S73. Cerebral blood flow and auto-regulation in acute TIA patients from a general hospital in Qatar

Abstract

Introduction The Arabian Gulf region is rapidly developing, with major changes in lifestyle that can increase the risk of cardiovascular diseases, including TIA and stroke. Stroke constitutes a major cause of morbidity and mortality in Qatar. Cerebral auto-regulation (AR) is an intrinsic protective mechanism guaranteeing hemodynamic integrity of cerebral circulation. It modulates cerebral blood flow (CBF) in order to meet regional perfusion demands despite variations in arterial blood pressure. Impaired cerebral AR is associated with poor functional and prognostic outcomes in patients with ischemic stroke. Our research investigated the feasibility of TCD study of cerebral AR as a biomarker for Stroke outcome inTIA patients in a large General Hospital in Qatar. Methods Fifty-eight patients (47 men, mean age, 49.7 yrs) with acute TIA and 66 patients (58 men, mean age 51.0) with small strokes (TIAs with tissue evidence of infarction) were enrolled between 2015 and 2017 for a total sample of 124. They were evaluated with bilateral, simultaneous TCD studies of their MCAs CBF within 72 h of the indexed event. In addition to the usual CBF parameters (mean/peak flow velocities), cerebrovascular reactivity (AR) to hypercapnia as measured by the Breath-Holding Index was calculated. On best medical therapy, the patients were followed up at one year for outcomes measures of death, stroke or recurrent TIAs in an attempt to correlate these TCD with poor stroke outcome. Results There was no significant difference for any of the TCD variables including BHI when comparing TIA patients to stroke mimics and patients with small strokes. These variables also failed to distinguish, thus far, acute TIA or small stroke patients from patients with death or a recurrent ischemic event at one year follow up (Statistically significant difference using independent samples t -test P -value Conclusion There was no significant difference for any of the TCD variables including BHI when comparing TIA patients compared to patients with a stroke mimics, or TIA patients and evidence of ischemic stroke on Neuro imaging. There was no significant difference for any US measures when comparing TIA patients and patients with and without a recurrent event at follow up. Though such studies are non-invasive in acute TIA patients continued follow up and larger sample sizes may be necessary to identify a functional or structural biomaker for poor strke outcome. This study was made possible by grant NPRP 6-565-3-141 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the author[s].