Management of Blood Pressure During and After Recanalization Therapy for Acute Ischemic Stroke

Blood Pressure Fluctuation During 72 Hours After Endovascular Therapy and Prognosis in Acute Ischemic Stroke Patients

PURPOSE

Our study aimed to investigate the relationship between fluctuations in different blood pressure (BP) components within 72 hours following endovascular therapy (EVT) and the prognosis of acute ischemic stroke (AIS) patients.

METHODS

This prospective multicenter study included 283 AIS patients who underwent EVT and had available BP data. The primary outcome was the ordinal modified Rankin Scale (mRS) score evaluated at 90 days. The secondary outcome was a combination of death and major disability, defined as an mRS score of 3 to 6 within 3 months.

RESULTS

After adjusting for imbalanced variables, the highest tertile of systolic blood pressure (SBP) fluctuation had an odds ratio (OR) of 1.747 (95% confidence interval [CI]=1.031-2.961; p for trend=0.035) for the primary outcome and 1.889 (95% CI=1.015-3.516; p for trend=0.039) for the secondary outcome, respectively. Fluctuations in diastolic blood pressure (DBP) (OR=1.914, 95% CI=1.134-3.230, p for trend=0.015) and mean arterial pressure (MAP) (OR=1.759, 95% CI=1.026-3.015, p for trend=0.039) were only associated with the primary outcome. The multivariate-adjusted restricted cubic spline analyses supported these findings. Furthermore, the fluctuations in both SBP and MAP exhibited the significant discriminatory capability in predicting the prognosis, comparable to their mean values.

CONCLUSION

Our study revealed that larger fluctuations in SBP, DBP, and MAP within 72 hours after EVT were associated with a higher risk of poor clinical outcomes within 3 months in AIS patients. Controlling BP fluctuations may be valuable for improving the prognosis in patients undergoing EVT.

CLINICAL IMPACT

How will this change clinical practice?It provides physicians a new approach to directly monitor BP fluctuations over an extended observation period in AIS patients after EVT in routine clinical practice.What does it mean for the clinicians?These results underscore the importance of giving equal attention to controlling long-term BP fluctuations, in addition to managing mean BP, as a means to improve the prognosis of AIS patients after EVT.What is the innovation behind the study?This study systematically evaluated the association between fluctuations in different blood pressure components and clinical outcomes in AIS patients over an extended period following EVT.

Stroke Risk Reduction in Migraine Patients Using Propranolol: Evidence from Two Large-Scale Real-World Data Analyses

Background

Propranolol, a non-selective beta-blocker, is commonly used for migraine prevention, but its impact on stroke risk among migraine patients remains controversial. Using two large electronic health records-based datasets, we examined stroke risk differences between migraine patients with- and without- documented use of propranolol.

Methods

This retrospective case-control study utilized EHR data from the Vanderbilt University Medical Center (VUMC) and the All of Us Research Program. Migraine patients were first identified based on the International Classification of Headache Disorders, 3rd edition (ICHD-3) criteria using diagnosis codes. Among these patients, cases were defined as those with a primary diagnosis of stroke following the first diagnosis of migraine, while controls had no stroke after their first migraine diagnosis. Logistic regression models, adjusted for potential factors associated with stroke risk, assessed the association between propranolol use and stroke risk, stratified by sex and migraine subtype. A Cox proportional hazards regression model was used to estimate the hazard ratio (HR) for stroke risk at 1, 2, 5, and 10 years from baseline.

Results

In the VUMC database, 378 cases and 15,209 controls were identified, while the All of Us database included 267 cases and 6,579 controls. Propranolol significantly reduced stroke risk in female migraine patients (VUMC: OR=0.52, p=0.006; All of Us: OR=0.39, p=0.007), but not in males. The effect was more pronounced for ischemic stroke and in females with migraines without aura (MO) (VUMC: OR=0.60, p=0.014; All of Us: OR=0.28, p=0.006). The Cox model showed lower stroke rates in propranolol-treated female migraine patients at 1, 2, 5, and 10 years (VUMC: HR=0.06-0.55, p=0.0018-0.085; All of Us: HR=0.23, p=0.045 at 10 years).

Conclusions

Propranolol is associated with a significant reduction in stroke risk, particularly ischemic stroke, among female migraine without aura patients. These findings suggest that propranolol may benefit stroke prevention in high-risk populations.

Procedural blood pressure and contrast extravasation on dual energy computed tomography after endovascular stroke treatment

BACKGROUND

Blood brain barrier disruption (BBBD) can be visualized by contrast extravasation (CE) after endovascular treatment (EVT) in patients with acute ischemic stroke. Elevated blood pressure is a risk factor for BBBD. However, the association between procedural blood pressure and CE post-EVT is unknown.

METHODS

In this single-center retrospective study, we analyzed 501 eligible patients who received a dual energy CT (DECT) immediately post-EVT for acute ischemic stroke. Procedural blood pressure values (SBPmean, SBPmax, SBPmax-min, and MAPmean) were collected. CE was quantified by measuring the maximum parenchymal iodine concentration on DECT iodine overlay map reconstructions. As a measure for the extent of BBBD, we created CE-ASPECTS by deducting one point per hyperdense ASPECTS region on iodine overlay maps. The association between blood pressure and CE was assessed using multivariable linear regression.

RESULTS

The procedural SBPmean, SBPmax, and MAPmean were 150 ± 26 mmHg, 173 ± 29 mmHg, and 101 ± 17 mmHg, respectively. The median maximum iodine concentration on post-EVT DECT was 1.2 mg/ml (IQR 0.7-2.0), and median CE-ASPECTS was 8 (IQR 5-11). The maximum iodine concentration was not associated with blood pressure. SBPmean, SBPmax, and MAPmean were significantly associated with CE-ASPECTS (per 10 mmHg, β = -0.2, 95 % CI -0.31 to -0.09, β = -0.15, 95 % CI -0.25 to -0.06, β = -0.33, 95 % CI -0.49 to -0.17, respectively).

CONCLUSION

In acute ischemic stroke patients undergoing EVT, particularly in patients achieving successful recanalization, SBPmean, SBPmax, and MAPmean are associated with the extent of BBBD on immediate post-EVT DECT, but not with maximum iodine concentration.

Safety and Efficacy of Intensive Blood Pressure-Lowering After Successful Endovascular Therapy in AIS: A Meta-Analysis

OBJECTIVES

Higher blood pressure has been proven to be associated with poorer functional outcomes after successful reperfusion by EVT. However, the effect of intensive blood pressure-lowering regimens in these patients remains controversial and ambiguous in clinical practice. We propose further analysis aimed at determining the effect of an intensive blood pressure-lowering regimen after EVT in AIS.

METHODS

The protocol registered in PROSPERO CRD42023360989. We performed a systematic search that was comprehensively executed in online databases for studies published up to June 2022. Eligibility criteria were established based on the PICOS model. The Cochrane risk of bias algorithm was used to evaluate the risk of bias. The effect models were applied to calculate the pooled ORs and CIs via Review Manager 5.4 software.

RESULTS

A total of 1582 citations were identified, 3 randomized clinical trials and 2 retrospective cohort studies were included. Data from 3211 patients were analyzed. We revealed that intensive blood pressure-lowering interventions could significantly reduce symptomatic intraparenchymal hemorrhage compared with standard blood pressure lowering. Nevertheless, favorable functional outcome, poor outcome, all-cause mortality within 3 months and intraparenchymal hemorrhage in 24 hours showed no significant differences. Subgroup analysis revealed the variability of systolic blood pressure within 24 hours after EVT was not associated with odds of poor outcome and intraparenchymal hemorrhage.

CONCLUSIONS

Based on the current evidence, intensive blood pressure-lowering regimen was superior to standard blood pressure-lowering regimen for a reduced risk of symptomatic intraparenchymal hemorrhage in AIS patients treated with EVT, but there was no statistically significant difference found between the 2 regimens for the other outcomes.

Evaluation of the correlation between cerebral hemodynamics and blood pressure by comparative analysis of variation in cerebral blood flow in hypertensive versus normotensive individuals: A systematic review and meta-analysis

Current understanding of the cerebral vascular response to variations in blood pressure (BP) among individuals with hypertension is limited. The aim of this meta-analysis was to determine the correlation between hypertension, risk of stroke, and cerebral blood flow (CBF). We reviewed studies published between 2000 and 2023 from PubMed, Google Scholar, and Science Direct that compared mean CBF in normotensive (NTN) and hypertensive (HTN) patients. A random effects model was used to construct the risk ratio (RR), 95% confidence interval (CI), forest plot, and inverse variance weighting. Additionally, a mixed-effects meta-regression was employed to examine the impact of study-specific patient variables. This meta-analysis included eight prospective cross-sectional studies published from 2002 to 2023. It revealed a significant average difference in the standard mean CBF of -0.45 (95% CI -0.60 to -0.30, I2 = 69%, P < 0.00001), distinguishing NTN from HTN subjects. A RR of 0.90 (95% CI 0.63 to 1.30, I2 = 89%, P = 0.04) indicated a significant decrease in CBF among individuals with hypertension. We found a statistically significant relationship between changes in diastolic and systolic BPs and the mean CBF (R -0.81, P = 0.001 and R = -0.90, P = 0.005, respectively). Our research demonstrates a strong relationship between elevated BP and reduced CBF, with hypertension reducing CBF compared to NTN individuals, by increasing cerebrovascular resistance.

