Blood Pressure after Endovascular Therapy for Ischemic Stroke (BEST): A Multicenter Prospective Cohort Study

Antihypertensive Drugs Affect the Association of Systolic Blood Pressure Variability with Outcomes in Patients with Acute Stroke who had Successful Recanalization after Endovascular Treatment

AIMS

Blood pressure variability (BPV) was associated with the clinical outcomes in patients with acute ischemic stroke (AIS) due to large-vessel occlusion (LVO) after endovascular treatment (EVT). This study aimed to investigate whether the use of antihypertensive drugs could affect this association in patients with AIS-LVO after EVT.

METHODS

We retrospectively screened consecutive patients with AIS-LVO who had successful recanalization after EVT and calculated their systolic BPV (SBPV) during the first 24 h after EVT using eight statistical methodologies based on previously published literature. Poor outcome was defined as a modified Rankin Scale score of 3-6 at 90 days. Logistic regression analysis was performed to assess this association, and different prediction models were constructed to assess the effect of the use of antihypertensive drugs.

RESULTS

A total of 214 patients were finally included, including 92 (43.0%) with good outcomes, and 136 (63.6%) who received antihypertensive drugs. SBPV indicators were significantly lower in patients with good outcomes versus those with poor outcomes. The logistic analysis showed that all SBPV indicators were consistently associated with poor outcomes (odds ratio, 1.031-1.282, all P＜0.05) in all populations, which was confirmed in patients not using antihypertensive drugs. However, no SBPV indicator was found to be associated with poor outcomes in patients using antihypertensive drugs. Receiver operating characteristic curves showed that the area under the curve (AUC) was larger in the model adjusting for antihypertensive drugs (AUC 0.774-0.783) compared with the one not adjusted for antihypertensive drugs (AUC 0.739-0.754).

CONCLUSION

In the anterior circulation of patients with AIS-LVO who had successful recanalization after EVT, the utilization of antihypertensive drugs may have some impact on the relationship between SBPV and clinical outcomes.

Systolic blood pressure reduction strategies in acute ischemic stroke patients following endovascular thrombectomy: a systematic review and meta-analysis

BACKGROUND AND AIMS

There is no clear consensus on ideal systolic blood pressure (SBP) target post-endovascular thrombectomy (EVT) in patients with acute ischemic stroke. This study intends to investigate the relationship between reducing SBP and clinical outcomes and to determine the therapeutic efficacy of moderate and intensive SBP reduction post EVT.

METHODS

A comprehensive search was conducted across five electronic databases to identify studies relevant to our analysis. Data from these studies were then analyzed using pooled relative risk (RR) along with their corresponding 95 % confidence intervals (CI) for our categorical outcomes. functional independence at 90 days post-EVT was defined as a modified Rankin score (mRS) 0-2.

RESULTS

Our meta-analysis included eight studies with 2922 patients: 1376 patients were treated with intensive SBP reduction, 306 with moderate SBP reduction, and 1243 with standard SBP reduction. There was no difference in the risk of functional independence at 90 days post-EVT with both intensive-SBP reduction (target 120-140 mmHg, relative risk (RR) =1.05, 95 % CI 0.82, 1.34, p = 0.72) and moderate-SBP reduction (>160 mm Hg) (RR= 0.95, 95 % CI 0.69, 1.31, p = 0.76) compared with standard SBP reduction (>180 mm Hg). The risk of symptomatic intracranial hemorrhage (sICH) did not significantly differ between standard-SBP reduction and intensive-SBP reduction (RR = 0.93, 95 % CI 0.66, 1.31, p = 0.36) or moderate-SBP reduction (0.72 (95 % CI [0.28, 1.87], p = 0.50) groups, respectively. Intensive-SBP reduction significantly decreased the risk of hemicraniectomy.

CONCLUSIONS

We did not identify any difference in functional independence at 90 days in acute ischemic stroke patients with either intensive-SBP reduction or moderate-SBP reduction compared with standard SBP reduction post-EVT.

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.

Blood pressure variability and outcome in atherosclerosis versus cardioembolism cerebral large vessel occlusion after successful thrombectomy

Higher blood pressure variability (BPV) has been proven associated with worse functional outcome after endovascular treatment (EVT). However, this association is not established according to different stroke etiologies. In this study, we compared patients with the two highest proportions of stroke etiologies-cardioembolism (CE) and large-artery atherosclerosis (LAA), aiming to explore appropriate strategies of BP management for different etiologies. We enrolled patients with large vessel occlusion (LVO) in anterior circulation who underwent EVT and achieved successful recanalization retrospectively. 24-h blood pressure (BP) and BPV measured as blood pressure reduction (BPr), standard deviation (SD), coefficient of variation (CV), successive variation (SV), average real variability (ARV) after EVT were collected for systolic blood pressure (SBP) and diastolic blood pressure (DBP). The favorable outcome was defined as functional independence by 90-day modified Rankin Scale (mRS 0-2). In our cohort, higher BPV parameters significantly resulted in 90d functional dependence in CE-LVO patients (SBPSV OR: 1.083, 95%CI = 1.009-1.163; SBPARV OR: 1.121, 95%CI = 1.019-1.233; DBPSD OR: 1.124, 95%CI = 1.007-1.1256; DBPCV OR: 1.078, 95%CI = 1.002-1.161). However, for LAA-LVO patients, no positive results correlated 90d functional dependence with 24-hour BPV. Additionally, 90d functional dependence in CE patients with poor collaterals were significantly dependent on post-procedural BPV (DBPmax OR: 1.044, 95%CI = 1.002-1.087; DBPSD OR: 1.229, 95%CI = 1.022-1.1.479; DBPCV OR: 1.143, 95%CI = 1.009-1.295). Whereas to patients with good collaterals, there did not exist such a correlation. In summary, stroke etiologies should probably be taken into consideration to optimize individualized BP management strategies. In order to achieve better clinical outcomes for patients with acute ischemic stroke due to large vessel occlusion, stricter blood pressure management should be taken in cardioembolic stroke patients in contrast with large artery atherosclerotic stroke patients after successful endovascular therapy.

Neuroprotection during Thrombectomy for Acute Ischemic Stroke: A Review of Future Therapies

Stroke is a major cause of death and disability worldwide. Endovascular thrombectomy has been impactful in decreasing mortality. However, many clinical results continue to show suboptimal functional outcomes despite high recanalization rates. This gap in recanalization and symptomatic improvement suggests a need for adjunctive therapies in post-thrombectomy care. With greater insight into ischemia-reperfusion injury, recent preclinical testing of neuroprotective agents has shifted towards preventing oxidative stress through upregulation of antioxidants and downstream effectors, with positive results. Advances in multiple neuroprotective therapies, including uric acid, activated protein C, nerinetide, otaplimastat, imatinib, verapamil, butylphthalide, edaravone, nelonemdaz, ApTOLL, regional hypothermia, remote ischemic conditioning, normobaric oxygen, and especially nuclear factor erythroid 2-related factor 2, have promising evidence for improving stroke care. Sedation and blood pressure management in endovascular thrombectomy also play crucial roles in improved stroke outcomes. A hand-in-hand approach with both endovascular therapy and neuroprotection may be the key to targeting disability due to stroke.

