International Journal of Cardiology 190 (2015) 349
Contents lists available at ScienceDirect
International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard
Letter to the Editor
Effect of antithrombotic and antiplatelet agents for ischemic stroke in atrial fibrillation patients with dialysis Chin-Wei Hsu a, Yaw-Bin Huang a,b,⁎, Chung-Yu Chen a,b,⁎ a b
School of Pharmacy, Master Program in Clinical Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan, ROC Department of Pharmacy, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan, ROC
a r t i c l e
i n f o
Article history: Received 21 April 2015 Accepted 23 April 2015 Available online 28 April 2015 Keywords: Aspirin Warfarin Atrial fibrillation Dialysis
Anticoagulation is recommended for patients with AF with a CHADS2 score ≥ 2, but there has been more variability in the choice of antithrombotic agent in patients at lower risk (CHADS2 score = 1). Aspirin or no treatment is recommended for patients at very low risk (CHADS2 score = 0) [3]. The authors used propensity score method to match all the potential confounders, but except CHADS2 score. Please also specify reasons why this variable was not considered. Fourth, the authors presented Kaplan–Meier survival curve of the ischemic stroke-free rate in their Fig. 1A and 1B. There was a crossing and it is difficult to keep proportionality of their statistical model. Finally, hemodialysis patients with anticoagulant therapy had a risk of hemorrhagic stroke [4], which Chen et al. included in their population. However, there is limited information about hemorrhagic stroke outcome in this study. Sensitivity analysis is needed to check the adverse effect by antiplatelet or anticoagulant drugs.
Dear Editor: Conflict of interest With great interest, we read Chen et al.'s study about antithrombotic agents in patients with end stage renal disease (ESRD) and atrial fibrillation (AF) [1]. The authors found that anti-platelet or warfarin treatment could not lower the risk of ischemic stroke in patients with ESRD. We have some concerns about this study. First, except aspirin, antiplatelet treatment may include clopidogrel and aspirin–dipyridamole combination. There was no definition of antiplatelet therapy. If not considering the effect of these drugs, there might be a potential bias. For the second concern, the authors reported that about 33% (280/840) of the patients in the antiplatelet group received longterm therapy (N120 days), and also in the warfarin group. Therefore, most patients did not receive long-term therapy. Because the mean follow-up period was long (1503 days) [1], the total treatment effect in patients who did not receive long-term therapy might be similar to the control group. Besides, please specify reasons why 2983 patients did not receive antiplatelet or anticoagulant therapy, which was a milder condition in control than other two groups. Third, a stroke risk index, CHADS2, can quantify risk of stroke for patients with AF and aid in selection of antithrombotic therapy [2]. ⁎ Corresponding authors at: No. 100, Shihcyuan 1st Rd., Sanmin District, Kaohsiung City 80708, Taiwan, ROC. E-mail addresses: [email protected] (Y.-B. Huang), [email protected] (C.-Y. Chen).
http://dx.doi.org/10.1016/j.ijcard.2015.04.193 0167-5273/© 2015 Elsevier Ireland Ltd. All rights reserved.
None. Acknowledgments Guarantor of the article: None. Financial support: None. References [1] J.J. Chen, L.Y. Lin, Y.H. Yang, J.J. Hwang, P.C. Chen, J.L. Lin, Anti-platelet or anticoagulant agent for the prevention of ischemic stroke in patients with end-stage renal disease and atrial fibrillation—a nation-wide database analyses, Int. J. Cardiol. 177 (3) (2014) 1008–1011. [2] B.F. Gage, A.D. Waterman, W. Shannon, M. Boechler, M.W. Rich, M.J. Radford, Validation of clinical classification schemes for predicting stroke: results from the national registry of atrial fibrillation, JAMA 285 (22) (2001) 2864–2870. [3] K.L. Furie, L.B. Goldstein, G.W. Albers, P. Khatri, R. Neyens, M.P. Turakhia, et al., Oral antithrombotic agents for the prevention of stroke in nonvalvular atrial fibrillation: a science advisory for healthcare professionals from the American Heart Association/American Stroke Association, Stroke 43 (12) (2012) 3442–3453. [4] W.C. Winkelmayer, J. Liu, S. Setoguchi, N.K. Choudhry, Effectiveness and safety of warfarin initiation in older hemodialysis patients with incident atrial fibrillation, Clin. J. Am. Soc. Nephrol. 6 (11) (2011) 2662–2668.
