UK: Small Vessel Disease (SVD) and Ischemic Stroke Risk

Small vessel disease (SVD) in patients anticoagulated for atrial fibrillation after stroke is associated with an increased risk of recurrent ischemic stroke, suggests a recent study in the journal Stroke.

Even after anticoagulation for atrial fibrillation, recurrent ischemic stroke may occur, the cause of which is uncertain but might include small vessel occlusion. David J. Werring, UCL Institute of Neurology, London, United Kingdom, and colleagues investigated whether MRI markers of cerebral SVD are associated with the risk of ischemic stroke during follow-up in patients anticoagulated for atrial fibrillation after transient ischemic attack or recent ischemic stroke.

For this purpose, the researchers analyzed data from a prospective multicenter inception cohort study of ischemic stroke or transient ischemic attack anticoagulated for atrial fibrillation (CROMIS-2 [Clinical Relevance of Microbleeds in Stroke Study]). Markers of SVD were rated on baseline brain magnetic resonance imaging:

• Basal ganglia perivascular spaces (number ≥11)
• Cerebral microbleeds (number ≥1)
• Lacunes (number ≥1)
• White matter hyperintensities (periventricular Fazekas grade 3 or deep white matter Fazekas grade ≥2)

The associations of SVD presence (defined as presence of ≥1 SVD marker) and severity (composite SVD score) with ischemic stroke risk were investigated during follow-up using a Cox proportional hazards model adjusted for congestive heart failure, hypertension, age >75, diabetes, stroke, vascular disease, age 65–74, female score. A total of 1419 patients were included in the study.

Key Findings of the Study

• The ischemic stroke rate during follow-up in patients with any SVD was 2.20 per 100-patient years, compared with 0.98 per 100 patient-years in those without SVD.
• After adjusting for congestive heart failure, hypertension, age >75, diabetes, stroke, vascular disease, age 65–74, female score, SVD presence remained significantly associated with ischemic stroke during follow-up (hazard ratio, 1.89); the risk of recurrent ischemic stroke increased with SVD score (hazard ratio per point increase, 1.33).

"In patients anticoagulated for atrial fibrillation after ischemic stroke or transient ischemic attack, magnetic resonance imaging markers of SVD are associated with an increased risk of ischemic stroke during follow-up; improved stroke prevention treatments are required in this population," wrote the authors.

The study, "Small Vessel Disease and Ischemic Stroke Risk During Anticoagulation for Atrial Fibrillation After Cerebral Ischemia," is published in the AHA journal Stroke.

DOI: https://www.ahajournals.org/doi/10.1161/STROKEAHA.120.029474