[Cerebral amyloid angiopathy and atrial fibrillation: anticoagulant dilemma].

Cerebral amyloid angiopathy and atrial fibrillation are two frequent comorbidities in older patients, leading to a therapeutic dilemma on the risk-benefit ratio of long-term anticoagulation. These patients both have a risk of cardioembolic complications due to atrial fibrillation, and a risk of cerebral haemorrhage from cerebral amyloid angiopathy. Since there is no therapeutic consensus, the best therapeutic strategy should be discussed during a multidisciplinary staff, based on four risk estimations: 1) the baseline risk of intracerebral haemorrhage without anticoagulation; 2) the risk of ischaemic stroke without anticoagulation; 3) the expected increase of intracerebral haemorrhage with anticoagulation; 4) the expected reduction in ischaemic stroke risk with anticoagulation. The risk of intracerebral haemorrhage varies according to the cerebral amyloid angiopathy phenotype. Patients with transient neurological episode or cortical superficial siderosis have the highest risk of intracerebral haemorrhage. Direct oral anticoagulant should be preferred to vitamin K antagonists, as the risk of intracerebral haemorrhage is lower with direct oral anticoagulants. If anticoagulation is introduced, a close clinical and radiological monitoring should be performed every 6-12 months minimum. If it has been decided not to anticoagulate, left atrial appendage occlusion should be proposed. In all situations, close blood pressure control is essential to reduce the risk of intracerebral haemorrhage.