Blood Pressure after Successful Endovascular Therapy: A Systematic Review and Meta-Analysis of Randomized Control Trials

OBJECTIVE

There are limited data evaluating the optimum blood pressure (BP) goal post mechanical thrombectomy (MT) and its effect on outcomes of patients with large vessel occlusions (LVO). The objective of this study was to compare the efficacy and safety of intensive versus conventional BP control after reperfusion with MT via a systematic review and meta-analysis of randomized controlled trials (RCTs).

METHODS

We searched PubMed and Embase to obtain articles related to BP control post MT through September 2023. The primary outcome was functional independence (modified Rankin Scale [mRS] 0-2) at 3 months, while secondary outcomes included excellent outcome (mRS 0-1), symptomatic intracranial hemorrhage (sICH), and mortality.

RESULTS

Four RCTs with 1,566 patients (762 randomized into intensive BP control vs. 806 randomized into conventional BP control) were included. Analysis showed that there was a lower likelihood of functional independence (mRS 0-2: odds ratio [OR]: 0.68, 95% confidence interval [CI] 0.51-0.91, p = 0.009) in the more intensive treatment group compared with the conventional treatment group. There was no statistically significant difference in achieving excellent outcome (mRS0-1: OR: 0.82, 95% CI: 0.63-1.07; p = 0.15), risk of sICH or mortality.

INTERPRETATION

This systematic review and meta- analysis Indicates that in patients who achieved successful MT for acute ischemic stroke with LVO, intensive BP control was associated with a lower likelihood of functional independence at 3 months without significant difference in likelihood of achieving excellent outcome, sICH risk, or mortality. ANN NEUROL 2024;95:858-865.

Intensive Versus Standard Blood Pressure Management after Endovascular Therapy for Acute Ischemic Stroke: A Systematic Review and Meta-analysis

Prospective clinical studies on blood pressure (BP) management targets after endovascular therapy (EVT) for acute ischemic stroke (AIS) have recently been published. Our objective was to assess the impact on clinical outcomes of BP management guided by established systolic BP (SBP) targets within the first 24 hours after successful EVT. Four randomized controlled trials (RCTs) including 1556 participants across 5 SBP target settings identified from 5 databases up to September 6, 2023 were included in this systematic review and meta-analysis. All the intensive SBP target groups in these RCTs were combined to facilitate head-to-head comparisons. Patients receiving intensive SBP management had lower risk of 90-day functional independence as assessed by the modified Rankin scale score (relative risk [RR], 0.81; 95% confidence interval [CI], 0.72 to 0.91; I2, 12%), excellent outcomes (RR,0.86; 95% CI, 0.75 to 0.99; I2, 7%), favorable outcomes (RR, 0.85; 95% CI, 0.78 to 0.92; I2, 0%), and quality of life (standardized mean difference, -0.22; 95% CI, -0.35 to -0.10; I2,0%). There were no differences in the probability of any intracerebral hemorrhage (RR, 1.04; 95% CI, 0.92 to 1.19; I2,0%), symptomatic intracerebral hemorrhage (RR, 1.10; 95% CI, 0.76 to 1.60; I2, 0%), stroke-related death (RR, 1.16; 95% CI, 0.80 to 1.68; I2, 0%), or parenchymal hematoma (RR, 1.71; 95% CI, 0.74 to 3.98; I2, 47%) between SBP targets. This meta-analysis provides evidence from RCTs suggesting that intensive SBP control (target<160 mm Hg) may be detrimental to clinical outcomes in AIS patients with successful reperfusion after EVT.

Hemodynamic changes in progressive cerebral infarction: An observational study based on blood pressure monitoring

Progressive cerebral infarction (PCI) is a common complication in patients with ischemic stroke that leads to poor prognosis. Blood pressure (BP) can indicate post-stroke hemodynamic changes which play a key role in the development of PCI. The authors aim to investigate the association between BP-derived hemodynamic parameters and PCI. Clinical data and BP recordings were collected from 80 patients with cerebral infarction, including 40 patients with PCI and 40 patients with non-progressive cerebral infarction (NPCI). Hemodynamic parameters were calculated from the BP recordings of the first 7 days after admission, including systolic and diastolic BP, mean arterial pressure, and pulse pressure (PP), with the mean values of each group calculated and compared between daytime and nighttime, and between different days. Hemodynamic parameters and circadian BP rhythm patterns  were compared between PCI and NPCI groups using t-test or non-parametric equivalent for continuous variables, Chi-squared test or Fisher's exact test for categorical variables, Cox proportional hazards regression analysis and binary logistic regression analysis for potential risk factors. In PCI and NPCI groups, significant decrease of daytime systolic BP appeared on the second and sixth days, respectively. Systolic BP and fibrinogen at admission, daytime systolic BP of the first day, nighttime systolic BP of the third day, PP, and the ratio of abnormal BP circadian rhythms were all higher in the PCI group. PCI and NPCI groups were significantly different in BP circadian rhythm pattern. PCI is associated with higher systolic BP, PP and more abnormal circadian rhythms of BP.

The Use of Screening Tests in Differential Diagnosis in Nursing Care

Geriatric syndromes involving instability are associated with a higher risk of further complications in patients with trauma requiring subsequent surgery. Acute stroke symptoms require prompt recognition and initiation of reperfusion treatment. This case study describes the patient's stroke symptoms in a timeline and explores the benefit of objective assessment using screening tests and their importance in the differential diagnosis in nursing. Dysphagia is one of the stroke symptoms that can lead to aspiration pneumonia and increase the risk of mortality. This article aims to inform general nurses about the importance of early recognition of dysphagia and other stroke symptoms using adequate screening tests to ensure quality care. Geriatric syndromes encompass instability, resulting in a higher risk of complications, especially in trauma patients. This case study describes a patient with acute ischemic stroke with vague and unrecognized symptoms of dysphagia and explores the rationale for objective screening tests in nursing care.

Association of blood pressure parameters post mechanical thrombectomy in anemic versus non-anemic patients and clinical outcomes

INTRODUCTION

Higher blood pressure (BP) is considered to be detrimental in patients who undergo mechanical thrombectomy (MT), however, the impact of BP post-MT based on comorbidities like anemia has not been well studied. We aim to determine the association of 24-h post-MT BP parameters with clinical outcomes depending on their anemia status.

METHODS

We conducted a retrospective chart review of patients who underwent MT at a comprehensive stroke center from 1/2015 to 12/2020. Patients were dichotomized into anemic and non-anemic groups based on the World Health Organization's definition of anemia [hemoglobin < 12.0 g/dL in women and < 13.0 g/dL in men]. We performed a multivariable analysis with binary logistic regression with the 24-h post-MT BP parameters as predictors. The outcomes were functional dependence (3-month mRS 3-6), mortality, and an early neurological improvement.

RESULTS

220 patients met the inclusion criteria. 158 (71.82 %) patients had functional dependence at 3-months. In the multivariable analysis, the parameters of a higher mean SBP (132.9 ± 11.94 vs.126.52 ± 13.3; OR, 1.05; 95 % CI, 1.02-1.09; P 0.011), a higher mean MAP (93.35 ± 8.44 vs.89.69 ± 10.03; OR,1.06; 95 % CI, 1.01-1.11; P 0.029) and a higher maximum MAP (115.26 ± 11.73 vs.109.37 ± 12.51; OR,1.05; 95 % CI, 1.01-1.08; P 0.023)were significantly associated with functional dependence in non-anemic patients, while a lower mean DBP (65.53 ± 9.73 vs. 71.94 ± 10.16; OR, 0.92; 95 % CI, 0.86-0.98; P 0.007), lower mean MAP (85.7 ± 8.65 vs. 91.38 ± 10; OR, 0.93; 95 % CI, 0.86-0.99; P 0.02), a lower minimum DBP (49.27 ± 10.51 vs. 55.1 ± 11.23; OR, 0.93; 95 % CI, 0.88-0.99; P 0.019), a lower minimum MAP (68.96 ± 9.54 vs. 74.73 ± 10.47; OR, 0.93; 95 % CI, 0.87-0.99; P 0.023) were significantly associated with mortality in patients with anemia, and a lower minimum DBP (54.75 ± 10.42 vs. 59.69 ± 8.87; OR, 0.95; 95 % CI, 0.91-0.99; P 0.012) and a lower minimum MAP (71.92 ± 14.7 vs.75.67 ± 14.17; OR, 0.97; 95 % CI, 0.94-0.99; P 0.047) were significantly associated with an early neurological improvement in non-anemic patients. For patients with anemia, there was no association between 24-hour BP Parameters post-MT and functional dependence and early neurological improvement, and between 24-hour BP Parameters post-MT and mortality in non-anemic patients.