A systematic review on the assessment of cerebral autoregulation in patients with Large Vessel Occlusion

As the majority of large vessel occlusion (LVO) patients are not treated with revascularization therapies or efficiently revascularized, complementary management strategies are needed. In this article we explore the importance of cerebral autoregulation (CA) assessment in the prediction and/or modification of infarct growth and hemorrhagic transformation. In patients with LVO, these are important factors that affect prognosis. A systematic search of the PubMed, EMBASE databases and a targeted Google search was conducted, resulting in the inclusion of 34 relevant articles. There is an agreement that CA is impaired in patients with LVO; several factors have been identified such as time course, revascularization status, laterality, disease subtype and location, some of which may be potentially modifiable and affect outcomes. The personalized CA assessment of these patients suggests potential for better understanding of the inter-individual variability. Further research is needed for the development of more accurate, noninvasive techniques for continuous monitoring and personalized thresholds for CA.

Evolving Clinical-Translational Investigations of Cerebroprotection in Ischemic Stroke

Ischemic stroke is a highly morbid disease, with over 50% of large vessel stroke (middle cerebral artery or internal carotid artery terminus occlusion) patients suffering disability despite maximal acute reperfusion therapy with thrombolysis and thrombectomy. The discovery of the ischemic penumbra in the 1980s laid the foundation for a salvageable territory in ischemic stroke. Since then, the concept of neuroprotection has been a focus of post-stroke care to (1) minimize the conversion from penumbra to core irreversible infarct, (2) limit secondary damage from ischemia-reperfusion injury, inflammation, and excitotoxicity and (3) to encourage tissue repair. However, despite multiple studies, the preclinical-clinical research enterprise has not yet created an agent that mitigates post-stroke outcomes beyond thrombolysis and mechanical clot retrieval. These translational gaps have not deterred the scientific community as agents are under continuous investigation. The NIH has recently promoted the concept of cerebroprotection to consider the whole brain post-stroke rather than just the neurons. This review will briefly outline the translational science of past, current, and emerging breakthroughs in cerebroprotection and use of these foundational ideas to develop a novel paradigm for optimizing stroke outcomes.

Blood Pressure Management After Endovascular Therapy for Acute Ischemic Stroke: The BEST-II Randomized Clinical Trial

Importance

The effects of moderate systolic blood pressure (SBP) lowering after successful recanalization with endovascular therapy for acute ischemic stroke are uncertain.

Objective

To determine the futility of lower SBP targets after endovascular therapy (<140 mm Hg or 160 mm Hg) compared with a higher target (≤180 mm Hg).

Design, Setting, and Participants

Randomized, open-label, blinded end point, phase 2, futility clinical trial that enrolled 120 patients with acute ischemic stroke who had undergone successful endovascular therapy at 3 US comprehensive stroke centers from January 2020 to March 2022 (final follow-up, June 2022).

Intervention

After undergoing endovascular therapy, participants were randomized to 1 of 3 SBP targets: 40 to less than 140 mm Hg, 40 to less than 160 mm Hg, and 40 to 180 mm Hg or less (guideline recommended) group, initiated within 60 minutes of recanalization and maintained for 24 hours.

Main Outcomes and Measures

Prespecified multiple primary outcomes for the primary futility analysis were follow-up infarct volume measured at 36 (±12) hours and utility-weighted modified Rankin Scale (mRS) score (range, 0 [worst] to 1 [best]) at 90 (±14) days. Linear regression models were used to test the harm-futility boundaries of a 10-mL increase (slope of 0.5) in the follow-up infarct volume or a 0.10 decrease (slope of -0.005) in the utility-weighted mRS score with each 20-mm Hg SBP target reduction after endovascular therapy (1-sided α = .05). Additional prespecified futility criterion was a less than 25% predicted probability of success for a future 2-group, superiority trial comparing SBP targets of the low- and mid-thresholds with the high-threshold (maximum sample size, 1500 with respect to the utility-weighted mRS score outcome).

Results

Among 120 patients randomized (mean [SD] age, 69.6 [14.5] years; 69 females [58%]), 113 (94.2%) completed the trial. The mean follow-up infarct volume was 32.4 mL (95% CI, 18.0 to 46.7 mL) for the less than 140-mm Hg group, 50.7 mL (95% CI, 33.7 to 67.7 mL), for the less than 160-mm Hg group, and 46.4 mL (95% CI, 24.5 to 68.2 mL) for the 180-mm Hg or less group. The mean utility-weighted mRS score was 0.51 (95% CI, 0.38 to 0.63) for the less than 140-mm Hg group, 0.47 (95% CI, 0.35 to 0.60) for the less than 160-mm Hg group, and 0.58 (95% CI, 0.46 to 0.71) for the high-target group. The slope of the follow-up infarct volume for each mm Hg decrease in the SBP target, adjusted for the baseline Alberta Stroke Program Early CT score, was -0.29 (95% CI, -0.81 to ∞; futility P = .99). The slope of the utility-weighted mRS score for each mm Hg decrease in the SBP target after endovascular therapy, adjusted for baseline utility-weighted mRS score, was -0.0019 (95% CI, -∞ to 0.0017; futility P = .93). Comparing the high-target SBP group with the lower-target groups, the predicted probability of success for a future trial was 25% for the less than 140-mm Hg group and 14% for the 160-mm Hg group.

Conclusions and Relevance

Among patients with acute ischemic stroke, lower SBP targets less than either 140 mm Hg or 160 mm Hg after successful endovascular therapy did not meet prespecified criteria for futility compared with an SBP target of 180 mm Hg or less. However, the findings suggested a low probability of benefit from lower SBP targets after endovascular therapy if tested in a future larger trial.

Trial Registration

ClinicalTrials.gov Identifier: NCT04116112.

Post-ischemic hyperemia following endovascular therapy for acute stroke is associated with lesion growth

A substantial proportion of acute stroke patients fail to recover following successful endovascular therapy (EVT) and injury to the brain and vasculature secondary to reperfusion may be a contributor. Acute stroke patients were included with: i) large vessel occlusion of the anterior circulation, ii) successful recanalization, and iii) evaluable MRI early after EVT. Presence of hyperemia on MRI perfusion was assessed by consensus using a modified ASPECTS. Three different approaches were used to quantify relative cerebral blood flow (rCBF). Sixty-seven patients with median age of 66 [59-76], 57% female, met inclusion criteria. Hyperemia was present in 35/67 (52%) patients early post-EVT, in 32/65 (49%) patients at 24 hours, and in 19/48 (40%) patients at 5 days. There were no differences in incomplete reperfusion, HT, PH-2, HARM, severe HARM or symptomatic ICH rates between those with and without early post-EVT hyperemia. A strong association (R2 = 0.81, p < 0.001) was found between early post-EVT hyperemia (p = 0.027) and DWI volume at 24 hours after adjusting for DWI volume at 2 hours (p < 0.001) and incomplete reperfusion at 24 hours (p = 0.001). Early hyperemia is a potential marker for cerebrovascular injury and may help select patients for adjunctive therapy to prevent edema, reperfusion injury, and lesion growth.

