What is the recommended immediate treatment for a patient presenting with a large cardioembolic ischemic stroke?

Immediate Treatment of Large Cardioembolic Ischemic Stroke

For a patient presenting with a large cardioembolic ischemic stroke, immediately obtain non-contrast head CT within 10-25 minutes of arrival to exclude hemorrhage, then administer IV alteplase (0.9 mg/kg, maximum 90 mg) if the patient presents within 4.5 hours of symptom onset and meets eligibility criteria, while simultaneously preparing for endovascular thrombectomy if CT angiography demonstrates large vessel occlusion. 1, 2, 3

Hyperacute Phase (First Minutes to Hours)

Immediate Imaging Protocol

• Perform non-contrast head CT immediately upon emergency department arrival (door-to-imaging ≤10-25 minutes) to rule out intracranial hemorrhage before any antithrombotic therapy 1, 3
• Obtain CT angiography from aortic arch to vertex simultaneously if the patient presents within 6 hours of symptom onset to identify large vessel occlusions amenable to thrombectomy 2, 3
• Do not delay IV alteplase for advanced imaging (CT perfusion or MRI) when non-contrast CT already confirms eligibility 3

Blood Pressure Management Before Thrombolysis

• Lower blood pressure to <185/110 mmHg before initiating alteplase using IV labetalol (10-20 mg) or nicardipine (5 mg/h) 1, 2, 3
• Maintain blood pressure ≤180/105 mmHg during the alteplase infusion and for 24 hours afterward 1, 2, 3
• Each 10% decline in blood pressure increases odds of unfavorable outcome by approximately 89%, so avoid rapid reductions 1

IV Alteplase Administration

Eligibility criteria for large cardioembolic strokes:

• Clearly defined symptom onset within 4.5 hours (3 hours is strongest evidence, 3-4.5 hours is Grade 2C) 1, 2
• Non-contrast CT shows no intracranial hemorrhage 2, 3
• If on oral anticoagulation, INR must be <1.5 (if INR >1.7, thrombolysis is contraindicated) 1, 3
• Platelet count >100 × 10³/µL and blood glucose >50 mg/dL 3

Dosing protocol:

• Total dose: 0.9 mg/kg (maximum 90 mg total) 1, 2, 3
• Give 10% as IV bolus over 1 minute 1, 2, 3
• Infuse remaining 90% over 60 minutes 1, 2, 3

Critical monitoring after alteplase:

• Neurological status and vital signs every 15 minutes during infusion and for 2 hours afterward 2, 3
• Then every 30 minutes for 6 hours, then hourly until 24 hours 2, 3

Endovascular Thrombectomy

• Perform mechanical thrombectomy for large vessel occlusions (internal carotid artery, M1/M2 MCA segments) within 6 hours of symptom onset 4, 2, 3
• Do not delay or withhold IV alteplase while awaiting endovascular therapy—both treatments are complementary and should be delivered in parallel 4, 2, 3
• For patients presenting 6-24 hours after last known well with large vessel occlusion, use advanced imaging (CT perfusion or DW-MRI) to determine eligibility based on core/perfusion mismatch 4
• Target reperfusion to modified TICI grade 2b/3 using combined stent-retriever and aspiration technique 2

Acute In-Hospital Management (First 24-48 Hours)

Stroke Unit Admission

• Admit all patients to a geographically defined stroke unit with specialized nursing staff within 24 hours—this reduces mortality and dependency across all stroke subtypes 4, 2, 3
• Approximately 25% of patients deteriorate neurologically during the first 24-48 hours, requiring close monitoring 4, 1

Cardiac Monitoring and Workup

• Institute continuous cardiac monitoring for at least 24 hours to detect atrial fibrillation and life-threatening arrhythmias 1, 2, 3
• Obtain 12-lead ECG to confirm atrial fibrillation, but do not let ECG acquisition delay neuroimaging or thrombolysis 1
• Perform echocardiography (at least transthoracic) to identify cardiac sources of embolism, especially when no other cause is identified 4

