Prehospital transdermal glyceryl trinitrate in patients with ultra-acute presumed stroke (RIGHT-2): an ambulance-based, randomised, sham-controlled, blinded, phase 3 trial

The effect of nitroglycerin treatment on cerebral ischaemia: A systematic review and meta-analysis of animal studies

BACKGROUND

Nitroglycerin has been of considerable interest as a treatment for ischaemic stroke. Recent clinical trials with nitroglycerin transdermal patches during the acute phase of stroke failed to improve functional outcomes. Systematic review and meta-analysis of the effectiveness of nitroglycerin in preclinical models of ischaemic stroke has not previously been reported, despite several clinical trials.

OBJECTIVE

To conduct a systematic review and meta-analysis of preclinical evidence regarding the effect of nitroglycerin on infarct volume in animal models of ischaemic stroke.

SUMMARY OF REVIEW

The protocol was registered in PROSPERO (CRD42023432644). Our search identified 238 publications. Three publications met inclusion criteria (including 10 comparisons of infarct size). Study quality was modest (median 6 out of 9), with no evidence of publication bias. Nitroglycerin did not significantly reduce infarct volume (NMD point estimate 20.2 % reduction, 95 % CI -1.52-52.7 %, p = 0.068). Subgroup analysis suggested greater efficacy of nitroglycerin with direct intracarotid administration to the ischaemic territory at the time of reperfusion.

CONCLUSIONS

A small number of studies (three) were included in this review. Overall, nitroglycerin did not reduce infarct volume in experimental stroke models. However, nitroglycerin may be of benefit when administered directly into the ischaemic territory. Given nitroglycerin's short half-life, we propose this route may minimise harmful reduction of cerebral perfusion pressure resulting from hypotension following systemic administration.

Mobile stroke units: Beyond thrombolysis

In the last decade, mobile stroke units (MSUs) have shown the potential to transform prehospital stroke care, marking a paradigm shift in delivering ultra-rapid thrombolysis and streamlining triage processes. These units bring acute stroke care directly to patients, significantly shortening treatment times. This review outlines the rationale for MSU care and discusses the potential applications beyond the original purpose of delivering thrombolysis, including large vessel occlusion detection, intracerebral hemorrhage management, and innovative forms of prehospital research.

Safety and efficacy of active blood-pressure reduction to the recommended thresholds for intravenous thrombolysis in patients with acute ischaemic stroke in the Netherlands (TRUTH): a prospective, observational, cluster-based, parallel-group study

BACKGROUND

Intravenous thrombolysis is contraindicated in patients with ischaemic stroke with blood pressure higher than 185/110 mm Hg. Prevailing guidelines recommend to actively lower blood pressure with intravenous antihypertensive agents to allow for thrombolysis; however, there is no robust evidence for this strategy. Because rapid declines in blood pressure can also adversely affect clinical outcomes, several Dutch stroke centres use a conservative strategy that does not involve the reduction of blood pressure. We aimed to compare the clinical outcomes of both strategies.

METHODS

Thrombolysis and Uncontrolled Hypertension (TRUTH) was a prospective, observational, cluster-based, parallel-group study conducted across 37 stroke centres in the Netherlands. Participating centres had to strictly adhere to an active blood-pressure-lowering strategy or to a non-lowering strategy. Eligible participants were adults (≥18 years) with ischaemic stroke who had blood pressure higher than 185/110 mm Hg but were otherwise eligible for intravenous thrombolysis. The primary outcome was functional status at 90 days, measured using the modified Rankin Scale and assessed through telephone interviews by trained research nurses. Secondary outcomes were symptomatic intracranial haemorrhage, the proportion of patients treated with intravenous thrombolysis, and door-to-needle time. All ordinal logistic regression analyses were adjusted for age, sex, stroke severity, endovascular thrombectomy, and baseline imbalances as fixed-effect variables and centre as a random-effect variable to account for the clustered design. Analyses were done according to the intention-to-treat principle, whereby all patients were analysed according to the treatment strategy of the participating centre at which they were treated.

FINDINGS

Recruitment began on Jan 1, 2015, and was prematurely halted because of a declining inclusion rate and insufficient funding on Jan 5, 2022. Between these dates, we recruited 853 patients from 27 centres that followed an active blood-pressure-lowering strategy and 199 patients from ten centres that followed a non-lowering strategy. Baseline characteristics of participants from the two groups were similar. The 90-day mRS score was missing for 15 patients. The adjusted odds ratio (aOR) for a shift towards a worse 90-day functional outcome was 1·27 (95% CI 0·96-1·68) for active blood-pressure reduction compared with no active blood-pressure reduction. 798 (94%) of 853 patients in the active blood-pressure-lowering group were treated with intravenous thrombolysis, with a median door-to-needle time of 35 min (IQR 25-52), compared with 104 (52%) of 199 patients treated in the non-lowering group with a median time of 47 min (29-78). 42 (5%) of 852 patients in the active blood-pressure-lowering group had a symptomatic intracranial haemorrhage compared with six (3%) of 199 of those in the non-lowering group (aOR 1·28 [95% CI 0·62-2·62]).

INTERPRETATION

Insufficient evidence was available to establish a difference between an active blood-pressure-lowering strategy-in which antihypertensive agents were administered to reduce blood pressure below 185/110 mm Hg-and a non-lowering strategy for the functional outcomes of patients with ischaemic stroke, despite higher intravenous thrombolysis rates and shorter door-to-needle times among those in the active blood-pressure-lowering group. Randomised controlled trials are needed to inform the use of an active blood-pressure-lowering strategy.

FUNDING

Fonds NutsOhra.

Blood pressure targets after successful reperfusion in mechanical thrombectomy for acute ischemic stroke: an updated systematic review and meta-analysis of randomized clinical trials

BACKGROUND

This study sought to determine whether intensive blood pressure (BP) control for patients with successful reperfusion following acute ischemic stroke (AIS) is beneficial, compared to conventional BP management.

METHODS

PubMed, Embase, and Cochrane databases were systematically searched for randomized controlled trials (RCTs) on the subject. The studied outcomes included dependency or death at 90 days (modified Rankin Scale [mRS] 3-6); severe disability at 90 days (mRS 3-5); mortality at 90 days; and symptomatic intracranial hemorrhage. Odds ratios (OR) with 95% confidence intervals were used to compare the treatment effects for categorical outcomes. We employed a fixed-effect model for analyses with low heterogeneity (I2 < 25%) and a random-effects model for analyses with higher heterogeneity.

