Short and long-term prognosis after tissue negative transient ischemic attack

Background: Recently, there has been a proposal to retire the concept of transient ischemic attack (TIA) because, in all likelihood, patients experiencing brief episodes of transient brain ischemia without associated cerebral lesions might be exceedingly rare or carry no risk of stroke recurrence (SR). However, only a few observational studies have evaluated the risk of SR exclusively among tissue-negative TIA patients. Our aim was to assess the early and long-term prognosis of consecutive tissue-negative TIA patients attended at an emergency department Methods: We carried out a prospective cohort study of consecutive TIA patients with tissue negative TIA from January 2006 to June 2010. All patients underwent diffusion-weighted imaging on MRI (DWI) (4.0 [SD 1.8] days) after the index event. The risk and predictors of SR were determined at 1 year and after a median follow-up time of 6.6 (interquartile range, 5.0-9.6) years. Results: A total of 370 patients were included. Previously, 244 DWI positive patients and 109 without DWI were excluded. ABCD2 score>5 was determined in 95 (26.2%) patients. 15 (4.1%) patients suffered SR at 1 year and 18 (4.9%) beyond 1 year. Predictive models for short-term and long-term prognosis were different. Large artery atherosclerosis etiology (Hazard ratio [HR] 3.7 [1.2-11.0]) was the only predictor of 1 year SR. In contrast, male sex (HR 4.17 [95% CI 1.14-15.23]; P=0.031), speech impairment (HR 4.90 [95% CI 1.05-22.93]; P=0.044), and presence of chronic microangiopathy expressed as Fazekas score of 3 (HR 1.84 [95% CI 1.15-2.97]; P=0.012) were predictors of long-term follow-up. Conclusion: The risk of SR after tissue negative TIA is not insignificant. Predictors of short and long-term prognosis are different. Sex, clinical characteristics at onset, etiology and chronic microangiopathy determine the risk of SR. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was supported by the Catalan Autonomous Government's Agència de Gestió d'Ajuts Universitaris i de Recerca (2021 suport a les activitats dels grups de recerca 1479) and the Instituto de Salud Carlos III, (08/1398, 11/02033 and 14/01574) and the RICORS Research Network. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Written informed consent or assent from relatives was obtained for all the participants. The study was approved by our local ethics committee: the Comité d'Etica i Investigació Clínica de l'Hospital Universitari Arnau de Vilanova de Lleida. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The corresponding author will consider requests for access to the data reported in this article.