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

BackgroundRecently, 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 MethodsWe 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. ResultsA total of 370 patients were included. Previously, 244 patients with positive DWI results and 109 patients without MRI performed 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 SR follow-up. ConclusionThe 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.