RESULTS

A total of 1519 patients were included, with 50% (n = 760) receiving intensive BP control (systolic BP < 140 mmHg). Functional disability or death at 90 days was significantly higher in the intensive group (54.9%) compared to the conventional treatment group (44.1%) (OR = 1.51; 95% Confidence Interval [CI]: 1.15-1.96; p = 0.003; I2 = 29%). Severe functional disability (mRS 3-5) was significantly higher in the intensive group (30.6% vs. 43.5%, OR = 1.75; 95%CI = 1.36-2.25; p < 0.0001; I2 = 0%). There was no difference in symptomatic intracranial hemorrhage (OR = 1.13; 95%CI = 0.76-1.67) or mortality (OR = 1.22; 95%CI = 0.9-1.64).

CONCLUSIONS

Intensive BP control is harmful in patients who underwent EVT for AIS and achieved successful reperfusion. It yields higher rates of functional dependence, with no differences in mortality or symptomatic intracranial hemorrhage.

Blood Pressure Management in Intracerebral Haemorrhage: when, how much, and for how long?

PURPOSE OF REVIEW

When compared to ischaemic stroke, there have been limited advances in acute management of intracerebral haemorrhage. Blood pressure control in the acute period is an intervention commonly implemented and recommended in guidelines, as elevated systolic blood pressure is common and associated with haematoma expansion, poor functional outcomes, and mortality. This review addresses the uncertainty around the optimal blood pressure intervention, specifically timing and length of intervention, intensity of blood pressure reduction and agent used.

RECENT FINDINGS

Recent pivotal trials have shown that acute blood pressure intervention, to a systolic target of 140mmHg, does appear to be beneficial in ICH, particularly when bundled with other therapies such as neurosurgery in selected cases, access to critical care units, blood glucose control, temperature management and reversal of coagulopathy. Systolic blood pressure should be lowered acutely in intracerebral haemorrhage to a target of approximately 140mmHg, and that this intervention is generally safe in the ICH population.

Facilitators and barriers to the delivery of the PARAMEDIC2 trial

Background

PARAMEDIC2 was a medicines trial comparing adrenaline with placebo in out-of-hospital cardiac arrest (OHCA). At the time, United Kingdom (UK) Emergency Medical Systems (EMS) were inexperienced in delivering such research.

Aim

To identify barriers and facilitators to delivery of the PARAMEDIC2 (Adrenaline) trial by five UK NHS EMS.

Methods

This qualitative study took a grounded theory approach to thematic analysis of workshop data. Members of the trial teams from each service attended a workshop in November 2018 and discussed their experiences in answer to two prompt questions. Data were coded and themes presented.

Results

Three main themes were identified: professionalism, organisational investment and unique features of EMS. The study provided an opportunity for recruiting paramedics and research paramedics to demonstrate their professionalism. Research paramedics felt it was part of their professional duty to initiate discussions with the patient/family regarding the trial rather than leave this task to the hospital teams as would usually happen. Organisational investment was reflected by prioritising trial training and further development of research paramedics. By these means, research culture was developed. The unique features of EMS such as geographical challenges were often addressed with technological solutions and through building relationships with internal teams.

Conclusion

Barriers to trial delivery included infrequent exposure to the condition of interest and lack of continuity in research paramedic roles. Facilitators identified included flexibility of the research protocol, and organisational investment in the development of research paramedics.Participating in PARAMEDIC2 was challenging for the EMS involved, but ultimately strengthened their research culture.

Effects of Mobile Stroke Unit dispatch on blood pressure management and outcomes in patients with intracerebral haematoma: Results from the Berlin_Prehospital Or Usual Care Delivery in acute Stroke (B_PROUD) controlled intervention study

INTRODUCTION

In patients with acute intracerebral haemorrhage (ICH) and elevated systolic blood pressure (BP), guidelines suggest that systolic BP reduction to <140 mmHg should be rapidly initiated. Compared with conventional care, Mobile Stroke Units (MSUs) allow for earlier ICH diagnosis through prehospital imaging and earlier BP lowering.

PATIENTS AND METHODS

ICH patients were prospectively evaluated as a cohort of the controlled B_PROUD-study in which MSU availability alone determined MSU dispatch in addition to conventional ambulance. We used inverse probability of treatment weighting to adjust for confounding to estimate the effect of additional MSU dispatch in ICH patients. Outcomes of interest were 7-day mortality (primary), systolic BP (sBP) at hospital arrival, dispatch-to-imaging time, largest haematoma volume, anticoagulation reversal, length of in-hospital stay, 3-month functional outcome.

RESULTS

Between February 2017 and May 2019, MSUs were dispatched to 95 (mean age: 72 ± 13 years, 45% female) and only conventional ambulances to 78 ICH patients (mean age: 71 ± 12 years, 44% female). After adjusting for confounding, we found shorter dispatch-to-imaging time (mean difference: -17.75 min, 95% CI: -27.16 to -8.21 min) and lower sBP at hospital arrival (mean difference = -16.31 mmHg, 95% CI: -30.64 to -6.19 mmHg) in the MSU group. We found no statistically significant difference for the other outcomes, including 7-day mortality (adjusted odds ratio: 1.43, 95% CI: 0.68 to 3.31) or favourable outcome (adjusted odds ratio = 0.67, 95% CI: 0.27 to 1.67).

CONCLUSIONS

Although MSU dispatch led to sBP reduction and lower dispatch-to-imaging time compared to conventional ambulance care, we found no evidence of better outcomes in the MSU dispatch group.

Intensive Ambulance-Delivered Blood-Pressure Reduction in Hyperacute Stroke

BACKGROUND

Treatment of acute stroke, before a distinction can be made between ischemic and hemorrhagic types, is challenging. Whether very early blood-pressure control in the ambulance improves outcomes among patients with undifferentiated acute stroke is uncertain.

METHODS

We randomly assigned patients with suspected acute stroke that caused a motor deficit and with elevated systolic blood pressure (≥150 mm Hg), who were assessed in the ambulance within 2 hours after the onset of symptoms, to receive immediate treatment to lower the systolic blood pressure (target range, 130 to 140 mm Hg) (intervention group) or usual blood-pressure management (usual-care group). The primary efficacy outcome was functional status as assessed by the score on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) at 90 days after randomization. The primary safety outcome was any serious adverse event.

RESULTS

A total of 2404 patients (mean age, 70 years) in China underwent randomization and provided consent for the trial: 1205 in the intervention group and 1199 in the usual-care group. The median time between symptom onset and randomization was 61 minutes (interquartile range, 41 to 93), and the mean blood pressure at randomization was 178/98 mm Hg. Stroke was subsequently confirmed by imaging in 2240 patients, of whom 1041 (46.5%) had a hemorrhagic stroke. At the time of patients' arrival at the hospital, the mean systolic blood pressure in the intervention group was 159 mm Hg, as compared with 170 mm Hg in the usual-care group. Overall, there was no difference in functional outcome between the two groups (common odds ratio, 1.00; 95% confidence interval [CI], 0.87 to 1.15), and the incidence of serious adverse events was similar in the two groups. Prehospital reduction of blood pressure was associated with a decrease in the odds of a poor functional outcome among patients with hemorrhagic stroke (common odds ratio, 0.75; 95% CI, 0.60 to 0.92) but an increase among patients with cerebral ischemia (common odds ratio, 1.30; 95% CI, 1.06 to 1.60).