Blood pressure management in ischemic stroke patients undergoing mechanical thrombectomy

The relationship between presenting blood pressure in acute ischemic stroke patients and outcome is complex. Several studies have demonstrated a U-shaped curve with worse outcomes when blood pressure is high or low. The American Heart Association/American Stroke Association guidelines recommend values of blood pressure < 185/110 mmHg in patients treated with intravenous t-PA and "permissive hypertension" up to 220/120 mmHg in those not treated with intravenous t-PA. The optimal blood pressure target is less clear in patients undergoing mechanical thrombectomy. Before thrombectomy, the guidelines recommend a blood pressure < 185/110 mmHg though patients with even lower systolic blood pressures may have better outcomes. During and after thrombectomy, the guidelines recommend a blood pressure < 180/105 mmHg. However, several studies have suggested that during thrombectomy the primary goal should be to prevent significant low blood pressure (e.g., target systolic blood pressure > 140 mmHg or MAP > 70 mmHg). After thrombectomy, the primary goal should be to prevent high blood pressure (e.g., target systolic blood pressure < 160 mmHg or MAP < 90 mmHg). To make more specific recommendations, large, randomized-control studies are needed that address factors such as the baseline blood pressure, timing and degree of revascularization, status of collaterals, and estimated risk of reperfusion injury.

Flat-panel dual-energy head computed tomography in the angiography suite after thrombectomy for acute stroke: A clinical feasibility study

BACKGROUND

Management of large vessel occlusion (LVO) patients after thrombectomy is affected by the presence of intracranial hemorrhage (ICH) on post-procedure imaging. Differentiating contrast staining from hemorrhage on post-procedural imaging has been facilitated by dual-energy computed tomography (DECT), traditionally performed in dedicated computed tomography (CT) scanners with subsequent delays in treatment. We employed a novel method of DECT using the Siemens cone beam CT (DE-CBCT) in the angiography suite to evaluate for post-procedure ICH and contrast extravasation.

METHODS

After endovascular treatment for LVO was performed and before the patient was removed from the operating table, DE-CBCT was performed using the Siemens Q-biplane system, with two separate 20-second CBCT scans at two energy levels: 70 keV (standard) and 125 keV with tin filtration (nonstandard). Post-procedurally, patients also underwent a standard DECT using Siemens SOMATOM Force CT scanner. Two independent reviewers blindly evaluated the DE-CBCT and DECT for hemorrhage and contrast extravasation.

RESULTS

We successfully performed intra-procedural DE-CBCT in 10 subjects with no technical failure. The images were high-quality and subjectively useful to differentiate contrast from hemorrhage. The one hemorrhage seen on standard DECT was very small and clinically silent. The interrater reliability was 100% for both contrast and hemorrhage detection.

CONCLUSION

We demonstrate that intra-procedural DE-CBCT after thrombectomy is feasible and provides clinically meaningful images. There was close agreement between findings on DE-CBCT and standard DECT. Our findings suggest that DE-CBCT could be used in the future to improve stroke thrombectomy patient workflow and to more efficiently guide the postoperative management of these 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.

7-Day National Institutes of Health Stroke Scale as a surrogate marker predicting ischemic stroke patients' outcome following endovascular therapy

Background

Early neurological deterioration after endovascular thrombectomy (EVT) is associated with poor prognosis. National Institutes of Health Stroke Scale (NIHSS) score measured at 24 h after EVT may be a better outcome predictor than other methods that focus on changes in NIHSS. Nevertheless, clinical fluctuations in ischemic stroke patients during the immediate phase after symptoms onset are well recognized. Therefore, a delayed NIHSS evaluation may improve prognostic accuracy. We evaluate the 7-day NIHSS in predicting long-term patient outcomes after EVT.

Methods

This was a multi-center retrospective cohort study of 300 consecutive ischemic stroke patients with large vessel occlusion who underwent EVT at three-stroke centers in China from August 2018 to March 2022. NIHSS was recorded on admission, pre-EVT, 24 h, and 7 days after EVT.

Results

A total of 236 eligible patients were subdivided into two groups: 7-day NIHSS ≤6 and NIHSS >6 post-EVT. 88.29% achieved a favorable outcome (modified Rankin Scale 0-2) in the NIHSS ≤6 group compared to 15.20% in the NIHSS >6 group at 90 days, and an improved favorable outcome in the former group was observed after adjusting for potential confounding factors (adjusted odds ratio 39.7, 95% confidence interval, 17.5-89.7, p < 0.001).

Conclusion

The 7-day NIHSS score may be a reliable predictor of 90-day stroke patient outcome after EVT.

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.

Association of Blood Pressure Within 6 h After Endovascular Thrombectomy and Functional Outcomes in Ischemic Stroke Patients With Successful Recanalization

Background and Purpose

Blood pressure in the days following endovascular thrombectomy (EVT) can influence functional outcomes of patients who have suffered an acute ischemic stroke, but whether the same is true of blood pressure during the first few hours after EVT is unclear.

Methods

Several blood pressure parameters were retrospectively analyzed in acute ischemic stroke patients who underwent EVT at West China Hospital from March 2016 to December 2019. Baseline blood pressure, speed of blood pressure reduction, postoperative blood pressure, degree of blood pressure reduction, and quality of blood pressure management were evaluated during the first 24 h after EVT. We explored whether these parameters during different time windows correlated significantly with patients' modified Rankin Scale (mRS) score at 90 days.

Results

Analysis of 163 patients showed that poor functional outcome (mRS scores 3–6) correlated significantly with higher postoperative blood pressure and worse blood pressure management during the first 6 h after EVT. Postoperative systolic blood pressure at 37 min after EVT was significantly higher in patients with poor outcome (141 mmHg) than in those with good outcome (mRS scores 0–2; 122 mmHg, p = 0.006), and systolic pressure >136 mmHg at this time point was associated with a significantly higher risk of poor outcome, before and after adjusting for other risk factors (adjusted OR 0.395, 95% CI 0.20–0.79).

Conclusions

Among acute ischemic patients who successfully undergo recanalization, adequate blood pressure management during the first 30–40 min after EVT may be important for ensuring good 90-day functional outcomes.

Blood Pressure Trajectory Groups and Outcome After Endovascular Thrombectomy: A Multicenter Study

BACKGROUND

Elevated blood pressure after endovascular thrombectomy (EVT) has been associated with an increased risk of hemorrhagic transformation and poor functional outcomes. However, the optimal hemodynamic management after EVT remains unknown, and the blood pressure course in the acute phase of ischemic stroke has not been well characterized. This study aimed to identify patient subgroups with distinct blood pressure trajectories after EVT and study their association with radiographic and functional outcomes.

