Bleeding risk in atrial fibrillation patients taking vitamin K antagonists: systematic review and meta-analysis

Clin Pharmacol Ther. 2013 Sep;94(3):367-75. doi: 10.1038/clpt.2013.99. Epub 2013 May 13.


Vitamin K antagonists (VKAs) prevent stroke in atrial fibrillation (AF) at the cost of bleeding risk. To determine major bleeding rates in AF patients, we conducted a systematic review that identified 51 eligible studies including more than 342,699 patients. The pooled estimate of the rate of major bleeding was 2.51 (99% confidence interval: 2.03-3.11) bleeds per 100 patient-years. The results represent the best estimates of bleeding risk that most patients contemplating VKA use may expect.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Review
  • Systematic Review

MeSH terms

  • Anticoagulants / adverse effects*
  • Atrial Fibrillation / drug therapy*
  • Hemorrhage / chemically induced*
  • Humans
  • Stroke / prevention & control*
  • Vitamin K / antagonists & inhibitors*


  • Anticoagulants
  • Vitamin K