CONCLUSIONS

In this trial, prehospital blood-pressure reduction did not improve functional outcomes in a cohort of patients with undifferentiated acute stroke, of whom 46.5% subsequently received a diagnosis of hemorrhagic stroke. (Funded by the National Health and Medical Research Council of Australia and others; INTERACT4 ClinicalTrials.gov number, NCT03790800; Chinese Trial Registry number, ChiCTR1900020534.).

Statistical Analysis Plan for the INTEnsive Ambulance-Delivered Blood Pressure Reduction in Hyper-ACute Stroke Trial

INTRODUCTION

Recruitment is complete in the fourth INTEnsive ambulance-delivered blood pressure Reduction in hyper-ACute stroke Trial (INTERACT4), a multicenter, prospective, randomized, open-label, blinded endpoint assessed trial of prehospital blood pressure (BP) lowering initiated in the ambulance for patients with a suspected acute stroke and elevated BP in China. According to the registered and published trial protocol and developed by the blinded trial Steering Committee and Operations team, this manuscript outlines a detailed statistical analysis plan for the trial prior to database lock.

METHODS

Patients were randomized (1:1) to intensive (target systolic BP 130-140 mm Hg within 30 min) or guideline-recommended BP management (BP lowering only considered if systolic BP >220 mm Hg) group. Primary outcome is an ordinal analysis of the full range of scores on the modified Rankin scale at 90 days. A modified sample size of 2,320 was estimated to provide 90% power to detect a 22% reduction in the odds (common odds ratio of 0.78) of a worse functional outcome using ordinal logistic regression, on the assumption of 5% patients with missing outcome and 6% patients with a stroke mimic.

CONCLUSION

The statistical analysis plan for the trial has been developed to ensure transparent, verifiable, and prespecified analysis and to avoid potential bias in the evaluation of the trial intervention.

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.

Rapid Intravenous Glyceryl Trinitrate in Ischemic Damage (RIGID): A potential neuroprotection strategy for acute ischemic stroke (AIS) patients

Despite advances in intravenous thrombolysis and endovascular thrombectomy, numerous acute ischemic stroke survivors continue to experience various disability levels. The nitric oxide (NO) donor, Glyceryl Trinitrate (GTN), has been identified as a potential neuroprotective agent against ischemic damage. We evaluated the safety and feasibility of intravenous GTN in AIS patients. Subsequently, we conducted a secondary analysis to assess for possible efficacy of GTN as a neuroprotectant. We conducted a prospective, double-blind, randomized controlled trial in the Stroke Intervention & Translational Center (SITC) in Beijing Luhe Hospital, Capital Medical University (ChiCTR2100046271). AIS patients within 24 h of stroke onset were evenly divided into GTN or control groups (n = 20 each). The GTN group received intravenous GTN (5 mg in 50 ml saline at a rate of 0.4 mg/h for 12.5 h/day over 2 days), while controls were administered an equivalent volume of 0.9% saline. Both groups followed standard Stroke Guidelines for treatment. Safety measures focused on SBP<110 mmHg and headache occurrence. Efficacy was assessed via the 90-day modified rankin score (mRS) and the national institutes of health stroke score (NIHSS). Of the 40 AIS patients, baseline characteristics such as age, gender, risk factors, and pre-mRS scores showed no significant difference between the groups. Safety measures of SBP<110 mmHg and headache occurrence were comparable. Overall, 90-day mRS (1 vs. 1) and NIHSS (1 vs. 1) did not significantly differ between groups. However, the GTN-treated group had a benefit in enhancing NIHSS recovery (△NIHSS 4.5 vs. 3, p = 0.028), indicating that GTN may augment recovery. Subgroup analyses revealed a benefit in the GTN group at the 90-day NIHSS score and △NIHSS follow up for non-thrombolysis patients (1 vs. 2, p = 0.016; 5 vs. 2, p = 0.001). Moreover, the GTN group may benefit mild stroke patients in NIHSS score at 90 day and △NIHSS observed at 90 days (1 vs. 1, p = 0.025; 3 vs. 2 p = 0.002). Overall, while preliminary data suggest GTN might aid recovery in NIHSS improvement, the evidence is tempered due to sample size limitations. The RIGID study confirms the safety and feasibility of intravenous GTN administration for AIS patients. Preliminary data also suggest that the GTN group may provide improvement in NIHSS recovery compared to the control group. Furthermore, a potential benefit for non-thrombolysis patients and those with mild stroke symptoms was identified, suggesting a possible potential role as a tailored intervention in specific AIS subgroups. Due to the limited sample size, further larger RCT will be necessary to replicate these results. TRIAL REGISTRATION: www.chictr.org.cn, identifier: ChiCTR2100046271.

Physiological Variability during Prehospital Stroke Care: Which Monitoring and Interventions Are Used?

Prehospital care is a fundamental component of stroke care that predominantly focuses on shortening the time between diagnosis and reaching definitive stroke management. With growing evidence of the physiological parameters affecting long-term patient outcomes, prehospital clinicians need to consider the balance between rapid transfer and increased physiological-parameter monitoring and intervention. This systematic review explores the existing literature on prehospital physiological monitoring and intervention to modify these parameters in stroke patients. The systematic review was registered on PROSPERO (CRD42022308991) and conducted across four databases with citation cascading. Based on the identified inclusion and exclusion criteria, 19 studies were retained for this review. The studies were classified into two themes: physiological-monitoring intervention and pharmacological-therapy intervention. A total of 14 included studies explored prehospital physiological monitoring. Elevated blood pressure was associated with increased hematoma volume in intracerebral hemorrhage and, in some reports, with increased rates of early neurological deterioration and prehospital neurological deterioration. A reduction in prehospital heart rate variability was associated with unfavorable clinical outcomes. Further, five of the included records investigated the delivery of pharmacological therapy in the prehospital environment for patients presenting with acute stroke. BP-lowering interventions were successfully demonstrated through three trials; however, evidence of their benefit to clinical outcomes is limited. Two studies investigating the use of oxygen and magnesium sulfate as neuroprotective agents did not demonstrate an improvement in patient's outcomes. This systematic review highlights the absence of continuous physiological parameter monitoring, investigates fundamental physiological parameters, and provides recommendations for future work, with the aim of improving stroke patient outcomes.

