Determinants of the impact of blood pressure variability on neurological outcome after acute ischaemic stroke

Association Between Collateral Status, Blood Pressure During Thrombectomy, and Clinical Outcomes in Patients With Basilar Artery Occlusion

BACKGROUND AND OBJECTIVES

We investigated the relationship between intraprocedural blood pressure (BP) and clinical outcomes in patients with basilar artery occlusion (BAO) undergoing endovascular treatment (EVT), exploring whether it is modifiable by collateral status.

METHODS

Patient data from the Endovascular Treatment for Acute Basilar Artery Occlusion (ATTENTION) randomized trial were analyzed for those with BAO who received EVT. Intraprocedural BP data were extracted, with collateral status assessed using the Basilar Artery on CT Angiography (BATMAN) score (BATMAN score ≥7 favorable collateral status, <7 unfavorable). Associations between BP parameters and outcomes were assessed using multivariable logistic regression and restricted cubic splines. The effect modification was assessed using an interaction term between BP parameters and collateral status. The primary outcome was a favorable outcome defined by a modified Rankin Scale (mRS) score of 0-3 at 90 days.

RESULTS

There were 212 patients included (median age 68 years, 32.1% female). Restricted cubic spline analysis showed that the SDs of systolic BP (SBP) and mean arterial pressure (MAP) had J-shaped relationships with favorable outcome (p for nonlinearity = 0.004 and <0.001, respectively), with inflection points at 12 and 8 mm Hg, respectively. Multivariable logistic regression showed that MAP of 80-110 mm Hg (adjusted odds ratio [aOR] 3.00, 95% CI 1.46-6.35) and MAP SD <8 mm Hg (aOR 2.28, 95% CI 1.24-4.25) were associated with favorable outcome. Significant interactions with collateral status were observed for MAP SD <8 mm Hg, SBP SD <12 mm Hg, MAP drop >20%, and minimum MAP and SBP (all pinteraction < 0.05). After Holm-Bonferroni correction, only the interaction between collateral status and MAP <80 mm Hg remained significant (corrected pinteraction = 0.036). In patients with unfavorable collateral status, MAP <80 mm Hg was associated with decreased probability of favorable outcome (aOR 0.04, 95% CI 0.00-0.21) while this association was not observed in patients with favorable collaterals.

DISCUSSION

For patients with BAO undergoing EVT, intraprocedural MAP between 80 and 110 mm Hg was associated with favorable outcome while MAP <80 mm Hg was associated with a lower probability of favorable outcome, especially in patients with unfavorable collateral status.

Anaesthesia modality on endovascular therapy outcomes in patients with large infarcts: a post hoc analysis of the ANGEL-ASPECT trial

OBJECTIVES

Endovascular therapy (EVT) now penetrates the once obscure realm of large infarct core volume acute ischaemic stroke (LICV-AIS). This research aimed to investigate the potential correlation between different anaesthetic approaches and post-EVT outcomes in LICV-AIS patients.

METHODS

Between October 2020 and May 2022, the China ANGEL-Alberta Stroke Programme Early CT Score (ASPECT) trial studied patients with LICV-AIS, randomly assigning them to the best medical management (BMM) or BMM with EVT. This post hoc subgroup analysis categorised subjects receiving BMM with EVT into general anaesthesia (GA) and non-GA groups based on anaesthesia type. We applied multivariable logistic regression to evaluate the relationship between anaesthesia during EVT and patient functional outcomes, as measured by the modified Rankin scale (mRS), in addition to the occurrence of complications. Further adjustment for selection bias was achieved through propensity score matching (PSM).

RESULTS

In total, 230 patients with LICV-AIS were enrolled (GA 84 vs Non-GA 146). No significant difference was observed between the two groups in terms of the proportion of patients who achieved an mRS score of 0-2 at 90 days (27.4% for the GA group vs 31.5% for the non-GA group, p=0.51). However, the GA group had significantly longer median surgical times (142 min vs 122 min, p=0.03). Furthermore, GA was associated with an increased risk of postoperative pneumonia (adjusted OR 2.03, 95% CI 1.04 to 3.98). The results of PSM analysis agreed with the results of the multivariate regression analysis. No significant difference in intracranial haemorrhage incidence or mortality rate was observed between the groups.

CONCLUSION

This post hoc analysis of subgroups of the ANGEL-ASPECT trial suggested that there may be no significant association between the choice of anaesthesia and neurological outcomes in LICV-AIS patients. However, compared with non-GA, GA prolongs the duration of EVT and is associated with a greater postoperative pneumonia risk.

TRIAL REGISTRATION NUMBER

NCT04551664.

Arterial blood pressure monitoring in stroke cohorts: the impact of reduced sampling rates to optimise remote patient monitoring

OBJECTIVE

Remote patient monitoring (RPM) beat-to-beat blood pressure (BP) provides an opportunity to measure poststroke BP variability (BPV), which is associated with clinical stroke outcomes. BP sampling interval (SI) influences ambulatory BPV, but RPM BP SI optimisation research is limited. SI and RPM device capabilities require compromises, meaning SI impact requires investigation. Therefore, this study assessed healthy and stroke subtype BPV via optimised BP sampling, aiding sudden BP change identification and potentially assisting cardiovascular event (recurrent stroke) prediction.

METHODS

Leicester Cerebral Haemodynamic Database ischaemic [acute ischaemic stroke (AIS), n  = 68] and haemorrhagic stroke (intracerebral haemorrhage, n  = 12) patient and healthy control (HC, n  = 40) baseline BP data were analysed. Intrasubject and interpatient SD (SD i /SD p ) represented individual/population variability with synthetically altered SIs. Matched-filter approaches using cross-correlation function detected sudden BP changes.

RESULTS

At SIs between 1 and 180 s, SBP and DBP SD i staticised while SD p increased at SI < 30 s. Mean BP and HR SD i and SD p increased at SI < 60s. AIS BPV, normalised to SI1s, increased at SI30s (26%-131%) and SI120s (1%-274%). BPV increased concomitantly with SI. Cross-correlation analysis showed HC and AIS BP sudden change detection accuracy reductions with increasing SI. Positive BP deviation detection fell 48.48% (SI10s) to 78.79% (SI75s) in HC and 67.5% (SI10s) to 100% (SI75s) in AIS. Negative BP deviation detection fell 50% (SI10s) to 82.35% (SI75s) in HC and 52.27% (SI10s) to 95.45% (SI75s) in AIS.

CONCLUSION

Sudden BP change detection and BPV are relatively robust to SI increases within certain limits, but accuracy reductions generate unacceptable estimates, considerable within RPM device design. This research warrants further SI optimisation.

Sleep and blood pressure variability: A systematic literature review

BACKGROUND

Blood pressure variability (BPV) is a prognostic marker of cardiovascular disease (CVD). Sleep is recognized as a significant risk factor for CVD; however, little is known about the relationship between sleep characteristics and BPV.

OBJECTIVE

In this systematic review, we aimed to (1) describe methods used to measure BPV and sleep and (2) describe the current evidence in the literature on the association between sleep and BPV.

METHODS

A systematic search was conducted using the search terms "sleep" AND ("blood pressure variability" OR "ambulatory blood pressure monitor") in CINAHL, PubMed, Web of Science, and PsycINFO databases.

RESULTS

Twenty-two studies were included in this systematic review. Sleep was measured using various methods, including polysomnography, actigraphy, sleep diaries, and questionnaires, while BPV was measured over various time intervals using different monitoring devices such as a beat-to-beat blood pressure (BP) monitoring device, a 24-h ambulatory BP monitor, or an automatic upper arm BP monitor. The studies demonstrated mixed results on the associations between sleep parameters (sleep quality, architecture, and duration) and increased BPV.

CONCLUSIONS

Although the mechanisms that explain the relationship between sleep and BPV are still unclear, accumulating evidence suggests potential associations between increased BPV with poor sleep quality and longer sleep duration. Given the recent development of sleep and BP monitoring technologies, further research is warranted to assess sleep and BPV under free-living conditions. Such studies will advance our understanding of complex interactions between sleep and CVD risk.

