Management of Stroke Post-Cardiac Surgery

Diagnostic Evaluation

The American College of Cardiology recommends performing an urgent non-contrast CT brain scan to differentiate hemorrhagic from ischemic stroke, as this determines all subsequent management decisions 1, 2, 3, 4
Assess for air embolism as the etiology, which is a recognized complication of mitral valve procedures due to inadequate de-airing techniques or device manipulation 5
Obtain transesophageal echocardiography (TEE) to evaluate for residual thrombus on the repair site, valve dysfunction, or ongoing embolic sources 1, 3

If air embolism is suspected, coordinate immediate transfer to a hyperbaric oxygen therapy (HBOT) facility while stabilizing the patient, as HBOT is the standard treatment for iatrogenic air embolism and can dramatically increase oxygen delivery to ischemic tissue 5
The American Heart Association/American Stroke Association recommends HBOT for ischemic neurological symptoms secondary to air embolism, though it is NOT recommended for routine ischemic stroke 5
If non-hemorrhagic thrombotic stroke, initiate anticoagulation with unfractionated heparin without a loading dose once the CT scan confirms absence of hemorrhage 1, 2, 3, 4

Begin heparin when the aPTT has decreased to less than twice the normal control value, targeting an aPTT of 1.5 to 2 times normal (55 to 80 seconds) 1, 2, 3, 4
The initial heparin dosage should be approximately 1,300 U/hour, with average total dosage of 20,000 to 40,000 U/24 hours 1, 2, 3, 4
Monitor aPTT closely: check four times every 6 hours for the first 24 hours, then three times every 8 hours, then daily due to rapidly changing levels of fibrinogen and heparin binding proteins 1, 2, 3, 4

Begin warfarin simultaneously with heparin once the patient is stabilized and hemorrhage has been definitively excluded 1, 2, 3, 4
Target INR of 2.5 to 3.5 for patients post-mitral valve repair, particularly given the thrombotic complication 1, 2, 3, 4
Add aspirin 81 to 100 mg daily to warfarin therapy, as this combination is strongly recommended after mitral valve procedures 1, 2, 3, 4

Do NOT administer thrombolytic therapy for the stroke itself in this post-operative setting, as the patient is at extremely high risk for hemorrhagic complications 1, 2, 3, 4
The 6-hour timeframe is within the window where endovascular thrombectomy could theoretically be considered for large vessel occlusion in non-surgical patients, but this is contraindicated immediately post-cardiac surgery due to bleeding risk 6

Obtain a second CT scan at 36 to 48 hours after stroke onset to definitively rule out delayed hemorrhagic transformation before considering any surgical intervention 1, 2, 3, 4
If both CT scans confirm non-hemorrhagic stroke, surgical re-exploration or revision may be performed 72 hours after the stroke if clinically indicated 1, 2, 3, 4