METHODS

This multicenter retrospective cohort study included consecutive patients with anterior circulation large-vessel occlusion ischemic stroke who underwent EVT. Repeated time-stamped blood pressure data were recorded for the first 72 hours after thrombectomy. Latent variable mixture modeling was used to separate subjects into five groups with distinct postprocedural systolic blood pressure (SBP) trajectories. The primary outcome was functional status, measured on the modified Rankin Scale 90 days after stroke. Secondary outcomes included hemorrhagic transformation, symptomatic intracranial hemorrhage, and death.

RESULTS

Two thousand two hundred sixty-eight patients (mean age [±SD] 69±15, mean National Institutes of Health Stroke Scale 15±7) were included in the analysis. Five distinct SBP trajectories were observed: low (18%), moderate (37%), moderate-to-high (20%), high-to-moderate (18%), and high (6%). SBP trajectory group was independently associated with functional outcome at 90 days (P<0.0001) after adjusting for potential confounders. Patients with high and high-to-moderate SBP trajectories had significantly greater odds of an unfavorable outcome (adjusted odds ratio, 3.5 [95% CI, 1.8-6.7], P=0.0003 and adjusted odds ratio, 2.2 [95% CI, 1.5-3.2], P<0.0001, respectively). Subjects in the high-to-moderate group had an increased risk of symptomatic intracranial hemorrhage (adjusted odds ratio, 1.82 [95% CI, 1-3.2]; P=0.04). No significant association was found between trajectory group and hemorrhagic transformation.

CONCLUSIONS

Patients with acute ischemic stroke demonstrate distinct SBP trajectories during the first 72 hours after EVT that have differing associations with functional outcome. These findings may help identify potential candidates for future blood pressure modulation trials.

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.

Blood Pressure Management for Ischemic Stroke in the First 24 Hours

High blood pressure (BP) is common after ischemic stroke and associated with a poor functional outcome and increased mortality. The conundrum then arises on whether to lower BP to improve outcome or whether this will worsen cerebral perfusion due to aberrant cerebral autoregulation. A number of large trials of BP lowering have failed to change outcome whether treatment was started prehospital in the community or hospital. Hence, nuances on how to manage high BP are likely, including whether different interventions are needed for different causes, the type and timing of the drug, how quickly BP is lowered, and the collateral effects of the drug, including on cerebral perfusion and platelets. Specific scenarios are also important, including when to lower BP before, during, and after intravenous thrombolysis and endovascular therapy/thrombectomy, when it may be necessary to raise BP, and when antihypertensive drugs taken before stroke should be restarted. This narrative review addresses these and other questions. Although further large trials are ongoing, it is increasingly likely that there is no simple answer. Different subgroups of patients may need to have their BP lowered (eg, before or after thrombolysis), left alone, or elevated.

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.

Association between systolic blood pressure course and outcomes after stroke thrombectomy

Background

Systolic blood pressure (SBP) after endovascular thrombectomy (EVT) for large artery occlusive stroke is dynamic, requiring adaptable early prediction tools for improving outcomes. We investigated if post-EVT SBP course was associated with outcomes.

Methods

EVT-treated patients who had a stroke at Karolinska University Hospital, Stockholm, Sweden, were included in the study during 12 February 2018–11 February 2020. SBP was recorded during the first 24 hours after EVT. Primary outcome was functional independence defined by a Modified Rankin Scale score of 0–2 at 3 months. Secondary outcomes were death by 3 months, symptomatic intracranial haemorrhage and any intracranial haemorrhage. Patients with favourable outcomes were used as a reference SBP course in mixed linear effects models and compared with SBP courses of patients with unfavourable outcomes using the empirical best linear unbiased predictor, measuring deviations from the reference SBP course using the random effects. We tested model predictive stability for SBP measurements of only 18, 12 or 6 hours after EVT.

Results

374 patients were registered, with mean age 71, median NIHSS score of 15, and 53.2% men. Deviating from a linear SBP course starting at 130 mm Hg and decreasing to 123 mm Hg at 24 hours after EVT was associated with lower chances of functional independence (adjusted OR 0.53, 95% CI 0.29 to 0.88, for reaching either 99 or 147 mm Hg at 24 hours after EVT). All SBP course models for the remaining outcomes did not show statistical significance. Functional independence models showed stable predictive values for all time periods.

Conclusion

Deviating from a linear SBP course was associated with lower chances of 3-month functional independence.

Association of asymptomatic hemorrhage after endovascular stroke treatment with outcomes

BACKGROUND

Intracerebral hemorrhage (ICH) occurs in ~20%-30% of stroke patients undergoing endovascular therapy (EVT). However, there is conflicting evidence regarding the effect of asymptomatic ICH (aICH) on post-EVT outcomes. We sought to evaluate the effect of aICH on immediate and 90-day post-EVT neurological outcomes.

METHODS

In this post-hoc analysis of the multicenter, prospective Blood Pressure after Endovascular Therapy (BEST) study we identified subjects with ICH following EVT. This population was divided into no ICH, aICH, and symptomatic ICH (sICH). Associations with 90-day modified Rankin Scale (mRS) dichotomized by functional independence (0-2 vs 3-6) and early neurological recovery (ENR) were determined using univariate/multivariate logistic regression models.

RESULTS

Of 485 patients enrolled in BEST, 446 had 90-day follow-up data available. 92 (20.6%) developed aICH, and 18 (4%) developed sICH. Compared with those without ICH, aICH was not associated with worse 90-day outcome or lower ENR (OR 0.84 [0.53-1.35], P=0.55, aOR 0.84 [0.48-1.44], P=0.53 for 90-day mRS 0-2; OR 0.77 [0.48-1.23], P=0.34, aOR 0.72 [0.43-1.22] for ENR). aICH was not associated with 90-day outcome or ENR in patients with mTICI ≥2 b (OR 0.78 [0.48-1.26], P=0.33 for 90-day mRS 0-2; OR 0.89 [0.69-1.12], P=0.15 for ENR). A higher proportion of patients with aICH had mTICI ≥2 b than those without ICH (97%vs 87%, P=0.01).

CONCLUSIONS

aICH was not associated with worse outcomes in patients with large-vessel stroke treated with EVT. aICH was more frequent in patients with successful recanalization. Further validation of our findings in large cohort studies of EVT-treated patients is warranted.

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.

Effect of blood pressure variability in the randomized controlled BP TARGET trial

BACKGROUND AND PURPOSE

The Blood Pressure Target in Acute Ischemic Stroke to Reduce Hemorrhage After Endovascular Therapy (BP TARGET) trial evaluated whether an intensive systolic blood pressure (SBP) target resulted in reduced rates of intracranial hemorrhage (ICH) after successful endovascular therapy (EVT) but did not assess the effect of blood pressure variability (BPV) on functional outcomes and ICH occurrence. We sought to evaluate this question in the BP TARGET trial.

METHODS

We performed a post hoc analysis of the BP TARGET trial and included patients with at least 50% of blood pressure (BP) recordings during the first 24 h after EVT. BPV parameters were SBP and diastolic BP (DBP) coefficient of variation (CV), standard deviation (SD), maximum-minimum (max-min), successive variation (SV), and time rate. The primary outcome was favorable functional outcome (3-month modified Rankin Scale between 0 and 2); the secondary outcome was the rate of ICH at 24 h.

RESULTS

We included 290 patients (mean number of BP measures = 30.4, SD = 8.0). BPV parameters (SBP_SD , SBP_max-min , SBP_CV ) were higher in the intensive SBP target group. Only DBP BPV parameters were associated with worse functional outcomes in the unadjusted model (DBP_SD , DBP_max-min , DBP_CV , and DBP_SV ), but not after adjustment. Higher SBP_max-min was associated with worse functional outcomes in Thrombolysis in Cerebral Infarction 2B patients (odds ratio [OR] = 0.62, 95% confidence interval [CI] = 0.38-1.02), but not in patients with complete reperfusion (OR = 1.27, 95% CI = 0.80-2.02, p for heterogeneity (p_het =0.037). None of the BPV parameters was associated with ICH, regardless of the randomization group or the reperfusion grade.

CONCLUSIONS

BPV was significantly higher in the intensive SBP target group but was not associated with functional outcome or ICH.

Periprocedural Management During Stroke Thrombectomy

PURPOSE OF REVIEW

Endovascular therapy (EVT) for acute ischemic stroke caused by large vessel occlusion is a powerful and evidence-based tool to achieve reperfusion and results in improved neurologic outcome. Focus has now shifted toward optimizing the procedure. We reviewed the relevant current literature on periprocedural stroke care such as pretreatment with IV tissue plasminogen activator (tPA), choice of anesthesia, ventilation strategy, and blood pressure management.

RECENT FINDINGS

IV tPA should not be withheld in a patients with stroke eligible for EVT. A meta-analysis of randomized trials on general anesthesia (GA) vs procedural sedation has shown better neurologic outcomes with protocol-based GA in centers with dedicated neuroanesthesia teams. There are no data from randomized trials on blood pressure control, but according to available evidence, systolic blood pressure should probably be held at >140 mm Hg during the procedure and <160 mm Hg after reperfusion. In ventilated patients, extreme deviations from normoxemia and normocapnia should be avoided.

SUMMARY

Periprocedural care influences the outcome after EVT for large vessel ischemic stroke. More evidence from prospective ongoing and future studies is urgently needed to identify its optimization.

Blood Pressure After Endovascular Thrombectomy and Outcomes in Patients With Acute Ischemic Stroke: An Individual Patient Data Meta-analysis

OBJECTIVE

To explore the association between blood pressure (BP) levels after endovascular thrombectomy (EVT) and the clinical outcomes of acute ischemic stroke (AIS) patients with large vessel occlusion (LVO).

METHODS

A study was eligible if it enrolled AIS patients older than 18 years, with an LVO treated with either successful or unsuccessful EVT, and provided either individual or mean 24-hour systolic BP values after the end of the EVT procedure. Individual patient data from all studies were analyzed using a generalized linear mixed-effects model.

RESULTS

A total of 5874 patients (mean age: 69±14 years, 50% women, median NIHSS on admission: 16) from 7 published studies were included. Increasing mean systolic BP levels per 10 mm Hg during the first 24 hours after the end of the EVT were associated with a lower odds of functional improvement (unadjusted common OR=0.82, 95%CI:0.80-0.85; adjusted common OR=0.88, 95%CI:0.84-0.93) and modified Ranking Scale score≤2 (unadjusted OR=0.82, 95%CI:0.79-0.85; adjusted OR=0.87, 95%CI:0.82-0.93), and a higher odds of all-cause mortality (unadjusted OR=1.18, 95%CI:1.13-1.24; adjusted OR=1.15, 95%CI:1.06-1.23) at 3 months. Higher 24-hour mean systolic BP levels were also associated with an increased likelihood of early neurological deterioration (unadjusted OR=1.14, 95%CI:1.07-1.21; adjusted OR=1.14, 95%CI:1.03-1.24) and a higher odds of symptomatic intracranial hemorrhage (unadjusted OR=1.20, 95%CI:1.09-1.29; adjusted OR=1.20, 95%CI:1.03-1.38) after EVT.

CONCLUSION

Increased mean systolic BP levels in the first 24 hours after EVT are independently associated with a higher odds of symptomatic intracranial hemorrhage, early neurological deterioration, three-month mortality, and worse three-month functional outcomes.

Blood Pressure After Endovascular Thrombectomy and Malignant Cerebral Edema in Large Vessel Occlusion Stroke

Background: Elevated blood pressure (BP) can cause blood–brain barrier disruption and facilitates brain edema formation. We aimed to investigate the association of BP level after thrombectomy with the development of malignant cerebral edema (MCE) in patients treated with endovascular thrombectomy (EVT).

Methods: Consecutive patients who underwent EVT for an anterior circulation ischemic stroke were enrolled from three comprehensive stroke centers. BP was measured hourly during the first 24 h after thrombectomy. MCE was defined as swelling causing a midline shift on the follow-up imaging within 5 days after EVT. Associations of various BP parameters, including mean BP, maximum BP (BP_max), and BP variability (BPV), with the development of MCE were analyzed.

Results: Of the 498 patients (mean age 66.9 ± 11.7 years, male 58.2%), 97 (19.5%) patients developed MCE. Elevated mean systolic BP (SBP) (OR, 1.035; 95% CI, 1.006–1.065; P = 0.017) was associated with a higher likelihood of MCE. The best SBP_max threshold that predicted the development of MCE was 165 mmHg. Additionally, increases in BPV, as evaluated by SBP standard deviation (OR, 1.061; 95% CI, 1.003–1.123; P = 0.039), were associated with higher likelihood of MCE.

Interpretation: Elevated mean SBP and BPV were associated with a higher likelihood of MCE. Having a SBP_max > 165 mm Hg was the best threshold to discriminate the development of MCE. These results suggest that continuous BP monitoring after EVT could be used as a non-invasive predictor for clinical deterioration due to MCE. Randomized clinical studies are warranted to address BP goal after thrombectomy.

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.

Hemodynamics of Leptomeningeal Collaterals after Large Vessel Occlusion and Blood Pressure Management with Endovascular Treatment

Endovascular therapy (EVT) is an effective treatment for ischemic stroke due to large vessel occlusion (LVO). Unlike intravenous thrombolysis, EVT enables visualization of the restoration of blood flow, also known as successful reperfusion in real time. However, until successful reperfusion is achieved, the survival of the ischemic brain is mainly dependent on blood flow from the leptomeningeal collaterals (LMC). It plays a critical role in maintaining tissue perfusion after LVO via pre-existing channels between the arborizing pial small arteries or arterioles overlying the cerebral hemispheres. In the ischemic territory where the physiologic cerebral autoregulation is impaired and the pial arteries are maximally dilated within their capacity, the direction and amount of LMC perfusion rely on the systemic perfusion, which can be estimated by measuring blood pressure (BP). After the EVT procedure, treatment focuses on mitigating the risk of hemorrhagic transformation, potentially via BP reduction. Thus, BP management may be a key component of acute care for patients with LVO stroke. However, the guidelines on BP management during and after EVT are limited, mostly due to the scarcity of high-level evidence on this issue. In this review, we aim to summarize the anatomical and physiological characteristics of LMC to maintain cerebral perfusion after acute LVO, along with a landscape summary of the literature on BP management in endovascular treatment. The objective of this review is to describe the mechanistic association between systemic BP and collateral perfusion after LVO and thus provide clinical and research perspectives on this topic.

