Retrospective Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 14, 2018; 24(14): 1540-1549
Published online Apr 14, 2018. doi: 10.3748/wjg.v24.i14.1540
Post-polypectomy bleeding and thromboembolism risks associated with warfarin vs direct oral anticoagulants
Naohiro Yanagisawa, Naoyoshi Nagata, Kazuhiro Watanabe, Tatsuhiro Iida, Mariko Hamada, Sakurako Kobayashi, Takuro Shimbo, Junichi Akiyama, Naomi Uemura
Naohiro Yanagisawa, Naoyoshi Nagata, Kazuhiro Watanabe, Tatsuhiro Iida, Mariko Hamada, Sakurako Kobayashi, Junichi Akiyama, Department of Gastroenterology and Hepatology, National Center for Global Health and Medicine, Tokyo 162-8655, Japan
Takuro Shimbo, Ohta Nishinouchi Hospital, Fukushima 963-8022, Japan
Naomi Uemura, Department of Gastroenterology and Hepatology, National Center for Global Health and Medicine, Kohnodai Hospital, Chiba 272-8516, Japan
Author contributions: Yanagisawa N collected the clinical data and drafted the manuscript; Nagata N designed the study and is equally a first author; Shimbo T was responsible for statistical analysis; Yanagisawa N, Iida T, Hamada M and Kobayashi S performed data collection and are the main authors of the manuscript; Watanabe K and Akiyama J assisted with treatment; Akiyama J and Uemura N edited the manuscript; all authors read and approved the submitted version of the manuscript.
Supported by Grant-in-Aid for Research from the National Center for Global Health and Medicine (29-2001) partly. The funding agency played no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Institutional review board statement: The study design was approved by the ethics committee of the National Center for Global Health and Medicine (Approval No. 2176).
Informed consent statement: This study was a retrospective observational study, and informed consent to participate was obtained by the opt-out method at our institution.
Conflict-of-interest statement: The authors have no conflicts of interest to declare.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Naoyoshi Nagata, MD, PhD, Doctor, Department of Gastroenterology and Hepatology, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo 162-8655, Japan. nnagata_ncgm@yahoo.co.jp
Telephone: +81-3-32027181 Fax: +81-3-32071038
Received: February 20, 2018
Peer-review started: February 21, 2018
First decision: March 9, 2018
Revised: March 15, 2018
Accepted: March 25, 2018
Article in press: March 25, 2018
Published online: April 14, 2018
ARTICLE HIGHLIGHTS
Research background

The number of oral anticoagulants (AC) used increases as the population ages, and the number of colonoscopic polypectomies is expected to increase in patients receiving AC.

Research motivation

Whether post-polypectomy bleeding (PPB) or thromboembolic risk differs between warfarin and direct oral anticoagulant (DOAC) users remains unknown.

Research objectives

We evaluated PPB risk in patients receiving warfarin or DOAC compared with patients not receiving any antithrombotics (controls). We also assessed the risks of PPB and thromboembolism between the three AC management methods mentioned above, discontinuing AC with heparin bridge (guideline recommendation), continuing AC, and discontinuing AC without heparin bridge.

Research methods

We conducted a retrospective cohort study and collected data from 218 patients receiving oral anticoagulants (73 DOAC users, 145 warfarin users) and 218 patients not receiving any antithrombotics (age- and sex-matched controls) who underwent polypectomy.

Research results

PPB rate was significantly higher in both warfarin users and DOAC users compared with controls. Two thromboembolic events occurred in warfarin users, but none in DOAC users. Compared with the continuing anticoagulant group, the discontinuing anticoagulant with heparin bridge group (guideline recommendation) had a higher PPB rate. One thrombotic event occurred in the discontinuing anticoagulant with heparin bridge group and the discontinuing anticoagulant without heparin bridge group; none occurred in the continuing anticoagulant group.

Research conclusions

Patients receiving oral anticoagulant had higher risks of bleeding after colonoscopic polypectomy compared with patients not receiving any antithrombotics. PPB risk was similar between warfarin and DOAC users, whereas thromboembolism risk was observed in warfarin users only. Heparin bridge increased bleeding risk, and may not prevent thromboembolism.

Research perspectives

The current guideline recommendation for heparin bridge should be re-considered, and continuing oral anticoagulant may be acceptable for polypectomy.