Carotid Implants for PreveNtion of STrokE ReCurrEnce From Large Vessel Occlusion in Atrial Fibrillation Patients Treated With Oral Anticoagulation

Patients with atrial fibrillation (AF) who have had a prior stroke are at very high risk of recurrent ischemic stroke. Oral anticoagulation (OAC) is very effective for stroke reduction, but despite this treatment, AF patients with stroke in the past year still have a very high risk of recurrent stroke which is often disabling; estimated to be between 3 and 7% per year. About 40% of these strokes are due to large emboli which result in large cerebral vessel occlusion (LVO). Thus, there is a well-documented unmet medical need to improve stroke reduction therapy for AF patients with prior ischemic stroke. This study aims to address this unmet need by testing whether use of bilateral carotid filter implants in addition to OAC will reduce the risk of stroke in AF patients with recent (e.g. within 12 months) ischemic stroke. These filters have been shown, in vitro, to capture all emboli ≥1.4 mm in length or diameter and additionally to capture some emboli of smaller diameter. Once placed bilaterally in the common carotid arteries, they are expected to prevent most emboli ≥1.4 mm in length or diameter and potentially some smaller ones from reaching the anterior cerebral circulation. Although the posterior circulation will not be protected, the majority of all large ischemic strokes in patients with AF occur in the anterior circulation (about 90%). It is hypothesized therefore that bilateral carotid implants will greatly reduce embolic strokes due to LVO (60% reduction) and will have an important but smaller effect on embolic strokes due to smaller emboli which cause non-LVO occlusion (10% reduction). LVO-associated strokes are more often large and disabling compared to non-LVO strokes. The primary goal of the study is to show that bilateral carotid implants reduce strokes due to LVO and that there is also a reduction in total ischemic stroke, both in comparison to a control arm (treatment with OAC only). The study will also evaluate the safety of the intervention.