The severity of acute ischemic stroke is associated with the decrease in peak systolic velocity in the common carotid arteries
Authors: Serova D , Serov V , Braun A , Kovalenko A , Shutov A 
Published: April 2021

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
A negative effect on the prognosis of ischemic stroke of the aggressive decrease in blood pressure, leading to a decrease in cerebral blood flow, is known. On the other side, increased blood pressure can be a compensatory mechanism. Currently, however, it is difficult to assess the adequacy of cerebral blood flow, one of the indicators of which is the blood flow velocity in the common carotid artery.

Purpose
The aim of this study was to estimate the peak systolic velocity in the common carotid arteries (CCA PSV) depending on the severity of acute ischemic stroke (IS).

Methods
180 patients with acute ischemic stroke (70 females and 110 males, mean age was 66.3 ± 12.3 years) were studied. Including 46 (25.6%) patients with cardioembolic stroke, 25 (13.9%) - with a thrombotic stroke, 27 (15.0%) – with a lacunar stroke and 82 (45.5%) – with undifferentiated stroke. Most of them 173 (96.1%) had grade 3 of arterial hypertension according to ESH/ESC Guidelines for the management of arterial hypertension, 2018. 59 (32.8%) patients had coronary artery disease, 52 (28.9%) - had atrial fibrillation. Patients were categorized according to National Institutes of Health Stroke Scale (NIHSS) severity in mild NIHSS (&lt;9) - 122 (67.8%) patients, moderate NIHSS (9–15) - 35 (19.4%) patients, and severe stroke NIHSS (&gt;16) - 23 (12.8%) patients. Median NIHSS score was 9.2 ± 0.9. All patients underwent a transthoracic echocardiography and a carotid ultrasound examination. A comparative assessment of echographic parameters was performed in patients of lower (NIHSS score ≤ 4.0) and upper (NIHSS score≥11.0) quartile according to the NIHSS score.

Results
It is shown a decrease of peak systolic velocity in the common carotid arteries with an increase in the severity of IS on the NIHSS scale: in mild stroke, it was 73.9 ± 18.7 cm/s, in moderate stroke - 66.3 ± 19.2 cm/s (p = 0.04), in severe stroke - 62.1 ± 17,4 cm/sec (p = 0.006 and p = 0.4, respectively). Peak systolic velocity in patients with the lower quartile of stroke severity was 73.8 ± 19.1 cm/sec, in the group of patients with the upper quartile – 64.3 ± 19.2 cm/sec (р=0.02). There were no differences in the resistance index of common carotid arteries: 0.75 ± 0.05, 0.76 ± 0.06 and 0.75 ± 0.07 for mild, moderate and severe severity, respectively, p &gt; 0.5). A multiple linear regression analysis in which the severity of ischemic stroke on the NIHSS scale was a dependent variable and age, CCA PSV, common carotid artery intima–media thickness and systolic, diastolic and pulse blood pressure were independent variables, showed that the severity of ischemic stroke was independently correlated with the CCA PSV (β =-0.13, p = 0.009).
Conclusions.1. It is shown the decrease of peak systolic velocity in the common carotid arteries with an increase in the severity of ischemic stroke on the NIHSS scale. 2. The reduction of CCA PSV exacerbates brain ischemia and reflecting disorders of autoregulation of cerebral blood flow.