That is a great question. There are no studies to demonstrate the efficacy and safety of aspirin for secondary stroke prevention specifically in CADASIL but this argument holds true to various other subgroups where aspirin is routinely used. I would favor using aspirin 81 mg daily in those who have ...

Single antiplatelet to help reduce the risk of stroke from the usual etiologies and avoid compounding the stroke burden from CADASIL.

If the person has no history of stroke or TIA and all other risk factors are well-controlled, I would stick to using an anti-platelet agent only if primary prevention steps fail.