Timing of Anticoagulation Resumption After Subarachnoid Hemorrhage

Assessment and Timing Recommendations

The American Heart Association recommends waiting at least 4 weeks after subarachnoid hemorrhage before restarting oral anticoagulation in patients without mechanical heart valves 1
A thorough neurological and neurosurgical evaluation is necessary to assess the risk of rebleeding versus the risk of thromboembolism, as recommended by the European Society of Cardiology 2, 3
Angiographic evaluation and treatment of any underlying aneurysm or arteriovenous malformation must be completed before considering anticoagulation resumption, according to the European Society of Cardiology 3
Brain imaging (CT or MRI) should be performed before reinitiating anticoagulation to confirm resolution of the hemorrhage, as suggested by the European Society of Cardiology 3, 4

The European Society of Cardiology notes that higher risk of recurrent bleeding is associated with lobar location of initial hemorrhage, older age, presence of microbleeds on gradient echo MRI, and ongoing anticoagulation 1
For patients with mechanical heart valves, a shorter period of 1-2 weeks may be considered before restarting anticoagulation, though this carries higher risk, as reported by the American Heart Association 5
The European Society of Cardiology recommends considering left atrial appendage occlusion (LAAO) as an alternative to anticoagulation for patients with atrial fibrillation after subarachnoid hemorrhage 2

The European Society of Cardiology advises against "bridging" with heparin when initiating NOACs, as this increases bleeding risk without additional benefit 4, 6
Anticoagulation should not be resumed until any ruptured aneurysm is definitively secured, as recommended by the American Heart Association 5