Abstract WMP93: Risk of Early Ischemic Stroke After Transient Ischemic Stroke: A Systematic Review and Meta-Analysis

Abstract

Objective: TIA is considered a heralding sign for stroke. Studies have reported a stroke risk of 12 to 20% within 90 days after an index TIA, of which 50% happen within 24 to 48 hours. In the current comprehensive meta-analysis, we calculated the pooled stroke risk at 2, 7, 30, and 90 days post TIA and compared the risk between two study cohorts with study population before and after 1999 (publication year of the consensus guidelines on the management of TIA). Methods: Considering PRISMA guidelines, all published studies of early stroke recurrence in TIA from 2000 to 2019 were included. We calculated risk of early stroke following index TIA event at 2, 7, 30, and 90 days. We excluded studies that had a combined early outcome of TIA and stroke, studies without independent encounter for the index TIA event or diagnosis of index TIA after patient encounter for early ischemic stroke. Patients with positive diffusion weighted imaging (DWI+ TIA), or low suspicious for TIA were also excluded. Results: In total, 82,292 (mean age: 69.7; man: %53.4) TIA patients out of 25 studies were included. Hypertension was the most common disease among population of the included studies followed by diabetes mellitus and coronary artery disease. Among included studies, the risk of stroke ranged from 0.1 % to 5.5%, 0.4 % to 8.0%, 1.5% to 11.5% and 0.6 % to 22.1% at 2, 7, 30 and 90 days, respectively. Total number of TIA patients included for meta-analysis at 2, 7, 30 and 90 days were 31,366, 29,634, 15,038, and 81,013 respectively. We calculated pooled estimation of stroke risk following index TIA event at 2, 7, 30, and 90 days, by application of random effect models (95% CI), as 1.5, 2.3, 4.0, and 4.4, respectively. These rates among three studies at 2, 30 and 90 days which studied a population before 1999 were 4.9, 5.7 and 15.0, respectively. Conclusion: Our study indicated that an early risk of stroke following an index TIA event at 2, 7, and 90 days is 1.5, 2.3, and 4.4, respectively. We also observed a stroke risk reduction among studies with recruited population after 1999.