CONCLUSION

In our study, higher BP parameters were associated with worse outcomes in patients without anemia, however, this effect was not found in patients with anemia. Certain lower BP parameters were associated with higher 3-month mortality in anemic patients; however, this effect was not found in non-anemic patients. Higher BP post-MT can potentially promote perfusion and thus is not associated with worse outcomes in anemic patients post-MT, whereas in non-anemic patients it may potentially lead to reperfusion injury While our study is limited because of size and its retrospective nature, the findings suggest that an individualized approach to tailor the target BP post-MT to a patient's risk factor profile and associated co-morbid conditions to achieve optimization of medical care post-MT and associated co-morbid conditions to achieve optimization of medical care post-MT.

Augmentation of perfusion with simultaneous vasodilator and inotropic agents in experimental acute middle cerebral artery occlusion: a pilot study

BACKGROUND

This study tests the hypothesis that simultaneous cerebral blood pressure elevation and potent vasodilation augments perfusion to ischemic tissue in acute ischemic stroke and it varies by degree of pial collateral recruitment.

METHODS

Fifteen mongrel canines were included. Subjects underwent permanent middle cerebral artery occlusion; pial collateral recruitment was scored before treatment. Seven treatment subjects received a continuous infusion of norepinephrine (0.1-1.52 µg/kg/min; titrated 25-45 mmHg above baseline mean arterial pressure while keeping systolic blood pressure below 180 mmHg) and hydralazine (20 mg) starting 30 min post-occlusion. Perfusion (cerebral blood flow-CBF) was evaluated with quantitative dynamic susceptibility contrast MRI 2.5 hours post-occlusion to produce images in mL/100 g/min, and relative CBF measured as ratios. Mean region of interest (ROI) values were reported, and compared and subject to regression analysis to elucidate trends.

RESULTS

Differences in quantitative CBF (qCBF) between treatment and control group varied by degree of pial collateral recruitment, based on Wilcoxon rank sum scores and regression model fit. For poorly collateralized subjects, ipsilateral anatomic, core infarct, and penumbra regions showed treatment with higher qCBF, raised above the ischemic threshold, compared with the control, while well collateralized subjects showed a paradoxical decrease maintained above the ischemic threshold for neuronal death. qCBF on the contralateral side increased regardless of collateralization.

CONCLUSION

Results suggest that perfusion can be augmented in ischemic stroke with norepinephrine and hydralazine. Perfusion augmentation depends on degree of collateralization and territory in question, with some evidence of vascular steal.

Major intracranial arterial stenosis influence association between baseline blood pressure and clinical outcomes after thrombolysis in ischemic stroke patients

BACKGROUND

This study aimed to investigate the relationship between baseline blood pressure (BP) and clinical outcomes after thrombolysis for acute ischemic stroke (AIS) in different intracranial arterial stenosis subgroups.

METHODS

AIS patients from multicenter with intravenous thrombolysis were retrospectively enrolled from January 2013 to December 2021. We categorized participants into severe (≥ 70%) and nonsevere (< 70%) stenosis of major intracranial arteries subgroups. The primary outcome was unfavorable functional outcome defined as 3-month modified Rankin Scale (mRS) ≥2. The association coefficients between baseline BP and functional outcomes were estimated in general linear regression model. The interactive effect was tested to determine the influence of intracranial arterial stenosis on the association between BP and clinical outcomes.

RESULTS

A total of 329 patients were included. Severe subgroup was detected in 151 patients with average age of 70.5. Association between baseline diastolic BP (DBP) and unfavorable functional outcome in intracranial artery stenosis subgroups was significantly different (p for interaction < .05). In nonsevere subgroup, higher baseline DBP was associated with higher risk of unfavorable outcome (OR 1.11, 95% CI 1.03 to 1.20, p = .009) compared with severe subgroup (OR 1.02, 95% CI 0.97 to 1.08, p = .341). Besides, intracranial artery stenosis also modified association between baseline systolic BP (SBP) and 3-month death (p for interaction < .05). In severe subgroup, higher baseline SBP was associated with decreased 3-month death risk (OR 0.88, 95% CI 0.78 to 1, p = .044) compared with nonsevere subgroup (OR 1, 95% CI 0.93 to 1.07, p = .908).

CONCLUSIONS

The major intracranial artery state modulates association between baseline BP and 3-month clinical outcomes after intravenous thrombolysis.

Relationship between mean blood pressure during hospitalization and clinical outcome after acute ischemic stroke

OBJECTIVE

The optimal blood pressure (BP) targets for acute ischemic stroke are unclear. We aimed to assess the relationship between Mean BP and clinical outcomes during hospitalization.

MATERIALS AND METHODS

We included 649 patients with Acute ischemic stroke (AIS) from December 2020 to July 2021. BP was measured daily, and mean blood pressure was calculated. Clinical events recorded within 90 days of randomization were: recurrent ischemic stroke, symptomatic intracranial hemorrhage, and death. The modified Rankin Scale (mRS) was used to measure primary outcomes 3 months after AIS. Logistic multiple regression analysis was performed by statistical software R.

RESULT

There is a nonlinear U-shaped relationship between SBP and poor outcomes. This means higher SBP and lower SBP will increase the incidence of poor outcomes. The optimal mean SBP during hospitalization was 135-150 mmHg, and patients with SBP < 135mmhg OR 2.4 [95% Cl, (1.16 ~ 4.97)], P = 0.018; and > 150mmhg OR 2.04 [95% Cl, 1.02 ~ 4.08], p = 0.045 had a higher probability of poor outcomes.

CONCLUSION

Our study shows that the optimal SBP of patients with AIS during hospitalization was 135-150 mmHg. The findings suggest that the relationship between mean SBP and 3-month functional outcome after AIS was U-shaped. Both higher SBP and lower SBP lead to poor prognosis in AIS patients.

The 2020 Taiwan Stroke Society guidelines for blood pressure control at the acute stage of ischemic stroke

The 2020 Taiwan Stroke Society (TSS) guidelines for blood pressure (BP) control related to ischemic stroke update the 2015 TSS BP guidelines. The early management of acute ischemic stroke has evolved rapidly in the previous two decades. Since the publication of the previous version of the TSS BP guidelines, many studies have addressed BP management in ischemic stroke. Particularly, several successful endovascular thrombectomy (EVT) trials published in 2015 led to a new era of acute treatment for ischemic stroke. With the ever-increasing use of EVT, evidence-based guidelines for ideal BP management during and after EVT are urgently needed. Consequently, the 2020 guidelines are updating and providing recommendations on BP control for the treatment and prevention of ischemic stroke based on new evidence. The present study encompasses the most important chapter of the 2020 Taiwan BP guidelines: BP control at the acute stage of ischemic stroke. We incorporated the most updated evidence regarding BP control at the acute stage of ischemic stroke in patients receiving or not receiving acute reperfusion therapy and provided specific recommendations for different treatment subgroups accordingly.

Periprocedure Management of Blood Pressure After Acute Ischemic Stroke

The management of acute ischemic stroke primarily revolves around the timely restoration of blood flow (recanalization/reperfusion) in the occluded vessel and maintenance of cerebral perfusion through collaterals before reperfusion. Mechanical thrombectomy is the most effective treatment for acute ischemic stroke due to large vessel occlusions in appropriately selected patients. Judicious management of blood pressure before, during, and after mechanical thrombectomy is critical to ensure good outcomes by preventing progression of cerebral ischemia as well hemorrhagic conversion, in addition to optimizing systemic perfusion. While direct evidence to support specific hemodynamic targets around mechanical thrombectomy is limited, there is increasing interest in this area. Newer approaches to blood pressure management utilizing individualized cerebral autoregulation-based targets are being explored. Early efforts at utilizing machine learning to predict blood pressure treatment thresholds and therapies also seem promising; this focused review aims to provide an update on recent evidence around periprocedural blood pressure management after acute ischemic stroke, highlighting its implications for clinical practice while identifying gaps in current literature.

Impact of leukoaraiosis or blood pressure on clinical outcome, mortality and symptomatic intracerebral hemorrhage after mechanical thrombectomy in acute ischemic stroke

We aimed to study the impact of leukoaraiosis (LA) and blood pressure (BP) on clinical outcome, mortality and symptomatic intracerebral hemorrhage (sICH) in acute ischemic stroke (AIS) patients treated with mechanical thrombectomy (MT). We analyzed data retrospectively from 521 patients with anterior large vessel occlusion treated with MT. LA was dichotomized in 0-2 (absent-to-moderate) versus 3-4 (moderate-to-severe) according to the van Swieten scale. Various systolic (SBP) and diastolic (DBP) BP parameters during the first 24 h were collected. Multivariable logistic regressions were performed to identify predictors of a poor 90-day outcome, mortality and sICH. LA was significantly associated with poor outcome (OR 3.2; p < 0.001) and mortality (OR 3.19; p = 0.008), but not sICH (p = 0.19). Higher maximum SBP was significantly associated with poor outcome (OR per 10 mmHg increase = 1.21; p = 0.009) and lower mean DBP was a predictor of mortality (OR per 10 mmHg increase = 0.53; p < 0.001). In the univariate analysis high SBP variability was associated with poor outcome, mortality and sICH, but not in the multivariate model. There was no association between BP and sICH. Severity of LA, SBP variability, high maximum SBP and low DBP are associated with either poor outcome or mortality in AIS patients undergoing MT. However, neither LA nor BP were associated with sICH in our cohort. Thus, mechanisms of the negative impact on outcome remain unclear. Further studies on impact of BP course and its mechanisms and interventions are needed to improve outcome in patients undergoing MT.

Increased blood pressure variability during general anaesthesia is associated with worse outcomes after mechanical thrombectomy: a prospective observational cohort study

OBJECTIVES

Optimal periprocedural blood pressure (BP) management during mechanical thrombectomy (MT) for acute ischaemic stroke is still controversial. The aim of this study was to investigate the association between intraprocedural BP variability (BPV) and outcomes in patients with large vessel occlusion (LVO) following MT with general anaesthesia.

DESIGN

A prospective observational cohort study.

SETTING

This study was conducted in a single tertiary hospital of Hangzhou in Zhejiang province.

PARTICIPANTS

A total of 141 patients with LVO treated with MT were finally included between January 2018 and September 2020.

MAIN OUTCOME MEASURES

Intraprocedural BP was recorded every 5 min throughout the procedure. BPV was measured as SD, coefficient of variation (CV), max-min (RANGE) and successive variation. Haemorrhagic transformation was assessed on 24-hour CT images according to European Cooperative Acute Stroke Study III trial. Poor functional outcome was defined as 90-day modified Rankin Scale score 3-6. Binary logistic regression analysis was used to investigate the association of BPV parameters with the incidence of parenchymal haemorrhage (PH) and poor functional outcome.

RESULTS

After controlling for age, female, history of smoking, hypertension and atrial fibrillation, baseline National Institutes of Health Stroke Scale, baseline systolic BP (SBP), baseline Alberta Stroke Program Early CT Score, bridging thrombolysis and times of retrieval attempts, the results demonstrated that intraprocedural SBP_RANGE (OR 1.029; 95% CI 1.003 to 1.055; p=0.027), SBP_SD (OR 1.135; 95% CI 1.023 to 1.259; p=0.017) and SBP_CV (OR 1.189; 95% CI 1.053 to 1.342; p=0.005) were independently associated with poor functional outcome. However, the independent association between intraprocedural BPV and PH at 24 hours has not been established in this study.

CONCLUSIONS

Increased intraprocedural BPV was more likely to have poor functional outcome in patients with LVO following MT with general anaesthesia. This finding indicates that special precautions should be taken to minimise BP fluctuation during procedure.

Clinical factors associated with cerebral autoregulation in ischemic stroke related to small artery occlusion

Background

Existing data suggest that cerebral autoregulation (CA) varies among different subtypes of ischaemic stroke. CA is globally impaired in patients with small artery occlusion (SAO). However, the factors influencing CA impairment in patients remains to be elucidated.

Methods

Stroke patients with SAO who underwent brain magnetic resonance imaging (MRI) were prospectively studied. Within 7 days after stroke onset, CA was recorded from the middle cerebral artery blood flow velocity and arterial blood pressure was simultaneously measured. Transfer function analysis was used to derive CA parameters, including gain and phase. Clinical characteristics, mean arterial pressure (MAP), biochemical findings, and cerebral small vessel disease (CSVD) markers on MRI were assessed in each patient. Factors associated with CA parameters were investigated. Univariate and multivariate linear regression analyses were conducted to determine the relationship between clinical factors and CA parameters.

Results

Sixty-three SAO patients (age, 56.3 ± 9.9 years; 55 men) were enrolled in the study. In the multiple linear regression analysis, after controlling for relevant clinical factors, MAP on admission (ipsilateral OR = 0.99 and contralateral OR = 0.99, both P < 0.005) was a significant independent predictor of bilateral gain. MAP > 105 mmHg on admission (OR = 0.77, P = 0.019) was significantly associated with ipsilateral gain. Diabetes mellitus was a significant predictive factor for bilateral gain (ipsilateral OR = 1.32 and contralateral OR = 1.22, both P < 0.005). No correlations were found between CA parameters and CSVD characteristics.

Conclusion

In SAO-related ischaemic stroke, patients with MAP > 105 mmHg on admission tended to have better ipsilateral CA. Diabetes mellitus appears to be an independent risk factor for CA impairment in patients with SAO-related stroke. CSVD may not be the main factor affecting bilateral CA in patients with SAO.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02854-4.

Neuroprotective Effects of a Cardioplegic Combination (Adenosine, Lidocaine, and Magnesium) in an Ischemic Stroke Model

Adenosine, lidocaine, and magnesium (ALM) are clinically available cardioplegic solutions. We examined the effects of low-dose ALM on ischemic stroke in cell and animal models. Cobalt chloride (CoCl₂)-treated SH-SY5Y cells were used as a surrogate model to mimic oxygen-glucose deprivation conditions. The cells were incubated with different dilutions of ALM authentic solution (1.0 mM adenosine, 2.0 mM lidocaine, and5 mM MgSO4 in Earle's balanced salt solution). At a concentration of 2.5%, ALM significantly reduced CoCl₂-induced cell loss. This protective effect persisted even when ALM was administered 1 h after the insult. We used transient middle cerebral artery occlusion to investigate the therapeutic effects of ALM in vivo. Rats were randomly assigned to two groups-the experimental (ALM) and control (saline) groups-and infusion was administered during the ischemia for 1 h. The infarction area was significantly reduced in the ALM group compared with the control group (5.0% ± 2.0% vs. 23.5% ± 5.5%, p = 0.013). Neurological deficits were reduced in the ALM group compared with the control group (modified Longa score: 0 [0-1] vs. 2 [1-2], p = 0.047). This neuroprotective effect was substantiated by a reduction in the levels of various neuronal injury markers in plasma. These results demonstrate the neuroprotective effects of ALM and may provide a new therapeutic strategy for ischemic stroke.

Challenges in the hemodynamic management of acute nontraumatic neurological injuries

PURPOSE OF REVIEW

To appraise the evidence from the literature and suggest an integrated hemodynamic approach of early and delayed phases of acute ischemic stroke (AIS), subarachnoid hemorrhage (SAH) and intracerebral hemorrhage (ICH).

RECENT FINDINGS

In AIS, the research aims to evaluate the optimal pressure control before, during and after the revascularization, to optimize the perfusion in the ischemic areas, minimizing the risk of hemorrhage or secondary damage to already infarcted areas. In the early phase of SAH, systemic pressure should be controlled to balance the risk of stroke, hypertension-related rebleeding, and maintenance of cerebral perfusion pressure. The late phase aims to minimize the risk of cerebral vasospasm by adapting systemic pressure and volemia to cerebral and systemic physiological hemodynamic targets. In the mild-to-moderate ICH, achieving SAP of less than 140 mmHg and greater than 110 mmHg may be considered as a beneficial target. Caution should be considered in lowering intensively SAP in severe ICH.

SUMMARY

In nontraumatic brain injuries, the hemodynamic management is strictly related to fluctuating physiology of these diseases, needing a strict control of pressure and flow variable to ensure both cerebral and systemic homeostasis.

TCD hemodynamics findings in the subacute phase of anterior circulation stroke patients treated with mechanical thrombectomy

Despite mechanical thrombectomy, the prognosis for many patients with anterior circulation ischemic stroke (ACIS) remains poor. This retrospective study reports consecutive mechanical thrombectomy procedures for ACIS at our hospital over 4 years. Hemodynamics were explored using transcranial Doppler ultrasound. The functional outcome was assessed using the modified Rankin scale. A total of 121 eligible cases were included: 61 (50.4%) exhibited good outcomes (modified Rankin scale score ≤2) by day 90. The logistic regression analysis showed that ipsilateral middle cerebral artery (iMCA) systolic blood flow (SBF) (OR = 0.983, 95% CI: 0.969–0.997, P = 0.014), preoperative National Institutes of Health Stroke Scale (NIHSS)score (OR = 1.160, 95% CI: 1.067–1.261, P < 0.001), intracranial hemorrhage after therapy (OR = 19.514, 95% CI: 4.364–87.265, P < 0.001), and Alberta Stroke Program Early Computed Tomography Score (OR = 0.639, 95% CI: 0.416–0.981, P = 0.040) were independently associated with prognosis. The iMCA SBF and preoperative NIHSS score were significantly predictive of a good outcome in the receiver operating characteristic analysis. In conclusion, elevated iMCA SBF might be a prognostic indicator of a good 90-day outcome following endovascular treatment in ACIS patients treated with mechanical thrombectomy, but large prospective studies are mandatory to validate the findings of our study.

Detrimental effect of increased blood pressure variability on clinical outcome in acute ischemic stroke treated with reperfusion therapy: a case control study

Background

Blood pressure variability (BPV) is related to clinical outcome in acute ischemic stroke (AIS) treated with reperfusion therapy, but still is not included in clinical practice. This study aims to associate BPV during the first week of AIS with the outcome at three months.

Methods

We included 236 AIS patients treated with reperfusion therapy, and then divided them into good outcome and poor outcome groups. BPV measurements, including standard deviation, coefficient of variation, average real variability (ARV), and range, were recorded at stages of 2 h, 24 h, and 7 days after reperfusion therapy, respectively. These measurements were compared between the two groups. Then, ROC curve analysis examined the ability of BPV measurements in differentiating good and poor outcome groups; logistic regression analysis detected variables associated with clinical outcome in all subjects.

Results

The good outcome group exhibited significantly less BPV at all stages relative to the poor outcome group. The BPV measurements exhibited the potential to differentiate the two groups by the ROC curve analysis, especially for those at the 24-h stage. Higher ARV of diastolic BP and higher range of systolic BP at the 24-h stage, together with greater disease severity at baseline, were associated with poor clinical outcome.

Conclusions

Greater BPV during the first week of AIS is associated with poor outcome for the patients treated with reperfusion therapy. The BPV measurements play an important role in modulating clinical outcome, and have the potential to be included in future AIS guidelines.

Magnitude of Blood Pressure Change After Endovascular Therapy and Outcomes: Insight From the BP-TARGET Trial

BACKGROUND AND PURPOSE

To assess the association between systolic blood pressure change (ΔSBP) at different time intervals after successful reperfusion with radiographic and clinical outcomes.

METHODS

This is a post hoc analysis of the BP-TARGET multicenter trial (Blood Pressure Target in Acute Stroke to Reduce Hemorrhage After Endovascular Therapy). ΔSBP was defined as end of procedure SBP minus mean SBP at different time intervals (15-60 minutes, 1-6 hours, and 6-24 hours postprocedure). The primary outcome was the poor functional outcome (90-day modified Rankin Scale score 3-6).

RESULTS

We included a total of 267 patients (130 in the intensive treatment group). Compared with patients with favorable outcome, patients with poor outcome had lower ΔSBP (less SBP reduction) at all times intervals. After adjusting for potential confounders including baseline SBP, both ΔSBP_15-60M and ΔSBP_6-24H were associated with lower odds of poor outcome (adjusted odds ratio per 5 mm Hg SBP reduction, 0.89 [95% CI, 0.81-0.99], and adjusted odds ratio 0.82 [95% CI, 0.73-0.92], respectively). Concerning safety outcomes, patients with intraparenchymal hemorrhage had lower ΔSBP at all time intervals. ΔSBP_15-60M was associated with lower odds of any intraparenchymal hemorrhage (adjusted odds ratio per 5 mm Hg SBP reduction 0.91 [95% CI, 0.83-0.99]). Conversely, ΔSBP was not associated with mortality or neurological deterioration at any time interval.

CONCLUSIONS

After successful reperfusion, ΔSBP had a linear relationship with poor outcome and the risk of poor outcome was higher with less reduction from the baseline SBP.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03160677.

Neuroprotective potential of nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element signaling modulator cucurbitacin I upon glucose and oxygen deprivation/reperfusion (OGD/RP)

This study aimed to investigate the inhibitory effect and mechanism of Cucurbitacin I (Cu I) on apoptosis, oxidative stress, and mitophagy in PC12 cells with glucose and oxygen deprivation/reperfusion (OGD/RP) injury. OGD/RP cell injury model was established by gas anoxic cell incubator and glucose-free medium. The cells were divided into the control group, OGD/RP group, OGD/RP + Cu I group, and OGD/RP + Cu I + 2 µM nuclear factor erythroid 2-related factor 2 (Nrf2) inhibitor ML385 group. The results showed that apoptotic rate and reactive oxygen species (ROS) production were significantly increased in OGD/RP group, which were reversed by Cu I pretreatment. Meanwhile, western blot analysis proved that Cu I inhibited OGD/RP-induced mitophagy, manifested as the decreased expression of PTEN-induced kinase 1 (PINK1) and parkin RBR E3 ubiquitin-protein ligase (Parkin), and light chain 3 (LC3) Ⅱ∕LC3 I, as well as the increased expression of P62. Furthermore, immunofluorescence (IF) staining showed that Cu I reduced the co-localized puncta of LC3 with TOM20 in OGD/RP-induced PC12 cells. Similarly, transmission electron microscope finding is consistent with the IF results. Mechanically, after Cu I and OGD/RP treatments, nuclear Nrf2 expression and the levels of downstream target genes were significantly upregulated compared with OGD/RP alone treatment. Nrf2 inhibition reversed the protective effects of Cu I on OGD/RP-induced injury in PC12 cells. The present study provides evidence of the neuroprotective effect of Cu I unraveling its potential as a potential therapeutic candidate for the treatment of ischemic stroke.

Hemorrhagic Transformation After Ischemic Stroke: Mechanisms and Management

Symptomatic hemorrhagic transformation (HT) is one of the complications most likely to lead to death in patients with acute ischemic stroke. HT after acute ischemic stroke is diagnosed when certain areas of cerebral infarction appear as cerebral hemorrhage on radiological images. Its mechanisms are usually explained by disruption of the blood-brain barrier and reperfusion injury that causes leakage of peripheral blood cells. In ischemic infarction, HT may be a natural progression of acute ischemic stroke and can be facilitated or enhanced by reperfusion therapy. Therefore, to balance risks and benefits, HT occurrence in acute stroke settings is an important factor to be considered by physicians to determine whether recanalization therapy should be performed. This review aims to illustrate the pathophysiological mechanisms of HT, outline most HT-related factors after reperfusion therapy, and describe prevention strategies for the occurrence and enlargement of HT, such as blood pressure control. Finally, we propose a promising therapeutic approach based on biological research studies that would help clinicians treat such catastrophic complications.

Ephedrine ameliorates cerebral ischemia injury via inhibiting NOD-like receptor pyrin domain 3 inflammasome activation through the Akt/GSK3β/NRF2 pathway

Ischemic stroke is a leading cause of death and long-term disability worldwide. The aim of this study is to explore the potential function of ephedrine in ischemic stroke and the underlying molecular mechanism. A middle cerebral artery occlusion (MCAO) rat model was established. The potential effects of ephedrine on MCAO rats and LPS-stimulated BV2 microglial cells were evaluated. Ephedrine reduced the infarct volume, cell apoptosis, brain water content, neurological score, and proinflammatory cytokines (TNF-α and IL-1β) production in MCAO rats. Ephedrine treatment also suppressed TNF-α and IL-1β production and NOD-like receptor pyrin domain 3 (NLRP3) inflammasome activation in BV2 microglial cells. The expression of NLRP3, caspase-1, and IL-1β was suppressed by ephedrine. Moreover, ephedrine treatment increased the phosphorylation of Akt and GSK3β and nuclear NRF2 levels in LPS-treated BV2 microglial cells. Meanwhile, LY294002 attenuated the inhibitory effects of ephedrine on NLRP3 inflammasome activation and TNF-α and IL-1β production. In addition, the level of pAkt was increased, while NLRP3, caspase-1, and IL-1β were decreased by ephedrine treatment in MCAO rats. In conclusion, ephedrine ameliorated cerebral ischemia injury via inhibiting NLRP3 inflammasome activation through the Akt/GSK3β/NRF2 pathway. Our results revealed a potential role of ephedrine in ischemic stroke treatment.

Alphabetical Mnemonic to Assist in the Treatment of an Acute Ischemic Stroke

Determining the treatment plan and how to successfully manage a patient suffering from an acute ischemic stroke can be challenging for a registered nurse (RN) in the emergency department. Using a mnemonic in the treatment process assists in reducing medical errors and increases the likelihood of making positive clinical outcomes. Mnemonics sum up complex strategies into relevant information that can be comprehensible for users. The authors have created a mnemonic strategy to provide RNs in the emergency department with a structured approach to the pharmacotherapeutic strategies used in treating patients with an acute ischemic stroke. All guidelines used throughout the article are in concurrence.

Regulation of cerebral blood flow in humans: physiology and clinical implications of autoregulation

Brain function critically depends on a close matching between metabolic demands, appropriate delivery of oxygen and nutrients, and removal of cellular waste. This matching requires continuous regulation of cerebral blood flow (CBF), which can be categorized into four broad topics: 1) autoregulation, which describes the response of the cerebrovasculature to changes in perfusion pressure; 2) vascular reactivity to vasoactive stimuli [including carbon dioxide (CO2)]; 3) neurovascular coupling (NVC), i.e., the CBF response to local changes in neural activity (often standardized cognitive stimuli in humans); and 4) endothelium-dependent responses. This review focuses primarily on autoregulation and its clinical implications. To place autoregulation in a more precise context, and to better understand integrated approaches in the cerebral circulation, we also briefly address reactivity to CO2 and NVC. In addition to our focus on effects of perfusion pressure (or blood pressure), we describe the impact of select stimuli on regulation of CBF (i.e., arterial blood gases, cerebral metabolism, neural mechanisms, and specific vascular cells), the interrelationships between these stimuli, and implications for regulation of CBF at the level of large arteries and the microcirculation. We review clinical implications of autoregulation in aging, hypertension, stroke, mild cognitive impairment, anesthesia, and dementias. Finally, we discuss autoregulation in the context of common daily physiological challenges, including changes in posture (e.g., orthostatic hypotension, syncope) and physical activity.