Overall and linked blood pressure variabilities in the first 24 hours and mortality after spontaneous intracerebral hemorrhage: a retrospective study of 1,036 patients

BACKGROUND

This study aims to establish the individual contributions of blood pressure variability (BPV) indexes, categorized into overall and linked variability, to mortality following intracerebral hemorrhage (ICH) by examining the risk factors.

METHODS

Patients with spontaneous ICH (n = 1,036) were identified with valid blood pressures (BP) from the first 24-h systolic BP records in the Medical Information Mart for Intensive Care IV version 2.2 database (MIMIC IV). Information on the baseline characteristics, including age, sex, initial Glasgow Coma Scale (GCS) and National Institutes of Health Stroke Scale (NIHSS) scores, ICH location, Charlson comorbidity index score, and presence of diabetes with or without complications, were collected. Three indexes of BPV-range, standard deviation (SD), and generalized BPV (GBPV)-were calculated using the first 24-h systolic BPs. An automated stepwise variable-selection procedure was used to develop the final logistic model for predicting in-hospital mortality.

RESULTS

Out of 1,036 patients, 802 (77.4%) survived and were discharged after spontaneous ICH. Factors associated with mortality included age; male sex; ICH in the brainstem, ventricle, or multiple locations; low GCS score (< 9); high NIHSS score (> 20); and diabetes with complications. Mean systolic BP, SD, and GBPV were also linked to mortality. Higher GBPV notably increased the risk of in-hospital death, with an odds ratio of 3.21 (95% confidence interval, 2.10 to 4.97) for every + 10 mmHg/h change in GBPV.

CONCLUSIONS

This study underscores the additional impact of GBPV, herein linked to BPV, on mortality following ICH, providing further insights into the management of blood pressure in the early stages of ICH treatment.

Impaired Peripheral Vascular Function Following Ischemic Stroke in Mice: Potential Insights into Blood Pressure Variations in the Post-Stroke Patient

High systolic blood pressure and increased blood pressure variability after the onset of ischemic stroke are associated with poor clinical outcomes. One of the key determinants of blood pressure is arteriolar size, determined by vascular smooth muscle tone and vasodilatory and vasoconstrictor substances that are released by the endothelium. The aim of this study is to outline alterations in vasomotor function in isolated peripheral arteries following ischemic stroke. The reactivity of thoracic aortic segments from male C57BL/6 mice to dilators and constrictors was quantified using wire myography. Acetylcholine-induced endothelium-dependent vasodilation was impaired after ischemic stroke (LogIC50 Sham = -7.499, LogIC50 Stroke = -7.350, p = 0.0132, n = 19, 31 respectively). The vasodilatory responses to SNP were identical in the isolated aortas in the sham and stroke groups. Phenylephrine-induced vasoconstriction was impaired in the aortas isolated from the stroke animals in comparison to their sham treatment counterparts (Sham LogEC50= -6.652 vs. Stroke LogEC50 = -6.475, p < 0.001). Our study demonstrates that 24 h post-ischemic stroke, peripheral vascular responses are impaired in remote arteries. The aortas from the stroke animals exhibited reduced vasoconstrictor and endothelium-dependent vasodilator responses, while the endothelium-independent vasodilatory responses were preserved. Since both the vasodilatory and vasoconstrictor responses of peripheral arteries are impaired following ischemic stroke, our findings might explain increased blood pressure variability following ischemic stroke.

Beat-to-Beat Blood Pressure Variability Within 24 Hours of Ischemic Stroke Onset: A Potential Predictor of Functional Prognosis

BACKGROUND

Beat-to-beat blood pressure variability (BPV) is based on each heartbeat and represents a dynamic equilibrium process modulated by artery and cardiac involvement of pressure-receptive reflexes. To date, there remains a lack of prospective studies illustrating the clinical value of beat-to-beat BPV within 24 hours of acute ischemic stroke onset.

METHODS AND RESULTS

This study prospectively monitored beat-to-beat blood pressure and heart rate in patients with acute ischemic stroke within 24 hours of onset using a noninvasive plethysmograph and calculated beat-to-beat BPV, heart rate variability, and the cross-correlation baroreflex sensitivity. A modified Rankin Scale score of ≥2 at 90 days was defined as an unfavorable prognosis. Multivariate logistic regression was performed, and the nomogram model was developed by adding the beat-to-beat BPV to the traditional model for predicting prognosis. Beat-to-beat BPV increased significantly in the unfavorable outcome group (P<0.05) compared with that in the favorable outcome group, whereas no difference was observed in beat-to-beat heart rate variability and cross-correlation baroreflex sensitivity between both groups (P>0.05). Furthermore, beat-to-beat BPV within 24 hours of acute ischemic stroke onset was independently associated with unfavorable outcome at 90 days (P<0.005). The addition of beat-to-beat BPV to the traditional model for predicting prognosis enhanced the area under the receiver operating characteristic curve from 0.816 to 0.830.

CONCLUSIONS

Increased beat-to-beat BPV within 24 hours of acute ischemic stroke onset was independently associated with a poor prognosis at 90 days and may be a potential predictor for discriminating unfavorable prognosis.

Association of systolic blood pressure variability with remote ischemic conditioning in acute ischemic stroke

Systolic blood pressure variability (SBPV) is associated with outcome in acute ischemic stroke. Remote ischemic conditioning (RIC) has been demonstrated to be effective in stroke and may affect blood pressure. Relationship between SBPV and RIC treatment after stroke warrants investigation. A total of 1707 patients from per-protocol analysis set of RICAMIS study were included. The SBPV was calculated based on blood pressure measured at admission, Day 7, and Day 12. (I) To investigate the effect of SBPV on efficacy of RIC in stroke, patients were divided into High and Low categories in each SBPV parameter. Primary outcome was excellent functional outcome at 90 days. Compared with Control, efficacy of RIC in each category and interaction between categories were investigated. (II) To investigate the effect of RIC treatment on SBPV, SBPV parameters were compared between RIC and Control groups. Compared with Control, a higher likelihood of primary outcome in RIC was found in high category (max-min: adjusted risk difference [RD] = 7.2, 95% CI 1.2-13.1, P = 0.02; standard deviation: adjusted RD = 11.5, 95% CI 1.6-21.4, P = 0.02; coefficient of variation: adjusted RD = 11.2, 95% CI 1.4-21.0, P = 0.03). Significant interaction of RIC on outcomes were found between High and Low standard deviations (adjusted P < 0.05). No significant difference in SBPV parameters were found between treatment groups. This is the first report that Chinese patients with acute moderate ischemic stroke and presenting with higher SBPV, who were non-cardioemoblic stroke and not candidates for intravenous thrombolysis or endovascular therapy, would benefit more from RIC with respect to functional outcomes at 90 days, but 2-week RIC treatment has no effect on SBPV during hospital.

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.

Machine learning models reveal the critical role of nighttime systolic blood pressure in predicting functional outcome for acute ischemic stroke after endovascular thrombectomy

Background

Blood pressure (BP) is a key factor for the clinical outcomes of acute ischemic stroke (AIS) receiving endovascular thrombectomy (EVT). However, the effect of the circadian pattern of BP on functional outcome is unclear.

Methods

This multicenter, retrospective, observational study was conducted from 2016 to 2023 at three hospitals in China (ChiCTR2300077202). A total of 407 patients who underwent endovascular thrombectomy (EVT) and continuous 24-h BP monitoring were included. Two hundred forty-one cases from Beijing Hospital were allocated to the development group, while 166 cases from Peking University Shenzhen Hospital and Hainan General Hospital were used for external validation. Postoperative systolic BP (SBP) included daytime SBP, nighttime SBP, and 24-h average SBP. Least absolute shrinkage and selection operator (LASSO), support vector machine-recursive feature elimination (SVM-RFE), Boruta were used to screen for potential features associated with functional dependence defined as 3-month modified Rankin scale (mRS) score ≥ 3. Nine algorithms were applied for model construction and evaluated using area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and accuracy.

