Article Text


Replacement of warfarin with a novel oral anticoagulant in endoscopic mucosal resection: a multicentre, open-label, randomised controlled trial


Introduction This randomised controlled trial aims to compare the efficacy of warfarin replacement with apixaban without postoperative resumption of heparin with that of conventional heparin bridging in patients taking warfarin and scheduled to undergo endoscopic mucosal resection (EMR): specifically, by checking for reduction in proportion of postoperative bleeding following EMR.

Methods and analysis The multicentre, open-label randomised parallel-group, controlled intervention study regards patients taking warfarin who are scheduled to undergo colon EMR. Enrolled patients have been taking oral warfarin for non-valvular atrial fibrillation or venous thrombosis on an outpatient basis, and have been found to have a colorectal polyp (including adenoma or early-stage cancer) for which EMR was indicated. They are assigned to one of two groups.

The primary endpoint is proportion of postoperative bleeding. The secondary endpoints are hospital stay length, therapeutic endoscopy outcomes such as proportion of en bloc resection, proportion of perforation, proportion of intraoperative bleeding, incidence of cerebral infarction/systemic embolism events, incidence of adverse events and serious adverse events, and proportion of postoperative therapeutic endoscopy.

Ethics and dissemination This trial was approved by the National Hospital Organization Central Review Board for Clinical Trials (19 April 2016).

Discussion The paucity of reports with high evidence levels was considered problematic when the Japan Gastroenterological Endoscopy Society’s gastroenterological endoscopy guidelines were revised in 2012. The results of this trial will have high medical significance, as its data could serve as the basis for revisions in the next edition of the guidelines.

Trial registration number This trial was registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) accepted from the International Committee of Medical Journal Editors (ICMJE). UMIN000021947; Pre-results.

  • endoscopic mucosal resection
  • direct oral anticoagulant
  • warfarin
  • heparin
  • apixaban

This is an Open Access article 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:

Statistics from


  • Contributors TY participated in the design of the study. AK participated in the design and statistical analysis plan of the study. TY and AS are responsible for registering cases, managing data and handling central monitoring. TY, TK, TU, NW, YS, KM, YT, TK, TK, HH and NH conceived of the study, and participated in its design and coordination and helped to draft the manuscript. All authors read and approved the final manuscript.

  • Funding This study is being conducted using an operating expense grant for research from the National Hospital Organization.

  • Competing interests None declared.

  • Ethics approval This trial was approved by the National Hospital Organization Central Review Board for Clinical Trials (19 April 2016).

  • Provenance and peer review Not commissioned; externally peer reviewed.

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.