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Response to Letter Regarding Article, “Ischemic Stroke and Intracranial Hemorrhage With Aspirin, Dabigatran, and Warfarin: Impact of Quality of Anticoagulation Control” We face the same challenge as Dr Feng et al1 in managing Chinese patients with atrial fibrillation (AF). Despite a lower prevalence, AF remains a major health threat, affecting >4 million people in Mainland China. Warfarin therapy is the cornerstone in AF management, which reduces ischemic events by two thirds when good time in therapeutic range can be achieved. However, its use has been disturbingly low among Chinese patients ranging from 5% to 20%. Warfarin is commonly been blamed as the root of the problem. In our study involving a real-world cohort of 8754 Chinese patients with AF, the time in therapeutic range, a measure of the quality of anticoagulation, is embarrassingly low, 38.8%.2 The poor time in treatment range is not only associated with a higher ischemic stroke risk but also with a higher incidence of intracranial hemorrhage. On the contrary, such risks of ischemic stroke and intracranial hemorrhage in patients receiving dabigatran are much lower. Indeed, the risk of ischemic stroke even among patients with time in therapeutic range >70% remains higher than those on dabigatran. Apparently, non–vitamin K antagonist oral anticoagulants seem to be the answer. However, some commonly quoted arguments by clinicians for not initiating anticoagulation therapy in Chinese patients are not directly related to warfarin therapy itself. These include a perceived lower risk of stroke attributable to AF and a higher risk of intracranial hemorrhage in Chinese when compared with other ethnic groups. In a stark contrast to these beliefs, the risk of ischemic stroke among Chinese patients with AF is at least comparable with that of white in recently published large series. In fact, the stroke risk in those with low CHA2DS2-VASc (congestive heart failure [1 point]; hypertension [1 point]; age 65–74 years [1 point] and age ≥75 years [2 points]; diabetes mellitus [1 point]; prior stroke or transient ischemic attack [2 points]; vascular disease [1 point]; and sex category [female, 1 point] score) score may even be 2- to 3-fold higher than the white counterparts.3,4 More importantly, net-clinical-benefit analysis (the annual number of ischemic stroke avoided subtracting the annual number of intracranial hemorrhage events attributable to treatment strategies) has consistently shown that the optimal antithrombotic therapy for Chinese patients with AF clearly favors oral anticoagulation therapy in almost all combinations of CHA2DS2-VASc (≥1) and HAS-BLED (uncontrolled hypertension [systolic blood pressure >160 mm Hg, 1 point];
abnormal renal function [serum creatinine >200 umol/L, 1 point]; abnormal liver function [cirrhosis or bilirubin >2x upper limits of normal or AST/ALT/ALP >3x upper limits of normal, 1 point]; previous stroke [1 point]; prior major bleeding [1 point]; labile international normalized ratio [65 years [elderly, 1 point]; drugs predisposing to bleeding, alcohol [>8 drinks/week]) scores, except those with previous intracranial hemorrhage.3,5 After all, with the availability of safer alternatives, and redefinition of the risk of ischemic stroke among Chinese patients with AF, it is time to dedicate resources to raise clinicians’ and patients’ awareness of the condition to better combat the high stroke burden in Chinese population.
Acknowledgments P.-H. Chan and J.J. Hai contributed equally.
Disclosures None.
Pak-Hei Chan, MBBS Jo Jo Hai, MBBS Chung-Wah Siu, MD Cardiology Division, Department of Medicine Queen Mary Hospital The University of Hong Kong Pokfulam, Hong Kong 1. Feng X, Huan Y, Lv Y. Letter by Feng et al regarding article, “Ischemic stroke and intracranial hemorrhage with aspirin, dabigatran, and warfarin: impact of quality of anticoagulation control.” Stroke. 2015;46: e71. doi: 10.1161/STROKEAHA.114.008578. 2. Ho CW, Ho MH, Chan PH, Hai JJ, Cheung E, Yeung CY, et al. Ischemic stroke and intracranial hemorrhage with aspirin, dabigatran, and warfarin: impact of quality of anticoagulation control. Stroke. 2015;46:23–30. doi: 10.1161/STROKEAHA.114.006476. 3. Siu CW, Lip GY, Lam KF, Tse HF. Risk of stroke and intracranial hemorrhage in 9727 Chinese with atrial fibrillation in Hong Kong. Heart Rhythm. 2014;11:1401–1408. doi: 10.1016/j.hrthm.2014.04.021. 4. Chao TF, Liu CJ, Wang KL, Lin YJ, Chang SL, Lo LW, et al. Using the CHA2DS2-VASc score for refining stroke risk stratification in ‘low-risk’ Asian patients with atrial fibrillation. J Am Coll Cardiol. 2014;64:1658– 1665. doi: 10.1016/j.jacc.2014.06.1203. 5. Siu CW, Tse HF. Net clinical benefit of warfarin therapy in elderly Chinese patients with atrial fibrillation. Circ Arrhythm Electrophysiol. 2014;7:300–306. doi: 10.1161/CIRCEP.113.000858.