Statistical analyses of ordinal outcomes in randomised controlled trials: a scoping review

BACKGROUND

Randomised controlled trials (RCTs) aim to estimate the causal effect of one or more interventions relative to a control. One type of outcome that can be of interest in an RCT is an ordinal outcome, which is useful to answer clinical questions regarding complex and evolving patient states. The target parameter of interest for an ordinal outcome depends on the research question and the assumptions the analyst is willing to make. This review aimed to provide an overview of how ordinal outcomes have been used and analysed in RCTs.

METHODS

The review included RCTs with an ordinal primary or secondary outcome published between 2017 and 2022 in four highly ranked medical journals (the British Medical Journal, New England Journal of Medicine, The Lancet, and the Journal of the American Medical Association) identified through PubMed. Details regarding the study setting, design, the target parameter, and statistical methods used to analyse the ordinal outcome were extracted.

RESULTS

The search identified 309 studies, of which 144 were eligible for inclusion. The most used target parameter was an odds ratio, reported in 78 (54%) studies. The ordinal outcome was dichotomised for analysis in 47 ( 33 % ) studies, and the most common statistical model used to analyse the ordinal outcome on the full ordinal scale was the proportional odds model (64 [ 44 % ] studies). Notably, 86 (60%) studies did not explicitly check or describe the robustness of the assumptions for the statistical method(s) used.

CONCLUSIONS

The results of this review indicate that in RCTs that use an ordinal outcome, there is variation in the target parameter and the analytical approaches used, with many dichotomising the ordinal outcome. Few studies provided assurance regarding the appropriateness of the assumptions and methods used to analyse the ordinal outcome. More guidance is needed to improve the transparent reporting of the analysis of ordinal outcomes in future trials.

European stroke organisation (ESO) guideline on cerebral small vessel disease, part 2, lacunar ischaemic stroke

A quarter of ischaemic strokes are lacunar subtype, typically neurologically mild, usually resulting from intrinsic cerebral small vessel pathology, with risk factor profiles and outcome rates differing from other stroke subtypes. This European Stroke Organisation (ESO) guideline provides evidence-based recommendations to assist with clinical decisions about management of lacunar ischaemic stroke to prevent adverse clinical outcomes. The guideline was developed according to ESO standard operating procedures and Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. We addressed acute treatment (including progressive lacunar stroke) and secondary prevention in lacunar ischaemic stroke, and prioritised the interventions of thrombolysis, antiplatelet drugs, blood pressure lowering, lipid lowering, lifestyle, and other interventions and their potential effects on the clinical outcomes recurrent stroke, dependency, major adverse cardiovascular events, death, cognitive decline, mobility, gait, or mood disorders. We systematically reviewed the literature, assessed the evidence and where feasible formulated evidence-based recommendations, and expert concensus statements. We found little direct evidence, mostly of low quality. We recommend that patients with suspected acute lacunar ischaemic stroke receive intravenous alteplase, antiplatelet drugs and avoid blood pressure lowering according to current acute ischaemic stroke guidelines. For secondary prevention, we recommend single antiplatelet treatment long-term, blood pressure control, and lipid lowering according to current guidelines. We recommend smoking cessation, regular exercise, other healthy lifestyle modifications, and avoid obesity for general health benefits. We cannot make any recommendation concerning progressive stroke or other drugs. Large randomised controlled trials with clinically important endpoints, including cognitive endpoints, are a priority for lacunar ischaemic stroke.

Prehospital transdermal glyceryl trinitrate for ultra-acute ischaemic stroke: data from the RIGHT-2 randomised sham-controlled ambulance trial

BACKGROUND

The effect of transdermal glyceryl trinitrate (GTN, a nitrovasodilator) on clinical outcome when administered before hospital admission in suspected stroke patients is unclear. Here, we assess the safety and efficacy of GTN in the prespecified subgroup of patients who had an ischaemic stroke within the Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2).

METHODS

RIGHT-2 was an ambulance-based multicentre sham-controlled blinded-endpoint study with patients randomised within 4 hours of onset. The primary outcome was a shift in scores on the modified Rankin scale (mRS) at day 90. Secondary outcomes included death; a global analysis (Wei-Lachin test) containing Barthel Index, EuroQol-5D, mRS, telephone interview for cognitive status-modified and Zung depression scale; and neuroimaging-determined 'brain frailty' markers. Data were reported as n (%), mean (SD), median [IQR], adjusted common OR (acOR), mean difference or Mann-Whitney difference (MWD) with 95% CI.

RESULTS

597 of 1149 (52%) patients had a final diagnosis of ischaemic stroke; age 75 (12) years, premorbid mRS>2 107 (18%), Glasgow Coma Scale 14 (2) and time from onset to randomisation 67 [45, 108] min. Neuroimaging 'brain frailty' was common: median score 2 [2, 3] (range 0-3). At day 90, GTN did not influence the primary outcome (acOR for increased disability 1.15, 95% CI 0.85 to 1.54), death or global analysis (MWD 0.00, 95% CI -0.10 to 0.09). In subgroup analyses, there were non-significant interactions suggesting GTN may be associated with more death and dependency in participants randomised within 1 hour of symptom onset and in those with more severe stroke.

CONCLUSIONS

In patients who had an ischaemic stroke, ultra-acute administration of transdermal GTN in the ambulance did not improve clinical outcomes in a population with more clinical and radiological frailty than seen in previous in-hospital trials.

Evaluating artificial intelligence software for delineating hemorrhage extent on CT brain imaging in stroke: AI delineation of ICH on CT

BACKGROUND

The extent and distribution of intracranial hemorrhage (ICH) directly affects clinical management. Artificial intelligence (AI) software can detect and may delineate ICH extent on brain CT. We evaluated e-ASPECTS software (Brainomix Ltd.) performance for ICH delineation.

METHODS

We qualitatively assessed software delineation of ICH on CT using patients from six stroke trials. We assessed hemorrhage delineation in five compartments: lobar, deep, posterior fossa, intraventricular, extra-axial. We categorized delineation as excellent, good, moderate, or poor. We assessed quality of software delineation with number of affected compartments in univariate analysis (Kruskall-Wallis test) and ICH location using logistic regression (dependent variable: dichotomous delineation categories 'excellent-good' versus 'moderate-poor'), and report odds ratios (OR) and 95 % confidence intervals (95 %CI).

