The rationale for the acute use of anticoagulant therapy lies in preventing acute recurrence of stroke; however, trials have shown that this risk of early recurrent stroke is low and that heparin does not provide any functional or survival advantage. Nonetheless, this remains a controversial area, with some stroke experts having strong opinions about acute anticoagulation.
In general, the stroke mechanism should be identified so that a better, informed decision can be made before long-term anticoagulation is chosen. PCA strokes that arise from vertebral artery dissection are more frequently treated with anticoagulation, although again there is a paucity of data to support this use.
Early anticoagulation may be the most appropriate preventive strategy in specific circumstances that are considered high-risk, such as the presence of an intracardiac thrombus or a dissection with visualized large intraluminal thrombus. Strokes caused by atrial fibrillation do not require early anticoagulation with heparin. Studies have demonstrated that the risk of recurrent stroke within the first weeks is approximately 1%. [24] Early heparinization in this setting is associated with no clear stroke prevention benefit but is associated with increased hemorrhagic complications.
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Unenhanced head computed tomography (CT) scan demonstrating a subacute L posterior cerebral artery (PCA) infarct.
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Unenhanced head computed tomography (CT) scan demonstrating hemorrhagic conversion of an ischemic stroke, approximately 72 hours after symptom onset.
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Brain magnetic resonance imaging (MRI) scan demonstrating acute stroke. Diffusion restriction is seen on diffusion-weighted imaging.
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Magnetic resonance (MR) angiogram demonstrating bilateral fetal posterior cerebral artery (PCA) variants (black arrows) with the basilar artery terminating in bilateral superior cerebellar arteries (blue arrows).
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Digital subtraction angiogram demonstrating an acute L posterior cerebral artery (PCA) occlusion (red arrow) following balloon-assisted coiling of a basilar tip aneurysm.
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Digital subtraction angiogram demonstrating revascularization of acute L posterior cerebral artery (PCA) occlusion (red arrow) during a balloon-assisted basilar tip aneurysm revascularization with use of balloon angioplasty.
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Computed tomography (CT) scan of the brain showing hypodense areas in the right occipital lobe consistent with a recent posterior cerebral artery (PCA) ischemic infarct.