(Stroke. 2015;46:e72. DOI: 10.1161/STROKEAHA.114.008581.) © 2015 American Heart Association, Inc. Stroke is available at http://stroke.ahajournals.org
DOI: 10.1161/STROKEAHA.114.008581
Downloaded from http://stroke.ahajournals.org/ at New York e72 University/ Medical Center--New York on June 29, 2015
Response to Letter Regarding Article, ''Ischemic Stroke and Intracranial Hemorrhage With Aspirin, Dabigatran, and Warfarin: Impact of Quality of Anticoagulation Control'' Pak-Hei Chan, Jo Jo Hai and Chung-Wah Siu Stroke. 2015;46:e72; originally published online February 3, 2015; doi: 10.1161/STROKEAHA.114.008581 Stroke is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231 Copyright © 2015 American Heart Association, Inc. All rights reserved. Print ISSN: 0039-2499. Online ISSN: 1524-4628
The online version of this article, along with updated information and services, is located on the World Wide Web at: http://stroke.ahajournals.org/content/46/3/e72
Permissions: Requests for permissions to reproduce figures, tables, or portions of articles originally published in Stroke can be obtained via RightsLink, a service of the Copyright Clearance Center, not the Editorial Office. Once the online version of the published article for which permission is being requested is located, click Request Permissions in the middle column of the Web page under Services. Further information about this process is available in the Permissions and Rights Question and Answer document. Reprints: Information about reprints can be found online at: http://www.lww.com/reprints Subscriptions: Information about subscribing to Stroke is online at: http://stroke.ahajournals.org//subscriptions/
Downloaded from http://stroke.ahajournals.org/ at New York University/ Medical Center--New York on June 29, 2015
Response to Letter Regarding Article, “Ischemic Stroke and Intracranial Hemorrhage With Aspirin, Dabigatran, and Warfarin: Impact of Quality of Anticoagulation Control” We face the same challenge as Dr Feng et al1 in managing Chinese patients with atrial fibrillation (AF). Despite a lower prevalence, AF remains a major health threat, affecting >4 million people in Mainland China. Warfarin therapy is the cornerstone in AF management, which reduces ischemic events by two thirds when good time in therapeutic range can be achieved. However, its use has been disturbingly low among Chinese patients ranging from 5% to 20%. Warfarin is commonly been blamed as the root of the problem. In our study involving a real-world cohort of 8754 Chinese patients with AF, the time in therapeutic range, a measure of the quality of anticoagulation, is embarrassingly low, 38.8%.2 The poor time in treatment range is not only associated with a higher ischemic stroke risk but also with a higher incidence of intracranial hemorrhage. On the contrary, such risks of ischemic stroke and intracranial hemorrhage in patients receiving dabigatran are much lower. Indeed, the risk of ischemic stroke even among patients with time in therapeutic range >70% remains higher than those on dabigatran. Apparently, non–vitamin K antagonist oral anticoagulants seem to be the answer. However, some commonly quoted arguments by clinicians for not initiating anticoagulation therapy in Chinese patients are not directly related to warfarin therapy itself. These include a perceived lower risk of stroke attributable to AF and a higher risk of intracranial hemorrhage in Chinese when compared with other ethnic groups. In a stark contrast to these beliefs, the risk of ischemic stroke among Chinese patients with AF is at least comparable with that of white in recently published large series. In fact, the stroke risk in those with low CHA2DS2-VASc (congestive heart failure [1 point]; hypertension [1 point]; age 65–74 years [1 point] and age ≥75 years [2 points]; diabetes mellitus [1 point]; prior stroke or transient ischemic attack [2 points]; vascular disease [1 point]; and sex category [female, 1 point] score) score may even be 2- to 3-fold higher than the white counterparts.3,4 More importantly, net-clinical-benefit analysis (the annual number of ischemic stroke avoided subtracting the annual number of intracranial hemorrhage events attributable to treatment strategies) has consistently shown that the optimal antithrombotic therapy for Chinese patients with AF clearly favors oral anticoagulation therapy in almost all combinations of CHA2DS2-VASc (≥1) and HAS-BLED (uncontrolled hypertension [systolic blood pressure >160 mm Hg, 1 point];
abnormal renal function [serum creatinine >200 umol/L, 1 point]; abnormal liver function [cirrhosis or bilirubin >2x upper limits of normal or AST/ALT/ALP >3x upper limits of normal, 1 point]; previous stroke [1 point]; prior major bleeding [1 point]; labile international normalized ratio [65 years [elderly, 1 point]; drugs predisposing to bleeding, alcohol [>8 drinks/week]) scores, except those with previous intracranial hemorrhage.3,5 After all, with the availability of safer alternatives, and redefinition of the risk of ischemic stroke among Chinese patients with AF, it is time to dedicate resources to raise clinicians’ and patients’ awareness of the condition to better combat the high stroke burden in Chinese population.