Results

Three hundred twenty-eight of 407 (80.6%) patients achieved successful recanalization and 182 patients (44.7%) were functional independent. NIHSS at onset, modified cerebral infarction thrombolysis grade, atrial fibrillation, coronary atherosclerotic heart disease, hypertension were identified as prognostic factors by the intersection of three algorithms to construct the baseline model. Compared to daytime SBP and 24-h SBP models, the AUC of baseline + nighttime SBP showed the highest AUC in all algorithms. The XGboost model performed the best among all the algorithms. ROC results showed an AUC of 0.841 in the development set and an AUC of 0.752 in the validation set for the baseline plus nighttime SBP model, with a brier score of 0.198.

Conclusion

This study firstly explored the association between circadian BP patterns with functional outcome for AIS. Nighttime SBP may provide more clinical information regarding the prognosis of patients with AIS after EVT.

Review of Cerebral Collateral Circulation and Insight into Cardiovascular Strategies to Limit Collateral Damage in Ischemic Stroke

Cerebral collateral circulation is a dynamic and adaptive process by which alternative vascular pathways supply perfusion to ischemic brain tissue in the event of an arterial occlusion. This complicated network of blood vessels that acts as a natural bypass plays a pivotal role in stroke pathophysiology and has become a key area of study given its significance in stroke treatment and patient outcomes. In this review, we will study the factors influencing the formation, recruitment, and endurance of collateral vessels; discuss imaging modalities for quantitative and qualitative assessment of this network; explore the role of collaterals in stroke management; and highlight several cardiovascular strategies to minimize damage to collaterals and optimize stroke outcomes.

Effect of Postoperative Prolonged sedation with Dexmedetomidine after successful reperfusion with Endovascular Thrombectomy on long-term prognosis in patients with acute ischemic stroke (PPDET): study protocol for a randomized controlled trial

BACKGROUND

Endovascular thrombectomy (EVT) is a standard treatment for acute ischemic stroke (AIS) with large vessel occlusion. Hypertension and increased blood pressure variability within the first 24 h after successful reperfusion are related to a higher risk of symptomatic intracerebral hemorrhage and higher mortality. AIS patients might suffer from ischemia-reperfusion injury following reperfusion, especially within 24 h. Dexmedetomidine (DEX), a sedative commonly used in EVT, can stabilize hemodynamics by inhibiting the sympathetic nervous system and alleviate ischemia-reperfusion injury through anti-inflammatory and antioxidative properties. Postoperative prolonged sedation for 24 h with DEX might be a potential pharmacological approach to improve long-term prognosis after EVT.

METHODS

This single-center, open-label, prospective, randomized controlled trial will include 368 patients. The ethics committee has approved the protocol. After successful reperfusion (modified thrombolysis in cerebral infarction scores 2b-3, indicating reperfusion of at least 50% of the affected vascular territory), participants are randomly assigned to the intervention or control group. In the intervention group, participants will receive 0.1~1.0 μg/kg/h DEX for 24 h. In the control group, participants will receive an equal dose of saline for 24 h. The primary outcome is the functional outcome at 90 days, measured with the categorical scale of the modified Rankin Scale, ranging from 0 (no symptoms) to 6 (death). The secondary outcome includes (1) the changes in stroke severity between admission and 24 h and 7 days after EVT, measured by the National Institute of Health Stroke Scale (ranging from 0 to 42, with higher scores indicating greater severity); (2) the changes in ischemic penumbra volume/infarct volume between admission and 7 days after EVT, measured by neuroimaging scan; (3) the length of ICU/hospital stay; and (4) adverse events and the all-cause mortality rate at 90 days.

DISCUSSION

This randomized clinical trial is expected to verify the hypothesis that postoperative prolonged sedation with DEX after successful reperfusion may promote the long-term prognosis of patients with AIS and may reduce the related socio-economic burden.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04916197. Prospectively registered on 7 June 2021.

Blood pressure variability predicts poor outcomes in acute stroke patients without thrombolysis: a systematic review and meta-analysis

BACKGROUND

Stroke is a significant medical condition, and blood pressure stands out as the most prevalent treatable risk factor associated with it. Researches link blood pressure variability (BPV) with stroke; however, the specific relationship between with the outcomes of stroke patients remains unclear. As blood pressure variability and mean blood pressure are interrelated, it remains uncertain whether BPV adds additional information to understanding the outcome of acute stroke patients.

OBJECTIVE

To systematically review studies investigating the association between blood pressure variability and prognosis in acute stroke patients.

METHODS

Embase, PubMed, Web of Science, and the Cochrane Library were searched for English language full-text articles from the inception to 1 January 2023. Stroke patients aged ≥ 18 years were included in this analysis. Stroke types were not restricted.

RESULTS

This meta-analysis shows that higher systolic blood pressure variability is linked to a higher risk of poor outcome, including function disability, mortality, early neurological deterioration, and stroke recurrence, among acute stroke patients without thrombolysis. A higher diastolic blood pressure variability is linked with to a higher risk of mortality and functional disability.

CONCLUSIONS

This review reveals that blood pressure variability is a novel and clinically relevant risk factor for stroke patients' outcome. Future studies should investigate how best to measure and define BPV in acute stroke. Larger studies are warranted to provide more robust evidence in this area.

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.

Intraoperative Blood Pressure Variability and Early Postoperative Stroke: A Case-Control Study

BACKGROUND

This study aims to assess the association of postoperative stroke with intraoperative hemodynamic variability and transfusion management.

METHODS

In this case-control study, adult patients (≥ 18 years) who had a stroke within 72 hours of a surgical procedure were matched to 2 control patients according to age, sex, and procedure type. Primary risk factors assessed were intraoperative fluid administration, blood product transfusion, vasopressor use, and measures of variability in systolic and diastolic blood pressure and heart rate: maximum, minimum, range, SD, and average real variability. The variables were analyzed with conditional logistic regression, which accounted for the 1:2 matched case-control study design.

RESULTS

Among 687 581 procedures, we identified 64 postoperative strokes (incidence, 9.3 [95% CI, 7.2-11.9] strokes per 100 000 procedures). These cases were matched with 128 controls. Stroke cases had higher Charlson cmorbidity index scores than did controls (P = .046). Blood pressure and heart rate variability measures were not associated with stroke. The risk of stroke was increased with red blood cell (RBC) transfusion (odds ratio [OR], 14.82; 95% CI, 3.40-64.66; P < .001), vasopressor use (OR, 3.91; 95% CI, 1.59-9.60; P = .003), and longer procedure duration (OR, 1.23/h; 95% CI, 1.01-1.51; P = .04). Multivariable analysis of procedure duration, RBC transfusion, and vasopressor use showed that only RBC transfusion was independently associated with an increased risk of stroke (OR, 10.10; 95% CI, 2.14-47.72; P = .004).

CONCLUSIONS

Blood pressure variability was not associated with an increased risk of postoperative stroke; however, RBC transfusion was an independent risk factor.

Systematic Analysis of RNA Expression Profiles in Different Ischemic Cortices in MCAO Mice

The prognosis of ischemic stroke patients is highly associated with the collateral circulation. And the competing endogenous RNAs (ceRNAs) generated from different compensatory supply regions may also involve in the regulation of ischemic tissues prognosis. In this study, we found the apoptosis progress of ischemic neurons in posterior circulation-supplied regions (close to PCA, cortex2) was much slower than that in anterior circulation-supplied territory (close to ACA, cortex1) in MCAO-3-h mice. Using the RNA sequencing and functional enrichment analysis, we analyzed the difference between RNA expression profile in cortex1 and cortex2 and the related biological processes. The results indicated that the differential expressed ceRNAs in cortex1 were involved in cell process under acute injury, while the differential expressed ceRNAs in cortex2 was more likely to participate in long-term injury and repair process. Besides, by establishing the miRNA-ceRNA interaction network we further sorted out two specifically distributed miRNAs, namely mmu-miR446i-3p (in cortex1) and mmu-miR3473d (in cortex2). And the specifically increased mmu-miR3473d in cortex2 mainly involved the angiogenesis and cell proliferation after ischemic stroke, which may be the critical reason for the longer therapeutic time window in cortex2. In conclusion, the present study reported the specific changes of ceRNAs in distinct compensatory regions potentially involved in the evolution of cerebral ischemic tissues and the unbalance prognosis after stroke. It provided more evidence for the collateral compensatory effects on patients' prognosis and carried out the new targets for the ischemic stroke therapy.

