Abstract
Atrial fibrillation (AF) and cerebral amyloid angiopathy (CAA) present risks of ischemic stroke and intracerebral hemorrhage (ICH). Vitamin K antagonist use is associated with fluctuations in international normalized ratio (INR), which predispose to a higher bleeding risk. Patients with a diagnosis of AF and ICH while on a vitamin K antagonist were identified using the Rochester Epidemiology Project. Sixty patients were identified (mean age 81.3 years; 24 men). Thirty-three (55%) exhibited characteristics consistent with possible (n = 25) or probable (n = 8) CAA. Mean time in therapeutic range in the 30 days preceding ICH was 55.4%, with no difference between CAA and non-CAA patients. Mean time spent above therapeutic range (INR > 3.0) was 17.7%, with no difference between CAA and non-CAA patients. Following ICH, 21 (35%) died within 30 days, with total mortality at 76.7% after 176.4 person-years of follow-up (mean 2.9 years). Time in therapeutic range in the 30 days prior to ICH had no significant impact on 7-day mortality, nor risk of recurrent ICH or ischemic stroke. Patients with warfarin-related ICH were often outside of the therapeutic range within the month preceding hemorrhage but more frequently were subtherapeutic. Even with careful avoidance of supratherapeutic INR, vitamin K antagonist use in CAA patients is unlikely to have a major effect in preventing ICH and must be used with caution.