RESULTS

From 651 patients with ICH (median age 75 years, 53 % male), we included 628 with assessable CTs. Software delineation of ICH extent was 'excellent' in 189/628 (30 %), 'good' in 255/628 (41 %), 'moderate' in 127/628 (20 %), and 'poor' in 57/628 cases (9 %). The quality of software delineation of ICH was better when fewer compartments were affected (Z = 3.61-6.27; p = 0.0063). Software delineation of ICH extent was more likely to be 'excellent-good' quality when lobar alone (OR = 1.56, 95 %CI = 0.97-2.53) but 'moderate-poor' with any intraventricular (OR = 0.56, 95 %CI = 0.39-0.81, p = 0.002) or any extra-axial (OR = 0.41, 95 %CI = 0.27-0.62, p<0.001) extension.

CONCLUSIONS

Delineation of ICH extent on stroke CT scans by AI software was excellent or good in 71 % of cases but was more likely to over- or under-estimate extent when ICH was either more extensive, intraventricular, or extra-axial.

Randomized Clinical Trials in Cerebrovascular Neurosurgery From 2018 to 2022

There has been an exponential increase in randomized controlled trials (RCTs) on cerebrovascular disease within neurosurgery. The goal of this study was to review, outline the scope, and summarize all phase 2b and phase 3 RCTs impacting cerebrovascular neurosurgery practice since 2018. We searched PubMed, MEDLINE, Embase, ClinicalTrials.gov, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases for relevant RCTs published between January 1, 2018, and July 1, 2022. We searched for studies related to eight major cerebrovascular disorders relevant to neurosurgery, including acute ischemic stroke, cerebral aneurysms and subarachnoid hemorrhage, intracerebral hemorrhage, subdural hematomas, cerebral venous thrombosis, arteriovenous malformations, Moyamoya disease and extracranial-intracranial bypass, and carotid and intracranial atherosclerosis. We limited our search to phase 2b or 3 RCTs related to cerebrovascular disorders published during the study period. The titles and abstracts of all relevant studies meeting our search criteria were included. Pediatric studies, stroke studies related to rehabilitation or cardiovascular disease, study protocols without published results, prospective cohort studies, registry studies, cluster randomized trials, and nonrandomized pivotal trials were excluded.  From an initial total of 2,797 records retrieved from the database searches, 1,641 records were screened after duplicates and studies outside of our time period were removed. After screening, 511 available reports within our time period of interest were assessed for eligibility. Pediatric studies, stroke studies related to rehabilitation or cardiovascular disease, study protocols without published results, prospective cohort studies, registry studies, cluster randomized trials, and nonrandomized pivotal trials were excluded. We found 80 unique phase 2b or 3 RCTs that fit our criteria, with 165 topic-relevant articles published within the study period.  Numerous RCTs in cerebrovascular neurosurgery have been published since 2018. Ischemic stroke, including mechanical thrombectomy and thrombolysis, accounted for a majority of publications, but there were large trials in intracerebral hemorrhage, subdural hemorrhage, aneurysms, subarachnoid hemorrhage, and cerebral venous thrombosis, among others. This review helps define the scope of the large RCTs published in the last four years to guide future research and clinical care.

Update on the INTEnsive ambulance-delivered blood pressure Reduction in hyper-ACute stroke Trial (INTERACT4): progress and baseline features in 2053 participants

BACKGROUND AND AIMS

Uncertainty persists over the effects of blood pressure (BP) lowering in acute stroke. The INTEnsive ambulance-delivered blood pressure Reduction in hyper-Acute stroke Trial (INTERACT4) aims to determine efficacy and safety of hyperacute intensive BP lowering in patients with suspected acute stroke. Given concerns over the safety of this treatment in the pre-hospital setting, particularly in relation to patients with intracerebral hemorrhage, we provide an update on progress of the study and profile of participants to date.

METHODS

INTERACT4 is an ongoing multicentre, ambulance-delivered, randomized, open-label, blinded endpoint trial of pre-hospital BP lowering in patients with suspected acute stroke and elevated BP in China. Patients are randomized via a mobile phone digital system to intensive (target systolic BP [SBP] <140mmHg within 30 min) or guideline-recommended BP management. Primary outcome is an ordinal analysis of the full range of scores on the modified Rankin scale scores at 90 days.

RESULTS

Between March 2020 and April 2023, 2053 patients (mean age 70 years, female 39%) were recruited with a mean BP 178/98 mmHg in whom 45% have a diagnosis of primary intracerebral hemorrhage upon arrival at hospital. At the time of presentation to hospital, the mean SBP was 160 and 170mmHg in the intensive and control groups (Δ10 mmHg), respectively. The independent data and safety monitoring board has not identified any safety concerns and recommended continuation of the trial. The sample size was reduced from 3116 to 2320 after meetings in August 2022 as the stroke mimic rate was persistently lower than initially estimated (6% vs 30%). The study is expected to be completed in late 2023 and the results announced in May 2024.

CONCLUSIONS

INTERACT4 is on track to provide reliable evidence of the effectiveness of ambulance-delivered intensive BP lowering in patients with suspected acute stroke.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03790800 ; registered on 2 January 2019. Chinese Trial Registry ChCTR1900020534 , registered on 7 January 2019.

Challenges and Experiences in Multicenter Prehospital Stroke Research: Narrative Data from the Rapid Intervention with Glyceryl Trinitrate in Hypertensive Stroke Trial-2 (RIGHT-2)

BACKGROUND

Ambulance services are increasingly research active and the Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2) is the largest United Kingdom (UK) ambulance-based randomized controlled trial in stroke. We explore the complexities and challenges encountered during RIGHT-2.

METHODS

Five hundred and sixteen of 1487 paramedics from eight UK ambulance services serving 54 comprehensive or primary stroke care centers screened and consented 1149 patients presenting within 4 h of FAST-positive stroke and with systolic blood pressure >120 mmHg; participants were randomized to treatment with transdermal glyceryl trinitrate versus sham patch in the ambulance.

KEY FINDINGS

Working with multiple ambulance services demanded flexibility in the trial protocol to overcome variation in operating procedures to ensure deliverability. Many paramedics are novice researchers, and research concepts and practices are emerging including consent strategies in emergency stroke care. Regional variation in hospital participation and hours/days of operation presented paramedics with additional considerations prior to patient recruitment. The working hours of hospital research staff often do not reflect the 24/7 nature of ambulance work, which challenged deliverability until trial processes became fully embedded. Management of investigational medicinal product between ambulance stations, in-transit when on ambulance vehicles and on handover at hospital, necessitated an in-depth review to maintain accountability.

CONCLUSION

RIGHT-2 demonstrated that although there are significant practical challenges to conducting multicenter ambulance-based research in a time-dependent environment, careful planning and management facilitated delivery. Lessons learned here will help inform the design and conduct of future ambulance-based trials.