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.

Factors affecting physician decision-making regarding antiplatelet therapy in minor ischemic stroke

Purpose

To identify the most important factors affecting physician decision-making regarding antiplatelet therapy.

Methods

We retrospectively gathered data from minor ischemic stroke patients with NIHSS scores ≤ 5 within 72 h of onset from 2010 to 2018. The population was divided into four groups by initial antiplatelet therapy: aspirin monotherapy (AM), dual antiplatelet therapy with aspirin and a loading dose of clopidogrel (clopidogrel loading dose of 300 mg on the first day; DAPT-ALC), dual antiplatelet therapy with aspirin and no loading dose of clopidogrel (clopidogrel 75 mg daily, no loading dose; DAPT-AUC), and clopidogrel monotherapy (CM).

Results

In total, 1,377 patients were included in the analysis (excluding patients who accepted thrombolytic drugs, participated in other clinical trials, or had not used antiplatelet drugs). The mean ± S.D. age was 62.0 ± 12.7 years; 973 (70.7%) patients were male. The four groups were AM (n = 541, 39.3%), DAPT-ALC (n = 474, 34.4%), DAPT- AUC (n = 301, 21.9%), and CM (n = 61, 4.4%). Patients receiving antiplatelet monotherapy were older than those receiving dual antiplatelet therapy (63.7–65.7 vs. 59.6–61.4 years), and the median initial systolic blood pressure level was higher in the DAPT-ALC group than in the other groups (all P < 0.05). Patients under 75 years old with an admission SBP lower than 180 mmHg, a history of AM, coronary heart disease, no history of intracerebral hemorrhage, stroke onset occurring after guideline recommendations were updated (the year of 2015), onset-to-arrival time within 24 h, and initial NIHSS score ≤ 3 were more likely to take DAPT-ALC than AM. Compared with DAPT-ALC, DAPT-AUC was associated with an initial SBP level lower than 180 mmHg, a history of smoking, hypertension, no history of ICH, previous treatment with antihypertensives, and onset year after the recommendations were updated.

Conclusions

Many factors affect doctors' decisions regarding antiplatelet therapy, especially guidelines, age, admission SBP level, and hypertensive disease.

Association of blood pressure variability with short- and long-term cognitive outcomes in patients with critical illness

BACKGROUND

Blood pressure variability (BPV), a modifiable risk factor, can compromise cerebral perfusion in critically ill patients. We studied the association between BPV in the intensive care unit (ICU) and short- and long-term cognitive outcomes.

METHODS

All patients were ≥50 years old. The short-term cognitive end points were delirium and depressed alertness without delirium. The long-term outcome was change in the slope of longitudinal cognitive scores. Primary BPV measure was average real variability (ARV) of systolic blood pressure. Associations were assessed with multivariable multinominal logistic regression and linear mixed effects models.

RESULTS

Of 794 patients (1130 admissions) 185 developed delirium and 274 developed depressed alertness. There was a dose-response association of 24-h systolic ARV with delirium (adjusted OR, 95% CI 2.15 per 5 mm Hg increase, 1.31-3.06, P < 0.017) and with depressed alertness (OR 1.89, 95% CI 1.18-3.03, P < 0.008). For 371 patients with available longitudinal cognitive scores, the decline in cognitive trajectory was accelerated after discharge (annual change OR -0.097, 95% CI -0.122 to -0.073). This acceleration increased with delirium (additional decline -0.132 [-0.233 to 0.030], P = 0.011). We found no significant association between BPV and post-ICU cognitive trajectory.

CONCLUSIONS

BPV was associated with increased likelihood of delirium in the ICU. Delirium, but not BPV, was associated with long-term cognitive decline.

Blood Pressure Variability After Cerebrovascular Events—A Possible New Therapeutic Target: A Narrative Review

Blood pressure variability, the variation of blood pressure during a certain period, results from the interaction of hemodynamic, neuronal, humoral, behavioral, and environmental factors. Cerebral autoregulation is impaired in acute cerebrovascular disease. In these patients, increased blood pressure variability may provoke or exacerbate secondary brain injury. In fact, available data showed that increased Blood pressure variability is associated with worse outcomes after acute ischemic stroke, intracerebral hemorrhage, and aneurysmal subarachnoid hemorrhage. Consequently, blood pressure variability may represent a usual modifiable therapeutic target. This concept this particularly attractive because reduction of blood pressure variability can be feasible in regions with lower resources and can be applicable to patients with various forms of acute stroke. Prospective studies are needed to further clarify the relationship between blood pressure variability and secondary brain damage, and the determinants of blood pressure variability in different clinical populations. Ultimately, cerebrovascular disease-specific randomized controlled trials aimed at reducing blood pressure variability, irrespective of the absolute blood pressure values, are needed to determine if reduction of blood pressure variability can improve outcomes in patients with acute cerebrovascular disease.

Blood Pressure Variability Indices for Outcome Prediction After Thrombectomy in Stroke by Using High-Resolution Data

Background

Blood pressure variability (BPV) is associated with outcome after endovascular thrombectomy in acute large vessel occlusion stroke. We aimed to provide the optimal sampling frequency and BPV index for outcome prediction by using high-resolution blood pressure (BP) data.

Methods

Patient characteristics, 3-month outcome, and BP values measured intraarterially at 1 Hz for up to 24 h were extracted from 34 patients treated at a tertiary care center neurocritical care unit. Outcome was dichotomized (modified Rankin Scale 0–2, favorable, and 3–6, unfavorable) and associated with systolic BPV (as calculated by using standard deviation, coefficient of variation, averaged real variability, successive variation, number of trend changes, and a spectral approach using the power of specific BP frequencies). BP values were downsampled by either averaging or omitting all BP values within each prespecified time bin to compare the different sampling rates.

Results

Out of 34 patients (age 72 ± 12.7 years, 67.6% men), 10 (29.4%) achieved a favorable functional outcome and 24 (70.6%) had an unfavorable functional outcome at 3 months. No group differences were found in mean absolute systolic BP (SBP) (130 ± 18 mm Hg, p = 0.82) and diastolic BP (DBP) (59 ± 10 mm Hg, p = 1.00) during the monitoring time. BPV only reached predictive significance when using successive variation extracted from downsampled (averaged over 5 min) SBP data (median 4.8 mm Hg [range 3.8–7.1]) in patients with favorable versus 7.1 mmHg [range 5.5–9.7] in those with unfavorable outcome, area under the curve = 0.74 [confidence interval (CI) 0.57–0.85; p = 0.031], or the power of midrange frequencies between 1/20 and 1/5 min [area under the curve = 0.75 (CI 0.59–0.86), p = 0.020].

Conclusions

Using high-resolution BP data of 1 Hz, downsampling by averaging all BP values within 5-min intervals is essential to find relevant differences in systolic BPV, as noise can be avoided (confirmed by the significance of the power of midrange frequencies). These results demonstrate how high-resolution BP data can be processed for effective outcome prediction.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12028-022-01519-x.

