Author Response: Association of Alternative Anticoagulation Strategies and Outcomes in Patients With Ischemic Stroke While Taking a Direct Oral Anticoagulant

We sincerely thank Wolfe et al. for the comments. The low rate of large artery atherosclerotic disease (LAD) in our atrial fibrillation (AF) cohort¹ echoed our other study that among ischemic strokes, the proportion of intracranial atherosclerotic disease declined from 23.3% to 8.8% from 2004 to 2018 in Hong Kong.² This difference may explain the disparity in LAD rates because the cohort of minor strokes/TIA quoted was recruited from 2011 to 2015.³ Moreover, elaborated as a limitation in the Discussion, underinvestigation of small-artery or large-artery atherosclerosis in apparent cardioembolic stroke might also contribute to the low LAD rate. Regarding tobacco consumption, the smoking prevalence in Hong Kong had been declining: The rate of older male smokers was 15.7%–17.5% and that of female was 1.2%–1.5% during the study period.⁴ Furthermore, we categorized smoking status after the first ischemic stroke despite direct oral anticoagulant, in which almost all patients did quit smoking. Future studies should determine whether ever-smoking may increase recurrent stroke risk in these patients. Finally, the study on minor stroke/TIA quoted was mainly associated with atherosclerosis, thus smoking.³ This may explain the higher smoking prevalence compared with our AF cohort.²