Background and objectives: Prior ischemic stroke is a risk factor for intracerebral hemorrhage (ICH) in patients taking warfarin, but the mechanism is not known. This study investigates radiographic and clinical characteristics of patients with warfarin-related ICH following ischemic stroke.
Methods: In this case-control study, the authors selected all patients with warfarin-related ICH and previous symptomatic ischemic stroke from a prospective cohort of consecutive patients with ICH. Control subjects were similarly aged patients with history of symptomatic stroke randomly chosen from an anticoagulant therapy unit. The 26 eligible ICH cases and 56 controls were compared for vascular risk factors, stroke characteristics, and extent of leukoaraiosis (graded in anterior and posterior brain regions on a validated scale of 0 to 4).
Results: The presence and severity of leukoaraiosis on CT scan correlated strongly with the occurrence of ICH. Leukoaraiosis was seen in 24 of 26 cases (92%) compared with 27 of 56 controls (48%), yielding an odds ratio of 12.9 (95% CI 2.8 to 59.8). Other clinical factors associated with ICH included an international normalized ratio >3.0, history of multiple previous strokes, and the presence of carotid artery stenosis. The relationship between leukoaraiosis and ICH persisted in multivariable analyses controlling for these risk factors as well as hypertension and diabetes mellitus.
Conclusions: Leukoaraiosis is an independent risk factor for warfarin-related ICH in survivors of ischemic stroke, including those in the commonly employed range of anticoagulation.