1. Home>
2. Specialties>
3. Neurology>
4. Summary and Comment

Anticoagulant-Associated Intracerebral Hemorrhage

The incidence increased in greater Cincinnati during the 1990s, coinciding with increasing warfarin use in the community.

In this serial, cross-sectional study, the authors determined the incidence of anticoagulant-associated intracerebral hemorrhage in Cincinnati during three periods: 1988, 1993–1994, and 1999.

During the entire study period, the annual incidence of anticoagulant-associated intracerebral hemorrhage increased 5.5-fold, while the national dispensation of warfarin increased 4.4-fold. More of the hemorrhages were associated with warfarin use in 1999 than in 1993–1994 (98% vs. 91%). Extrapolating to 2004, the authors estimated an annual incidence of anticoagulation-associated hemorrhage in the Cincinnati area (5.1 to 6.5 cases per 100,000) similar to that of subarachnoid hemorrhage (6.6 cases per 100,000).

Comment: Warfarin is highly effective at reducing the risk for ischemic stroke in the presence of atrial fibrillation (Chest 2004; 126:429S). Warfarin use has increased substantially in the past decade in response to clinical trial data and expert guidelines. This increased use has, not surprisingly, led to an increase in the incidence of anticoagulant-associated intracerebral hemorrhage. The reason for the disproportionate increase in Cincinnati-area anticoagulant-associated intracerebral hemorrhage, relative to the increase expected based on the national warfarin dispensation rate, is unknown. But it likely reflects differences between local and national warfarin use or increasing warfarin use in the elderly, who are at elevated risk for warfarin-related intracerebral hemorrhage.

Despite the known risks, warfarin should continue to be used for stroke prevention in atrial fibrillation, in accordance with guidelines. The magnitude of the problem of warfarin-related intracerebral hemorrhage, well documented in this study, suggests that prevention of warfarin-related hemorrhage would substantially reduce the burden of hemorrhagic stroke. Further research is sorely needed to prevent warfarin-related hemorrhage and to develop safer, equally effective alternatives to warfarin, which we currently lack (Lancet 2006; 367:1903).

— Eric E. Smith, MD, MPH, FRCP(C)

Dr. Smith is Associate Director of Acute Stroke Services, Massachusetts General Hospital, and Assistant Professor of Neurology, Harvard Medical School, Boston.

Published in Journal Watch Neurology February 20, 2007

Citation(s):

Flaherty ML et al. The increasing incidence of anticoagulant-associated intracerebral hemorrhage. Neurology 2007 Jan 9; 68:116-21.

• Original article (Subscription may be required)
• Medline abstract (Free)