Association of Anticoagulant Use With Hemorrhage Location and Etiology in Incident Spontaneous Intracerebral Hemorrhage

BACKGROUND: It is unknown whether hypertensive microangiopathy or cerebral amyloid angiopathy (CAA) predisposes more to anticoagulant-associated intracerebral hemorrhage (AA-ICH). The purpose of our study was to determine whether AA-ICH is associated with lobar location and probable CAA. METHODS: This was a cross-sectional analysis of patients with first-ever spontaneous ICH admitted to a tertiary hospital in Boston, between 2008 and 2023. Univariable and multivariable logistic regression were used to investigate the association between anticoagulation use and both lobar hemorrhage location and probable CAA on magnetic resonance imaging (MRI) by Boston Criteria 2.0 or computed tomography by Simplified Edinburgh Criteria. RESULTS: A total of 1104 patients (mean SD age, 73 12; 499 females 45.0%) were included. Of the 1104 patients, 268 (24.3%) had AA-ICH: 148 (55.2%) with vitamin K antagonists and 107 (39.9%) with direct oral anticoagulants. Brain MRI was performed in 695 (63.0%) patients. The proportion of patients with lobar hemorrhage was not different between those with and without AA-ICH (121/268 45.1% versus 424/836 50.7%; odds ratio OR, 0.80 95% CI, 0.61–1.05; P =0.113). Patients with AA-ICH were less likely to have probable CAA on MRI (17/146 11.6% versus 127/549 23.1%; OR, 0.44 95% CI, 0.25–0.75; P =0.002) and probable CAA on MRI or computed tomography if MRI not performed (27/268 10.0% versus 200/836 23.9%; OR, 0.36 95% CI, 0.23–0.55; P <0.001). Among patients with AA-ICH, there were no differences in the proportion with lobar hemorrhage (63/148 42.6% versus 46/107 43.0%; OR, 1.02 95% CI, 0.62–1.68; P =0.946) or probable CAA on MRI (10/72 13.9% versus 7/69 10.1%; OR, 0.70 95% CI, 0.25–1.96; P =0.495) between vitamin K antagonists and direct oral anticoagulant users. CONCLUSIONS: AA-ICH was not associated with lobar hemorrhage location but was associated with reduced odds of probable CAA. These results suggest that hypertensive microangiopathy may predispose more toward incident AA-ICH than CAA and emphasize the importance of blood pressure control among anticoagulant users. These findings require replication in additional cohorts.