Transient global amnesia does not increase the risk of subsequent ischemic stroke: a propensity score-matched analysis

Abstract

Data regarding the risk of cerebrovascular events following transient global amnesia (TGA) remain controversial. While some neuroradiological studies suggest an underlying cerebrovascular etiology, results from the clinical studies have been largely conflicting. We, therefore, aimed to evaluate the risk of ischemic stroke in a large, nationally representative sample of patients with TGA. We utilized the Nationwide Readmissions Database 2010–2015 to identify all hospitalizations with the primary discharge diagnosis of TGA. We selected a 2% random sample of all elective admissions to be included as controls. A propensity score-matched analysis was performed to match patients with TGA and the controls. The primary outcome was readmission due to ischemic stroke up to 1 year following discharge from the index hospitalization, assessed using the Kaplan–Meier survival analysis in the propensity-matched groups. There were 24,803 weighted hospitalizations due to TGA (mean\u2009±\u2009SD age: 65.6\u2009±\u200910.4 years, female: 54.9%) and 699,644 corresponding controls. At baseline, patients with TGA were significantly older, more likely to be male, and had a higher prevalence of hypertension, hyperlipidemia, coronary artery disease, cerebrovascular disease, and migraine, as compared to the controls. However, after propensity score matching, we obtained 21,202 cases and 21,293 well-matched corresponding controls, and the risk of readmission due to ischemic stroke in patients with TGA was not different compared to the control group (HR: 1.13, 95% CI 0.62–2.05, P 0.686) during the mean (SD) follow-up period of 192.2 (102.4) days. After adjustment for demographics and cerebrovascular risk factors, TGA is not associated with an increased risk of subsequent ischemic stroke.