Promising Cerebral Blood Flow Enhancers in Acute Ischemic Stroke

Ischemic stroke presents a major global economic and public health burden. Although recent advances in available endovascular therapies show improved functional outcome, a good number of stroke patients are either ineligible or do not have access to these treatments. Also, robust collateral flow during acute ischemic stroke independently predicts the success of endovascular therapies and the outcome of stroke. Hence, adjunctive therapies for cerebral blood flow (CBF) enhancement are urgently needed. A very clear overview of the pial collaterals and the role of genetics are presented in this review. We review available evidence and advancement for potential therapies aimed at improving CBF during acute ischemic stroke. We identified heme-free soluble guanylate cyclase activators; Sanguinate, remote ischemic perconditioning; Fasudil, S1P agonists; and stimulation of the sphenopalatine ganglion as promising potential CBF-enhancing therapeutics requiring further investigation. Additionally, we outline and discuss the critical steps required to advance research strategies for clinically translatable CBF-enhancing agents in the context of acute ischemic stroke models.

A systematic review of ambulance service-based randomised controlled trials in stroke

BACKGROUND

Treatment for stroke is time-dependent, and ambulance services play a vital role in the early recognition, assessment and transportation of stroke patients. Innovations which begin in ambulance services to expedite delivery of treatments for stroke are developing. However, research delivery in ambulance services is novel, developing and not fully understood.

AIMS

To synthesise literature encompassing ambulance service-based randomised controlled interventions for acute stroke with consideration to the characteristics of the type of intervention, consent modality, time intervals and issues unique to research delivery in ambulance services. Online searches of MEDLINE, EMBASE, Web of Science, CENTRAL and WHO IRCTP databases and hand searches identified 15 eligible studies from 538. Articles were heterogeneous in nature and meta-analysis was partially available as 13 studies reported key time intervals, but terminology varied. Randomised interventions were evident across all points of contact with ambulance services: identification of stroke during the call for help, higher dispatch priority assigned to stroke, on-scene assessment and clinical interventions, direct referral to comprehensive stroke centres and definitive care delivery at scene. Consent methods ranged between informed patient, waiver and proxy modalities with country-specific variation. Challenges unique to the prehospital setting comprise the geographical distribution of ambulance resources, low recruitment rates, prolonged recruitment phases, management of investigational medicinal product and incomplete datasets.

CONCLUSION

Research opportunities exist across all points of contact between stroke patients and ambulance services, but randomisation and consent remain novel. Early collaboration and engagement between trialists and ambulance services will alleviate some of the complexities reported.

REGISTRATION NUMBER

PROSPERO 2018CRD42018075803.

Results of an international survey on the status of prehospital care

BACKGROUND

Prehospital care including recognition of stroke symptoms by the public and professionals combined with an efficient and effective emergency medical service (EMS) is essential to increase access to effective acute stroke care. We undertook a survey to document the status of stroke prehospital care globally.

METHODS

A survey was distributed via email to the World Stroke Organization (WSO) members. Information was sought on the current status of stroke prehospital delay globally, including (1) ambulance availability and whether payment for use is required, (2) ambulance response times and the proportion of patients arriving at hospital by ambulance, (3) the proportion of patients arriving within 3 h and more than 24 h after symptom, (4) whether stroke care training of paramedics, call handlers, and primary care staff, (5) availability of specialist centers, and (6) the proportion of patients taken to specialist centers. Respondents were also asked to identify the top three changes in prehospital care that would benefit their population. Data were analyzed descriptively at both country and continent level.

RESULTS

Responses were received from 116 individuals in 43 countries, with a response rate of 4.7%. Most respondents (90%) reported access to ambulances, but 40% of respondents reported payment was required by the patient. Where an ambulance service was available (105 respondents) 37% of respondents reported that less than 50% of patients used an ambulance and 12% less than 20% of patients used an ambulance. Large variations in ambulance response times were reported both within and between countries. Most of the participating high-income countries (HIC) offered a service used by patients, but this was rarely the case for the low- and middle-income countries (LMIC). Time to admission was often much longer in LMIC, and there was less access to stroke training for EMS and primary care staff.

CONCLUSIONS

Significant deficiencies in stroke prehospital care exist globally especially in LMIC. In all countries, there are opportunities to improve the quality of the service in ways that would likely result in improved outcomes after acute stroke.

Optimizing Patient-Centered Stroke Care and Research in the Prehospital Setting

Over the past decades, continuous technological advances and the availability of novel therapies have enabled treatment of more acute medical conditions than ever before. Many of these treatments, such as intravenous thrombolysis and mechanical thrombectomy for acute ischemic stroke, are highly time sensitive. This has raised interest in shifting advanced acute care from hospitals to the prehospital setting. Key objectives of advanced prehospital stroke care may include (1) early targeted treatments in the prehospital setting, for example, intravenous thrombolysis for acute stroke, and (2) advanced prehospital diagnostics such as prehospital large vessel occlusion and intracranial hemorrhage detection, to help inform patient triage and potentially reduce subsequent workload in emergency departments. Major challenges that may hamper a swift transition to more advanced prehospital care are related to conducting clinical trials in the prehospital setting to provide sufficient evidence for emergency interventions, as well as ambulance design, infrastructure, emergency medical service personnel training and workload, and cost barriers. Utilizing new technologies such as telemedicine, mobile stroke units and portable diagnostic devices, customized software applications, and smart storage space management may help surmount these challenges and establish efficient, targeted care strategies that are achievable in the prehospital setting. In this article, we delineate the paradigm of shifting advanced stroke care to the prehospital setting and outline future directions in providing evidence-based, patient-centered prehospital care. While we use acute stroke as an illustrative example, these principles are not limited to stroke patients and can be applied to prehospital triage for any time-critical disease.

Blood pressure medication and acute kidney injury after intracerebral haemorrhage: an analysis of the ATACH-II trial

Background

Acute blood pressure (BP) reduction is standard of care after acute intracerebral haemorrhage (ICH). More acute BP reduction is associated with acute kidney injury (AKI). It is not known if the choice of antihypertensive medications affects the risk of AKI.

Methods

We analysed data from the ATACH-II clinical trial. AKI was defined by the Kidney Disease: Improving Global Outcomes criteria. We analysed antihypertensive medication from two sources. The first was a case report form that specified the use of labetalol, diltiazem, urapidil or other. We tested the hypothesis that the secondary medication was associated with AKI with χ2 test. Second, we tested the hypotheses the dosage of diltiazem was associated with AKI using Mann-Whitney U test.

Results

AKI occurred in 109 of 1000 patients (10.9%). A higher proportion of patients with AKI received diltiazem after nicardipine (12 (29%) vs 21 (12%), p=0.03). The 95%ile (90%-99% ile) of administered diltiazem was 18 (0-130) mg in patients with AKI vs 0 (0-30) mg in patients without AKI (p=0.002). There was no apparent confounding by indication for diltiazem use.

