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The Antithrombotic Effect of Dabigatran
Canadian Journal of Cardiology 30 (2014) 248.e1e248.e2 www.onlinecjc.ca
Images in Cardiology
The Antithrombotic Effect of Dabigatran Chao-Lin Lee, MD PhD,a Hsueh-Han Wang, MD,b and Hsuan-Ming Tsao, MDa a
Department of Internal Medicine, National Yang Ming University Hospital, Yi-Lan, Taiwan b
Department of Radiology, National Yang Ming University Hospital, Yi-Lan, Taiwan
A 72-year-old man presented to the emergency department because of a sudden onset of left-sided weakness. The patient had his first cerebral vascular accident at the age of 49 years. Atrial fibrillation (AF) and hypertension were diagnosed at that time. He received warfarin with good adherence (Congestive Heart Failure, Hypertension, Age, Diabetes, Stroke/Transient Ischemic Attack [CHADS2] score ¼ 3). However, the international normalized ratio was between 1.26 and 1.81 in the year before this presentation. Physical examination revealed a Glasgow Coma Score of 15, with muscle power score of 4 on the left side. Magnetic resonance imaging with gadolinium (Fig. 1A) showed an acute ischemic stroke on the right posterior parietal lobe. Transthoracic echocardiography revealed a suspected left atrial appendage (LAA) thrombus (Fig. 1B). Sixty-foureslice multidetector computed tomography (MDCT) showed 2 filling defects in the LAA. The virtual endoscopic view delineated a pedunculate thrombus (14 12 12 mm) at the body and a mural thrombus around the apex. We prescribed dabigatran 150 mg twice daily on the 15th day after the stroke. After 1 month of treatment with dabigatran, the resolution of thrombi was noted (Fig. 1, C-F). AF carries a substantial risk of stroke. Investigating the origin of thromboembolism is an important step in treating Received for publication August 15, 2013. Accepted September 24, 2013. Corresponding author: Dr Hsuan-Ming Tsao, National Yang Ming University Hospital, No 152, Xin-Min Road, Yi-Lan, Taiwan. Tel.: þ886-3925192. E-mail: [email protected] See page 248.e1 for disclosure information.
patients with AF-related stroke. Currently, MDCT can be used noninvasively to recognize intracardiac thrombus with high diagnostic accuracy.1 Dabigatran is an orally available direct inhibitor of thrombin. It can inhibit thrombin bound to fibrin and inactivate it. It appears to produce a predictable anticoagulant effect.2 The Canadian Cardiovascular Society’s atrial fibrillation guideline of 2010 recommended that patients at moderate risk of stroke should receive oral anticoagulant therapy, and most of these patients should receive dabigatran in preference to warfarin.3 Our findings may offer evidence for the antithrombotic effect of dabigatran in patients with inadequate response to warfarin treatment. Disclosures The authors have no conflicts of interest to disclose. References 1. Romero J, Husain SA, Kelesidis I, et al. Detection of left atrial appendage thrombus by cardiac computed tomography in patients with atrial fibrillation: a meta-analysis. Circ Cardiovasc Imaging 2013;6:185-94. 2. Vidal A, Vanerio G. Dabigatran and left atrial appendage thrombus. J Thromb Thrombolysis 2012;34:545-7. 3. Cairns JA, Connolly S, McMurtry S, Stephenson M, Talajic M; CCS Atrial Fibrillation Guidelines Committee. Canadian Cardiovascular Society atrial fibrillation guidelines 2010: prevention of stroke and systemic thromboembolism in atrial fibrillation and flutter. Can J Cardiol 2011;27:74-90.
0828-282X/$ - see front matter Ó 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.cjca.2013.09.028
248.e2
Canadian Journal of Cardiology Volume 30 2014
Figure 1. (A) A high-signal area is seen on the right side posterior parietal lobe in diffusion-weighted imaging series. (B) Transthoracic echocardiography suspected a left atrial (LA) thrombus (arrow). (C) Two filling defects (arrows) in LA appendage (LAA) shown by multidetector computed tomography (MDCT) (axial view). (D) Virtual endoscopic view showed a pedunculated thrombus of body and a mural thrombus (arrows) of apex in LAA. (E, F) Disappearance of the pedunculate thrombus and partial resolution of the mural thrombus after dabigatran treatment. Ao, aorta; LSPV, left superior pulmonary vein; LV, left ventricle; MV, mitral valve; RSPV, right superior pulmonary vein; RV, right ventricle.
