Oral anticoagulation challenges and therapeutic dilemmas in the very elderly: to treat and how to treat octogenarians and nonagenarians? Authors: Andreas S. Papazoglou, Dimitrios V. Moysidis, Anastasios Kartas, Alexandra Bekiaridou, Athanasios Samaras, George Giannakoulas Article type: Review article Received: March 23, 2023. Revision accepted: May 19, 2023. Published online: May 25, 2023. ISSN: 1897-9483 Pol Arch Intern Med. doi:10.20452/pamw.16508 Copyright by the Author(s), 2023 This is an Open Access article distributed under the terms of the Creative Commons Attribution‑NonCommercial‑ShareAlike 4.0 International License (CC BY‑NC‑SA 4.0), allowing third parties to copy and redistribute the material in any medium or format and to remix, transform, and build upon the material, provided the original work is properly cited, distributed under the same license, and used for noncommercial purposes only. For commercial use, please contact the journal office at pamw@mp.pl.