scholarly journals Predictors of the pulsatility index in the middle cerebral artery of acute stroke patients

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Olivier Bill ◽  
Dimitris Lambrou ◽  
Guillermo Toledo Sotomayor ◽  
Ivo Meyer ◽  
Patrik Michel ◽  
...  

Abstract Cervical and transcranial Doppler (TCD) are widely used as non-invasive methods in the evaluation of acute ischemic stroke (AIS) patients. High-grade carotid artery stenosis induces haemodynamic changes such as collateral flow and a so-called post-stenotic flow pattern of the middle cerebral artery (MCA), which appears flattened, with a reduction of the velocity difference between systole and diastole. We studied the influence of carotid artery stenosis and other variables on the flow pattern in the MCA using the pulsatility index (PI), a quantitative TCD parameter reflecting the flow spectrum in a large of cohort AIS patients. We performed ultrasound examinations of 1825 AIS patients at the CHUV from October 2004 to December 2014. We extracted patient characteristics from the ASTRAL registry. Carotid stenosis severity was classified as < 50%, 50–70%, 70–90% and > 90%, or occlusion, according to Doppler velocity criteria. We first determined variables associated with stenosis grade. Then we performed a multivariate analysis after adjusting for baseline differences, using MCA PI as dependent variable. Carotid stenosis > 70% (− 0.07) and carotid stenosis > 90%, or occlusion (− 0.14) and left side (− 0.02) are associated with lower MCA PI values. Age (+0.006 PI units per decade), diabetes (+0.07), acute ischemic changes on initial CT (+0.03) and severe plaque morphology (+0.18) are associated with higher MCA PI values. We found a number of clinical and radiological conditions that significantly influence the PI of the MCA, including high-grade ipsilateral carotid stenosis in AIS patients. We provide for the first time a quantitative evaluation of the effect of these influencing factors from a large cohort of AIS patients.

1992 ◽  
Vol 83 (3) ◽  
pp. 357-366 ◽  
Author(s):  
Heinrich Fürst ◽  
Wolfgang H. Hartl ◽  
Ingrid Jansen ◽  
Barbara Fink ◽  
Axel Piepgras ◽  
...  

1. Transcranial flow velocity waves were measured via Doppler sonography of the middle cerebral artery during hypo-, hyper- and normo-capnia. Applying the principle of vascular impedance, flow velocity waves were analysed in 30 young subjects, 37 elderly subjects and 18 patients with high-grade unilateral internal carotid artery disease. 2. There was evidence that the relative peak-to-peak velocity in the middle cerebral artery could serve as an index of peripheral wave reflection and cerebral resistance (CRi). The response of CRi to changes in arterial CO2 concentration (CRi reactivity) showed a clear age-dependency. However, the absolute side-to-side asymmetry of CRi reactivity (ΔR) did not vary with age and could be used to define a normal range (0–4%CRi/vol.%CO2). 3. Selective angiography demonstrated no cerebral cross-flow through the anterior part of the circle of Willis in nine patients with carotid artery stenosis whose absolute ΔR was above the normal range and whose CRi reactivity of the affected hemisphere was lower than that of the healthy opposite hemisphere. Conversely, another group of nine patients, whose ipsilateral CRi reactivity was higher than the contralateral CRi reactivity, demonstrated cross-flow through the anterior part of the circle of Willis. 4. ΔR may be used to identify patients who have high-grade internal carotid artery stenosis and present with low cerebral vascular resistance owing to poor intracerebral collaterals.


2014 ◽  
Vol 120 (1) ◽  
pp. 126-131 ◽  
Author(s):  
Eric J. Heyer ◽  
Joanna L. Mergeche ◽  
E. Sander Connolly

Object Transcranial Doppler (TCD) is frequently used to evaluate peripheral cerebral resistance and cerebral blood flow (CBF) in the middle cerebral artery prior to and during carotid endarterectomy (CEA). Patients with symptomatic carotid artery stenosis may have reduced peripheral cerebral resistance to compensate for inadequate CBF. The authors aim to determine whether symptomatic patients with reduced peripheral cerebral resistance prior to CEA demonstrate increased CBF and cognitive improvement as early as 1 day after CEA. Methods Fifty-three patients with symptomatic CEA were included in this observational study. All patients underwent neuropsychometric evaluation 24 hours or less preoperatively and 1 day postoperatively. The MCA was evaluated using TCD for CBF mean velocity (MV) and pulsatility index (PI). Pulsatility index ≤ 0.80 was used as a cutoff for reduced peripheral cerebral resistance. Results Significantly more patients with baseline PI ≤ 0.80 exhibited cognitive improvement 1 day after CEA than those with PI > 0.80 (35.0% vs 6.1%, p = 0.007). Patients with cognitive improvement had a significantly greater increase in CBF MV than patients without cognitive improvement (13.4 ± 17.1 cm/sec vs 4.3 ± 9.9 cm/sec, p = 0.03). In multivariate regression model, a baseline PI ≤ 0.80 was significantly associated with increased odds of cognitive improvement (OR 7.32 [1.40–59.49], p = 0.02). Conclusions Symptomatic CEA patients with reduced peripheral cerebral resistance, measured as PI ≤ 0.80, are likely to have increased CBF and improved cognitive performance as early as 1 day after CEA for symptomatic carotid artery stenosis. Revascularization in this cohort may afford benefits beyond prevention of future stroke. Clinical trial registration no: NCT00597883 (ClinicalTrials.gov).


Author(s):  
Bernardo Crespo Pimentel ◽  
Jan Sedlacik ◽  
Julian Schröder ◽  
Marlene Heinze ◽  
Leif Østergaard ◽  
...  

Abstract Introduction Revascularization procedures in carotid artery stenosis have shown a positive effect in the restoration of cerebral oxygen metabolism as assessed by T2’ (T2 prime) imaging as well as capillary homeostasis by measurement of capillary transit time heterogeneity (CTH); however, data in patients with asymptomatic carotid stenosis without manifest brain lesions are scarce. Patients and Methods The effect of revascularization on the hemodynamic profile and capillary homeostasis was evaluated in 13 patients with asymptomatic high-grade carotid stenosis without ischemic brain lesions using dynamic susceptibility contrast perfusion imaging and oxygenation-sensitive T2’ mapping before and 6–8 weeks after revascularization by endarterectomy or stenting. The cognitive performance at both timepoints was further assessed. Results Perfusion impairment at baseline was accompanied by an increased CTH (p = 0.008) in areas with a time to peak delay ≥ 2 s in the affected hemisphere compared to contralateral regions. Carotid intervention improved the overall moderate hemodynamic impairment at baseline by leading to an increase in normalized cerebral blood flow (p = 0.017) and a decrease in mean transit time (p = 0.027), oxygen extraction capacity (OEC) (p = 0.033) and CTH (p = 0.048). The T2’ values remained unchanged. Conclusion This study presents novel evidence of a state of altered microvascular function in patients with high-grade carotid artery stenosis in the absence of ischemic brain lesions, which shows sustained normalization after revascularization procedures.


2020 ◽  
Vol 4 (1) ◽  
pp. 2514183X2093241
Author(s):  
Philipp Gruber ◽  
Jatta Berberat ◽  
Timo Kahles ◽  
Javier Anon ◽  
Michael Diepers ◽  
...  

Background: One of the major periprocedural risks of carotid artery stenting is embolism caused either by plaque debris or by local thrombus forming. Double-layer micromesh stent design has shown to lower the chance of debris embolism but might have a slightly higher risk of local thrombus forming. Thus, we compared two different stent designs regarding safety and outcome profile in elective patients with high-grade carotid artery stenosis using a self-expanding, double-layer micromesh carotid stent system (DLCS) or a self-expanding hybrid carotid stent system (HCS). Methods: A single-center, open-label, retrospective cohort study of 67 consecutive, elective patients with high-grade symptomatic and asymptomatic carotid stenosis was executed at a comprehensive stroke center. Outcome measures were reocclusion rate, periprocedural symptomatic ischemic events, as well as other periprocedural complications, and recurrent stroke and mortality at 30 days’ follow-up. Results: Thirty-two patients (24% women, median age 75 years (interquartile range (IQR) 71–80) were treated with DLCS, and 35 patients (29% women, median age 71 years (IQR 63–76) years) with HCS. In both groups, pretreatment carotid stenosis degree was similar (median NASCET of 80%). Successful deployment was achieved in all cases without technical failure, and both groups did not differ in reocclusion rates, recurrent stroke, and mortality within 30 days. Conclusions: DCLS and HCS revealed to have similar safety and outcome profile in elective patients with high-grade symptomatic as well as asymptomatic carotid artery stenosis.


Stroke ◽  
2001 ◽  
Vol 32 (9) ◽  
pp. 2075-2080 ◽  
Author(s):  
Christopher M. McPherson ◽  
Daniel Woo ◽  
Paul L. Cohen ◽  
Arthur M. Pancioli ◽  
Brett M. Kissela ◽  
...  

Stroke ◽  
2021 ◽  
Author(s):  
Brajesh K. Lal ◽  
James F. Meschia ◽  
Thomas G. Brott ◽  
Michael Jones ◽  
Herbert D. Aronow ◽  
...  

Background and Purpose: Despite a higher incidence of stroke and a more adverse cardiovascular risk factor profile in Blacks and Hispanics compared with Whites, carotid artery revascularization is performed less frequently among these subpopulations. We assessed racial differences in high-grade (≥70% diameter-reducing) carotid stenosis. Methods: Consecutive clients in a Nationwide Life Line for-Profit Service to screen for vascular disease, 2005 to 2019 were evaluated in a cross-sectional study. The prevalence of high-grade stenosis, defined by a carotid ultrasound peak systolic velocity of ≥230 cm/s, was assessed. Participants self-identified as White, Black, Hispanic, Asian, Native American, or other. Race/ethnic differences were assessed using Poisson regression. The number of individuals in the United States with high-grade stenosis was estimated by applying prevalence estimates to 2015 US Census population estimates. Results: The prevalence of high-grade carotid stenosis was estimated in 6 130 481 individuals. The prevalence of high-grade stenosis was higher with increasing age in all race-sex strata. Generally, Blacks and Hispanics had a lower prevalence of high-grade stenosis compared with Whites, while Native Americans had a higher prevalence. For example, for men aged 55 to 65, the relative risk of stenosis compared with Whites was 0.40 (95% CI, 0.29–0.55) and 0.61 (95% CI, 0.46–0.81) for Blacks and Hispanics, respectively; and 1.53 (95% CI, 1.12–2.10) for Native Americans. When these prevalence estimates were applied to the Census estimates of the US population, an estimated 327 721 individuals have high-grade stenosis, of whom 7% are Black, 7% Hispanic, and 43% women. Conclusions: Despite their having a more adverse cardiovascular risk profile, there was a lower prevalence of high-grade carotid artery stenosis for both the Black and Hispanic relative to the White clients. This lower prevalence of high-grade stenosis is a potential contributor to the lower use of carotid revascularization procedures in these minority populations.


2020 ◽  
pp. 1-7
Author(s):  
Ching-I Wu ◽  
Chia-Lun Wu ◽  
Feng-Chieh Su ◽  
Shun-Wen Lin ◽  
Wen-Yi Huang

<b><i>Background:</i></b> The coincidence of coronary artery disease (CAD) and carotid artery stenosis (CAS) was observed. However, the association between pre-existing CAD and ischemic stroke (IS) outcome in patients with high-grade CAS remains unclear. We aimed to investigate the association between pre-existing CAD and outcomes of acute IS patients with high-grade CAS. <b><i>Methods:</i></b> From January 1, 2007, to April 30, 2012, we enrolled 372 acute IS patients with high-grade CAS and prospectively observed them for 5 years. Demographic features, vascular risk factors, comorbidities, and outcomes were compared between patients with and without pre-existing CAD. <b><i>Results:</i></b> Among 372 individuals, 75 (20.2%) patients had pre-existing CAD and 297 (79.8%) patients did not have pre-existing CAD. The prevalence rates of hypertension, congestive heart failure, chronic kidney disease, and gout in patients with pre-existing CAD were significantly higher than in those without pre-existing CAD (<i>p</i> = 0.017, <i>p</i> &#x3c; 0.001, <i>p</i> = 0.002, and <i>p</i> &#x3c; 0.001, respectively). The multivariate Cox proportional hazards model revealed that pre-existing CAD was a significant risk factor for a 5-year all-cause mortality in acute IS patients with high-grade CAS (hazard ratio = 2.26; 95% confidence interval = 1.35–3.79; <i>p</i> = 0.002). <b><i>Conclusion:</i></b> Pre-existing CAD was associated with an increased risk of 5-year mortality in acute IS patients with high-grade CAS. Intensive treatment for the pre-existing CAD may reduce long-term mortality in acute IS patients with high-grade CAS.


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