====== 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 drug]]s or [[anticoagulant]]s.