Blood Pressure Management After Endovascular Thrombectomy

Endovascular thrombectomy (EVT) has changed the landscape of acute stroke therapy and has become the standard of care for selected patients presenting with anterior circulation large-vessel occlusion (LVO) stroke. Despite successful reperfusion, many patients with LVO stroke do not regain functional independence. Particularly, patients presenting with extremes of blood pressure (BP) or hemodynamic variability are found to have a worse clinical recovery, suggesting blood pressure optimization as a potential neuroprotective strategy. Current guidelines acknowledge the lack of randomized trials to evaluate the optimal hemodynamic management during the immediate post-stroke period. Following reperfusion, lower blood pressure targets may be warranted to prevent reperfusion injury and promote penumbral recovery, but adequate BP targets adjusted to individual patient factors such as degree of reperfusion, infarct size, and overall hemodynamic status remain undefined. This narrative review outlines the physiological mechanisms of BP control after EVT and summarizes key observational studies and clinical trials evaluating post-EVT BP targets. It also discusses novel treatment strategies and areas of future research that could aid in the determination of the optimal post-EVT blood pressure.

Blood pressure variability and outcomes after mechanical thrombectomy based on the recanalization and collateral status

BACKGROUND

Blood pressure (BP), recanalization status, and collateral circulation are important factors for cerebral autoregulation after stroke. We aimed to investigate the association of various BP variability (BPV) parameters with clinical outcomes after mechanical thrombectomy (MT) according to recanalization and collateral status.

METHODS

We included 502 consecutive patients who underwent MT due to anterior circulation large vessel occlusion stroke at three comprehensive stroke centers. BPV parameters were standard deviation (SD), maximum/minimum BP, coefficient of variation (CV) and successive variation (SV). The clinical outcomes included 90-day functional outcome assessed by modified Rankin Scale score and symptomatic intracranial hemorrhage (sICH).

RESULTS

Among the included patients, 219 (43.6%) achieved good functional outcomes and 59 (11.8%) developed sICH. After adjusting for confounders, higher systolic BP (SBP) variability [CV (odds ratio (OR), 1.089, p = 0.035), SV (OR, 1.082, p = 0.004). and SD (OR, 1.074, p = 0.027)] was associated with a lower likelihood of a favorable outcome. In addition, higher SBP [CV (OR, 1.156, p = 0.001) and SD (OR, 1.118, p = 0.001)] were significantly associated with increased odds of sICH. Moreover, the relationship between BPV and the outcomes depended on recanalization status. However, regardless of collateral status, a higher BPV after MT was associated with worse outcomes.

CONCLUSIONS

Higher SBP SD and CV during the first 24 h after MT was a powerful predictor of worse clinical outcomes, regardless of the collateral status. However, the effects of BPV on outcomes were more substantial among patients with successful reperfusion.

Blood Pressure Thresholds and Neurologic Outcomes After Endovascular Therapy for Acute Ischemic Stroke: An Analysis of Individual Patient Data From 3 Randomized Clinical Trials

Importance

The optimal blood pressure targets during endovascular therapy (EVT) for acute ischemic stroke (AIS) are unknown.

Objective

To study whether procedural blood pressure parameters, including specific blood pressure thresholds, are associated with neurologic outcomes after EVT.

Design, Setting, and Participants

This retrospective cohort study included adults with anterior-circulation AIS who were enrolled in randomized clinical trials assessing anesthetic strategy for EVT between February 2014 and February 2017. The trials had comparable blood pressure protocols, and patients were followed up for 90 days. A total of 3630 patients were initially approached, and 3265 patients were excluded.

Exposure

Endovascular therapy.

Main Outcomes and Measures

The primary efficacy variable was functional outcome as defined by the modified Rankin Scale (mRS) score at 90 days. Associations of blood pressure parameters and time less than and greater than mean arterial blood pressure (MABP) thresholds with outcome were analyzed.

Results

Of the 365 patients included in the analysis, the mean (SD) age was 71.4 (13.0) years, 163 were women (44.6%), and the median National Institutes of Health Stroke Scale score was 17 (interquartile range [IQR], 14-21). For the entire cohort, 182 (49.9%) received general anesthesia and 183 (50.1%) received procedural sedation. A cumulated period of minimum 10 minutes with less than 70 mm Hg MABP (adjusted OR, 1.51; 95% CI, 1.02-2.22) and a continuous episode of minimum 20 minutes with less than 70 mm Hg MABP (adjusted OR, 2.30; 95% CI, 1.11-4.75) were associated with a shift toward higher 90-day mRS scores, corresponding to a number needed to harm of 10 and 4, respectively. A cumulated period of minimum 45 minutes with greater than 90 mm Hg MABP (adjusted OR, 1.49; 95% CI, 1.11-2.02) and a continuous episode of minimum 115 minutes with greater than 90 mm Hg MABP (adjusted OR, 1.89; 95% CI, 1.01-3.54) were associated with a shift toward higher 90-day mRS scores, corresponding to a number needed to harm of 10 and 6, respectively.

Conclusions and Relevance

Critical MABP thresholds and durations for poor outcome were found to be MABP less than 70 mm Hg for more than 10 minutes and MABP greater than 90 mm Hg for more than 45 minutes, both durations with a number needed to harm of 10 patients. Mean arterial blood pressure may be a modifiable therapeutic target to prevent or reduce poor functional outcome after EVT.

Blood Pressure Management Before, During, and After Endovascular Thrombectomy for Acute Ischemic Stroke

There is an absence of specific evidence or guideline recommendations on blood pressure management for large vessel occlusion stroke patients. Until randomized data are available, the periprocedural blood pressure management of patients undergoing endovascular thrombectomy can be viewed in two phases relative to the achievement of recanalization. In the hyperacute phase, prior to recanalization, hypotension should be avoided to maintain adequate penumbral perfusion. The American Heart Association guidelines should be followed for the upper end of prethrombectomy blood pressure: ≤185/110 mm Hg, unless post-tissue plasminogen activator administration when the goal is <180/105 mm Hg. After successful recanalization (thrombolysis in cerebral infarction [TICI]: 2b-3), we recommend a target of a maximum systolic blood pressure of < 160 mm Hg, while the persistently occluded patients (TICI < 2b) may require more permissive goals up to <180/105 mm Hg. Future research should focus on generating randomized data on optimal blood pressure management both before and after endovascular thrombectomy, to optimize patient outcomes for these divergent clinical scenarios.

Hypertensive Crisis in Acute Cerebrovascular Diseases Presenting at the Emergency Department: A Narrative Review

Hypertensive crisis, defined as an increase in systolic blood pressure >179 mmHg or diastolic blood pressure >109 mmHg, typically causes end-organ damage; the brain is an elective and early target, among others. The strong relationship between arterial hypertension and cerebrovascular diseases is supported by extensive evidence, with hypertension being the main modifiable risk factor for both ischemic and hemorrhagic stroke, especially when it is uncontrolled or rapidly increasing. However, despite the large amount of data on the preventive strategies and therapeutic measures that can be adopted, the management of high BP in patients with acute cerebrovascular diseases presenting at the emergency department is still an area of debate. Overall, the outcome of stroke patients with high blood pressure values basically depends on the occurrence of hypertensive emergency or hypertensive urgency, the treatment regimen adopted, the drug dosages and their timing, and certain stroke features. In this narrative review, we provide a timely update on the current treatment, debated issues, and future directions related to hypertensive crisis in patients referred to the emergency department because of an acute cerebrovascular event. This will also focus greater attention on the management of certain stroke-related, time-dependent interventions, such as intravenous thrombolysis and mechanic thrombectomy.

Hypertensive Crisis in Acute Cerebrovascular Diseases Presenting at the Emergency Department: A Narrative Review

Hypertensive crisis, defined as an increase in systolic blood pressure >179 mmHg or diastolic blood pressure >109 mmHg, typically causes end-organ damage; the brain is an elective and early target, among others. The strong relationship between arterial hypertension and cerebrovascular diseases is supported by extensive evidence, with hypertension being the main modifiable risk factor for both ischemic and hemorrhagic stroke, especially when it is uncontrolled or rapidly increasing. However, despite the large amount of data on the preventive strategies and therapeutic measures that can be adopted, the management of high BP in patients with acute cerebrovascular diseases presenting at the emergency department is still an area of debate. Overall, the outcome of stroke patients with high blood pressure values basically depends on the occurrence of hypertensive emergency or hypertensive urgency, the treatment regimen adopted, the drug dosages and their timing, and certain stroke features. In this narrative review, we provide a timely update on the current treatment, debated issues, and future directions related to hypertensive crisis in patients referred to the emergency department because of an acute cerebrovascular event. This will also focus greater attention on the management of certain stroke-related, time-dependent interventions, such as intravenous thrombolysis and mechanic thrombectomy.

