Letter to the Editor Predictors of Stroke in Atrial Fibrillation Dear Editor, We have greatly enjoyed reading the recently pub- lished article by Broughton et al. 1 The authors analyzed the data of 4572 participants from the Cardiovascular Health Study and found that the echocardiographic left atrial enlargement detected by echocardiography does not influence the stroke risk observed with atrial fibrilla- tion. We want to remind the predictive role of biomarkers in atrial fibrillation and acute ischemic stroke. Brain na- triuretic peptide (BNP) is frequently elevated after an acute stroke and has been shown to be an independent pre- dictor of mortality and a biological marker to distinguish cardioembolic from other stroke subtypes. 2 Tamura et al 3 showed previously that elevated plasma BNP concen- trations may be a reliable surrogate marker for the prediction of left atrial appendage dysfunction and car- diogenic stroke in patients with acute ischemic stroke. Rost et al 4 also showed that elevated BNP was associ- ated with lower ejection fraction and left atrial dilatation in patients with acute ischemic stroke. Nakamura et al 5 recently showed that plasma BNP is a valuable biomarker both singly or in combination with an established scoring system for assessing general cardiovascular risk includ- ing stroke, heart failure, and acute coronary syndrome in real-world atrial fibrillation patients. Therefore, we would be grateful if the authors have and would provide the data regarding BNP levels and their relationship with left atrial enlargement and stroke in patients with atrial fibrillation. Bülent Özlek, MD Eda Özlek, MD Özcan Bas ¸aran, MD Volkan Dog ˘ an, MD Murat Biteker, MD Department of Cardiology, Faculty of Medicine, Mug ˘la University, Turkey E-mail: bulent_ozlek@hotmail.com http://dx.doi.org/10.1016/j.jstrokecerebrovasdis.2016.06.029 References 1. Broughton ST, O’Neal WT, Salahuddin T, et al. The influence of left atrial enlargement on the relationship between atrial fibrillation and stroke. J Stroke Cerebrovasc Dis 2016;25:1396-1402. doi:10.1016/ j.jstrokecerebrovasdis.2016.02.004; [Epub 2016 Mar 21]. 2. Biteker M, Özden T, Dayan A, et al. Aortic stiffness and plasma brain natriuretic peptide predicts mortality in acute ischemic stroke. Int J Stroke 2015;10:679-685. 3. Tamura H, Watanabe T, Nishiyama S, et al. Elevated plasma brain natriuretic peptide levels predict left atrial appendage dysfunction in patients with acute ischemic stroke. J Cardiol 2012;60:126-132. doi:10.1016/ j.jjcc.2012.02.010; [Epub 2012 Apr 21]. 4. Rost NS, Biffi A, Cloonan L, et al. Brain natriuretic peptide predicts functional outcome in ischemic stroke. Stroke 2012;43:441-445. doi:10.1161/strokeaha.111.629212; [Epub 2011 Nov 23]. 5. Nakamura M, Koeda Y, Tanaka F, et al. Plasma B-type natriuretic peptide as a predictor of cardiovascular events in subjects with atrial fibrillation: a community-based study. PLoS ONE 2013;8:e81243. doi:10.1371/journal.pone.0081243; eCollection 2013. 1052-3057/$ - see front matter © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved. ARTICLE IN PRESS Journal of Stroke and Cerebrovascular Diseases, Vol. ■■, No. ■■ (■■), 2016: p ■■ 1