Conclusions

The use of diltiazem, and more diltiazem, was associated with AKI in patients with acute ICH.

Accuracy of artificial intelligence software for CT angiography in stroke

OBJECTIVE

Software developed using artificial intelligence may automatically identify arterial occlusion and provide collateral vessel scoring on CT angiography (CTA) performed acutely for ischemic stroke. We aimed to assess the diagnostic accuracy of e-CTA by Brainomix™ Ltd by large-scale independent testing using expert reading as the reference standard.

METHODS

We identified a large clinically representative sample of baseline CTA from 6 studies that recruited patients with acute stroke symptoms involving any arterial territory. We compared e-CTA results with masked expert interpretation of the same scans for the presence and location of laterality-matched arterial occlusion and/or abnormal collateral score combined into a single measure of arterial abnormality. We tested the diagnostic accuracy of e-CTA for identifying any arterial abnormality (and in a sensitivity analysis compliant with the manufacturer's guidance that software only be used to assess the anterior circulation).

RESULTS

We include CTA from 668 patients (50% female; median: age 71 years, NIHSS 9, 2.3 h from stroke onset). Experts identified arterial occlusion in 365 patients (55%); most (343, 94%) involved the anterior circulation. Software successfully processed 545/668 (82%) CTAs. The sensitivity, specificity and diagnostic accuracy of e-CTA for detecting arterial abnormality were each 72% (95% CI = 66-77%). Diagnostic accuracy was non-significantly improved in a sensitivity analysis excluding occlusions from outside the anterior circulation (76%, 95% CI = 72-80%).

INTERPRETATION

Compared to experts, the diagnostic accuracy of e-CTA for identifying acute arterial abnormality was 72-76%. Users of e-CTA should be competent in CTA interpretation to ensure all potential thrombectomy candidates are identified.

Prehospital transdermal glyceryl trinitrate in patients with ultra-acute presumed stroke (RIGHT-2): effects on outcomes at day 365 in a randomised, sham-controlled, blinded, phase III, superiority ambulance-based trial

Background

The Rapid Intervention with Glyceryl Trinitrate in Hypertensive Stroke Trial-2 (RIGHT-2) reported no overall treatment difference between glyceryl trinitrate (GTN) and sham at day 90. Here we assess participants' outcomes 1 year after randomisation.

Methods

RIGHT-2 was an ambulance-based prospective randomised controlled trial where patients with presumed stroke and systolic blood pressure (BP) of >120 mm Hg received either GTN (5 mg/day) or sham patch. Centralised blinded telephone follow-up was performed at days 90 (primary endpoint) and 365 (secondary endpoint). The lead outcome was dependency assessed with the modified Rankin Scale (mRS).

Results

1149 patients were recruited to RIGHT-2 between October 2015 and May 2018, and 1097 (95.5%) had outcome data recorded at day 365. At baseline, the patients were; female (48%), had a mean age of 73 (15) years, BP of 162 (25)/92 (18) mm Hg, onset to randomisation of 70 (45-115) min, diagnosis of ischaemic stroke (52%), intracerebral haemorrhage (ICH) (13%), transient ischaemic attack (TIA) (9%) and mimics (26%). There was no effect of GTN on mRS score at day 365 in participants with confirmed stroke/TIA (adjusted common odds ratio (acOR) 1.10, 95% CI 0.86 to 1.42) or in all patients. In patients randomised to GTN, mRS at day 365 tended to be worse in those with ICH (acOR 1.65, 95% CI 0.84 to 3.25) and better in those with a mimic diagnosis (acOR 0.53, 95% CI 0.33 to 0.84).

Conclusion

At 1 year post randomisation, dependency did not differ between GTN and sham treatment in either the target population or overall. In prespecified subgroup analyses, GTN was associated with reduced dependency in participants with a final diagnosis of mimic and a non-significant worse outcome in participants with ICH.

Trial registration number

ISRCTN26986053.

What factors contribute towards ambulance on-scene times for suspected stroke patients? An observational study

INTRODUCTION

Pre-hospital stroke care focusses on rapid access to specialist stroke units, but UK ambulance data shows increasing pre-hospital times. This study aimed to describe factors contributing towards ambulance on-scene times (OST) for suspected stroke patients and identify targets for a future intervention.

PATIENTS AND METHODS

Ambulance clinicians in North East Ambulance Service were asked to complete a survey after transporting any suspected stroke patients to describe the patient encounter, interventions and timings. Completed surveys were linked with electronic patient care records. Potentially modifiable factors were identified by the study team. Poisson regression analysis quantified the association of selected potentially modifiable factors with OST.

RESULTS

About 2037 suspected stroke patients were conveyed between July and December 2021, resulting in 581 fully completed surveys by 359 different clinicians. The median age of patients was 75 years (interquartile range (IQR) 66-83) and 52% of patients were male. Median OST was 33 min (IQR 26-41). Three potentially modifiable factors were identified as contributors to extended OST. Performing additional advanced neurological assessments added 10% to OST (34 vs 31 min, p = 0.008); intravenous cannulation added 13% (35 vs 31 min, p = <0.001) and ECGs added 22% (35 vs 28 min, p = <0.001).

CONCLUSIONS

This study identified three potentially modifiable factors that increased pre-hospital OST with suspected stroke patients. This type of data can be used to target interventions at behaviours that extend pre-hospital OST but which have questionable patient benefit. This approach will be evaluated in a follow up study in the North East of England.

Prehospital Stroke Care Part 2: On-Scene Evaluation and Management by Emergency Medical Services Practitioners

The prehospital phase is a critical component of delivering high-quality acute stroke care. This topical review discusses the current state of prehospital acute stroke screening and transport, as well as new and emerging advances in prehospital diagnosis and treatment of acute stroke. Topics include prehospital stroke screening, stroke severity screening, emerging technologies to aid in the identification and diagnosis of acute stroke in the prehospital setting, prenotification of receiving emergency departments, decision support for destination determination, and the capabilities and opportunities for prehospital stroke treatment in mobile stroke units. Further evidence-based guideline development and implementation of new technologies are critical for ongoing improvements in prehospital stroke care.

