What are the current 2023‑2024 guidelines for acute ischemic stroke evaluation, reperfusion therapy, and secondary prevention?

Recent Stroke Guidelines (2023–2024): Acute Ischemic Stroke Evaluation, Reperfusion Therapy, and Secondary Prevention

Acute Evaluation and Initial Imaging

Obtain an urgent non-contrast CT or MRI immediately upon hospital arrival to exclude intracranial hemorrhage before any specific treatment is initiated. 1 This imaging must not be delayed by laboratory testing, though a fingerstick glucose should be checked simultaneously. 2

• Assess stroke severity using the NIH Stroke Scale (NIHSS) to quantify the deficit and guide treatment decisions; minor stroke is defined as NIHSS ≤3, moderate-to-severe as NIHSS >3. 1, 3
• Perform non-invasive vascular imaging (CT angiography or MR angiography) to identify large vessel occlusion, particularly in patients with suspected internal carotid artery or middle cerebral artery occlusion. 2
• Obtain basic laboratory tests (complete blood count, coagulation studies, electrolytes, creatinine, glucose, HbA1c, lipid profile, troponin) but do not delay reperfusion therapy while awaiting results. 1
• Perform at least 24 hours of cardiac monitoring to screen for atrial fibrillation and other arrhythmias; for patients with embolic stroke of undetermined source, extend monitoring to at least 14 days. 1

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Reperfusion Therapy

Intravenous Thrombolysis

Administer IV alteplase (0.9 mg/kg, maximum 90 mg over 60 minutes with 10% as initial bolus) to eligible patients within 4.5 hours of symptom onset or last known well. 2, 4 The treatment effect is time-dependent, with maximal benefit when given within the first 90 minutes. 5

• Eligibility criteria: Ischemic stroke with measurable neurological deficit, symptom onset <4.5 hours, no intracranial hemorrhage on imaging, systolic BP <185 mmHg and diastolic BP <110 mmHg. 2
• For patients with unclear time of onset >4.5 hours from last known well, IV alteplase may be beneficial if MRI demonstrates DWI-FLAIR mismatch (indicating stroke occurred <4.5 hours before imaging). 2
• Only blood glucose assessment must precede IV alteplase initiation; do not delay for other laboratory results. 2
• Tenecteplase is emerging as an alternative to alteplase in select patients, though alteplase remains the standard of care in most guidelines. 4

Mechanical Thrombectomy

Mechanical thrombectomy is strongly recommended for patients with large vessel occlusion (internal carotid artery or proximal middle cerebral artery) who meet the following criteria: age ≥18 years, pre-stroke modified Rankin Scale (mRS) 0–1, NIHSS ≥6, ASPECTS ≥6, and treatment can be initiated within 6 hours of symptom onset. 2

• Extended time window (6–24 hours): Thrombectomy is also recommended in patients with sizable mismatch between ischemic core and hypoperfusion area on CT perfusion or MRI perfusion imaging. 2, 4
• Do not wait to evaluate response to IV thrombolysis before proceeding with catheter angiography for mechanical thrombectomy; eligible patients should receive both treatments without delay. 2
• The technical goal is reperfusion to modified Thrombolysis in Cerebral Infarction (mTICI) grade 2b/3. 1, 2
• Posterior circulation strokes (basilar artery occlusion) are also candidates for mechanical thrombectomy, with treatment windows extending up to 24 hours in select cases. 4

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Acute In-Hospital Management

Admit all stroke patients to a specialized stroke unit, which reduces mortality and improves functional outcomes compared with general medical wards. 1, 2

Blood Pressure Management

• Before IV thrombolysis: Lower BP to <185/110 mmHg. 2
• After reperfusion therapy: Maintain BP <180/105 mmHg for at least 24 hours. 2
• For patients not receiving reperfusion therapy: Permissive hypertension is generally recommended unless BP exceeds 220/120 mmHg or there are other compelling indications for acute BP lowering. 1

Antiplatelet Therapy

Administer aspirin 160–325 mg as a single loading dose within 24–48 hours after intracranial hemorrhage has been excluded on imaging. 3, 6 This reduces early recurrent stroke and mortality. 6

