Letter by Freeman et al Regarding Article, “Using Dabigatran in Patients With Stroke: A Practical Guide for Clinicians”
To the Editor:
We read with great interest the article by Alberts et al1 on “Using Dabigatran in Patients With Stroke: A Practical Guide for Clinicians.” The authors provided an excellent review on dabigatran and the issues encountered in patients with stroke. One challenge with dabigatran is the treatment of acute ischemic stroke for which intravenous tissue-type plasminogen activator administration or endovascular cerebral intervention may be warranted. We recently had a 66-year-old female patient who had been taking 150 mg dabigatran orally twice daily for prevention of stroke in atrial fibrillation. Dabigatran was held 3 days before a cardiac ablation procedure but was resumed immediately after the ablation. Within 1 hour of the procedure, she developed an acute ischemic stroke of the right middle cerebral artery M1 artery on CT angiogram, which resulted in global aphasia and left-sided hemiparesis. The stroke onset was within the timeframe for tissue-type plasminogen activator administration and the activated partial thromboplastin time was 32 seconds (normal range, 22.7–36.1 seconds). The referring physicians felt that the risk of bleeding was too great for intravenous tissue-type plasminogen activator administration. She was started on a heparin drip and emergently transferred to our facility for intra-arterial removal of the clot. When the patient arrived to our institution, >6 hours had passed since symptom onset and her National Institutes of Health Stroke Scale was 7 for disorientation (1), left-sided arm weakness (measured at 2), left facial weakness (2), sensory loss (1), and left arm ataxia (1). Repeat CT angiogram showed the clot had migrated to the distal right middle cerebral artery M1 and M2 bifurcations and on formal angiogram trickle flow present with some collaterals providing flow to the right middle cerebral artery territory from the ipsilateral anterior cerebral artery and external carotid–superficial temporal branches but no large infarct by cerebral blood flow/cerebral blood volume, time to peak imaging, only a large right middle cerebral artery penumbra. Thrombin time was obtained and elevated at 84 seconds (14.4–22.2 seconds). The patient had normal renal function and was aggressively hydrated to enhance dabigatran clearance. The clot was mechanically aspirated, and there was robust recanalization of the right middle cerebral artery M1 and M2 branches 9 hours postonset. There were no perioperative bleeding complications. There was a tiny distal cortical M4 infarct seen on noncontrast CT imaging the subsequent day. The patient's National Institutes of Health Stroke Scale on postprocedure Day 1 was only 2 for subjective left sensory loss and trace left facial asymmetry with all other components normal. Dabigatran was discontinued permanently and the patient was switched to warfarin therapy because of the uncertainty of this medication in relation to the embolic event. We feel this event was most likely cardioembolic in nature and not directly related to the medication. However a transesophageal echocardiogram failed to reveal any cardio embolic source. Clinicians are likely to encounter future acute ischemic stroke events in patients taking dabigatran. There are limited data1–5 on dabigatran and tissue-type plasminogen activator therapy for treatment of acute ischemic stroke and no consensus on the appropriate level of dabigatran at which administration of intravenous tissue-type plasminogen activator is considered safe. Clinical experience with endovascular recanalization is also lacking, and to our knowledge, this is the first case in which a patient on dabigatran underwent successful endovascular intra-arterial intervention. We hope future trials or a “dabigatran registry” address this new anticoagulant's safety and efficacy in regard to acute ischemic stroke and hemorrhagic complications.
W. David Freeman, MD
Departments of Neurology, Critical Care, and Neurosurgery
Ruth S. Kuo, PharmD
Ricardo A. Hanel, MD
Department of Neurosurgery
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- © 2012 American Heart Association, Inc.