A 5-Decade Analysis Of Incidence Trends Of Ischemic Stroke After Transient Ischemic Attack A Systematic Review And Meta-Analysis

This systematic review and meta-analysis calculates the pooled event rate for ischemic stroke within 2, 7, 30, and 90 days of a transient ischemic attack and compares this incidence among patients recruited before 1999, from 1999 to 2007, and after 2007.Question What is the incidence of subsequent ischemic stroke after a transient ischemic attack (TIA)? Findings In this systematic review and meta-analysis of 206 455 unique patients in 68 unique studies during 5 decades, the subsequent risk of ischemic stroke was 2.4% within 2 days, 3.8% within 7 days, 4.1% within 30 days, and 4.7% within 90 days. The incidence among the study population recruited before 1999 was significantly higher. Meaning These findings suggest that TIA is associated with a high risk of early stroke, although the rate of post-TIA stroke might have decreased slightly during the past 2 decades.Importance Management of transient ischemic attack (TIA) has gained significant attention during the past 25 years after several landmark studies indicated the high incidence of a subsequent stroke. Objective To calculate the pooled event rate of subsequent ischemic stroke within 2, 7, 30, and 90 days of a TIA and compare this incidence among the population with TIA recruited before 1999 (group A), from 1999 to 2007 (group B), and after 2007 (group C). Data Sources All published studies of TIA outcomes were obtained by searching PubMed from 1996, to the last update on January 31, 2020, irrespective of the study design, document type, or language. Study Selection Of 11516 identified citations, 175 articles were relevant to this review. Both the classic time-based definition of TIA and the new tissue-based definition were accepted. Studies with a combined record of patients with TIA and ischemic stroke, without clinical evaluation for the index TIA, with diagnosis of index TIA event after ischemic stroke occurrence, with low suspicion for TIA, or duplicate reports of the same database were excluded. Data Extraction and Synthesis The study was conducted and reported according to the PRISMA, MOOSE, and EQUATOR guidelines. Critical appraisal and methodological quality assessment used the Quality in Prognosis Studies tool. Publication bias was visualized by funnel plots and measured by the Begg-Mazumdar rank correlation Kendall tau(2)statistic and Egger bias test. Data were pooled using double arcsine transformations, DerSimonian-Laird estimator, and random-effects models. Main Outcomes and Measures The proportion of the early ischemic stroke after TIA within 4 evaluation intervals (2, 7, 30, and 90 days) was considered as effect size. Results Systematic review yielded 68 unique studies with 223 866 unique patients from 1971 to 2019. The meta-analysis included 206 455 patients (58% women) during a span of 4 decades. The overall subsequent ischemic stroke incidence rates were estimated as 2.4% (95% CI, 1.8%-3.2%) within 2 days, 3.8% (95% CI, 2.5%-5.4%) within 7 days, 4.1% (95% CI, 2.4%-6.3%) within 30 days, and 4.7% (95% CI, 3.3%-6.4%) within 90 days. There was a significant risk reduction of 3.4% among group A in comparison with 2.1% in group B or 2.1% in group C within 2 days; 5.5% in group A vs 3.2% in group B or 2.9% in group C within 7 days; 6.3% in group A vs 3.4% in group B or 2.9% in group C within 30 days, and 7.4% in group A vs 3.9% in group B or 3.9% in group C within 90 days. Conclusions and Relevance These findings suggest that TIA continues to be associated with a high risk of early stroke; however, the rate of post-TIA stroke might have decreased slightly during the past 2 decades.