Warfarin-associated intracerebral hemorrhage: volume, anticoagulation intensity and location

J Neurol Sci. 2013 Sep 15;332(1-2):75-9. doi: 10.1016/j.jns.2013.06.020. Epub 2013 Jul 30.


Background: Warfarin use increases mortality in patients with intracerebral hemorrhage (ICH). Larger hematoma volume and infratentorial location are both major determinants of poor outcome in ICH. Although warfarin-associated intracerebral hemorrhages have greater volumes, there is uncertainty about the effects of location. We aimed to investigate the influence of warfarin on hematoma volume and location.

Methods: We conducted a retrospective study of all patients hospitalized for ICH at a large stroke center from October 2007 to January 2012. Initial CT scans were used to quantify hematoma volumes using the computer-assisted planimetric analysis. Univariate and multivariable analyses determined the influence of warfarin on hemorrhage location. Median regression analysis was performed to estimate the effects of INR on hematoma volumes.

Results: We included 404 consecutive patients with ICH of whom 69 were on warfarin. Patients on warfarin had larger hematoma volumes (median 23.9mL vs. 14.2mL; P=0.046). In patients excessively anticoagulated with warfarin (defined as INR>3.0), compared with those in the therapeutic range, brainstem ICH was more frequent (24.0% vs. 6.1%; P=0.005). Patients with INR>3.0 had increased odds of infratentorial hemorrhage (OR 3.63; 95% CI 1.52-8.64; P=0.004) when compared to non-warfarin ICH patients. After adjustment for hematoma location, there was no significant association between INR and hematoma volume.

Conclusions: Patients with warfarin-associated ICH have a predilection for brainstem ICH. After adjustment for ICH location, no relationship between admission INR and hematoma volume was found.

Keywords: Brain stem hemorrhage; Hematoma; International normalized ratio; Intracerebral hemorrhage; Oral anticoagulant; Warfarin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Anticoagulants / adverse effects*
  • Cerebral Hemorrhage / diagnostic imaging
  • Cerebral Hemorrhage / drug therapy*
  • Female
  • Hematoma / chemically induced
  • Humans
  • Male
  • Middle Aged
  • Retrospective Studies
  • Tomography, X-Ray Computed
  • Warfarin / adverse effects*


  • Anticoagulants
  • Warfarin