From the Research
The TOAST classification system is used to categorize ischemic strokes into five subtypes: large-artery atherosclerosis, cardioembolism, small-vessel occlusion (lacunar), stroke of other determined etiology, and stroke of undetermined etiology, which is crucial for guiding treatment and secondary prevention strategies. The classification of a stroke according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) is based on clinical features, brain imaging, cardiac evaluation, and vascular studies.
Key Points
- The TOAST classification system is essential for determining the underlying cause of a stroke and guiding appropriate treatment.
- The five subtypes of ischemic strokes are:
- Large-artery atherosclerosis
- Cardioembolism
- Small-vessel occlusion (lacunar)
- Stroke of other determined etiology
- Stroke of undetermined etiology
- Proper classification using TOAST helps clinicians determine the most effective prevention strategy, as the recurrence risk and optimal treatment differ significantly between subtypes 1.
Diagnosis and Classification
The diagnosis and classification of a stroke using the TOAST system involve a comprehensive evaluation of the patient's clinical features, brain imaging, cardiac evaluation, and vascular studies.
Treatment and Secondary Prevention
The treatment and secondary prevention strategies for each subtype of ischemic stroke are:
- Large-artery atherosclerosis: antiplatelet therapy (aspirin 81-325 mg daily, clopidogrel 75 mg daily, or aspirin plus extended-release dipyridamole), statins, and risk factor modification.
- Cardioembolic strokes: anticoagulation with warfarin (target INR 2-3) or direct oral anticoagulants like apixaban (5 mg twice daily), rivaroxaban (20 mg daily), or dabigatran (150 mg twice daily).
- Small-vessel occlusion strokes: antiplatelet therapy and aggressive blood pressure control (target <130/80 mmHg) 2, 3, 4.