Anticoagulation preceding intracerebral hemorrhage

10% of patients on warfarin (Coumadin®) develop a significant bleeding complication per year (not all are intracranial), including ICH (65% mortality in this group). The risk of ICH in patients treated with warfarin for a-fib varies between 0–0.3% per year (historically, this was as high as ≈ 1.8% in older studies from the 1960s and 1970s), but when an elderly subgroup (mean age 80 yrs) was analyzed, this rate was 1.8% per year. ICH was the only cause of fatal bleeding complications of warfarin therapy in one series where the cumulative risk of a fatal hemorrhage was 1% at 1 year and 2% at 3 yrs.

The risk of hemorrhagic complications was increased with the length and also the variability of the PT, and during the first three months of anticoagulation.

Patients with cerebral amyloid angiopathy (CAA) are also at increased risk of ICH following administration of antiplatelet drugs or anticoagulants.