Response to Letter Regarding Article, “Dabigatran Versus Warfarin: Effects on Ischemic and Hemorrhagic Strokes and Bleeding in Asians and Non-Asians With Atrial Fibrillation”
We acknowledge Dr Kawada’s comments1 on our subgroup analyses2 of Randomized Evaluation of Long-Term Anticoagulant Therapy (RE-LY) looking at differences between Asian and non-Asian patients. For ischemic stroke he states that there is an ethnic difference for the comparison of dabigatran etexilate 150 mg bid and warfarin, because the confidence interval of the hazard ratio does not cross the line of identity. However, the interaction P value for this comparison in Table 3 is not significant (P=0.20), leading to the conclusion that the relative benefits of dabigatran etexilate 150 mg bid over warfarin are not different between Asians and non-Asians.2 For major bleeding, however, the ethnic differences showed significant interactions (P=0.008), and Dr Kawada correctly points out that the Cox regression analysis should be conducted separately for Asian and non-Asian patients. We therefore reanalyzed the data as suggested. The results do not differ from our initial analysis for major bleeding (hazard ratio, 0.57; 95% confidence interval, 0.38–0.84 for dabigatran etexilate 150 mg bid), and only minimally differ for intracranial hemorrhage (hazard ratio 0.40→0.39; 95% confidence interval, [0.18–0.92]→[0.17–0.89] for dabigatran etexilate 150 mg bid; see Table 4).Thus, our conclusion remains unchanged. We thank Dr Kawada for his comments and his interest in our article.
Masatsugu Hori, MD, PhD
Osaka Medical Center for Cancer and Cardiovascular Diseases
Michael D. Ezekowitz, MBChB, DPhil
Cardiovascular Research Foundation NY
Thomas Jefferson Medical College
Paul A. Reilly, PhD
Boehringer Ingelheim Pharmaceutical Inc
Both Drs Hori and Ezekowitz have acted as consultants for Boehringer Ingelheim. Dr Reilly is an employee of Boehringer Ingelheim.
- © 2014 American Heart Association, Inc.
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