Recurrent Ischemic Stroke – A Systematic Review and Meta-Analysis

Objectives: Recurrent stroke remains a challenge though secondary prevention is initiated immediately post-stroke. Stroke subtype may determine the risk of recurrent stroke and require specific preventive measures. We aimed to identify subtype-specific stroke recurrence and associated risk factors over time. Methods and materials: A systematic review was performed using PubMed and Embase for studies including adults >18 years, first-ever ischemic stroke in population-based observational studies or registries, documented TOAST-criteria and minimum 1-year follow-up. Meta-analysis on stroke recurrence rate was performed. Final search: November 2019. Results: The search retrieved 26 studies (between 1997 and 2019). Stroke recurrence rate ranged from 5.7% to 51.3%. Recurrent stroke was most frequent in large artery atherosclerosis (LAA) and cardioembolic (CE) stroke with recurrent stroke similar to index stroke subtype. We identified a lower recurrence rate for small vessel occlusion (SVO) stroke with recurrence frequently of another stroke subtype. Based on a meta-analysis the summary proportion recurrence rate of recurrent stroke in studies using TOAST-criteria = 0.12 and = 0.14 in studies using TOAST-like criteria. Hypertension, diabetes mellitus, atrial fibrillation previous transient ischemic attack, and high stroke severity were independent risk factors for recurrence. Conclusion: Stroke recurrence rates seem unchanged over time despite the use of secondary prevention. The highest recurrence rate is in LAA and CE stroke eliciting same subtype recurrent stroke. A lower recurrence rate is seen with SVO stroke with a more diverse recurrence pattern. Extensive workup is important in all stroke subtypes - including SVO stroke. Future research needs to identify better preventive treatment and improve compliance to risk factor prevention to reduce stroke recurrence.