A Current Estimation of the Early Risk of Stroke after Transient Ischemic Attack: A Systematic Review and Meta-Analysis of Recent Intervention Studies

Abstract

Objective: Recent studies have demonstrated that there is a decrease in the risk of subsequent stroke after transient ischemic attack (TIA) when urgent care (UC) is administered. However, no meta-analysis has been developed with contemporaneous TIA studies. We perform a systematic review and a meta-analysis to establish the risk of early stroke recurrence (SR) considering data from studies that offered UC to TIA patients. Methods: We searched for studies, without language restriction, from January 2007 to January 2015 according to PRISMA guidelines. We included studies with TIA patients who underwent UC and reported the proportion of SR at 90 days. We excluded studies that were centered on less than 100 patients and cohorts including both stroke and TIA, if stroke risk after TIA was not described. For its relevance, we included the TIAregistry.org study published in 2016. We performed both fixed and random effects meta-analyses to determine SR and assess sources of heterogeneity. Results: From 4,103 identified citations, we selected 15 papers that included 14,889 patients. There was great variation in terms of the number of patients included in each study, ranging from 115 to 4,160. Seven studies were TIA clinic based. The mean age and the percentage of men were similar among studies, ranging from 62.4 to 73.1 years and 45.1-62%, respectively. The reported risk of stroke ranged from 0 to 1.46% 2 days after TIA (9 studies included), 0-2.55% 7 days after TIA (11 studies included), 1.91-2.85% 30 days after TIA (4 studies included), and 0.62-4.76% 90 days after TIA (all studies included). The pooled stroke risk was 3.42% (95% CI 3.14-3.74) at 90 days, 2.78% (95% CI 2.47-3.12) at 30 days, 2.06% (95% CI 1.83-2.33) at 7 days and 1.36% (95% CI 1.15-1.59) at 2 days. Although we did not find statistically significant heterogeneity in SR among studies, those with a higher proportion of patients with motor weakness had a significantly higher risk of SR. No statistically significant association was observed between TIA clinic management and SR. Conclusion: The pooled early SR is lower than in previous meta-analyses and homogeneous for all studies with an urgent assessment and management strategy regardless of vascular risk factors and clinical characteristics. Therefore, the best setting for TIA management can be individualized for each center.