Acknowledgments P.-H. Chan and J.J. Hai contributed equally.
Disclosures None.
Pak-Hei Chan, MBBS Jo Jo Hai, MBBS Chung-Wah Siu, MD Cardiology Division, Department of Medicine Queen Mary Hospital The University of Hong Kong Pokfulam, Hong Kong 1. Feng X, Huan Y, Lv Y. Letter by Feng et al regarding article, “Ischemic stroke and intracranial hemorrhage with aspirin, dabigatran, and warfarin: impact of quality of anticoagulation control.” Stroke. 2015;46: e71. doi: 10.1161/STROKEAHA.114.008578. 2. Ho CW, Ho MH, Chan PH, Hai JJ, Cheung E, Yeung CY, et al. Ischemic stroke and intracranial hemorrhage with aspirin, dabigatran, and warfarin: impact of quality of anticoagulation control. Stroke. 2015;46:23–30. doi: 10.1161/STROKEAHA.114.006476. 3. Siu CW, Lip GY, Lam KF, Tse HF. Risk of stroke and intracranial hemorrhage in 9727 Chinese with atrial fibrillation in Hong Kong. Heart Rhythm. 2014;11:1401–1408. doi: 10.1016/j.hrthm.2014.04.021. 4. Chao TF, Liu CJ, Wang KL, Lin YJ, Chang SL, Lo LW, et al. Using the CHA2DS2-VASc score for refining stroke risk stratification in ‘low-risk’ Asian patients with atrial fibrillation. J Am Coll Cardiol. 2014;64:1658– 1665. doi: 10.1016/j.jacc.2014.06.1203. 5. Siu CW, Tse HF. Net clinical benefit of warfarin therapy in elderly Chinese patients with atrial fibrillation. Circ Arrhythm Electrophysiol. 2014;7:300–306. doi: 10.1161/CIRCEP.113.000858.
(Stroke. 2015;46:e72. DOI: 10.1161/STROKEAHA.114.008581.) © 2015 American Heart Association, Inc. Stroke is available at http://stroke.ahajournals.org
DOI: 10.1161/STROKEAHA.114.008581
Downloaded from http://stroke.ahajournals.org/ at New York e72 University/ Medical Center--New York on June 29, 2015
Response to Letter Regarding Article, ''Ischemic Stroke and Intracranial Hemorrhage With Aspirin, Dabigatran, and Warfarin: Impact of Quality of Anticoagulation Control'' Pak-Hei Chan, Jo Jo Hai and Chung-Wah Siu Stroke. 2015;46:e72; originally published online February 3, 2015; doi: 10.1161/STROKEAHA.114.008581 Stroke is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231 Copyright © 2015 American Heart Association, Inc. All rights reserved. Print ISSN: 0039-2499. Online ISSN: 1524-4628
The online version of this article, along with updated information and services, is located on the World Wide Web at: http://stroke.ahajournals.org/content/46/3/e72
Permissions: Requests for permissions to reproduce figures, tables, or portions of articles originally published in Stroke can be obtained via RightsLink, a service of the Copyright Clearance Center, not the Editorial Office. Once the online version of the published article for which permission is being requested is located, click Request Permissions in the middle column of the Web page under Services. Further information about this process is available in the Permissions and Rights Question and Answer document. Reprints: Information about reprints can be found online at: http://www.lww.com/reprints Subscriptions: Information about subscribing to Stroke is online at: http://stroke.ahajournals.org//subscriptions/
Downloaded from http://stroke.ahajournals.org/ at New York University/ Medical Center--New York on June 29, 2015
