgent Diagnostic Workup

Neuroimaging (Priority #1)

• Brain imaging (CT or MRI) plus noninvasive vascular imaging (CTA or MRA from aortic arch to vertex) within 24 hours 1
• CT angiography is the preferred initial test as it simultaneously evaluates extracranial and intracranial circulation in one study 1
• MRI with DWI/FLAIR sequences is more sensitive than CT for detecting small infarcts and posterior circulation strokes; obtain if initial CT is negative 2
• Up to 24% of concurrent strokes may be missed by CT alone, particularly in retinal artery occlusion patients 2

Vascular Assessment

• CTA from aortic arch to vertex identifies large-vessel stenosis, occlusions, arterial dissection, and moyamoya disease 1, 2
• Carotid ultrasound or MRA are acceptable alternatives if CTA unavailable, based on immediate availability 1
• Vascular imaging is mandatory to identify symptomatic carotid stenosis requiring revascularization 1

Cardiac Evaluation

• 12-lead ECG without delay to detect atrial fibrillation 1
• Transthoracic echocardiography as initial cardiac assessment 2
• Long-term rhythm monitoring (mobile cardiac telemetry or implantable loop recorder) for cryptogenic cases to detect paroxysmal atrial fibrillation 2
• Consider transesophageal echocardiography, cardiac CT, or cardiac MRI when embolic stroke of undetermined source is suspected 2

Laboratory Tests (Do Not Delay Imaging)

Complete within 48 hours but never postpone neuroimaging while awaiting results: 1, 2

• Complete blood count, PT/aPTT, INR (verify before thrombolysis in warfarin patients) 1, 2
• Electrolytes, creatinine, eGFR 1
• Random glucose or HbA1c 1
• Troponin 1
• Fasting or non-fasting lipid profile 1, 2

Secondary Prevention Strategy

Antiplatelet Therapy

The Canadian Stroke Best Practice guidelines recommend initiating antiplatelet therapy immediately, with options including aspirin, clopidogrel, or aspirin plus extended-release dipyridamole for noncardioembolic stroke 1, 3

Anticoagulation

For cardioembolic stroke (particularly atrial fibrillation), anticoagulation is the recommended preventive treatment 3, 4

Carotid Revascularization

Patients with symptomatic carotid stenosis identified on vascular imaging require urgent referral for possible carotid endarterectomy or stenting 1, 4

Aggressive Risk Factor Management

Immediate initiation of: 1

• Antihypertensive agents
• High-intensity statin therapy (lipid-lowering agents)
• Glucose control for diabetics
• Lifestyle modification counseling (though information alone without behavioral intervention is ineffective) 1

Critical Pitfalls to Avoid

• Never delay imaging or treatment waiting for laboratory results unless clinical suspicion of bleeding disorder, thrombocytopenia, or anticoagulant use 2
• Do not rely solely on CT within first 24 hours—19-25% of patients with acute retinal or cerebral artery occlusion have silent infarctions detectable only on DWI-MRI 2
• Avoid dismissing recurrent TIAs as low-risk—patients with multiple risk factors have up to 36% 7-day stroke risk 1
• Rapid-access TIA clinics reduce 90-day stroke risk from 10.3% to 2.1% compared to delayed assessment 1

Evidence for Urgent Intervention

The EXPRESS study and TIA Registry.Org data demonstrate that immediate specialist evaluation and treatment initiation through rapid-access TIA clinics reduces stroke recurrence rates by approximately 80%, with 90-day stroke risk dropping from historical rates of 12-20% to 2.1-3.7% 1, 5, 4