Acute reperfusion therapies for acute ischemic stroke patients with unknown time of symptom onset or in extended time windows: an individualized approach

Recent randomized controlled clinical trials (RCTs) have revolutionized acute ischemic stroke care by extending the use of intravenous thrombolysis and endovascular reperfusion therapies in time windows that have been originally considered futile or even unsafe. Both systemic and endovascular reperfusion therapies have been shown to improve outcome in patients with wake-up strokes or symptom onset beyond 4.5 h for intravenous thrombolysis and beyond 6 h for endovascular treatment; however, they require advanced neuroimaging to select stroke patients safely. Experts have proposed simpler imaging algorithms but high-quality data on safety and efficacy are currently missing. RCTs used diverse imaging and clinical inclusion criteria for patient selection during the dawn of this novel stroke treatment paradigm. After taking into consideration the dismal prognosis of nonrecanalized ischemic stroke patients and the substantial clinical benefit of reperfusion therapies in selected late presenters, we propose rescue reperfusion therapies for acute ischemic stroke patients not fulfilling all clinical and imaging inclusion criteria as an option in a subgroup of patients with clinical and radiological profiles suggesting low risk for complications, notably hemorrhagic transformation as well as local or remote parenchymal hemorrhage. Incorporating new data to treatment algorithms may seem perplexing to stroke physicians, since treatment and imaging capabilities of each stroke center may dictate diverse treatment pathways. This narrative review will summarize current data that will assist clinicians in the selection of those late presenters that will most likely benefit from acute reperfusion therapies. Different treatment algorithms are provided according to available neuroimaging and endovascular treatment capabilities.

Predicting 90-Day Outcome After Thrombectomy: Baseline-Adjusted 24-Hour NIHSS Is More Powerful Than NIHSS Score Change

BACKGROUND AND PURPOSE

The National Institutes of Health Stroke Scale (NIHSS) measured at an early time point is an appealing surrogate marker for long-term functional outcome of stroke patients treated with endovascular therapy. However, definitions and analytical methods for an early NIHSS-based outcome measure that optimize power and precision in clinical studies are not well-established.

METHODS

In this post-hoc analysis of our prospective observational study that enrolled endovascular therapy-treated patients at 12 comprehensive stroke centers across the US, we compared the ability of 24-hour NIHSS, ΔNIHSS (baseline minus 24-hour NIHSS), and percentage change (NIHSS×100/baseline NIHSS), analyzed as continuous and dichotomous measures, to predict 90-day modified Rankin Scale (mRS) using logistic regression (adjusted for age, baseline NIHSS, glucose, hypertension, Alberta Stroke Program Early CT Score, time to recanalization, recanalization status, and intravenous thrombolysis) and Spearman ρ.

RESULTS

Of 485 patients in the BEST (Blood Pressure After Endovascular Stroke Therapy) cohort, 446 (92%) with 90-day follow-up data were included. An absolute 24-hour NIHSS, adjusted for baseline in multivariable modeling, had the highest predictive power of all definitions evaluated (aR² 0.368 and adjusted odds ratio 0.79 [0.75-0.84], P<0.001 for mRS score 0-2; aR² 0.444 and adjusted odds ratio 0.84 [0.8-0.86] for ordinal mRS). For predicting mRS score of 0-2 with a cut point, the second most efficient approach, the optimal threshold for 24-hour NIHSS score was ≤7 (sensitivity 80.1%, specificity 80.4%; adjusted odds ratio 12.5 [7.14-20], P<0.001), followed by percent change in NIHSS (sensitivity 79%, specificity 58.5%; adjusted odds ratio 4.55 [2.85-7.69], P<0.001).

CONCLUSIONS

Twenty-four-hour NIHSS, adjusted for baseline, was the strongest predictor of both dichotomous and ordinal 90-day mRS outcomes for endovascular therapy-treated patients. A dichotomous 24-hour NIHSS score of ≤7 was the second-best predictor. Although ΔNIHSS, continuous and dichotomized at ≥4, predicted 90-day outcomes, absolute 24-hour NIHSS definitions performed better.

Magnitude of blood pressure change and clinical outcomes after thrombectomy in stroke caused by large artery occlusion

BACKGROUND

Extremes of both high and low systolic blood pressure (SBP) after mechanical thrombectomy (MT) in large artery occlusion stroke are known predictors of unfavorable outcome. However, the effect of SBP change (∆SBP) during the first 24 h on thrombectomy outcomes remains unclear. We aimed to investigate the association between ∆SBP at different time intervals and thrombectomy outcomes.

METHODS

We analyzed MT-treated patients registered in the SITS International Stroke Thrombectomy Registry from January 1, 2014 to September 3, 2019. Primary outcome was 3-month unfavorable outcome (modified Rankin scale scores 3-6). We defined ∆SBP as the mean SBP of a given time interval after MT (0-2, 2-4, 4-12, 12-24 h) minus admission SBP. Multivariable mixed logistic regression models were used to adjust for known confounders and center as random effect. Subgroup analyses were included to contrast specific subpopulations. Restricted cubic splines were used to model the associations.

RESULTS

The study population consisted of 5835 patients (mean age 70 years, 51% male, median NIHSS 16). Mean ∆SBP was -12.3, -15.7, -17.2, and -16.9 mmHg for the time intervals 0-2, 2-4, 4-12 h, and 12-24 h, respectively. Higher ∆SBP was associated with unfavorable outcome at 0-2 h (odds ratio 1.065, 95% confidence interval 1.014-1.118), 2-4 h (1.140, 1.081-1.203), 4-12 h (1.145, 1.087-1.203), and 12-24 h (1.145, 1.089-1.203), for every increase of 10 mmHg. Restricted cubic spline models suggested that increasing ∆SBP was associated with unfavorable outcome, with higher values showing increased risk of unfavorable outcome.

CONCLUSION

SBP increase after thrombectomy in large artery occlusion stroke is associated with poor functional outcome.