Hemodynamics in acute stroke: Cerebral and cardiac complications

Hemodynamics is the study of blood flow, where parameters have been defined to quantify blood flow and the relationship with systemic circulatory changes. Understanding these perfusion parameters, the relationship between different blood flow variables and the implications for ischemic injury are outlined in the ensuing discussion. This chapter focuses on the hemodynamic changes that occur in ischemic stroke, and their contribution to ischemic stroke pathophysiology. We discuss the interaction between cardiovascular response and hemodynamic changes in stroke. Studying hemodynamic changes has a key role in stroke prevention, therapeutic implications and prognostic importance in acute ischemic stroke: preexisting hemodynamic and autoregulatory impairments predict the occurrence of stroke. Hemodynamic failure predisposes to the formation of thromboemboli and accelerates infarction due to impairing compensatory mechanisms. In ischemic stroke involving occlusion of a large vessel, persistent collateral circulation leads to preservation of ischemic penumbra and therefore justifying endovascular thrombectomy. Following thrombectomy, impaired autoregulation may lead to reperfusion injury and hemorrhage.

Blood Pressure Management in Acute Ischemic Stroke

PURPOSE OF REVIEW

Abrupt blood pressure (BP) rise is the most common clinical symptom of acute ischemic stroke (AIS). However, BP alterations during AIS reflect many diverse mechanisms, both stroke-related and nonspecific epiphenomena, which change over time and across patients. While extremes of BP as well as high BP variability have been related with worse outcomes in observational studies, optimal BP management after AIS remains challenging.

RECENT FINDINGS

This review discusses the complexity of the factors linking BP changes to the clinical outcomes of patients with AIS, depending on the treatment strategy and local vessel status and, in particular, the degree of reperfusion achieved. The evidence for possible additional clinical markers, including the presence of arterial hypertension, and comorbid organ dysfunction in individuals with AIS, as informative and helpful factors in therapeutic decision-making concerning BP will be reviewed, as well as recent data on neurovascular monitoring targeting person-specific local cerebral perfusion and metabolic demand, instead of the global traditional parameters (BP among others) alone. The individualization of BP management protocols based on a complex evaluation of the homeostatic response to focal cerebral ischemia, including but not limited to BP changes, may be a valuable novel goal proposed in AIS, but further trials are warranted.

Artificial neural network based prediction of postthrombolysis intracerebral hemorrhage and death

Despite the salient benefits of the intravenous tissue plasminogen activator (tPA), symptomatic intracerebral hemorrhage (sICH) remains a frequent complication and constitutes a major concern when treating acute ischemic stroke (AIS). This study explored the use of artificial neural network (ANN)-based models to predict sICH and 3-month mortality for patients with AIS receiving tPA. We developed ANN models based on evaluation of the predictive value of pre-treatment parameters associated with sICH and mortality in a cohort of 331 patients between 2009 and 2018. The ANN models were generated using eight clinical inputs and two outputs. The generalizability of the model was validated using fivefold cross-validation. The performance of each model was assessed according to the accuracy, precision, sensitivity, specificity, and area under the receiver operating characteristic curve (AUC). After adequate training, the ANN predictive model AUC for sICH was 0.941, with accuracy, sensitivity, and specificity of 91.0%, 85.7%, and 92.5%, respectively. The predictive model AUC for 3-month mortality was 0.976, with accuracy, sensitivity, and specificity of 95.2%, 94.4%, and 95.5%, respectively. The generated ANN-based models exhibited high predictive performance and reliability for predicting sICH and 3-month mortality after thrombolysis; thus, its clinical application to assist decision-making when administering tPA is envisaged.

Association of circulating long non-coding RNA MALAT1 in diagnosis, disease surveillance, and prognosis of acute ischemic stroke

We aimed to investigate the association of long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (lnc-MALAT1) with acute ischemic stroke (AIS), and its association with disease severity, inflammation, and recurrence-free survival (RFS) in AIS patients. One hundred and twenty AIS patients and 120 controls were recruited. Venous blood samples from AIS patients (within 24 h after symptoms onset) and controls (at entry to study) were collected to detect plasma lnc-MALAT1 expression by real-time quantitative polymerase chain reaction. AIS severity was assessed by the National Institutes of Health Stroke Scale (NIHSS) score. Plasma concentrations of inflammation factors (including C-reactive protein (CRP), tumor necrosis factor α (TNF-α), interleukin (IL)-6, IL-8, IL-10, IL-17, and IL-22) were measured and RFS was calculated. lnc-MALAT1 expression was decreased in AIS patients compared to controls, and it had a close correlation with AIS (AUC=0.791, 95% CI: 0.735-0.846). For disease condition, lnc-MALAT1 expression negatively correlated with NIHSS score and pro-inflammatory factor expression (including CRP, TNF-α, IL-6, IL-8, and IL-22), while it positively correlated with anti-inflammatory factor IL-10 expression. Furthermore, lnc-MALAT1 expression was elevated in AIS patients with diabetes. For prognosis, no statistical correlation of lnc-MALAT1 expression with RFS was found, while a trend for longer RFS was observed in patients with lnc-MALAT1 high expression compared to those with lnc-MALAT1 low expression.

Admission Blood Pressure in Relation to Clinical Outcomes and Successful Reperfusion After Endovascular Stroke Treatment

Supplemental Digital Content is available in the text.

Background and Purpose:

Optimal blood pressure (BP) targets before endovascular treatment (EVT) for acute ischemic stroke are unknown. We aimed to assess the relation between admission BP and clinical outcomes and successful reperfusion after EVT.

Methods:

We used data from the MR CLEAN (Multicenter Randomized Controlled Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) Registry, an observational, prospective, nationwide cohort study of patients with ischemic stroke treated with EVT in routine clinical practice in the Netherlands. Baseline systolic BP (SBP) and diastolic BP (DBP) were recorded on admission. The primary outcome was the score on the modified Rankin Scale at 90 days. Secondary outcomes included successful reperfusion (extended Thrombolysis in Cerebral Infarction score 2B-3), symptomatic intracranial hemorrhage, and 90-day mortality. Multivariable logistic and linear regression were used to assess the associations of SBP and DBP with outcomes. The relations between BPs and outcomes were tested for nonlinearity. Parameter estimates were calculated per 10 mm Hg increase or decrease in BP.

Results:

We included 3180 patients treated with EVT between March 2014 and November 2017. The relations between admission SBP and DBP with 90-day modified Rankin Scale scores and mortality were J-shaped, with inflection points around 150 and 81 mm Hg, respectively. An increase in SBP above 150 mm Hg was associated with poor functional outcome (adjusted common odds ratio, 1.09 [95% CI, 1.04–1.15]) and mortality at 90 days (adjusted odds ratio, 1.09 [95% CI, 1.03–1.16]). Following linear relationships, higher SBP was associated with a lower probability of successful reperfusion (adjusted odds ratio, 0.97 [95% CI, 0.94–0.99]) and with the occurrence of symptomatic intracranial hemorrhage (adjusted odds ratio, 1.06 [95% CI, 0.99–1.13]). Results for DBP were largely similar.

Conclusions:

In patients with acute ischemic stroke treated with EVT, higher admission BP is associated with lower probability of successful reperfusion and with poor clinical outcomes. Further research is needed to investigate whether these patients benefit from BP reduction before EVT.

Anaesthesia and haemodynamic management of acute ischaemic stroke patients before, during and after endovascular therapy

Endovascular therapy (EVT) is now standard of care for eligible patients with acute ischaemic stroke caused by large vessel occlusion in the anterior circulation. EVT can be performed with general anaesthesia (GA) or with monitored anaesthesia care, involving local anaesthesia with or without conscious sedation (LA/CS). Controversies remain regarding the optimal choice of anaesthetic strategy and observational studies suggested poorer functional outcome and higher mortality in patients treated under GA, essentially because of its haemodynamic consequences and the delay to put patients under GA. However, these studies are limited by selection bias, the most severe patients being more likely to receive GA and recent randomised trials and meta-analysis showed that protocol-based GA compared with LA/CS is significantly associated with less disability at 3 months. Unlike for intravenous thrombolysis, few data exist to guide management of blood pressure (BP) before and during EVT, but arterial hypotension should be avoided as long as the occlusion persists. BP targets following EVT should probably be adapted to the degree of recanalisation and the extent of ischaemia. Lower BP levels may be warranted to prevent reperfusion injuries even if prospective haemodynamic management evaluations after EVT are lacking.