Time point of nocturnal trough systolic blood pressure as an independent predictor of cardiovascular events

Nocturnal trough systolic blood pressure (NTSBP) and Time Point of Nocturnal Trough Systolic Blood Pressure (T‐NTSBP) were important parameters of nocturnal blood pressure, the predictive values of which are unclear for stroke outcome. This study aimed to examine the relationship between NTSBP/T‐NTSBP and stroke outcome. The authors used data from a nationwide ambulatory blood pressure monitoring cohort study conducted in China, which recruited 2348 ischemic stroke and transient ischemic attack (TIA) patients. NTSBP was defined as the lowest SBP during nighttime (22:00–6:00), and T‐NTSBP was defined as the corresponding time point of NTSBP. The associations between NTSBP/T‐NTSBP and stroke outcome (stroke recurrence and combined vascular event [CVE]) at 90 days or 1 year were analyzed using cox regression models. According to NTSBP classified by quartile, hazard ratio (HR) with 95% confidence interval (CI) for NTSBP quartile 4 (>129 mm Hg) was 2.727 (1.148–6.478) for CVE at 90‐day, compared with quartile 1 (≤102 mm Hg). However, an attenuated association between NTSBP and CVE was observed at 1 year. In addition, we observed the group of T‐NTSBP at 4:00–6:00 had a lowest CVE incidence at 90 days among four groups (22:00–23:59, 00:00–1:59 2:00–3:59, 4:00–6:00). After multivariable adjustment, T‐NTSBP was significantly associated with CVE incidence at 90 days (T‐NTSBP at the 4:00–6:00 versus the 22:00–23:59 group: HR, 0.433; 95%CI, 0.190–0.986), independent of NTSBP and average nocturnal SBP. Both of NTSBP and T‐NTSBP were important predictors for short‐term cardiovascular risk in ischemic stroke and TIA patients.

Increased blood pressure variability predicts poor outcomes from endovascular treatment for aneurysmal subarachnoid hemorrhage

BACKGROUND

Predictors of outcomes following endovascular treatment (ET) for aneurysmal subarachnoid hemorrhage (aSAH) are not well-defined. Identifying them would be beneficial in determining which patients might benefit from ET.

OBJECTIVE

To identify the predictive factors for poor outcomes following ET for aSAH.

METHODS

120 patients with ruptured cerebral aneurysms underwent endovascular embolization between January 2017 and December 2018. Blood pressure variability was examined using the standard deviation of the 24-hour systolic blood pressure (24hSSD) and 24-hour diastolic blood pressure (24hDSD). Predictors were identified through univariate and multivariate regression analysis. All patients were followed up for three months.

RESULTS

At follow-up, 86 patients (71.7%) had good outcomes and 34 (28.3%) had poor outcomes. Patients with poor outcomes had significantly higher 24hSSD than those with good outcomes (19.3 ± 5.5 vs 14.1 ± 4.8 mmHg; P < 0.001). The 24hDSD did not differ significantly between patients with good outcomes and those with poor outcomes (9.5 ± 2.3 vs 9.9 ± 3.5 mmHg; P = 0.464). The following were significant risk factors for poor outcomes after endovascular embolization: age ≥ 65 years (odds ratio [OR] = 23.0; 95% confidence interval [CI]: 3.0-175.9; P = 0.002); Hunt-Hess grade 3-4 (OR = 6.8; 95% CI: 1.1-33.7; P = 0.039); Fisher grade 3-4 (OR = 47.1; 95% CI: 3.8-586.5; P = 0.003); postoperative complications (OR = 6.1; 95% CI: 1.1-34.8; P = 0.042); and 24hSSD ≥ 15 mmHg (OR = 14.9; 95% CI: 4.0-55.2; P < 0.001).

CONCLUSION

Elevated 24hSSD is a possibly treatable predictive factor for poor outcomes after ET for aSAH.

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.

An update on hyper-acute management of ischaemic stroke

This article aims to provide a comprehensive overview of key advances on various aspects of hyper-acute management of acute ischaemic stroke. These include neuroimaging, acute stroke unit care, management of blood pressure, reperfusion therapy including intravenous thrombolysis, mechanical thrombectomy and decompressive hemicraniectomy for malignant stroke syndrome. The challenge ahead is to ensure these evidence-based treatments are now being delivered and implemented to maximise the benefits across the population.

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.

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.

Blood Pressure Variability and Optimal Cerebral Perfusion Pressure-New Therapeutic Targets in Traumatic Brain Injury

BACKGROUND

Optimal cerebral perfusion pressure (CPPopt) is an autoregulatory-oriented target in the neurointensive care (NIC) of patients with traumatic brain injury (TBI), and deviation from CPPopt is associated with poor outcome. We recently found that blood pressure variability (BPV) is associated with deviation from CPPopt.

OBJECTIVE

To evaluate BPV and other variables related to deviation from CPPopt and to evaluate challenges and strategies for autoregulatory-oriented treatment in TBI.

METHODS

Data including arterial blood pressure and intracranial pressure (ICP) from 362 TBI patients treated at the NIC unit, Uppsala University Hospital, Sweden, between 2008 and 2016, were retrospectively analyzed day 2 to 5.

RESULTS

Higher BPV was a strong predictor of both CPP deviation below and above CPPopt after multiple regression analyses. There was no other explanatory variable for CPP deviation above CPPopt, whereas also higher ICP and worse autoregulation (higher pressure reactivity index) were associated with CPP deviation below CPPopt. A higher BPV was, in turn, explained by older age, lower ICP, higher mean arterial blood pressure, and higher slow arterial blood pressure amplitude (0.018-0.067 Hz).

CONCLUSION

BPV was strongly associated with deviation from CPPopt. High age is a risk factor for high BPV and hence CPP insults. Our treatment protocol is focused on avoiding CPP below 60 mm Hg. It is possible that a more restrictive upper level could generate more stable blood pressure and less deviation from CPPopt.

Short-term outcome after ischemic stroke and 24-h blood pressure variability: association and predictors

To examine the association between blood pressure (BP) variability measured within 24 h after admission for acute ischemic stroke and functional outcome 30 days after stroke onset and to find outcome predictors. A total of 174 patients were included in this retrospective study. Supine BP was measured every 4 h during the first 24 h after admission. The functional outcome was assessed using the modified Rankin Scale. BP parameters including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure (PP) were examined. A set of six variability indices was calculated, including standard deviation (SD), successive variation (SV), difference between maximum and minimum value (DMM), and maximal successive change (MSC). Patients with high SBP or PP variability measures were significantly more likely to develop an unfavorable outcome. All PP variability indices displayed the highest correlations with the outcome. This association was confirmed in logistic regression analysis, both in univariable model and a model adjusted to the baseline National Institute of Health Stroke Scale score and mean BP (the OR for an unfavorable outcome following a 10-mmHg increase in SD, SV, MSC, and DMM parameters was in the interval 1.4-2.7, p < 0.05). Following receiver operating characteristic analysis, the PP parameters yielded area under the curve (AUC) values between 0.654 and 0.666, p < 0.005. Thus, in the acute phase of ischemic stroke, the SD and MSC indices of PP variability during the first 24 h after admission were robustly associated with patients' 30-day outcomes and served as predictors of unfavorable outcomes with thresholds of 14 and 26 mmHg, respectively.

Nitroglycerin Is Not Associated with Improved Cerebral Perfusion in Acute Ischemic Stroke

OBJECTIVE

The study was conducted to test the hypothesis that nitroglycerin (NTG) increases cerebral perfusion focally and globally in acute ischemic stroke patients, using serial perfusion-weighted imaging (PWI) magnetic resonance imaging measurements.

PATIENTS AND METHODS

Thirty-five patients underwent PWI immediately before and 72 h after administration of a transdermal NTG patch or no treatment. Patients with baseline mean arterial pressure (MAP) > 100 mmHg (NTG group, n = 20) were treated with transdermal NTG (0.2 mg/h) for 72 h, without a nitrate-free interval. Patients with MAP ≤ 100 mmHg (untreated group, n = 15) were not treated. The primary outcome measure was absolute cerebral blood flow (CBF) in the hypoperfused region at 72 h.

RESULTS

The mean baseline absolute CBF in the hypoperfused region was similar in the NTG group (33.3 ± 10.2 ml/100 g/min) and untreated (32.7 ± 8.4 ml/100 g/min, p = 0.4) groups. The median (IQR) baseline infarct volume was 10.4 (2.5-49.3) ml in the NTG group and 32.6 (8.6-96.7) ml in the untreated group (p = 0.09). MAP change in the NTG group was 1.2 ± 12.6 and 8 ± 20.7 mmHg at 2 h and 72 h, respectively. Mean absolute CBF in the hypoperfused region at 72 h was similar in the NTG (29.9 ± 12 ml/100 g/min) and untreated groups (24.1 ± 10 ml/100 g/min, p = 0.8). The median infarct volume increased in untreated (11.8 (5.7-44.2) ml) than the NTG group (3.2 (0.5-16.5) ml; p = 0.033) on univariate analysis, however, there was no difference on regression analysis.

