Letter to the Editor On interactions between body mass index, type of anticoagulation and outcomes Marko Lucijanic a, ⁎ ,1 , Marko Skelin b,1 , Ivana Jurin c,1 , Irzal Hadzibegovic d,e,1 a Hematology Department, University Hospital Dubrava, Av. Gojka Suska 6, 10000 Zagreb, Croatia b Pharmacy Department, General Hospital Sibenik, Ul. Stjepana Radica 83, 22000 Sibenik, Croatia c Cardiology Department, University Hospital Dubrava, Av. Gojka Suska 6, 10000 Zagreb, Croatia d Cardiology Department, University Hospital Dubrava, Av. Gojka Suska 6, 10000 Zagreb, Croatia e Faculty of Medicine, University of Osijek, Ul. Josipa Huttlera 4, 31000 Osijek, Croatia article info Article history: Received 28 March 2020 Received in revised form 8 April 2020 Accepted 22 April 2020 We highly appreciate the author's interest in our work [1]. We did not directly compare warfarin to DOAC treated cohorts in the given study. However, we did not observe the same associations of BMI and outcomes in our warfarin-treated cohort (data not published). In line with this were the tests for interaction between BMI, anticoagulation type (DOAC vs warfarin) and survival (P b 0.001), thrombosis (P = 0.048) and event-free-survival (P = 0.002). The author has provided us with several papers, which unfortunately provided evidences in the form of pharmacokinetic studies or retrospective analyses without ap- propriate adjustments, and can hardly be put into the correlation with the results of our study which represent real-life data. In addition, some works describe an increase of dabigatran concentration with de- crease in body weight [2] which makes discussion on this issue even more important. We are well aware of study limitations which we have recognized inside the paper. Median follow-up is a major strength of our study. All patients/families were repeatedly contacted by telephone to assess their status with full assessment of investigated outcomes. We do not agree on the presence of immortal-time-bias, this is a feature of differ- ent types of studies [3]. Contrary to the provided opinion, our conclusions were supported by given data. Our real-life data are repre- sentative of our institutional experience which is that dabigatran has poor efficacy when given to patients with higher BMI. It is clear that sin- gle institution, retrospective findings cannot represent definitive opin- ion and our results need to be validated in independent cohorts. Funding This research did not receive any specific grant from funding agen- cies in the public, commercial, or not-for-profit sectors. Declaration of competing interest IJ has received speaker honoraria from Boehringer Ingelheim. IH has received speaker honoraria from Boehringer Ingelheim, Pfizer and Bayer. Other authors report no conflict of interest. Acknowledgements None. References [1] M. Lucijanic, I. Jurin, H. Jurin, T. Lucijanic, B. Starcevic, M. Skelin, et al., Patients with higher body mass index treated with direct/novel oral anticoagulants (DOAC/ NOAC) for atrial fibrillation experience worse clinical outcomes, Int. J. Cardiol. 301 (2020) 90–95. [2] J.P. Patel, L.N. Roberts, R. Arya, Anticoagulating obese patients in the modern era, Br. J. Haematol. 155 (2011) 137–149. [3] M. Skelin, M. Lucijanic, Longer Survival with Anti-Programmed Cell Death 1 and De- velopment of Cutaneous Toxic Effects, an Expected Association, JAMA Oncol, 2019 https://doi.org/10.1001/jamaoncol.2019.3817. International Journal of Cardiology 312 (2020) 107 ⁎ Corresponding author at: Hematology Department, University Hospital Dubrava, Av. Gojka Suska 6, 10000 Zagreb, Croatia. E-mail address: markolucijanic@yahoo.com (M. Lucijanic). 1 This author takes responsibility for all aspects of the reliability and freedom from bias of the data presented and their discussed interpretation. https://doi.org/10.1016/j.ijcard.2020.04.064 0167-5273/© 2020 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard