Assumptions in modelling of large artery hemodynamics

Author(s):  
David A. Steinman
Keyword(s):  
2020 ◽  
Vol 133 (1) ◽  
pp. 152-158 ◽  
Author(s):  
Umeshkumar Athiraman ◽  
Diane Aum ◽  
Ananth K. Vellimana ◽  
Joshua W. Osbun ◽  
Rajat Dhar ◽  
...  

OBJECTIVEDelayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (SAH) is characterized by large-artery vasospasm, distal autoregulatory dysfunction, cortical spreading depression, and microvessel thrombi. Large-artery vasospasm has been identified as an independent predictor of poor outcome in numerous studies. Recently, several animal studies have identified a strong protective role for inhalational anesthetics against secondary brain injury after SAH including DCI—a phenomenon referred to as anesthetic conditioning. The aim of the present study was to assess the potential role of inhalational anesthetics against cerebral vasospasm and DCI in patients suffering from an SAH.METHODSAfter IRB approval, data were collected retrospectively for all SAH patients admitted to the authors’ hospital between January 1, 2010, and December 31, 2013, who received general anesthesia with either inhalational anesthetics only (sevoflurane or desflurane) or combined inhalational (sevoflurane or desflurane) and intravenous (propofol) anesthetics during aneurysm treatment. The primary outcomes were development of angiographic vasospasm and development of DCI during hospitalization. Univariate and logistic regression analyses were performed to identify independent predictors of these endpoints.RESULTSThe cohort included 157 SAH patients whose mean age was 56 ± 14 (± SD). An inhalational anesthetic–only technique was employed in 119 patients (76%), while a combination of inhalational and intravenous anesthetics was employed in 34 patients (22%). As expected, patients in the inhalational anesthetic–only group were exposed to significantly more inhalational agent than patients in the combination anesthetic group (p < 0.05). Multivariate logistic regression analysis identified inhalational anesthetic–only technique (OR 0.35, 95% CI 0.14–0.89), Hunt and Hess grade (OR 1.51, 95% CI 1.03–2.22), and diabetes (OR 0.19, 95% CI 0.06–0.55) as significant predictors of angiographic vasospasm. In contradistinction, the inhalational anesthetic–only technique had no significant impact on the incidence of DCI or functional outcome at discharge, though greater exposure to desflurane (as measured by end-tidal concentration) was associated with a lower incidence of DCI.CONCLUSIONSThese data represent the first evidence in humans that inhalational anesthetics may exert a conditioning protective effect against angiographic vasospasm in SAH patients. Future studies will be needed to determine whether optimized inhalational anesthetic paradigms produce definitive protection against angiographic vasospasm; whether they protect against other events leading to secondary brain injury after SAH, including microvascular thrombi, autoregulatory dysfunction, blood-brain barrier breakdown, neuroinflammation, and neuronal cell death; and, if so, whether this protection ultimately improves patient outcome.


2020 ◽  
Vol 17 (1) ◽  
pp. 18-26 ◽  
Author(s):  
Ho Jun Yi ◽  
Jae Hoon Sung ◽  
Dong Hoon Lee

Objective: We investigated whether intravenous thrombolysis (IVT) affected the outcomes and complications of mechanical thrombectomy (MT), specifically focusing on thrombus fragmentation. Methods: The patients who underwent MT for large artery occlusion (LAO) were classified into two groups: MT with prior IVT (MT+IVT) group and MT without prior IVT (MT-IVT) group. The clinical outcome, successful recanalization with other radiological outcomes, and complications were compared, between two groups. Subgroup analysis was also performed for patients with simultaneous application of stent retriever and aspiration. Results: There were no significant differences in clinical outcome and successful recanalization rate, between both groups. However, the ratio of pre- to peri-procedural thrombus fragmentation was significantly higher in the MT+IVT group (14.6% and 16.2%, respectively; P=0.004) compared to the MT-IVT group (5.1% and 6.8%, respectively; P=0.008). The MT+IVT group required more second stent retriever (16.2%), more stent passages (median value = 2), and more occurrence of distal emboli (3.9%) than the MT-IVT group (7.9%, median value = 1, and 8.1%, respectively) (P=0.004, 0.008 and 0.018, respectively). In subgroup analysis, the results were similar to those of the entire patients. Conclusion: Thrombus fragmentation of IVT with t-PA before MT resulted in an increased need for additional rescue therapies, and it could induce more distal emboli. The use of IVT prior to MT does not affect the clinical outcome and successful recanalization, compared with MT without prior IVT. Therefore, we need to reconsider the need for IVT before MT.


2020 ◽  
Vol 18 (4) ◽  
pp. 410-417 ◽  
Author(s):  
Rigas G. Kalaitzidis ◽  
Thalia Panagiotopoulou ◽  
Dimitrios Stagikas ◽  
Kosmas Pappas ◽  
Olga Balafa ◽  
...  

:The incidence of hypertension (HTN) and its cardiovascular (CV) complications are increasing throughout the world. Blood pressure (BP) control remains unsatisfactory worldwide. Medical inertia and poor adherence to treatment are among the factors that can partially explain, why BP control rate remains low. The introduction of a method for measuring the degree of adherence to a given medication is now a prerequisite. Complex treatment regimes, inadequate tolerance and frequent replacements of pharmaceutical formulations are the most common causes of poor adherence. In contrast, the use of stable combinations of antihypertensive drugs leads to improved patient adherence.:We aim to review the relationships between arterial stiffness, cognitive function and adherence to medication in patients with HTN.:Large artery stiffening can lead to HTN. In turn, arterial stiffness induced by HTN is associated with an increased CV and stroke risk. In addition, HTN can induce disorders of brain microcirculation resulting in cognitive dysfunction. Interestingly, memory cognitive dysfunction leads to a reduced adherence to drug treatment. Compliance with antihypertensive treatment improves BP control and arterial stiffness indices. Early treatment of arterial stiffness is strongly recommended for enhanced cognitive function and increased adherence.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Fan Yu ◽  
Xiaolu Liu ◽  
Qiong Yang ◽  
Yu Fu ◽  
Dongsheng Fan

Abstract Acute ischemic stroke (AIS) has a high risk of recurrence, particularly in the early stage. The purpose of this study was to assess the frequency and risk factors of in-hospital recurrence in patients with AIS in China. A retrospective analysis was performed of all of the patients with new-onset AIS who were hospitalized in the past three years. Recurrence was defined as a new stroke event, with an interval between the primary and recurrent events greater than 24 hours; other potential causes of neurological deterioration were excluded. The risk factors for recurrence were analyzed using univariate and logistic regression analyses. A total of 1,021 patients were included in this study with a median length of stay of 14 days (interquartile range,11–18). In-hospital recurrence occurred in 58 cases (5.68%), primarily during the first five days of hospitalization. In-hospital recurrence significantly prolonged the hospital stay (P < 0.001), and the in-hospital mortality was also significantly increased (P = 0.006). The independent risk factors for in-hospital recurrence included large artery atherosclerosis, urinary or respiratory infection and abnormal blood glucose, whereas recurrence was less likely to occur in the patients with aphasia. Our study showed that the patients with AIS had a high rate of in-hospital recurrence, and the recurrence mainly occurred in the first five days of the hospital stay. In-hospital recurrence resulted in a prolonged hospital stay and a higher in-hospital mortality rate.


2021 ◽  
pp. 174749302110062
Author(s):  
Bin Yan ◽  
Jian Yang ◽  
Li Qian ◽  
Fengjie Gao ◽  
Ling Bai ◽  
...  

Background: Observational studies have found an association between visceral adiposity and stroke. Aims: The purpose of this study was to investigate the role and genetic effect of visceral adipose tissue (VAT) accumulation on stroke and its subtypes. Methods: In this two-sample Mendelian randomization (MR) study, genetic variants (221 single nucleotide polymorphisms; P<5×10-8) using as instrumental variables for MR analysis was obtained from a genome-wide association study (GWAS) of VAT. The outcome datasets for stroke and its subtypes were obtained from the MEGASTROKE consortium (up to 67,162 cases and 453,702 controls). MR standard analysis (inverse variance weighted method) was conducted to investigate the effect of genetic liability to visceral adiposity on stroke and its subtypes. Sensitivity analysis (MR-Egger, weighted median, MR-PRESSO) were also utilized to assess horizontal pleiotropy and remove outliers. Multi-variable MR analysis was employed to adjust potential confounders. Results: In the standard MR analysis, genetically determined visceral adiposity (per 1 SD) was significantly associated with a higher risk of stroke (odds ratio [OR] 1.30; 95% confidence interval [CI] 1.21-1.41, P=1.48×10-11), ischemic stroke (OR 1.30; 95% CI 1.20-1.41, P=4.01×10-10), and large artery stroke (OR 1.49; 95% CI 1.22-1.83, P=1.16×10-4). The significant association was also found in sensitivity analysis and multi-variable MR analysis. Conclusions: Genetic liability to visceral adiposity was significantly associated with an increased risk of stroke, ischemic stroke, and large artery stroke. The effect of genetic susceptibility to visceral adiposity on the stroke warrants further investigation.