Images in Cardiology
The Antithrombotic Effect of Dabigatran Chao-Lin Lee, MD PhD,a Hsueh-Han Wang, MD,b and Hsuan-Ming Tsao, MDa a
Department of Internal Medicine, National Yang Ming University Hospital, Yi-Lan, Taiwan b
Department of Radiology, National Yang Ming University Hospital, Yi-Lan, Taiwan
A 72-year-old man presented to the emergency department because of a sudden onset of left-sided weakness. The patient had his first cerebral vascular accident at the age of 49 years. Atrial fibrillation (AF) and hypertension were diagnosed at that time. He received warfarin with good adherence (Congestive Heart Failure, Hypertension, Age, Diabetes, Stroke/Transient Ischemic Attack [CHADS2] score ¼ 3). However, the international normalized ratio was between 1.26 and 1.81 in the year before this presentation. Physical examination revealed a Glasgow Coma Score of 15, with muscle power score of 4 on the left side. Magnetic resonance imaging with gadolinium (Fig. 1A) showed an acute ischemic stroke on the right posterior parietal lobe. Transthoracic echocardiography revealed a suspected left atrial appendage (LAA) thrombus (Fig. 1B). Sixty-foureslice multidetector computed tomography (MDCT) showed 2 filling defects in the LAA. The virtual endoscopic view delineated a pedunculate thrombus (14 12 12 mm) at the body and a mural thrombus around the apex. We prescribed dabigatran 150 mg twice daily on the 15th day after the stroke. After 1 month of treatment with dabigatran, the resolution of thrombi was noted (Fig. 1, C-F). AF carries a substantial risk of stroke. Investigating the origin of thromboembolism is an important step in treating Received for publication August 15, 2013. Accepted September 24, 2013. Corresponding author: Dr Hsuan-Ming Tsao, National Yang Ming University Hospital, No 152, Xin-Min Road, Yi-Lan, Taiwan. Tel.: þ886-3925192. E-mail: [email protected] See page 248.e1 for disclosure information.
patients with AF-related stroke. Currently, MDCT can be used noninvasively to recognize intracardiac thrombus with high diagnostic accuracy.1 Dabigatran is an orally available direct inhibitor of thrombin. It can inhibit thrombin bound to fibrin and inactivate it. It appears to produce a predictable anticoagulant effect.2 The Canadian Cardiovascular Society’s atrial fibrillation guideline of 2010 recommended that patients at moderate risk of stroke should receive oral anticoagulant therapy, and most of these patients should receive dabigatran in preference to warfarin.3 Our findings may offer evidence for the antithrombotic effect of dabigatran in patients with inadequate response to warfarin treatment. Disclosures The authors have no conflicts of interest to disclose. References 1. Romero J, Husain SA, Kelesidis I, et al. Detection of left atrial appendage thrombus by cardiac computed tomography in patients with atrial fibrillation: a meta-analysis. Circ Cardiovasc Imaging 2013;6:185-94. 2. Vidal A, Vanerio G. Dabigatran and left atrial appendage thrombus. J Thromb Thrombolysis 2012;34:545-7. 3. Cairns JA, Connolly S, McMurtry S, Stephenson M, Talajic M; CCS Atrial Fibrillation Guidelines Committee. Canadian Cardiovascular Society atrial fibrillation guidelines 2010: prevention of stroke and systemic thromboembolism in atrial fibrillation and flutter. Can J Cardiol 2011;27:74-90.
0828-282X/$ - see front matter Ó 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.cjca.2013.09.028
248.e2
Canadian Journal of Cardiology Volume 30 2014
Figure 1. (A) A high-signal area is seen on the right side posterior parietal lobe in diffusion-weighted imaging series. (B) Transthoracic echocardiography suspected a left atrial (LA) thrombus (arrow). (C) Two filling defects (arrows) in LA appendage (LAA) shown by multidetector computed tomography (MDCT) (axial view). (D) Virtual endoscopic view showed a pedunculated thrombus of body and a mural thrombus (arrows) of apex in LAA. (E, F) Disappearance of the pedunculate thrombus and partial resolution of the mural thrombus after dabigatran treatment. Ao, aorta; LSPV, left superior pulmonary vein; LV, left ventricle; MV, mitral valve; RSPV, right superior pulmonary vein; RV, right ventricle.