Outcome of aneurysmal subarachnoid hemorrhage in patients on anticoagulant treatment

Background and Purpose Intracranial hemorrhage is an important complication of treatment with anticoagulants. We studied outcome of aneurysmal subarachnoid hemorrhage (SAH) occurring in patients on anticoagulant drugs because this may influence management of patients needing anticoagulant treatment but with increased risk of aneurysmal hemorrhage. Methods From the prospective database of patients admitted with SAH to the Utrecht University Hospital, we compared 3-month outcome in patients with or without anticoagulant drugs by means of stratified analyses to adjust relative risks for biological and clinical differences between the two groups. Results Death or dependency after SAH occurred in 14 of 15 patients on anticoagulant treatment and in 62 of 126 patients not being treated with anticoagulants (relative risk, 1.9; 95% confidence interval, 1.5 to 2.4). The patients on treatment with anticoagulants were more often comatose on admission; the frequencies of rebleeding, secondary ischemia, and hydrocephalus were not higher in patients on anticoagulants. In the stratified analysis, the worse outcome in the group on anticoagulant drugs was not essentially influenced by differences in sex, age, cardiovascular history, site of aneurysm, amount of cisternal blood, or extension of hemorrhage into the ventricles. Conclusions The outcome of aneurysmal SAH in patients on anticoagulant drugs is extremely poor. The explanation for the worse prognosis in patients on anticoagulants lies in a worse clinical condition from the outset. The poor outcome urges a reconsideration of the balance of risks for anticoagulant treatment in patients with an unoperated intracranial aneurysm or with a family history of SAH and may lead to withholding treatment with anticoagulant drugs or to a preventive operation.