2021 ◽  
pp. 1-4
Author(s):  
Simone Vidale

<b><i>Background and Purpose:</i></b> Coronavirus disease 2019 (CO­VID-19) infection is an ongoing pandemic and worldwide health emergency that has caused important changes in healthcare systems. Previous studies reported an increased risk of thromboembolic events, including stroke. This systematic review aims to describe the clinical features and etiological characteristics of ischemic stroke patients with CO­VID-19 infection. <b><i>Method:</i></b> A literature search was performed in principal databases for studies and case reports containing data concerning risk factors, clinical features, and etiological characteristics of patients infected with COVID-19 and suffering from stroke. Descriptive and analytical statistics were applied. <b><i>Results:</i></b> Overall, 14 articles were included for a total of 93 patients. Median age was 65 (IQR: 55–75) years with prevalence in males. Stroke occurred after a median of 6 days from COVID-19 infection diagnosis. Median National of Institute of Health Stroke Scale (NIHSS) score was 19. Cryptogenic (Cry) strokes were more frequent (51.8%), followed by cardioembolic etiology, and they occurred a long time after COVID-19 diagnosis compared with large-artery atherosclerosis strokes (<i>p</i><sub>trend</sub>: 0.03). The clinical severity of stroke was significantly associated with the severity grade of COVID-19 infection (<i>p</i><sub>trend</sub>: 0.03). <b><i>Conclusions:</i></b> Ischemic strokes in COVID-19-infected patients were clinically severe, affecting younger patients mainly with Cry and cardioembolic etiologies. Further multicenter prospective registries are needed to better describe the causal association and the effect of COVID-19 infection on stroke.


2021 ◽  
Vol 14 ◽  
pp. 175628642199901
Author(s):  
Meredeth Zotter ◽  
Eike I. Piechowiak ◽  
Rupashani Balasubramaniam ◽  
Rascha Von Martial ◽  
Kotryna Genceviciute ◽  
...  

Background and aims: To investigate whether stroke aetiology affects outcome in patients with acute ischaemic stroke who undergo endovascular therapy. Methods: We retrospectively analysed patients from the Bernese Stroke Centre Registry (January 2010–September 2018), with acute large vessel occlusion in the anterior circulation due to cardioembolism or large-artery atherosclerosis, treated with endovascular therapy (±intravenous thrombolysis). Results: The study included 850 patients (median age 77.4 years, 49.3% female, 80.1% with cardioembolism). Compared with those with large-artery atherosclerosis, patients with cardioembolism were older, more often female, and more likely to have a history of hypercholesterolaemia, atrial fibrillation, current smoking (each p < 0.0001) and higher median National Institutes of Health Stroke Scale (NIHSS) scores on admission ( p = 0.030). They were more frequently treated with stent retrievers ( p = 0.007), but the median number of stent retriever attempts was lower ( p = 0.016) and fewer had permanent stent placements ( p ⩽ 0.004). Univariable analysis showed that patients with cardioembolism had worse 3-month survival [72.7% versus 84%, odds ratio (OR) = 0.51; p = 0.004] and modified Rankin scale (mRS) score shift ( p = 0.043) and higher rates of post-interventional heart failure (33.5% versus 18.5%, OR = 2.22; p < 0.0001), but better modified thrombolysis in cerebral infarction (mTICI) score shift ( p = 0.025). Excellent (mRS = 0–1) 3-month outcome, successful reperfusion (mTICI = 2b–3), symptomatic intracranial haemorrhage and Updated Charlson Comorbidity Index were similar between groups. Propensity-matched analysis found no statistically significant difference in outcome between stroke aetiology groups. Stroke aetiology was not an independent predictor of favourable mRS score shift, but lower admission NIHSS score, younger age and independence pre-stroke were (each p < 0.0001). Stroke aetiology was not an independent predictor of heart failure, but older age, admission antithrombotics and dependence pre-stroke were (each ⩽0.027). Stroke aetiology was not an independent predictor of favourable mTICI score shift, but application of stent retriever and no permanent intracranial stent placement were (each ⩽0.044). Conclusion: We suggest prospective studies to further elucidate differences in reperfusion and outcome between patients with cardioembolism and large-artery atherosclerosis.


Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 820
Author(s):  
Keshav Jayaraman ◽  
Meizi Liu ◽  
Gregory J. Zipfel ◽  
Umeshkumar Athiraman

Numerous studies have demonstrated the ability of isoflurane conditioning to provide multifaceted protection against aneurysmal subarachnoid hemorrhage (SAH)-associated delayed cerebral ischemia (DCI); however, preclinical studies have not yet examined whether other commonly used inhalational anesthetics in neurological patients such as sevoflurane or desflurane are also protective against SAH-induced neurovascular deficits. We therefore sought to identify the potential for sevoflurane and desflurane conditioning to protect against DCI in an endovascular perforation mouse model of SAH. Neurological function was assessed daily via neuroscore. Large artery vasospasm and microvessel thrombosis were assessed three days after SAH or sham surgery. Four groups were examined: Sham, SAH + room air, SAH + 2% Sevoflurane, and SAH + 6% Desflurane. For the SAH groups, one hour after surgery, mice received 2% sevoflurane, 6% desflurane, or room air for one hour. We found that conditioning with sevoflurane or desflurane attenuated large artery vasospasm, reduced microvessel thrombosis, and improved neurologic function. Given their frequent clinical use and strong safety profile in patients (including those with SAH), these data strongly support further studies to validate these findings in preclinical and clinical studies and to elucidate the mechanisms by which these agents might be acting.


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