Risk factors and short-term outcome in patients with angiographically negative subarachnoid hemorrhage.

The objective of this study was to identify prognostic factors for clinical outcome in patients with non-traumatic, angiographically negative subarachnoid hemorrhage. Furthermore, the aim was to investigate if patients on anticoagulant therapy may have a more unfavorable outcome than patients not receiving anticoagulant therapy.This study contains a retrospective analysis of 95 patients with non-traumatic, non-aneurysmal subarachnoid hemorrhage who were admitted to our institution in the period 2000-2011. The patients were classified according to risk factors, clinical presentation at admission, anticoagulant therapy at the time of hemorrhage and complications. The outcome was assessed with modified Rankin Score at discharge.Patients who were exposed to risk factors combined with a higher WFNS score at admission had an unfavorable outcome according to the modified Rankin Score at discharge. Unfavorable outcome was evaluated in relation to sex, anticoagulant therapy, hypertension, smoking and alcohol abuse. A strong correlation with anticoagulant therapy, smoking and alcohol abuse was found. None of the patients who developed vasospasms in this study were receiving anticoagulant therapy.There is a correlation between antithrombotic state at admission and unfavorable outcome for patients with non-traumatic, non-aneurysmal subarachnoid hemorrhage. The results from this study indicate that patients on anticoagulant therapy have a higher risk of developing complications after non-aneurysmal angiographically negative subarachnoid hemorrhage compared to patients who were not receiving anticoagulant therapy.