Antiplatelet Therapy Timing

• Delay aspirin for 24 hours after IV alteplase 2, 3
• Obtain follow-up head CT at 24 hours post-thrombolysis; if no hemorrhage is present, start aspirin 150-325 mg daily 2, 3
• For patients who did not receive thrombolysis, give aspirin 160-325 mg within 24-48 hours of stroke onset 4, 1, 2

Anticoagulation Timing for Cardioembolic Stroke

The timing of anticoagulation initiation depends on stroke severity (NIHSS score): 1

• TIA (no infarct): Start oral anticoagulation 1 day after the event 1
• Mild stroke (NIHSS <8): Start oral anticoagulation 3 days after the event 1
• Moderate stroke (NIHSS 8-15): Start oral anticoagulation 6 days after the event 1
• Severe stroke (NIHSS ≥16): Start oral anticoagulation 12 days after the event 1

This algorithm balances the risk of recurrent embolism against the risk of hemorrhagic transformation in large infarcts 1

Physiological Parameter Management

• Maintain oxygen saturation >94% with supplemental oxygen 4, 2
• Monitor temperature every 4 hours for 48 hours; treat fever >37.5-38°C aggressively with antipyretics and investigate the source 2, 3
• Check capillary blood glucose immediately; treat hypoglycemia (<60 mg/dL or 3.3 mmol/L) with IV dextrose 4
• Correct hypotension and hypovolemia to maintain systemic perfusion; use isotonic normal saline for euvolemia (volume expanders for hemodilution are not recommended) 4, 1

Venous Thromboembolism Prophylaxis

• Apply thigh-high intermittent pneumatic compression devices for patients with restricted mobility 1, 3
• Prophylactic-dose heparin is also recommended for immobile patients 1
• Elastic compression stockings are not recommended for DVT prevention 1

Management of Malignant Cerebral Edema (Critical Complication in Large Strokes)

Risk Identification and Monitoring

• Identify high-risk patients: large territorial infarcts involving >50% of MCA territory or >1/3 of MCA territory on early CT 3
• Monitor closely with serial neurological examinations and repeat head CT as clinical status changes 3

Decompressive Hemicraniectomy

For patients ≤60 years with malignant MCA infarction: 3

• Perform decompressive hemicraniectomy within 48 hours of symptom onset if the patient deteriorates despite medical therapy 3
• Surgery reduces mortality by ~50%; at 12 months, 55% achieve moderate disability (mRS 3) and 18% achieve independence (mRS 0-2) 3

For patients >60 years: 3

• Surgery may be considered but outcomes are less favorable: mortality falls to 42%, but none achieve independence and only 11% attain moderate disability 3

For cerebellar infarctions with brainstem compression: 3

• Perform decompressive suboccipital craniectomy within 48 hours 3
• Consider ventriculostomy for symptomatic obstructive hydrocephalus 3

Transfer patients at risk for malignant edema early to a center with neurosurgical expertise 3

Critical Pitfalls to Avoid

• Never delay thrombolysis to obtain perfusion imaging or MRI when eligibility is established by non-contrast CT 3
• Never administer antiplatelet agents or anticoagulants within 24 hours after alteplase without confirming absence of hemorrhage on follow-up imaging 2, 3
• Never use systemic anticoagulation acutely in large cardioembolic strokes—follow the severity-based timing algorithm to prevent hemorrhagic transformation 1
• Every 30-minute delay in recanalization decreases good functional outcome by 8-14%, so parallel processing of imaging, laboratory studies, and treatment decisions is essential 2
• Do not evaluate response to IV thrombolysis before proceeding with catheter angiography for mechanical thrombectomy 4
• Do not use corticosteroids for cerebral edema in ischemic stroke 2
• Failure to obtain follow-up imaging at 24 hours before starting antiplatelets or anticoagulants significantly increases hemorrhage risk 2