Contents lists available at ScienceDirect
International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard
Letter to the Editor
Effect of antithrombotic and antiplatelet agents for ischemic stroke in atrial fibrillation patients with dialysis Chin-Wei Hsu a, Yaw-Bin Huang a,b,⁎, Chung-Yu Chen a,b,⁎ a b
School of Pharmacy, Master Program in Clinical Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan, ROC Department of Pharmacy, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan, ROC
a r t i c l e
i n f o
Article history: Received 21 April 2015 Accepted 23 April 2015 Available online 28 April 2015 Keywords: Aspirin Warfarin Atrial fibrillation Dialysis
Anticoagulation is recommended for patients with AF with a CHADS2 score ≥ 2, but there has been more variability in the choice of antithrombotic agent in patients at lower risk (CHADS2 score = 1). Aspirin or no treatment is recommended for patients at very low risk (CHADS2 score = 0) [3]. The authors used propensity score method to match all the potential confounders, but except CHADS2 score. Please also specify reasons why this variable was not considered. Fourth, the authors presented Kaplan–Meier survival curve of the ischemic stroke-free rate in their Fig. 1A and 1B. There was a crossing and it is difficult to keep proportionality of their statistical model. Finally, hemodialysis patients with anticoagulant therapy had a risk of hemorrhagic stroke [4], which Chen et al. included in their population. However, there is limited information about hemorrhagic stroke outcome in this study. Sensitivity analysis is needed to check the adverse effect by antiplatelet or anticoagulant drugs.
Dear Editor: Conflict of interest With great interest, we read Chen et al.'s study about antithrombotic agents in patients with end stage renal disease (ESRD) and atrial fibrillation (AF) [1]. The authors found that anti-platelet or warfarin treatment could not lower the risk of ischemic stroke in patients with ESRD. We have some concerns about this study. First, except aspirin, antiplatelet treatment may include clopidogrel and aspirin–dipyridamole combination. There was no definition of antiplatelet therapy. If not considering the effect of these drugs, there might be a potential bias. For the second concern, the authors reported that about 33% (280/840) of the patients in the antiplatelet group received longterm therapy (N120 days), and also in the warfarin group. Therefore, most patients did not receive long-term therapy. Because the mean follow-up period was long (1503 days) [1], the total treatment effect in patients who did not receive long-term therapy might be similar to the control group. Besides, please specify reasons why 2983 patients did not receive antiplatelet or anticoagulant therapy, which was a milder condition in control than other two groups. Third, a stroke risk index, CHADS2, can quantify risk of stroke for patients with AF and aid in selection of antithrombotic therapy [2]. ⁎ Corresponding authors at: No. 100, Shihcyuan 1st Rd., Sanmin District, Kaohsiung City 80708, Taiwan, ROC. E-mail addresses: [email protected] (Y.-B. Huang), [email protected] (C.-Y. Chen).
http://dx.doi.org/10.1016/j.ijcard.2015.04.193 0167-5273/© 2015 Elsevier Ireland Ltd. All rights reserved.
None. Acknowledgments Guarantor of the article: None. Financial support: None. References [1] J.J. Chen, L.Y. Lin, Y.H. Yang, J.J. Hwang, P.C. Chen, J.L. Lin, Anti-platelet or anticoagulant agent for the prevention of ischemic stroke in patients with end-stage renal disease and atrial fibrillation—a nation-wide database analyses, Int. J. Cardiol. 177 (3) (2014) 1008–1011. [2] B.F. Gage, A.D. Waterman, W. Shannon, M. Boechler, M.W. Rich, M.J. Radford, Validation of clinical classification schemes for predicting stroke: results from the national registry of atrial fibrillation, JAMA 285 (22) (2001) 2864–2870. [3] K.L. Furie, L.B. Goldstein, G.W. Albers, P. Khatri, R. Neyens, M.P. Turakhia, et al., Oral antithrombotic agents for the prevention of stroke in nonvalvular atrial fibrillation: a science advisory for healthcare professionals from the American Heart Association/American Stroke Association, Stroke 43 (12) (2012) 3442–3453. [4] W.C. Winkelmayer, J. Liu, S. Setoguchi, N.K. Choudhry, Effectiveness and safety of warfarin initiation in older hemodialysis patients with incident atrial fibrillation, Clin. J. Am. Soc. Nephrol. 6 (11) (2011) 2662–2668.
