From the Guidelines
The most common cause of ischemic stroke is cardioembolic, originating from the heart, specifically from conditions such as atrial fibrillation, which accounts for approximately 20-25% of all ischemic strokes, slightly edging out large-vessel atherosclerotic strokes, including those from carotid artery disease, which account for about 30% of ischemic strokes 1.
Key Points to Consider
- Cardioembolic strokes, often resulting from atrial fibrillation, are a leading cause of ischemic strokes, highlighting the importance of managing cardiac conditions to prevent stroke.
- Carotid artery disease, characterized by atherosclerotic plaque buildup, is also a significant contributor to ischemic stroke risk, but slightly less common than cardioembolic causes.
- The management of stroke risk involves addressing both cardiac and carotid sources, as both are major contributors to overall stroke risk.
- Conditions such as hypertension, heart disease, cigarette smoking, diabetes mellitus, heavy alcohol use, and hypercholesterolemia are modifiable risk factors for stroke that should be managed as part of a comprehensive stroke prevention strategy 1.
Clinical Implications
- The identification and management of atrial fibrillation and other cardiac conditions are crucial in preventing cardioembolic strokes.
- Carotid endarterectomy may be beneficial for symptomatic patients with high degrees of carotid stenosis, but the evidence is less clear for asymptomatic patients or those with lower degrees of stenosis 1.
- A comprehensive approach to stroke prevention should include the management of modifiable risk factors, consideration of surgical options like carotid endarterectomy when appropriate, and the use of medical treatments to reduce stroke risk.
From the Research
Ischemic Stroke Causes
The most common cause of ischemic stroke can be attributed to two main sources: carotid (carotid artery) disease and cardiac (heart) embolism.
Cardiac Embolism as a Cause
- Cardiac conditions such as atrial fibrillation, acute myocardial infarction, valvular heart disease, infective endocarditis, nonbacterial thrombotic endocarditis, and atrial myxoma are main cardiac causes of cerebral embolism 2.
- Atrial fibrillation is the most common cause of cardioembolic stroke, and anticoagulation is usually recommended 3, 4, 5.
- At least 20% of all ischemic strokes are cardioembolic 2, and about one-fifth of all ischemic strokes are cardioembolic 4.
- Cardiac sources of emboli account for over one quarter of all ischemic strokes 5.
Comparison with Carotid Disease
- While carotid artery disease is a significant cause of ischemic stroke, the provided evidence suggests that cardiac embolism, particularly from atrial fibrillation, is a more common cause 3, 2, 4, 5.
- The evidence does not provide a direct comparison of the incidence of carotid artery disease and cardiac embolism as causes of ischemic stroke, but it highlights the importance of cardiac embolism in the etiology of ischemic stroke 3, 2, 4, 5, 6.