Management of Acute Ischemic Stroke from Left Atrial Myxoma
Urgent surgical excision of the left atrial myxoma should be performed as soon as feasible after acute stroke stabilization, ideally within hours to days, to prevent recurrent embolization and sudden death. 1
Immediate Acute Stroke Management
Initial Stabilization and Assessment
Establish the exact time of symptom onset to determine eligibility for reperfusion therapies (thrombolysis ≤4.5 hours, thrombectomy ≤24 hours in selected cases). 2, 3
Obtain non-contrast CT or MRI within 30 minutes of arrival to exclude hemorrhage and assess infarct size before any intervention. 3
Perform transthoracic echocardiography (TTE) immediately when cardiac source is suspected; if TTE is non-diagnostic, proceed urgently to transesophageal echocardiography (TEE), which has superior sensitivity for detecting left atrial masses. 1
Obtain CT angiography or MR angiography from aortic arch to vertex to identify large vessel occlusions amenable to mechanical thrombectomy and to assess for myxomatous aneurysms (which occur in up to 50% of myxoma embolic stroke cases). 1, 3
Reperfusion Therapy Considerations
Intravenous thrombolysis with alteplase (0.9 mg/kg, max 90 mg) can be administered safely in myxoma-related stroke if the patient meets standard eligibility criteria and presents within 4.5 hours. 4, 5
Case series demonstrate that IV alteplase does not increase hemorrhagic complications specifically related to myxoma embolization. 4, 5
However, efficacy may be limited because tumor emboli (unlike thrombus) do not respond well to fibrinolytic agents; lack of recanalization should not delay definitive surgical management. 5
Mechanical thrombectomy with stent-retriever devices is effective for large vessel occlusions caused by myxoma emboli and should be performed within 6 hours (up to 24 hours in selected cases with favorable imaging). 6, 3
- Stent-retriever thrombectomy successfully removes tumor fragments from cerebral vessels and restores perfusion. 6
Blood Pressure Management
Avoid aggressive blood pressure reduction unless systolic BP >220 mmHg or diastolic BP >120 mmHg, as lowering BP can worsen cerebral perfusion in acute stroke. 2
If BP reduction is required, lower cautiously by approximately 15% using easily titratable agents such as labetalol or nicardipine. 2
Cardiac Surgical Timing: The Critical Decision
Rationale for Urgent Surgery
The American College of Cardiology assigns urgent surgical resection of symptomatic left atrial myxoma a Class I recommendation because the tumor carries a 25% overall embolism rate, with stroke being the presenting symptom in up to 50% of cases. 1
Villous or papillary surface architecture (visible on echocardiography or cardiac MRI) indicates markedly higher embolic risk and reinforces the need for immediate surgery. 1
Delaying surgery exposes the patient to recurrent embolization, sudden death from mitral valve obstruction, and progressive neurological deterioration. 1, 7
Timing Algorithm
Emergency cardiac surgery within 2–24 hours of stroke onset is recommended when:
The ischemic infarct is small to moderate on imaging (not involving >1/3 of MCA territory). 7, 8
The patient is neurologically stable without signs of malignant cerebral edema or herniation. 7
No hemorrhagic transformation is present on initial or 24-hour follow-up imaging. 4, 8
Case reports document successful outcomes with myxoma resection performed as early as 2 hours post-stroke in carefully selected patients. 7
Delay surgery by 7–14 days if:
Hemorrhagic transformation develops on follow-up imaging, as systemic anticoagulation during cardiopulmonary bypass may extend hemorrhage. 4, 8
The infarct is large (>1/3 MCA territory) with significant mass effect or risk of malignant edema. 8
The patient demonstrates neurological instability or deterioration. 9
Surgical Technique
Complete tumor excision with an adequate margin of atrial septum (typically including the fossa ovalis attachment site) is essential to prevent recurrence (1–5% in sporadic cases). 1
Histopathologic confirmation is mandatory; myxomas show characteristic lepidic cells in myxoid matrix, positive for vimentin and calretinin. 1
Perioperative Antithrombotic Management
Before Cardiac Surgery
Do not initiate therapeutic anticoagulation (unfractionated heparin or LMWH) for acute stroke in the setting of myxoma, as it increases hemorrhagic risk without preventing tumor embolization. 9, 2, 3
- Anticoagulation and antiplatelet therapy alone are inadequate to prevent embolic complications from myxoma and should not substitute for definitive surgical resection. 1
Administer aspirin 160–325 mg within 24–48 hours after stroke onset (after imaging excludes hemorrhage) unless surgery is planned within that timeframe. 2, 3
- If the patient received IV alteplase, delay aspirin until >24 hours post-thrombolysis to minimize hemorrhage risk. 2, 3
VTE Prophylaxis
Use subcutaneous LMWH (e.g., enoxaparin 40 mg daily) or unfractionated heparin 5,000 IU twice daily for venous thromboembolism prophylaxis in immobilized stroke patients. 3
Add intermittent pneumatic compression for additional VTE risk reduction. 3
Management of Associated Myxomatous Aneurysms
Screen for intracranial myxomatous aneurysms with CT or MR angiography in all patients with myxoma-related stroke, as these fusiform aneurysms form from tumor cell metastasis to vessel walls and carry high rupture risk. 1, 7
Perform endovascular coiling or stenting of myxomatous aneurysms 7–14 days after cardiac surgery once the patient is stable and the myxoma source has been eliminated. 7
- Early treatment (within 1–2 weeks) is recommended because these aneurysms are friable and prone to rupture. 7
Post-Surgical Monitoring and Follow-Up
Admit to a stroke unit or neurocritical care unit for at least 24–48 hours post-operatively, as 25–30% of stroke patients experience neurological worsening during this period. 9, 2
Perform serial echocardiography at 6 months and then annually to monitor for myxoma recurrence (1–5% risk in sporadic cases, higher in familial Carney complex). 1
Initiate secondary stroke prevention with antiplatelet therapy (clopidogrel 75 mg daily preferred over aspirin alone), high-intensity statin therapy (target LDL <70 mg/dL), and blood pressure control. 3
Critical Pitfalls to Avoid
Do not delay cardiac surgery for weeks or months in stable patients; the risk of recurrent embolization outweighs concerns about operating in the subacute stroke period. 1, 7
Do not rely on anticoagulation or antiplatelet therapy as definitive treatment; these agents do not prevent tumor embolization or relieve mechanical obstruction. 1
Do not overlook hemorrhagic transformation on 24-hour and day 7–11 follow-up imaging, as this finding mandates postponing surgery until hemorrhage resolves. 4, 8
Do not assume all embolic strokes in young patients are cryptogenic; obtain TEE to exclude cardiac sources such as myxoma, especially when atherosclerotic risk factors are absent. 1