Location and characteristics of warfarin associated intracranial hemorrhage

In the so-called primary intracerebral hemorrhage (ICH), lobar and deep ICH were mainly due to cerebral amyloid angiopathy and deep perforating arterial disease. Our aim was to identify specifics of warfarin associated ICH (WAICH) and to focus on differences in susceptibility to warfarin according to the underlying vasculopathies, expressed by ICH location.

We identified all subjects aged ≥ 18 years who were admitted with primary ICH between January 1, 2007 and September 30, 2012. We retrospectively collected demographic characteristics, the presence of vascular risk factors and pre-ICH medication by chart reviews. We categorized ICH into four types according to location: lobar, deep, posterior fossa, and undetermined. We investigated characteristics (including hematoma volume and expansion) of ICH according to the location of ICH.

WAICH accounted for 35 patients (5.6%) of 622 ICH cases. In WAICH, 13 patients (37.1%) had lobar ICH and 22 patients (60.0%) had non-lobar ICH. Compared to other locations of ICH, lobar ICH showed an excess risk of WAICH (OR 2.53, 95% CI 1.03-6.21, p = 0.042). The predictors of lobar location of ICH were warfarin (OR 2.29, 95% CI 1.05-5.04, p = 0.038) and diabetes mellitus (DM) (OR 0.54, 95% CI 0.29-0.98, p = 0.044). The lobar location of ICH showed significant association with larger hematoma volume (p = 0.001) and high ratio of hematoma expansion (p = 0.037) compared with other locations of ICH.

In our study, warfarin showed significant association with lobar ICH and it caused larger hematoma volume and more expansion of hematoma in lobar ICH.