• If IV thrombolysis was given, delay aspirin for at least 24 hours after thrombolysis and obtain repeat imaging to confirm no hemorrhagic transformation. 3, 6
• For minor stroke (NIHSS ≤3) or high-risk TIA (ABCD² ≥4) presenting within 24 hours: Initiate dual antiplatelet therapy (DAPT) with clopidogrel 300 mg loading dose plus aspirin 160–325 mg loading dose, followed by clopidogrel 75 mg daily plus aspirin 75–100 mg daily for exactly 21 days, then transition to single antiplatelet therapy. 3
• Do not use DAPT beyond 21–30 days in routine secondary prevention, as bleeding risk outweighs benefit. 3

Other Supportive Measures

• Provide supplemental oxygen to maintain oxygen saturation ≥94%. 2
• Monitor and treat fever (>38°C) with antipyretics. 2
• Screen for dysphagia before allowing oral intake to prevent aspiration pneumonia. 1
• Initiate DVT prophylaxis with intermittent pneumatic compression or subcutaneous heparin in immobilized patients. 1
• Begin early mobilization within 24–48 hours if medically stable. 1

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Management of Massive Stroke with Cerebral Edema

Perform serial neurological examinations and repeat head CT to identify worsening brain swelling, particularly in patients with large hemispheric infarctions. 2

• Decompressive hemicraniectomy is indicated within 48 hours of symptom onset in patients ≤60 years old with massive hemispheric infarction (>50% of middle cerebral artery territory), NIHSS >15, and worsening neurological condition despite medical management. 2
• Immediately intubate patients who develop neurological deterioration with respiratory insufficiency. 2

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Secondary Prevention

Antiplatelet Therapy

For noncardioembolic stroke, continue single antiplatelet therapy indefinitely:

• First-line: Aspirin 75–100 mg daily. 3, 6
• Alternative for aspirin intolerance or diabetes: Clopidogrel 75 mg daily. 3, 6
• Alternative regimen: Aspirin 25 mg plus extended-release dipyridamole 200 mg twice daily. 3

Anticoagulation

If atrial fibrillation is detected (CHA₂DS₂-VASc score ≥2 in men or ≥3 in women), switch from antiplatelet therapy to oral anticoagulation:

• Preferred: Direct oral anticoagulants (apixaban, dabigatran, rivaroxaban, edoxaban). 6
• Alternative: Warfarin with target INR 2.0–3.0. 6
• Do not use oral anticoagulation for noncardioembolic stroke; antiplatelet therapy is the standard. 3

Lipid Management

Initiate high-intensity statin therapy (atorvastatin 80 mg daily) targeting LDL <70 mg/dL in all patients with ischemic stroke or TIA. 6

Blood Pressure Control

Target systolic BP <140 mmHg (or <130 mmHg if tolerated), especially in patients with intracranial atherosclerosis. 6 Select antihypertensive class based on comorbidities (ACE inhibitors or ARBs for diabetes, thiazide diuretics for isolated systolic hypertension). 6

Carotid Revascularization

For patients with symptomatic 70–99% internal carotid artery stenosis, carotid endarterectomy is recommended if the 30-day risk of procedural death/stroke is <6%. 2 Surgery should be performed within 14 days of symptom onset. 2

• After carotid endarterectomy or stenting: Continue DAPT (aspirin plus clopidogrel) for at least 1 month, then transition to single antiplatelet therapy. 2
• Revascularization is not recommended for stenosis <50%. 2

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Follow-Up and Surveillance

Schedule follow-up within 72 hours of hospital discharge with a stroke specialist or primary care provider to assess rehabilitation needs and medication adherence. 1

• Perform vascular imaging (carotid Doppler ultrasound) at 1 month, 6 months, then annually to assess for stenosis progression. 6
• Review cardiovascular risk factors and treatment compliance at least yearly. 2
• Encourage participation in evidence-based community exercise programs and structured aerobic exercise. 1

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Common Pitfalls to Avoid

• Do not delay reperfusion therapy while awaiting complete laboratory results or specialty consultation; time is brain. 5
• Do not substitute aspirin for thrombolysis or thrombectomy in eligible patients; this delays definitive treatment and worsens outcomes. 3
• Do not use glycoprotein IIb/IIIa inhibitors (abciximab, eptifibatide, tirofiban) in acute ischemic stroke; they are potentially harmful. 3
• Do not extend DAPT beyond 21–30 days without a separate cardiac indication (e.g., recent coronary stent); bleeding risk outweighs benefit. 3
• Do not use ticagrelor instead of clopidogrel for acute minor stroke; it carries higher bleeding risk without proven benefit. 3