MPS 08-07 CEREBROVASCULAR RESISTANCE INDEX AND COGNITIVE IMPAIRMENT IN ESSENTIAL HYPERTENSIVE PATIENTS

Abstract

Objective: To evaluate the relationship between parameters of cerebral blood flow and cognitive function in pts with essential hypertension (EH). Design and Method: Doppler ultrasonography, 24 h blood pressure monitoring were performed in 141 pts (61.8 ± 0.94 years; 78 males) with EH. We measured blood flow velocities (BFV) in media (MCA), anterior (ACA), posterior (PCA) cerebral arteries and calculated cerebrovascular resistance index (CVRI) for each artery. Cognitive function was assessed in all pts by Montreal cognitive assessment (MoCA) test. All patients were divided into 2 groups depending on the MoCA results: group I (n = 79) – MoCA score ≥26, group II (n = 62) - MoCA score < 26. Results: Patients of II gr. had significantly lower BFV min in MCA, ACA, PCA (accordingly: MCA – 0.46 ± 0.03 vs 0.62 ± 0.04 m/s, p < 0.05, ACA – 0.34 ± 0.02 vs 0.45 ± 0.03 m/s, p < 0.05, PCA – 0.25 ± 0.01 vs 0.36 ± 0.02 m/s, p < 0.05) and significantly higher CVRI than pts of I gr. (accordingly: MCA – 169.21 ± 10.28 vs 130.47 ± 8.47 mmHg/m/s, ACA – 271.65 ± 21.32 vs 180.16 ± 20.25 mmHg/m/s, PCA – 407.12 ± 24.28 vs 252.03 ± 21.58 mmHg/m/s, p < 0.05). Changes of BFV max and mean were not significant. MoCA results were related to MCA BFV min (r = −0.46; p < 0.01), CVRI (r = 0.52; p < 0.05). The same relations were between MoCA results and BFV parameters of ACA and PCA. After adjustment for 24 h SBP and DBP, 24hI SBP, variability of nighttime SBP and DBP these relationships were not significant. Multiple regression analysis has shown that CVRI is predictor of cognitive impairment in pts with EH. Conclusions: Cognitive function in patients with EH related to increase vascular resistance manifesting through decrease minimal blood flow and increase vascular resistance indexes in media, anterior, posterior cerebral arteries. These changes are caused by high 24 h SBP and DBP, variability of nighttime SBP and DBP, low SBP 24 h index. CVRI is predictor of cognitive impairment in pts with EH.