Management of Acute Ischemic Stroke-Specific Focus on Anesthetic Management for Mechanical Thrombectomy

Acute ischemic stroke is a neurological emergency with a high likelihood of morbidity, mortality, and long-term disability. Modern stroke care involves multidisciplinary management by neurologists, radiologists, neurosurgeons, and anesthesiologists. Current American Heart Association/American Stroke Association (AHA/ASA) guidelines recommend thrombolytic therapy with intravenous (IV) alteplase within the first 3-4.5 hours of initial stroke symptoms and endovascular mechanical thrombectomy within the first 16-24 hours depending on specific inclusion criteria. The anesthesia and critical care provider may become involved for airway management due to worsening neurologic status or to enable computerized tomography (CT) or magnetic resonance imaging (MRI) scanning, to facilitate mechanical thrombectomy, or to manage critical care of stroke patients. Existing data are unclear whether the mechanical thrombectomy procedure is best performed under general anesthesia or sedation. Retrospective cohort trials favor sedation over general anesthesia, but recent randomized controlled trials (RCT) neither suggest superiority nor inferiority of sedation over general anesthesia. Regardless of anesthesia type, a critical element of intraprocedural stroke care is tight blood pressure management. At different phases of stroke care, different blood pressure targets are recommended. This narrative review will focus on the anesthesia and critical care providers' roles in the management of both perioperative stroke and acute ischemic stroke with a focus on anesthetic management for mechanical thrombectomy.

Thrombolysis in Cerebral Infarction 2b Reperfusions: To Treat or to Stop?

In patients undergoing mechanical thrombectomy, achieving complete (Thrombolysis in Cerebral Infarction 3) rather than incomplete successful reperfusion (Thrombolysis in Cerebral Infarction 2b) is associated with better functional outcome. Despite technical improvements, incomplete reperfusion remains the final angiographic result in 40% of patients according to recent trials. As most incomplete reperfusions are caused by distal vessel occlusions, they are potentially amenable to rescue strategies. While observational data suggest a net benefit of up to 20% in functional independence of incomplete versus complete reperfusions, the net benefit of secondary improvement from Thrombolysis in Cerebral Infarction 2b to 3 reperfusion might differ due to lengthier procedures and delayed reperfusion. Current strategies to tackle distal vessel occlusions consist of distal (microcatheter) aspiration, small adjustable stent retrievers, and administration of intra-arterial thrombolytics. While there are promising reports evaluating those techniques, all available studies show relevant limitations in terms of selection bias, single-center design, or nonconsecutive patient inclusion. Besides an assessment of risks associated with rescue maneuvers, we advocate that the decision-making process should also include a consideration of potential outcomes if complete reperfusion would successfully be achieved. These include (1) a futile angiographic improvement (hypoperfused territory is already infarcted), (2) an unnecessary angiographic improvement (the patient would not have developed infarction if no rescue maneuver was performed), and (3) a successful rescue maneuver with clinical benefit. Currently there is paucity of data on how these scenarios can be predicted and the decision whether to treat or to stop in a patient with incomplete reperfusion involves many unknowns. To advance the status quo, we outline current knowledge gaps and avenues of potential research regarding this clinically important question.

Influence of simultaneous pressor and vasodilatory agents on the evolution of infarct growth in experimental acute middle cerebral artery occlusion

BACKGROUND

This study sought to test the hypothesis that simultaneous central blood pressure elevation and potent vasodilation can mitigate pial collateral-dependent infarct growth in acute ischemic stroke.

METHODS

Twenty mongrel canines (20-30 kg) underwent permanent middle cerebral artery occlusion (MCAO). Eight subjects received continuous infusion of norepinephrine (0.1-1.5200 µg/kg/min; titrated to a median of 34 mmHg above baseline mean arterial pressure) and hydralazine (20 mg) starting 30 min following MCAO. Pial collateral recruitment was scored prior to treatment and used to predict infarct volume based on a previously reported parameterization. Serial diffusion magnetic resonance imaging (MRI) acquisitions tracked infarct volumes over a 4-hour time frame. Infarct volumes and infarct volume growth between treatment and control groups were compared with each other and to predicted values. Fluid-attenuated inversion recovery (FLAIR) MRI, susceptibility weighted imaging (SWI), and necropsy findings were included in the evaluation.

RESULTS

Differences between treatment and control group varied by pial collateral recruitment based on indicator-variable regression effects analysis with interaction confirmed by regression model fit. Benefit in treatment group was only in subjects with poor collaterals which had 35.7% less infarct volume growth (P=0.0008; ANOVA) relative to controls. Measured infarct growth was significantly lower than predicted by the model (linear regression partial F-test, slope P<0.001, intercept=0.003). There was no evidence for cerebral hemorrhage or posterior reversible encephalopathy syndrome.

CONCLUSION

Our results indicate that a combination of norepinephrine and hydralazine administered in the acute phase of ischemic stroke mitigates infarct evolution in subjects with poor but not good collateral recruitment.

Blood Pressure Management Following Large Vessel Occlusion Strokes: A Narrative Review

Stroke is one of the leading causes of morbidity and mortality worldwide. Intravenous tissue plasminogen activator and mechanical thrombectomy comprise the two major treatments for acute ischemic stroke. Tissue plasminogen activator has been used for more than two decades and guidelines for hemodynamic management following tissue plasminogen activator administration are well established. However, mechanical thrombectomy is a relatively newer therapy and there is a paucity of evidence regarding hemodynamic management following large vessel occlusion strokes. The important tenets guiding the pathophysiology of large vessel occlusion strokes include understanding of cerebral autoregulation, collateral circulation, and blood pressure variability. In this narrative review, we discuss the current American Heart Association-American Stroke Association guidelines for the early management of acute ischemic stroke during different phases of the illness, encountered at different sections of a hospital including the emergency room, the neuro-interventional suite, and the intensive care unit. There is emerging evidence with regard to post-recanalization blood pressure management following large vessel occlusion strokes. Future research directions will include rea-ltime blood pressure variability assessments, identifying the extent of impaired autoregulation, and providing guidelines related to range and personalized blood pressure trajectories for patients following large vessel occlusion strokes.

rLj-RGD4, the shortened peptide of rLj-RGD3 from Lampetra japonica, protects against cerebral ischemia/reperfusion injury via the PI3K/Akt pathway

The toxic RGD peptide, rLj-RGD4, characterized by 4 (Arg-Gly-Asp) (RGD) motifs, is a novel mutant of rLj-RGD3 from the salivary gland of Lampetra japonica. Our previous study showd that rLj-RGD3 exerts a protective effect against cerebral ischemia injury in rats. Through the induction of middle cerebral artery occlusion/reperfusion (MCAO) injuries in rats, the present study investigated the effects and the mechanism through which rLj-RGD4 protects against ischemic stroke. In rats, treatment with rLj-RGD4 2 h after MCAO enhanced survival rate, improved movement and ameliorated the severity of brain infarction and apoptosis by diminishing pathological changes. This study demonstrated that rLj-RGD4 can reverse the downregulation of Bcl2, and the upregulation of Caspase-3. Mechanistic studies showed that rLj-RGD4 upregulated the expression levels of FAK, p-FAK, PI3K and p-Akt. In contrast, caspase-3 expression was inhibited. These results showed that rLj-RGD4 may reduce cerebral ischemia-reperfusion injury.

Reperfusion Into Severely Damaged Brain Tissue Is Associated With Occurrence of Parenchymal Hemorrhage for Acute Ischemic Stroke

Background and Purpose: This study aims to quantify the reperfusion status within severely damaged brain tissue and to evaluate its relationship with high grade of hemorrhagic transformation (HT).

Methods: Pseudo-continuous ASL was performed along with DWI in 102 patients within 24 h post-treatments. The infarction core was identified using ADC values <550 × 10⁻⁶ mm²/s. CBF within the infarction core and its contralateral counterpart were acquired. CBF at the 25th, median, and 75th percentiles of the contralateral counterpart were used as thresholds and the ASL reperfusion volume above the threshold was labeled as vol-25, -50, and -75, respectively. Recanalization was defined according to Thrombolysis in Myocardial Infarction (TIMI) criteria.

Results: Quantified reperfusion within the infarction core differed significantly in patients with complete and incomplete recanalization. In the ROC analysis for the prediction of parenchymal hematoma (PH), ASL reperfusion vol-25 had the highest area under the curve (AUC) when compared with ASL vol-50 and ASL vol-75. ASL reperfusion vol-25 had significantly higher AUC compared with ADC threshold volume in the prediction of PH (0.783 vs. 0.685, P = 0.0036) and PH-2 (0.844 vs. 0.754, P = 0.0035). In stepwise multivariate logistic regression analysis, only ASL reperfusion vol-25 emerged as an independent predictor of PH (OR = 3.51, 95% CI: 1.65–7.45, P < 0.001) and PH-2 (OR = 2.32, 95% CI: 1.13–4.76, P = 0.022).

Conclusions: Increased reperfusion volume within severely damaged brain tissue is associated with the occurrence of higher grade of HT.