Care of the Patient With Acute Ischemic Stroke (Endovascular/Intensive Care Unit-Postinterventional Therapy): Update to 2009 Comprehensive Nursing Care Scientific Statement: A Scientific Statement From the American Heart Association

Ischemic stroke remains the fifth leading cause of death in the United States. Nurses play a pivotal role in the care of patients throughout the continuum. With the advances in stroke care, including mechanical thrombectomy, the American Heart Association/American Stroke Association charged the writing panel to complement the 2009 clinical practice guideline, "Comprehensive Overview of Nursing and Interdisciplinary Care of the Acute Ischemic Stroke Patient," with current evidence-based nursing care. This update is 1 of a 3-part series focusing on emergency medical services/emergency care, endovascular/intensive care unit care, and postacute care. The aim of this scientific statement is to review and present current evidence, complications, best practices, and clinical practice strategies to provide current comprehensive scientific information for nursing care in the neuroendovascular area and intensive care unit in conjunction with medical treatments, including intravenous thrombolysis and mechanical thrombectomy.

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.

Systemic arterial blood pressure and intracerebral hemorrhage after mechanical thrombectomy in anterior cerebral circulation

The relationship between systemic arterial blood pressure (BP) and intracerebral hemorrhage (ICH) after mechanical thrombectomy (MT) of the cerebral artery remains unclear. This study aimed to determine the effect of BP variables on ICH after MT in patients with acute occlusions of the anterior cerebral circulation. Patients undergoing MT due to acute occlusions of the anterior cerebral circulation were enrolled in this single-center study. Non-invasive BP data following MT were obtained within the first 24 hours, including mean, maximum, minimum, difference between maximum and minimum, SD and coefficient of variation for systolic BP (SBP) and diastolic BP (DBP) and mean arterial pressure. ICH was defined and classified according to the European Cooperative Acute Stroke Study-II. In 164 enrolled patients (median age 65 (IQR 56–75) years; 31.7% female), higher maximum (89.5 mm Hg vs 98.5 mm Hg, p=0.001) and SD (9.8 mm Hg vs 10.9 mm Hg, p=0.038) of DBP were associated with higher risk of ICH. The optimal cut-off values associated with ICH for maximum SBP were 155 mm Hg and for maximum DBP 92.5 mm Hg, respectively. Higher BP within 24 hours after MT in acute occlusions of the anterior cerebral circulation is associated with a greater risk of ICH. More studies are needed to further determine optimal BP goals in the acute phase after MT.

Adverse Outcomes Associated With Higher Mean Blood Pressure and Greater Blood Pressure Variability Immediately After Successful Embolectomy in Those With Acute Ischemic Stroke, and the Influence of Pretreatment Collateral Circulation Status

Background

To investigate whether collateral status could modify the associations between post‐thrombectomy blood pressure (BP) measures and outcomes.

Methods and Results

Patients with anterior‐circulation large‐vessel‐occlusion successfully recanalized in a multicenter endovascular thrombectomy registry were enrolled. Pretreatment collateral status was graded and dichotomized (good/poor) in angiography. Maximum, minimum, and mean systolic BP (SBP) and BP variability (assessed by the SD, coefficient of variation) during the initial 24 hours after endovascular thrombectomy were obtained. The primary outcome was unfavorable 90‐day outcome (modified Rankin Scale score 3–6). Secondary outcomes included symptomatic intracranial hemorrhage and 90‐day mortality. Adjusted odds ratios (aOR) of BP parameters over the outcomes were obtained in all patients and in patients with good/poor collaterals. Among 596 patients (mean age 66 years; 59.9% males), 302 (50.7%) patients had unfavorable 90‐day outcome. In multivariable analyses, higher mean SBP (aOR, 1.59 per 10 mm Hg increment; 95% CI, 1.26–2.02; P<0.001), mean SBP >140 mm Hg (versus ≤120 mm Hg; aOR, 4.27; 95% CI, 1.66–10.97; P=0.002), and higher SBP SD (aOR, 1.08 per 1‐SD increment; 95% CI, 1.01–1.16; P=0.02) were respectively associated with unfavorable 90‐day outcome in patients with poor collateral but not in those with good collateral. A marginal interaction between SBP coefficient of variation tertiles and collaterals on 90‐day functional outcome (P for interaction, 0.09) was observed. A significant interaction between SBP coefficient of variation tertiles and collaterals on 90‐day mortality (P for interaction, 0.03) was observed.

Conclusions

Higher postprocedural BP is associated with 90‐day unfavorable outcomes after successful endovascular thrombectomy in patients with poor collateral.

Registration

URL: https://www.chictr.org.cn; Unique identifier: ChiCTR1900022154.

Management of Elevated Blood Pressure After Stroke Thrombectomy for Anterior Circulation

Thrombectomy is superior to intravenous thrombolysis for patients with large vessel occlusion in acute ischemic stroke, but nearly half of the patients still experience poor functional outcomes. Elevated blood pressure (BP) is widely observed in acute ischemic stroke, and BP may be one of the modifiable parameters that can potentially influence the outcomes; however, only observational studies exist to support current guidelines, and the recommended range for BP after thrombectomy is too wide to meet the clinical requirement. Randomized controlled trials are therefore needed to better understand the relationship between BP and outcomes after thrombectomy. In this review, we introduce the current management of BP after thrombectomy and several aspects of postthrombectomy BP management that should be resolved in future clinical trials.

Effect of Blood Pressure Management Strategies on Outcomes in Patients with Acute Ischemic Stroke After Successful Mechanical Thrombectomy

BACKGROUND

Variability, with no general consensus, exists in how patients' blood pressure should be managed after successful mechanical thrombectomy (MT) for large vessel ischemic stroke. We examined whether exceeding the systolic blood pressure (SBP) targets in patients during the first 24 hours after successful MT led to worse outcomes.

METHODS

We retrospectively studied a consecutive sample of adult patients who had undergone MT. We collected SBP data for the first 24 hours after MT and categorized the patients into 3 groups according to cases of the SBP exceeding 140, 160, or 180 mm Hg. The primary and secondary outcomes were the modified Rankin scale score at discharge and 90 days of follow-up, the incidence of symptomatic intracranial hemorrhage, malignant cerebral edema, and hemicraniectomy, mortality within 90 days, and discharge disposition.

RESULTS

A total of 117 patients were included (mean age, 65 ± 13.12 years; 53% female). The occurrence of ≥1 instance of SBP ≥180 mm Hg was significantly associated with poor functional outcomes at discharge (adjusted odds ratio [OR], 5.83; 95% confidence interval [CI], 1.41-32.9; P = 0.025) but not at 90 days of follow-up. The occurrence of SBP ≥160 mm Hg resulted in an independently increased odds of malignant cerebral edema (adjusted OR, 17.07; 95% CI, 2.56-174.4; P = 0.01), with a trend toward increased odds of symptomatic intracranial hemorrhage (adjusted OR, 4.42; 95% CI, 1.03-21.2; P = 0.0503).

CONCLUSIONS

These results suggest that individual instances of SBP elevation alone after successful MT, rather than a necessarily prolonged increased blood pressure as reflected by the mean or median SBP values, can significantly affect the clinical outcomes after successful MT.

Impact of the Perioperative Blood Pressure on Clinical Outcome after Thrombectomy in Acute Basilar Artery Occlusion

AIM

Optimal blood pressure (BP) management in vertebrobasilar circulation stroke patients undergoing thrombectomy remains undetermined. We aimed to evaluate the impact of perioperative BP on clinical outcome after MT in acute basilar artery occlusion (BAO) patients.