CONCLUSION

NTG was not associated with improvement in cerebral perfusion in acute ischemic stroke patients.

Sedation Patterns and Hyperosmolar Therapy in Emergency Departments were Associated with Blood Pressure Variability and Outcomes in Patients with Spontaneous Intracranial Hemorrhage

Background

Spontaneous intracranial hemorrhage (sICH) is associated with high mortality. Little information exists to guide initial resuscitation in the emergency department (ED) setting. However, blood pressure variability (BPV) and mechanical ventilation (MV) are known risk factors for poor outcome in sICH.

Objectives

The objective was to examine the associations between BPV and MV in ED (EDMV) and between two ED interventions - post-MV sedation and hyperosmolar therapy for elevated intracranial pressure - and BPV in the ED and in-hospital mortality.

Methods

We retrospectively studied adults with sICH and external ventricular drainage who were transferred to a quaternary academic medical center from other hospitals between January 2011 and September 2015. We used multivariable linear and logistic regressions to measure associations between clinical factors, BPV, and outcomes.

Results

We analyzed ED records from 259 patients. There were 143 (55%) EDMV patients who had more severe clinical factors and significantly higher values of all BPV indices than NoEDMV patients. Two clinical factors and none of the severity scores (i.e., Hunt and Hess, World Federation of Neurological Surgeons Grades, ICH score) correlated with BPV. Hyperosmolarity therapy without fluid resuscitation positively correlated with all BPV indices, whereas propofol infusion plus a narcotic negatively correlated with one of them. Two BPV indices, i.e., successive variation of blood pressure (BP_SV) and absolute difference in blood pressure between ED triage and departure (BP_{Depart - Triage}), were significantly associated with increased mortality rate.

Conclusion

Patients receiving MV had significantly higher BPV, perhaps related to disease severity. Good ED sedation, hyperosmolar therapy, and fluid resuscitation were associated with less BPV and lower likelihood of death.

Role of 24-Hr Blood Pressure Variability as a Target Therapeutic Risk Factor for Poor Functional Outcome of Acute Ischemic Stroke

Background and Purpose:

The present study aims to evaluate the role of blood pressure variability (BPV) as a target therapeutic risk factor for poor outcome of ischemic stroke by finding the association between the two and by finding the population attributable risk (PAR) of BPV compared to other baseline outcome predictors.

Methods:

A prospective observational study was carried out at GMCH, Nagpur, India from January to June 2019 in 75 patients diagnosed with acute ischemic stroke. BP was recorded hourly for the first 24 hours of admission and base line factors were collected along with measurement of stroke severity. BPV was measured by index of average real-time variability (ARV) while discharge outcome was measured by Barthel Index.

Results:

36.5% of patients had poor outcome at discharge. A significant association was found between 24-hr ARV of systolic BP and poor outcome (P = 0.002, 95% CI = 2.22-23.5). Five factors were found to be independent outcome predictors on multiple logistic regression (OR, 95% CI): age (1.07, 1.03–1.10), NIHSS score (1.12, 1.04–1.27), on admission SBP (5.12, 4.01–16.23), on admission RBS (2.23, 1.92–6.49) and 24 Hr ARV-SBP (9.65, 3.02–20.1). The PAR of 24 hr ARV-SBP was 23.6%, second only to NIHSS score (26.4%).

Conclusions:

Reduction in BP variability might have a beneficial impact on the outcome of patients with acute ischemic stroke. There is further scope to explore optimum therapeutic strategies to minimize BPV in the management of acute ischemic stroke.

Blood Pressure Variability and Neurologic Outcome After Endovascular Thrombectomy: A Secondary Analysis of the BEST Study

Background and Purpose- Although higher blood pressure variability (BPV) is associated with worse functional outcome after stroke, this association is not as well established in large vessel occlusion strokes treated with endovascular treatment (EVT). Methods- In this post hoc analysis of BEST (Blood Pressure after Endovascular Therapy for Ischemic Stroke), a prospective, multicenter cohort study of anterior circulation acute ischemic stroke patients undergoing EVT, we determined the association of BPV with poor outcome or death (90-day modified Rankin Scale, 3-6). We calculated BPV during the first 24 hours after EVT for systolic and diastolic BP using 5 methodologies, then divided BPV into tertiles and compared the highest to lowest tertile using logistic regression. Results- Of the 443 patients included in our analysis, 259 (58.5%) had a poor outcome, and 79 (17.8%) died. All measures of BPV were significantly higher in patients with poor outcome or death, but the difference was more pronounced for systolic than diastolic BPV. In the logistic regression, the highest tertile of systolic BPV consistently predicted poor outcome (odds ratio, 1.8-3.5, all P<0.05). The rate of death within 90 days was 10.1% in the tertile with the lowest systolic BPV versus 25.2% in the tertile with the highest BPV (P<0.001). Conclusions- In EVT-treated stroke patients, higher BPV in the first 24 hours is associated with worse 90-day outcome. This association was more robust for systolic BPV. The mechanism by which BPV may exert a negative influence on neurological outcome remains unknown, but the consistency of this association warrants further investigation and potentially intervention.

Blood Pressure Variability and Cardiovascular Outcomes in Patients With Prior Stroke: A Secondary Analysis of PRoFESS

Background and Purpose- Every year in the United States, almost 185 000 ischemic strokes occur in patients with a prior stroke. Recurrent stroke has significantly higher morbidity and mortality. Among modifiable risk factors for recurrent stroke, hypertension is the most prevalent. Reducing systolic blood pressure is standard of care for secondary stroke prevention. Recent literature suggests that increased blood pressure variability (BPV) is associated with primary stroke, although studies have not convincingly shown that it is associated with recurrent stroke, which was the goal of this analysis. Methods- We conducted a secondary analysis of 17 916 patients in the PRoFESS (Prevention Regimen for Effectively Avoiding Second Strokes) trial, which is the largest trial of patients with potential recurrent stroke. We calculated BPV and evaluated its effect on recurrent stroke (composite and stratified by ischemic or hemorrhagic stroke), major cardiovascular events (death from cardiovascular causes, recurrent stroke, myocardial infarction, or new or worsening heart failure), and all-cause death. Results- Both systolic and diastolic BPV were associated with recurrent stroke, major cardiovascular events, and all-cause death. The association with stroke was significant for ischemic, but not hemorrhagic, stroke. For every 10-point increase in BPV (systolic SD, range =0-54.2), the hazard ratio for a recurrent ischemic stroke was 1.15 (95% CI, 1.02-1.32; P=0.02), for major cardiovascular events was 1.19 (95% CI, 1.09-1.31; P<0.001), and for all-cause death was 1.24 (95% CI, 1.10-1.39; P<0.001). Conclusions- Our study adds to the growing body of literature suggesting that BPV is an important and potentially modifiable risk factor for ischemic stroke, cardiovascular events, and all-cause death. Specifically, it is the first study to demonstrate that increased BPV is associated with recurrent ischemic stroke and that diastolic BPV can be as important as systolic BPV. Future work should focus on evaluating whether actively reducing BPV, using widely available and inexpensive antihypertensive medications, reduces the risk of cardiovascular disease.

e-ASPECTS derived acute ischemic volumes on non-contrast-enhanced computed tomography images

Background and purpose

Validation of automatically derived acute ischemic volumes (AAIV) from e-ASPECTS on non-contrast computed tomography (NCCT).

Materials and methods

Data from three studies were reanalyzed with e-ASPECTS Version 7. AAIV was calculated in milliliters (ml) in all scored ASPECTS regions of the hemisphere detected by e-ASPECTS. The National Institute of Health Stroke Scale (NIHSS) determined stroke severity at baseline and clinical outcome was measured with the modified Rankin Scale (mRS) between 45 and 120 days. Spearman ranked correlation coefficients (R) of AAIV and e-ASPECTS scores with NIHSS and mRS as well as Pearson correlation of AAIV with diffusion-weighted imaging and CT perfusion-estimated ischemic “core” volumes were calculated. Multivariate regression analysis (odds ratio, OR with 95% confidence intervals, CI) and Bland–Altman plots were performed.

