Small vessel occlusion is a high-risk etiology for early recurrent stroke after transient ischemic attack.

Background: Recent prospective registration studies of transient ischemic attack in Western countries demonstrated that large artery atherosclerosis is the highest risk etiology for early stroke recurrence under urgent evaluation and treatment. On the other hand, some limited transient ischemic attack studies from East Asian countries showed transient ischemic attack patients due to small vessel occlusion were at a higher early stroke risk.

Aims: We aimed to assess the risk for early stroke in small vessel occlusion-transient ischemic attack patients in a Japanese large transient ischemic attack registry.

Methods: We analyzed the data of a prospective Japanese transient ischemic attack registry including 1320 transient ischemic attack patients within seven days after onset. Small vessel occlusion-transient ischemic attack was defined as the presence of lacunar transient ischemic attack syndrome, without other etiologies. The outcome measure was recurrent stroke within 30 days after transient ischemic attack. The predictors of 30-day recurrent stroke were estimated using the Cox proportional hazards model.

Results: The study population had a mean age of 69 ± 12 years and 470 were women. Recurrent stroke was observed in 61 patients (4.6%), and the highest rate was observed with small vessel occlusion-transient ischemic attack (7.8%), followed by large artery atherosclerosis (5.4%). In multivariate analysis, recurrent stroke was independently associated with small vessel occlusion-transient ischemic attack (hazard ratio (HR): 2.01, 95% confidence interval (CI): 1.19-3.35), higher systolic blood pressure (HR: 1.18, 95% CI: 1.08-1.28), and presentation within 3 h after onset (HR: 2.21, 95% CI: 1.27-4.04). Furthermore, small vessel occlusion-transient ischemic attack with acute small deep infarct on diffusion-weighted imaging was a stronger predictor of recurrent stroke (HR: 4.87, 95% CI: 2.09-10.0).

Conclusion: Small vessel occlusion-transient ischemic attack, especially with acute small deep infarct, had a higher early stroke risk compared with other etiologies in Japanese transient ischemic attack patients who received early management.