METHODS

We retrospectively analyzed all consecutive patients hospitalized with acute basilar artery occlusion administered endovascular treatment within 24 h from January 2012 to July 2018 in Beijing Tiantan Hospital. BP was measured at regular intervals during the first 24 h after stroke onset, during and after thrombectomy. The clinical outcomes assessed at 3-month follow up were functional independence (mRS score of 0-2) and mortality (mRS score of 6).

RESULTS

Of the 187 treated patients, 157 were male; patient ages were 60±10 years. The median NIHSS on admission was 22. Totally in 179 patients had complete BP level assessment. In these individuals, univariate analysis revealed significant associations of postoperative Max SBP and Max MAP with mortality (all P < 0.05). Multivariate regression analysis also demonstrated that postoperative Max SBP (OR=0.964, 95% CI 0.941 to 0.987, P < 0.003) and Max MAP (OR=0.942, 95% CI 0.907 to 0.979, P < 0.002) were independent predictors of mortality.

CONCLUSIONS

In acute BAO patients administered thrombectomy, Max SBP between 120 and 160 mmHg may be associated with better outcome, with a trend of reduced risk of mortality.

Blood pressure management after mechanical thrombectomy in stroke patients

Endovascular treatment of acute ischemic stroke (AIS) and mechanical thrombectomy (MT) is proven as a safe and effective novel treatment for emergent large vessel occlusion in the anterior cerebral circulation. However, there are still many unanswered questions on peri and post-procedural management including blood pressure (BP) control. The current guidelines recommend maintaining BP <180/105 mmHg in the first 24 h after MT. However, recent studies suggest that maintaining BP levels at lower levels in the first 24 h after successful revascularization have been associated with favorable functional outcome, reduced mortality rate, and hemorrhagic complications. Not only absolute BP but also its variation in the first 24 h after MT have been associated with neurological outcomes. Evidence on the effect of BP variability (BPV) after MT in AIS even though limited, it does indicate the association of the higher BPV in the first 24 h after MT and poor functional outcomes in AIS. In this review, we will discuss the current literature on BP management in the first 24 h after MT and the impact of BPV in the first 24 h after MT.

Impact of Blood Pressure After Successful Endovascular Therapy for Anterior Acute Ischemic Stroke: A Systematic Review

Background and Purpose: Optimal blood pressure (BP) targets after endovascular therapy (EVT) for acute ischemic stroke (AIS) still need to be assessed, especially according to the recanalization status. Facing the lack of randomized controlled trials addressing this question, we performed a systematic review of studies assessing the post-EVT BP impact on functional outcome and symptomatic intracranial hemorrhage (sICH).

Methods: Studies published after January 1, 2012 were included in the systematic review. The PRISMA checklist and flow diagram were followed for the design and reporting of this work.

Results: Five studies were included in the present analysis. Despite a significant heterogeneity among studies which precluded a meta-analysis, systolic BP (SBP) was the most frequently used parameter to describe BP. BP variability (standard deviation, successive variability) after EVT was associated with worse functional outcome, especially in studies without specific BP targets after successful EVT. Lower BP values after successful EVT were associated with lower odds of sICH. Four studies evaluated the post-EVT BP impact on recanalized patients solely, with only one specifically addressing the impact of a TICI 2B vs. 2C. Interestingly, SBP reduction was inversely associated with worse outcomes in TICI 3 patients but not in TICI 2B patients, pointing to the potential value of BP management according to the exact TICI.

Conclusions: BP post-EVT seems to be associated with worse functional outcomes and sICH. However, given the important heterogeneity depicted among the included studies, no decisive conclusion can be made from this systematic review, thus underlying the urgent need of randomized controlled trials evaluating this question.

Blood pressure reduction and outcome after endovascular therapy: a secondary analysis of the BEST study

BACKGROUND

Elevated systolic blood pressure (SBP) in the acute phase after endovascular therapy (EVT) is associated with worse outcome. However, the association between systolic blood pressure reduction (SBPr) and the outcome of EVT is not well understood.

OBJECTIVE

To determine the association between SBPr and clinical outcomes after EVT in a prospective multicenter cohort.

METHODS

A post hoc analysis of the Blood Pressure after Endovascular Stroke Therapy (BEST) prospective observational cohort study was carried out. SBPr was defined as the absolute difference between admission SBP and mean SBP in the first 24 hours after EVT. Logistic regression was used to assess the association between SBPr and poor functional outcome (modified Rankin Scale score 3-6) at 90 days.

RESULTS

A total of 259/433 (58.5%) patients had poor outcome. SBPr was higher in the poor outcome group than in the good outcome group (26.6±27.4 vs 19.0±22.3 mm Hg; p<0.001). However, in adjusted models, SBPr was not independently associated with poor outcome (OR=1.00 per 1 mm Hg increase, 95% CI 0.99 to 1.01) or death (OR=0.9 per 1 mm Hg increase; 95% CI 0.98 to 1.00). No association remained when SBPr was divided into tertiles. Subgroup analyses based on history of hypertension, revascularization status, and antihypertensive treatment yielded similar results.

CONCLUSION

The reduction in baseline SBP following EVT was not associated with poor functional outcomes. Most of the cohort (88%) achieved successful recanalization, and therefore, these results mainly apply to patients with successful recanalization.

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.

Blood Pressure Target in Acute Stroke to Reduce HemorrhaGe After Endovascular Therapy: The Randomized BP TARGET Study Protocol

Background: High systolic blood pressure (BP) is associated with an increased risk of intracranial hemorrhage (ICH) in patients undergoing reperfusion therapy. However, there are no data from randomized trials to guide BP management after reperfusion following endovascular therapy (EVT) for patients with acute ischemic stroke (AIS) with large vessel occlusion (LVO). The objective is to evaluate if BP control with a target of 100-129 mmHg systolic BP ("tight" SBP control) can reduce ICH as compared to 130-185 mmHg ("usual" SBP control) in AIS participants after reperfusion by EVT. Methods: The BP TARGET trial is a multicenter, prospective, randomized, controlled, open-label, blinded endpoint clinical trial. AIS participants with LVO experiencing successful reperfusion are randomly assigned, in a 1:1 ratio, to have a "tight" SBP control (100-129 mmHg) or a conservative SBP control (130-185 mmHg) during the following 24-36 h. The primary outcome is the rate of ICH (either symptomatic or asymptomatic) on follow-up CT scan at 24-36 h. Secondary outcomes include the rate of the symptomatic ICH, the overall distribution of the modified Rankin Scale (mRS) at 90 days, favorable outcome (90-day mRs 0-2), infarct volume at follow-up CT scan at 24-36 h, change in National Institute of Health Stroke Scale at 24 h, and all-cause mortality at 90 days. Conclusion: This is the first randomized trial directly comparing the efficacy of different SBP targets after EVT reperfusion. This prospective trial aims to determine whether a "tight" SBP control after EVT reperfusion can reduce the risk of ICH.