Results

We included 388 patients. Mean AAIV was 11.6 ± 18.9 ml and e-ASPECTS was 9 (8–10: median and interquartile range). AAIV, respectively e-ASPECTS correlated with NIHSS at baseline (R = 0.35, p < 0.001; R = −0.36, p < 0.001) and follow-up mRS (R = 0.29, p < 0.001; R = −0.3, p < 0.001). In subsets of patients, AAIV correlated strongly with diffusion-weighted imaging (n = 37, R = 0.68, p < 0.001) and computed tomography perfusion-derived ischemic “core” (n = 41, R = 0.76, p < 0.001) lesion volume and Bland–Altman plots showed a bias close to zero (−2.65 ml for diffusion-weighted imaging and 0.45 ml forcomputed tomography perfusion “core”). Within the whole cohort, the AAIV (OR 0.98 per ml, 95% CI 0.96–0.99) and e-ASPECTS scores (OR 1.3, 95%CI 1.07–1.57) were independent predictors of good outcome

Conclusion

AAIV on NCCT correlated moderately with clinical severity but strongly with diffusion-weighted imaging lesion and computed tomography perfusion ischemic “core” volumes and predicted clinical outcome.

Effect of short-term blood pressure variability on functional outcome after intra-arterial treatment in acute stroke patients with large-vessel occlusion

Background

Endovascular treatment (EVT) is advocated for acute ischaemic stroke with large-vessel occlusion (LVO), but perioperative periods are challenging. This study investigated the relationship between post-EVT short-term blood pressure variability (BPV) and early outcomes in LVO patients.

Methods

We retrospectively reviewed 72 LVO patients undergoing EVT between June 2015 and June 2018. Hourly systolic and diastolic blood pressures (SBP and DBP, respectively) were recorded in the first 24 h post-EVT. BPV were evaluated as standard deviation (SD), coefficient of variation (CV), and successive variation (SV) separately for SBP and DBP. Functional independence at 3 months was defined as a modified Rankin Scale (mRS) score of 0–2.

Results

For 58.3% patients with favorable outcomes, the median National Institutes of Health Stroke Scale and Alberta Stroke Program Early CT scores on admission were 14 and 8, respectively. The maximum SBP ([154.3 ± 16.8] vs. [163.5 ± 15.6], P = 0.02), systolic CV ([8. 8% ± 2.0%] vs. [11.0% ± 1.8], P < 0.001), SV ([11.4 ± 2.3] vs. [14.6 ± 2.0], P < 0.001), and SD ([10.5 ± 2.4] vs. [13.8 ± 3.9], P < 0.001) were lower in patients with favorable outcomes. On multivariable logistic regression analysis, systolic SV (OR: 4.273, 95% CI: 1.030 to 17.727, P = 0.045) independently predicted unfavorable prognosis. The area under the curve was 0.868 (95% CI: 0.781 to 0.955, P < 0.001), and sensitivity and specificity were 93.3% and 73.8%, respectively, showing excellent predictive value for 3-month poor-outcomes.

Conclusions

Decreased systolic SV following intra-arterial therapies result in favorable outcomes at 3 months. Systolic SV may be a novel predictor of functional prognosis in LVO patients.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12883-019-1457-5.

Increased blood pressure variability after acute ischemic stroke increases the risk of death: A secondary analysis of the Virtual International Stroke Trial Archive

Background

Despite promising epidemiological data, it remains unclear if increased blood pressure variability is associated with death after acute ischemic stroke. Our objective was to examine this association in a large cohort of acute ischemic stroke patients.

Methods

We conducted a retrospective analysis of anonymized, pooled, participant data from the Virtual International Stroke Trial Archive. We included patients with a 90-day modified Rankin Scale and blood pressure readings in the 24 h after study enrollment. The exposure was blood pressure variability during the day after study enrollment, calculated for the systolic and diastolic blood pressure using six statistical methodologies. The primary outcome was death within 90 days of stroke onset.

Results

Our cohort comprised 1891 patients of whom 277 (14.7%) died within 90 days. All indices of blood pressure variability were higher in patients who died, but the difference was more pronounced for systolic than diastolic blood pressure variability (systolic standard deviation for alive versus dead patients = 13.4 versus 15.9 mmHg, p < 0.001). Similar results were found in logistic regression models fit to the outcome of death, but only systolic blood pressure variability remained significant in adjusted models (Odds Ratio for death when comparing highest to lowest tercile of systolic blood pressure variability = 1.41–1.89, p < 0.03 for all).

Conclusions and relevance: These results reinforce prior studies that found increased blood pressure variability is associated with worse neurologic outcome after stroke. These data should help guide research on blood pressure variability after stroke and advocate for the inclusion of death as a clinical outcome in future studies that therapeutically reduce blood pressure variability.

Postreperfusion Blood Pressure Variability After Endovascular Thrombectomy Affects Outcomes in Acute Ischemic Stroke Patients With Poor Collateral Circulation

Background and Purpose: We evaluated the effect of 24 h blood pressure variability (BPV) on clinical outcomes in acute ischemic stroke patients with successful recanalization after endovascular recanalization therapy (ERT). Methods: Patients with anterior circulation occlusion were evaluated if they underwent ERT based on multiphase computed tomography angiography and achieved successful recanalization (≥thrombolysis in cerebral ischemia 2b). Collateral degrees were dichotomized based on the pial arterial filling score, with a score of 0-3 defined as a poor collateral status. BPV parameters include mean, standard deviation, coefficient of variation, and variation independent of the mean (VIM) for systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure, and pulse rate (PR). These parameters were measured for 24 h after ERT and were analyzed according to occlusion sites and stroke mechanisms. Associations of BPV parameters with clinical outcomes were investigated with stratification based on the baseline collateral status. Results: BPV was significantly different according to the occlusion sites and stroke mechanisms, and higher BPV was observed in patients with internal carotid artery occlusion or cardioembolic occlusion. After adjustment for confounders, most BPV parameters remained significant to predict functional outcomes at 3 months in patients with poor collateral circulation. However, no significant association was found between BPV parameters and clinical outcomes in patients with good collateral circulation. Conclusion: Postreperfusion BP management by decreasing BPV may have influence on improving clinical outcome in cases of poor collateral circulation among patients achieving successful recanalization after ERT.

Blood pressure variability and outcome in acute ischemic and hemorrhagic stroke: a post hoc analysis of the HeadPoST study

The Head Positioning in Acute Stroke Trial (HeadPoST) is a pragmatic, international, cluster crossover randomized trial of 11,093 patients with acute stroke assigned to a lying-flat (0°) or sitting-up (head elevated ≥30°) position. This post-hoc analysis aimed to determine the association between BPV and outcomes for patients from a wide range of international clinical settings and how the association was modified by randomized head position. BPV was defined according to standard criteria with the key parameter considered the coefficient of variation (CV) of systolic BP (SBP) over 24 hours. Outcome was ordinal 90-day modified Rankin Scale (mRS) score. The association was analyzed by ordinal, logistic regression, hierarchical, mixed models with fixed intervention (lying-flat vs. sitting-up), and fixed period, random cluster, and random cluster-period, effects. 9,156 (8,324 AIS and 817 ICH; mean age 68.1 years; 39.2% women) were included in the analysis. CV of SBP had a significant linear association with unfavorable shift of mRS at 90 days (adjusted odds ratio [OR] 1.06, 95% confidence interval [CI] 1.02-1.11; P=0.01). There was no heterogeneity of the association by randomized head positioning. In addition, CV of diastolic BP (DBP) (1.08, 1.03-1.12; P=0.001) over 24 hours post stroke, was significantly associated with 3-month poor outcome. The association was more apparent in sitting-up position (1.12, 1.06-1.19) compared with lying-flat position (1.03, 0.98-1.09) (P interaction = 0.005). BPV was associated with adverse stroke outcome, the magnitude of the association was greater with sitting-up head positioning in terms of DBP variability.

