What is the appropriate emergency department evaluation and management for a patient presenting with a transient ischemic attack?

Emergency Department Evaluation and Management of Transient Ischemic Attack

Immediate Actions Upon Arrival

All patients presenting within 48 hours of suspected TIA with unilateral weakness, facial weakness, or speech disturbance require immediate emergency department evaluation with advance notification of the stroke team—this is a medical emergency with stroke risk as high as 10% in the first week without urgent treatment. 1

Critical Time-Sensitive Triage

• Patients presenting within 48 hours with motor weakness or speech symptoms must have their complete diagnostic workup finished within 24 hours of arrival. 1
• The highest stroke risk occurs in the first 48 hours, with half of all recurrent strokes happening in the first 2 days. 1
• Modern specialized stroke care reduces 7-day stroke risk from historical rates of 10-11% down to approximately 2.1%, representing an 80% relative risk reduction—but only when evaluation is immediate. 1

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Mandatory Diagnostic Workup (Complete Within 24 Hours)

Brain Imaging

• MRI with diffusion-weighted imaging (DWI) is the preferred modality, detecting acute infarction in approximately 31% of TIA patients and identifying those at highest risk for recurrent stroke. 1, 2
• MRI-DWI has 77% sensitivity for detecting ischemic lesions compared to only 16% for CT in the first few hours. 2
• Non-contrast CT is acceptable when MRI is unavailable, but it must be performed immediately to exclude hemorrhage and stroke mimics. 1

Vascular Imaging

• CT angiography from aortic arch to vertex should be obtained immediately at the time of the initial brain CT to evaluate both extracranial and intracranial vessels in a single study. 1, 2
• CTA is the preferred first-line vascular imaging because it provides a complete cerebrovascular assessment concurrently with brain imaging. 1
• When CTA is unavailable or contraindicated, acceptable alternatives include carotid duplex ultrasound (extracranial only) or MR angiography. 1, 2
• Symptomatic carotid stenosis ≥70% requires urgent revascularization within 2 weeks; the benefit of carotid endarterectomy diminishes rapidly after this window. 1, 2

Cardiac Evaluation

• A 12-lead ECG must be obtained immediately upon arrival to detect atrial fibrillation, atrial flutter, or structural heart disease. 1, 2
• Continuous cardiac monitoring for at least 24 hours is recommended to detect paroxysmal atrial fibrillation in patients who may be candidates for anticoagulation. 1
• When a cardioembolic source such as atrial fibrillation is identified, anticoagulation should be started instead of antiplatelet therapy. 1

Laboratory Assessment

• Immediate laboratory panel must include: complete blood count, basic metabolic panel (electrolytes, renal function), coagulation studies (aPTT, INR), random glucose or HbA1c, and cardiac troponin. 1, 2
• Fasting lipid profile should be obtained during the initial hospitalization or early outpatient follow-up. 1, 2

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Admission Criteria (Mandatory Hospitalization)

Patients must be admitted when ANY of the following high-risk features are present: 1

• Acute cerebral infarction detected on brain imaging 1
• Large artery atherosclerosis with symptomatic carotid stenosis >50% 1
• Known cardiac embolic source (atrial fibrillation, mechanical valve) 1
• Crescendo TIAs (multiple, increasingly frequent episodes) 1
• Symptom duration >1 hour at presentation 1
• Known hypercoagulable state 1

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Safe Discharge Criteria (All Must Be Met)

Patients can be discharged after 24 hours only if the complete diagnostic workup demonstrates: 1

• No acute infarction on brain imaging (MRI-DWI preferred) 1
• No embolic source requiring immediate anticoagulation 1
• No significant carotid stenosis (≥50%) requiring urgent revascularization 1
• Complete vascular imaging from aortic arch to vertex has been performed 1
• Outpatient neurology follow-up within 2-4 weeks is confirmed and arranged 1

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Critical Pitfalls to Avoid

• Never discharge patients with crescendo TIAs under any circumstances—they require immediate hospitalization regardless of imaging results. 1
• Do not rely solely on ABCD² scores for disposition decisions; they supplement but do not replace comprehensive imaging and evaluation. 1
• Do not delay carotid imaging in anterior circulation TIAs, as the 2-week window for urgent revascularization begins at symptom onset. 1
• Never discharge without confirming outpatient follow-up arrangements and instructing patients to return immediately if symptoms recur. 1
• When MRA and transthoracic echo are normal, carotid duplex ultrasound is still mandatory—correlating findings from at least two imaging modalities is a quality-assurance requirement. 1

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Immediate Medical Management

• Antiplatelet therapy should be initiated immediately in the emergency department unless a cardioembolic source is identified. 1
• Statin therapy should be started regardless of baseline lipid levels. 1
• Blood pressure optimization should begin immediately, targeting <140/90 mmHg (<130/80 mmHg for diabetes). 1

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Special Consideration: Monocular Vision Loss

• Transient monocular vision loss (amaurosis fugax) is treated as an urgent TIA and requires immediate emergency department evaluation with stroke-center capabilities. 1
• These patients require the same comprehensive vascular imaging as other TIA presentations. 1

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Evidence Strength

The 2018 Canadian Stroke Best Practice Recommendations provide Level A (strong) evidence that immediate evaluation in specialized stroke centers reduces stroke recurrence by approximately 80%, with the EXPRESS and SOS-TIA trials demonstrating 90-day stroke risk reduction from historical 10-20% down to 2-3%. 1 Multiple high-quality guidelines from the American Heart Association/American Stroke Association converge on these Class I recommendations for comprehensive urgent evaluation. 1, 2