Acute Ischemic Stroke Following Cardioversion in a Patient Receiving Dabigatran

Abstract

To report a case of acute ischemic stroke following electrical cardioversion in a patient currently anticoagulated with dabigatran 150 mg twice daily. A 74-year-old man, who had been adherent with more than 6 weeks of dabigatran 150 mg twice daily therapy, presented with a dense left-sided hemiparesis 72 hours following a repeat electrical cardioversion. Both computed tomography and magnetic resonance angiogram confirmed a right middle cerebral artery infarct. A transesophageal echocardiogram performed after the cerebrovascular accident failed to demonstrate a cardiac source of embolus. The patient previously underwent cardioversion 4 weeks prior with no evidence at that time of thrombus or spontaneous echo contrast on transesophageal echocardiogram. Dabigatran was approved in the United States in late 2010 for the prevention of stroke and systemic embolism in nonvalvular atrial fibrillation. Post hoc data from the phase III trial suggest a low risk of embolism following cardioversion. Since there are no conventional coagulation measures to reliably demonstrate the level of anticoagulation in patients on dabigatran, clinicians must rely solely on patient history when assessing the safety of cardioverting a patient on this medication. Data have suggested increased pro-inflammatory mediators and increased risk of myocardial infarction with oral direct thrombin inhibitors, which may have manifested as a cerebral or carotid artery thrombosis in situ. Novel oral anticoagulants are attractive options for anticoagulation required with cardioversion. Although this case report may not preclude use of dabigatran for this purpose, it illustrates that use of this drug is not without risks. Additional investigation into the pro-inflammatory nature of the oral direct thrombin inhibitors is needed.