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Association between CHADS₂risk factors and anticoagulation-related bleeding: a systematic literature review

Wendy T Chen1, C Michael White, Olivia J Phung

  • 1University of Connecticut School of Pharmacy, Storrs, CT, USA.

Mayo Clinic Proceedings
|June 2, 2011
PubMed

Insights

Warfarin use in patients with CHADS(2) risk factors shows a weak association with bleeding, except for advanced age. Stroke risk, not bleeding risk, should guide warfarin prescription decisions for these patients.

Area of Science:

  • Cardiology
  • Pharmacology
  • Evidence-Based Medicine

Background:

  • The CHADS(2) score identifies patients at risk for stroke.
  • Warfarin is commonly prescribed to reduce stroke risk in these patients.
  • Understanding bleeding risk associated with CHADS(2) factors is crucial for safe warfarin use.

Purpose of the Study:

  • To evaluate the strength of evidence linking CHADS(2) risk factors to increased bleeding risk in patients taking warfarin.
  • To determine if specific CHADS(2) covariates are independently associated with bleeding events.

Main Methods:

  • Systematic literature search of MEDLINE and Cochrane CENTRAL (up to December 2009).
  • Inclusion of studies reporting multivariate results on CHADS(2) covariates and warfarin-associated bleeding.
  • Evaluation of evidence strength using Agency for Healthcare Research and Quality methods and GRADE criteria.

Main Results:

  • Forty-one studies yielded 127 multivariate evaluations.
  • No CHADS(2) covariate demonstrated high strength of evidence for association with bleeding.
  • Advanced age was the only covariate with moderate evidence for major bleeding risk.

Conclusions:

  • Evidence linking CHADS(2) covariates to warfarin-induced bleeding is generally weak, with age being a notable exception.
  • Warfarin prescribing decisions should prioritize stroke risk over bleeding risk for patients with CHADS(2) factors.
Abstract

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