P8.10: The Patients with Ischemic Stroke in the Posterior Circulation Territory Have Impaired Endothelial Function and Cerebrovascular Reactivity

The aim was to assess EF, CVR and intima-media thickness (IMT) in patients with IS in the posterior circulation territory (PCT). Methods The study population consisted of 13 patients with IS (without atrial fibrillation) in PCT (72 hours after stroke onset). For these subjects, EF and CVR were compared against an age and gender-matched group consisting of 10 healthy individuals (control group, CG). EF was assessed using the brachial flow-mediated vasodilatation (FMD). Breath-holding test (CVR_BHT=test/ baseline mean velocity) and hyperventilation (CVR_HV=baseline/test mean velocity) were used for CVR evaluation in basilar artery (using transcranial Doppler). Results We observed a significant difference in FMD between IS patients and CG (5.45±0.9% and 8.97±1.37% respectively, p=0.04). IS patients and CG differed in CVR_BHT (1.25±0.49 and 1.44±0.6 respectively, p=0.04), no difference was detected in CVR_HV (1.5±0.33 and 1.36±0.8 respectively, p>0,05). IMT was similar for IS patients and CG (0.95mm±0.12 and 0.91mm±0.1 respectively, p>0.05). Correlation analysis revealed significant interrelationships between FMD and CVR_BHT (r=0.38); no significant correlations were found between FMD and CVR_HV. Conclusion Patients with IS in PST showed impaired EF and CVR (vasodilatation reaction), both being strong indicators of stroke development. The significant correlation between these parameters is a sign that vasodilation of brain arterioles can be at least partially mediated by the endothelium. The absence of any significant differences in IMT is an evidence of equal prevalence of atherosclerosis among general population.