Death and Disability from Warfarin-Associated Intracranial and Extracranial Hemorrhages
published online 23 May 2007.
Abstract
Objectives
Little is known about the outcomes of patients who have hemorrhagic complications while receiving warfarin therapy. We examined the rates of death and disability resulting from warfarin-associated intracranial and extracranial hemorrhages in a large cohort of patients with atrial fibrillation.
Methods
We assembled a cohort of 13,559 adults with nonvalvular atrial fibrillation and identified patients hospitalized for warfarin-associated intracranial and major extracranial hemorrhage. Data on functional disability at discharge and 30-day mortality were obtained from a review of medical charts and state death certificates. The relative odds of 30-day mortality by hemorrhage type were calculated using multivariable logistic regression.
Results
We identified 72 intracranial and 98 major extracranial hemorrhages occurring in more than 15,300 person-years of warfarin exposure. At hospital discharge, 76% of patients with intracranial hemorrhage had severe disability or died, compared with only 3% of those with major extracranial hemorrhage. Of the 40 deaths from warfarin-associated hemorrhage that occurred within 30 days, 35 (88%) were from intracranial hemorrhage. Compared with extracranial hemorrhages, intracranial events were strongly associated with 30-day mortality (odds ratio 20.8 [95% confidence interval, 6.0-72]) even after adjusting for age, sex, anticoagulation intensity on admission, and other coexisting illnesses.
Conclusions
Among anticoagulated patients with atrial fibrillation, intracranial hemorrhages caused approximately 90% of the deaths from warfarin-associated hemorrhage and the majority of disability among survivors. When considering anticoagulation, patients and clinicians need to weigh the risk of intracranial hemorrhage far more than the risk of all major hemorrhages.
aThe Department of Medicine, University of California, San Francisco, Calif
bDepartment of Epidemiology and Biostatistics, University of California, San Francisco, Calif
cDivision of Research, Kaiser Permanente of Northern California, Oakland, Calif
dClinical Epidemiology Unit, Massachusetts General Hospital, Boston, Mass
eGeneral Internal Medicine and Clinical Epidemiology Unit, Boston University School of Medicine, Boston, Mass.
Requests for reprints should be addressed to Margaret C. Fang, MD, MPH, Department of Medicine, Hospitalist Group, University of California, San Francisco, 533 Parnassus Ave, Box 0131, San Francisco, CA 94143.
This work was supported by Public Health Services research grant AG15478 from the National Institute on Aging, the Eliot B. and Edith C. Shoolman Fund of Massachusetts General Hospital, and a Hartford Geriatrics Health Outcomes Research Scholars Award from the AGS Foundation for Health in Aging.
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