Dynamic cerebral autoregulation measurement using rapid changes in head positioning: experiences in acute ischemic stroke and healthy control populations

The ideal technique for dynamic cerebral autoregulation (dCA) assessment in critically ill patients should provide considerable variability in blood pressure (BP) but without the need for patient cooperation. We proposed using rapid head positioning (RHP) over spontaneous BP fluctuations for dCA assessment in patients with acute ischemic stroke (AIS). Cerebral blood velocity (transcranial Doppler), beat-to-beat BP (Finometer), and end-tidal CO2 (capnography) were recorded during 5-min baseline and RHP in 16 controls (8 women and 8 men, mean age: 57 ± 16 yr) and 15 patients with AIS (7 women and 8 men, mean age: 69 ± 8 yr) at two (12 ± 8 days) and three visits (13.3 ± 6.9 h, 4.8 ± 3.2 days, and 93.9 ± 11.5 days from the symptom onset), respectively. All participants were able to complete the RHP protocol without difficulty. Compared with controls, patients with AIS were hypocapnic (all visits, P < 0.0024) and hypertensive ( visit 1, P = 0.011), although BP gradually reduced after the acute phase. RHP demonstrated greater beat-to-beat BP variability (BPV) in controls ( visits 1 and 2, P < 0.001) but not in patients with AIS at any visit. Compared with controls, a reduced autoregulation index (ARI) was demonstrated in patients with AIS, at visit 2 for the baseline recording but not at other visits or during RHP. The area under the receiver-operating curve was 0.53 and 0.54 for baseline and RHP, respectively. The RHP paradigm required minimal patient cooperation and could be considered a feasible alternative for assessing dCA, mainly in conditions leading to increased BPV. The lack of BPV increase in AIS with RHP deserves further investigation.

NEW & NOTEWORTHY This study used rapid head positioning (RHP) to enhance blood pressure (BP) variability (BPV) to improve BP signal-to-noise ratio and reliability of dynamic cerebral autoregulation (dCA). RHP was well accepted by controls and acute ischemic stroke (AIS); the increased BPV induced in controls was not observed in AIS, suggesting BPV at rest was already elevated. RHP did not improve detection of impaired CA in AIS; further work is needed to understand the different responses observed.

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

Ischemic stroke is a common neurologic condition and can lead to significant long term disability and death. Observational studies have demonstrated worse outcomes in patients presenting with the extremes of blood pressure as well as with hemodynamic variability. Despite these associations, optimal hemodynamic management in the immediate period of ischemic stroke remains an unresolved issue, particularly in the modern era of revascularization therapies. While guidelines exist for BP thresholds during and after thrombolytic therapy, there is substantially less data to guide management during mechanical thrombectomy. Ideal blood pressure targets after attempted recanalization depend both on the degree of reperfusion achieved as well as the extent of infarction present. Following complete reperfusion, lower blood pressure targets may be warranted to prevent reperfusion injury and promote penumbra recovery however prospective clinical trials addressing this issue are warranted.

Impact of blood pressure levels within first 24 hours after mechanical thrombectomy on clinical outcome in acute ischemic stroke patients

INTRODUCTION

Despite early management and technical success of mechanical thrombectomy (MT) for acute ischemic stroke (AIS), not all patients reach a good clinical outcome. Different factors may have an impact and we aimed to evaluate blood pressure (BP) levels in the first 24 hours after MT.

METHODS

Consecutive AIS patients treated with MT were enrolled in the retrospective bi-center study. Neurological deficit was assessed with National Institutes of Health Stroke Scale (NIHSS) and functional outcome after 3 months with modified Rankin scale (mRS) with a score 0-2 for good outcome. The presence of symptomatic intracerebral hemorrhage (SICH) was assessed according to the SITS-MOST criteria.

RESULTS

Of 703 treated patients, completed BP levels were collected in 690 patients (350 males, mean age 71±13 years) with median of admission NIHSS 17 points. Patients with mRS 0-2 had a lower median of systolic BP (SBP) compared with those with poor outcome (131 vs 140 mm Hg, P<0.0001). The rate of SICH did not differ between the patients with a median of SBP <140 mm Hg and ≥140 mm Hg. (5.1% vs 5.1%, P=0.980). Multivariate regression analysis with adjustment for potential confounders showed a median of distolic BP (P=0.024, OR: 0.977, 95% CI: 0.957 to 0.997) as a predictor of good functional outcome after MT, and a median of maximal SBP (P=0.038; OR: 0.990, 95% CI: 0.981 to 0.999) in the patients with achieved recanalization.

CONCLUSION

Lowering of BP within the first 24 hours after MT may have a positive impact on clinical outcome in treated patients.

Interventions affecting blood pressure variability and outcomes after intubating patients with spontaneous intracranial hemorrhage

INTRODUCTION

Spontaneous intracranial hemorrhage (sICH) that increases intracranial pressure (ICP) is a life-threatening emergency often requiring intubation in Emergency Departments (ED). A previous study of intubated ED patients found that providing ≥5 interventions after initiating mechanical ventilation (pMVI) reduced mortality rate. We hypothesized that pMVIs would lower blood pressure variability (BPV) in patients with sICH and thus improve survival rates and neurologic outcomes.

METHOD

We performed a retrospective study of adults, who were transferred to a quaternary medical center between 01/01/2011 and 09/30/2015 for sICH, received an extraventricular drain during hospitalization. They were identified by International Classification of Diseases, version 9 (430.XX, 431.XX), and procedure code 02.21. Outcomes were BPV indices, death, and being discharged home.

RESULTS

We analyzed records from 147 intubated patients transferred from 40 EDs. Forty-one percent of patients received ≥5 pMVIs and was associated with lower median successive variation in systolic blood pressure (BP_SV) (31,[IQR 18-45) compared with those receiving 4 or less pMVIs (38[IQR 16-70]], p = 0.040). Three pMVIs, appropriate tidal volume, sedative infusion, and capnography were significantly associated with lower BPV. In addition to clinical factors, BP_SV (OR 26; 95% CI 1.2, >100) and chest radiography (OR 0.3; 95% CI 0.09, 0.9) were associated with mortality rate. Use of quantitative capnography (OR 8.3; 95%CI, 4.7, 8.8) was associated with increased likelihood of being discharged home.

CONCLUSIONS

In addition to disease severity, individual pMVIs were significantly associated with BPV and patient outcomes. Emergency physicians should perform pMVIs more frequently to prevent BPV and improve patients' outcomes.

Insomnia is associated with increased mortality in patients with first-ever stroke: a 6-year follow-up in a Chinese cohort study

Objective

Insomnia is a highly prevalent disorder among patients suffering from stroke. The association between insomnia and stroke mortality is less studied, particularly using the latest diagnostic criteria. The current study examined the relationship between insomnia and mortality among patients with first-evonal hazard models were used to calculate HRs for stroke er stroke in China.

Methods

Patients with acute cerebrovascular diseases (stroke) were recruited from 56 hospitals in mainland China. Insomnia was defined as difficulty falling asleep, or difficulty staying asleep or waking up early, for at least two consecutive visits. Demographic data, medical history and clinical data were collected. Four follow-up visits occurred within the first year after stroke, and the last follow-up call was conducted 6 years later. Cox proportional hazard models were used to calculate HRs for stroke mortality.

Results

Insomnia was reported by 38.4% (489/1273) of patients at baseline. During the 6 years of follow-up, after adjusting for all confounders, insomnia was found to be associated with increased mortality (HR=1.66, 95% CI 1.10 to 2.48). Old age (HR=1.08, 95% CI 1.06 to 1.10), stroke recurrence in the first year of follow-up (HR=2.53, 95% CI 1.48 to 4.31) and stroke survivors with hypertension (HR=1.62, 95% CI 1.04 to 2.53) had substantially higher risk of mortality.

Conclusions

Besides old age, stroke recurrence in the first year of follow-up and hypertension, insomnia is associated with increased risk of mortality in patients with first-ever stroke in China. More studies about prompt and efficient interventions for insomnia are expected in the future.

Trial registration number

rctn62169508.