Warfarin, hematoma expansion, and outcome of intracerebral hemorrhage

Abstract

Warfarin did not increase ICH volume at presentation but did raise the risk of in-hospital hematoma expansion. This expansion appears to mediate part of warfarin's effect on ICH mortality.

Experimental Intracerebral Hemorrhage: Avoiding Pitfalls in Translational Research

“…Oral anticoagulant therapy-ICH carries a short-term mortality rate of over 50% that has failed to improve with time (Aguilar et al, 2007;Sjoblom et al, 2001). Of note, rebleeding is commoner in OAT-ICH compared with ICH in the setting of normal coagulation (Flibotte et al, 2004). Since coagulation cascade activation and thrombin production are important steps in cellular damage and disruption of the BBB following ICH, it seems logical that OAT-ICH will result in a different tissue response than spontaneous ICH as hematomas may contain noncoagulated blood (Levine et al, 2007;Xi et al, 2006).…”

Therapeutic Strategies in Acute Intracerebral Hemorrhage

“…The apolipoprotein E ε2 allele is associated with larger hematomas, which appears to explain its effect on outcome [15]. The relation between oral anticoagulation use and baseline hematoma volume is unclear; some studies have shown increased baseline volumes [16,17], whereas others have not [15,18].…”

“…Seventy three percent of patients express some degree of expansion, and 30 to 40% of patients expand more than 33% from baseline volume [13,18,30,31]. The pathophysiological mechanism by which hematoma expansion occurs remains unclear.…”

“…The occurrence of hematoma expansion is related to initial hematoma size; smaller hematomas are less likely to expand [16,34,35]. Other risk factors for expansion include early presentation [36], warfarin use [16,18], and contrast extravasation on CT angiography (CTA) [36][37][38]. The latter will be discussed more extensively in the "Neuroimaging" section.…”

“…The observed increase is most likely due to the increased use of warfarin by patients with atrial fibrillation [58]. The use of warfarin at the time of ICH is associated with hematoma expansion [16,18] and increased mortality [15][16][17]59].…”