Super resolution imaging reconstruction reveals that gold standard methods may not correctly conclude neural/brain functional recovery

The status of cerebral perfusion and its restoration level play a vital role in the prognosis and clinical decision making of many neurosurgical diseases. As such, gold standard methods including CT, MR and ICP monitoring, which can indicate and measure cerebral perfusion and restoration, have been widely adopted to evaluate whether or not a patient has recovered from neurofunctional disabilities. This robust combination of methods, however, is confronted with a growing number of contradictions in recent years due to its inability to measure the status of cerebral reperfusion in microvasculature level, even though this has been shown to determine neurofunctional restoration as well or even better. To this date, nevertheless, we have very limited imaging methods that could evaluate human cerebral microperfusion both safely and accurately under most neurosurgical conditions. We herein report a new method of acquiring a patient's cerebral microperfusion status noninvasively which could display the precise distribution of microvasculature in deep cerebral regions with a resolution of ∼30 µm, using everyday bed-side ultrasonography combined with a computerized super-resolution reconstruction algorithm. Using this imaging modality, we found that a patient's cerebral microperfusion might not be improved by some routine administrations even though the gold standard method had yielded the opposite conclusions. Our imaging modality retains the safe, portable feature of ordinary ultrasonography while possesses the extraordinary super-resolution nature, which enables an efficient, precise diagnosis of cerebral perfusion. Most importantly, the super resolution nature of this method may also facilitate early-stage evaluation of a patient's neurofunctional restoration level and avoid overoptimistic conclusions from conventional angiography or ICP monitoring.

Neurologic Improvement in Acute Cerebral Ischemia: Frequency, Magnitude, Predictors, and Clinical Outcomes

BACKGROUND AND OBJECTIVES

Investigations of rapid neurologic improvement (RNI) in patients with acute cerebral ischemia (ACI) have focused on RNI occurring after hospital arrival. However, with stroke routing decisions and interventions increasingly migrating to the prehospital setting, there is a need to delineate the frequency, magnitude, predictors, and clinical outcomes of patients with ACI with ultra-early RNI (U-RNI) in the prehospital and early postarrival period.

METHODS

We analyzed prospectively collected data of the prehospital Field Administration of Stroke Therapy-Magnesium (FAST-MAG) randomized clinical trial. Any U-RNI was defined as improvement by 2 or more points on the Los Angeles Motor Scale (LAMS) score between the prehospital and early post-emergency department (ED) arrival examinations and classified as moderate (2-3 point) or dramatic (4-5 point) improvement. Outcome measures included excellent recovery (modified Rankin Scale [mRS] score 0-1) and death by 90 days.

RESULTS

Among the 1,245 patients with ACI, the mean age was 70.9 years (SD 13.2); 45% were women; the median prehospital LAMS was 4 (interquartile range [IQR] 3-5); the median last known well to ED-LAMS time was 59 minutes (IQR 46-80 minutes), and the median prehospital LAMS to ED-LAMS time was 33 minutes (IQR 28-39 minutes). Overall, any U-RNI occurred in 31%, moderate U-RNI in 23%, and dramatic U-RNI in 8%. Any U-RNI was associated with improved outcomes, including excellent recovery (mRS score 0-1) at 90 days 65.1% (246/378) vs 35.4% (302/852), p < 0.0001; decreased mortality by 90 days 3.7% (14/378) vs 16.4% (140/852), p < 0.0001; decreased symptomatic intracranial hemorrhage 1.6% (6/384) vs 4.6% (40/861), p = 0.0112; and increased likelihood of being discharged home 56.8% (218/384) vs 30.2% (260/861), p < 0.0001.

DISCUSSION

U-RNI occurs in nearly 1 in 3 ambulance-transported patients with ACI and is associated with excellent recovery and decreased mortality at 90 days. Accounting for U-RNI may be useful for routing decisions and future prehospital interventions. TRIAL REGISTRATION INFORMATION: clinicaltrials.gov. Unique identifier: NCT00059332.

Significance of pulse pressure variability in predicting functional outcome in acute ischemic stroke: a retrospective, single-center, observational cohort study

This study aimed to determine the association between pulse pressure variability (PPV) and short- and long-term outcomes of acute ischemic stroke (AIS) patients. We studied 203 tertiary stroke center patients with AIS. PPV during 72 h after admission was analyzed using different variability parameters including standard deviation (SD). Patients' outcome was assessed after 30 and 90 days post-stroke with modified Rankin Scale. The association between PPV and outcome was investigated using logistic regression analysis with adjustment for potential confounders. The predictive significance of PPV parameters was determined using area under the curve (AUC) of receiver operating characteristics. In the unadjusted logistic regression analysis, all PPV indicators were independently associated with unfavorable outcome at 30 days (i.a. Odds ratio (OR) = 4.817, 95%CI 2.283-10.162 per 10 mmHg increase in SD, p = 0.000) and 90 days (i.a. OR = 4.248, 95%CI 2.044-8.831 per 10 mmHg increase in SD, p = 0.000). After adjustment for confounders, ORs for all PPV indicators remained statistically significant. On the basis of AUC values, all PPV parameters were found relevant outcome predictors (p < 0.01). In conclusion, elevated PPV during first 72 h after admission due to AIS is associated with unfavorable outcome at 30 and 90 days, independent of mean blood pressure levels.

Key design elements of successful acute ischemic stroke treatment trials

PURPOSE

We review key design elements of positive randomized controlled trials (RCTs) in acute ischemic stroke (AIS) treatment and summarize their main characteristics.

METHOD

We searched Medline, Pubmed and Cochrane databases for positive RCTs in AIS treatment. Trials were included if (1) they had a randomized controlled design, with (at least partial) blinding for endpoints, (2) they tested against placebo (or on top of standard therapy in a superiority design) or against approved therapy; (3) the protocol was registered and/or published before trial termination and unblinding (if required at study commencement); (4) the primary endpoint was positive in the intention to treat analysis; and (5) the study findings led to approval of the investigational product and/or high ranked recommendations. A topical approach was used, therefore the findings were summarized as a narrative review.

FINDINGS

Seventeen positive RCTs met the inclusion criteria. The majority of trials included less than 1000 patients (n = 15), had highly selective inclusion criteria (n = 16), used the modified Rankin score as a primary endpoint (n = 15) and had a frequentist design (n = 16). Trials tended to be national (n = 12), investigator-initiated and performed with public funding (n = 11).

DISCUSSION

Smaller but selective trials are useful to identify efficacy in a particular subgroup of stroke patients. It may also be of advantage to limit the number of participating countries and centers to avoid heterogeneity in stroke management and bureaucratic burden.

CONCLUSION

The key characteristics of positive RCTs in AIS treatment described here may assist in the design of further trials investigating a single intervention with a potentially high effect size.

External Validation of e-ASPECTS Software for Interpreting Brain CT in Stroke

OBJECTIVE

The purpose of this study was to test e-ASPECTS software in patients with stroke. Marketed as a decision-support tool, e-ASPECTS may detect features of ischemia or hemorrhage on computed tomography (CT) imaging and quantify ischemic extent using Alberta Stroke Program Early CT Score (ASPECTS).

METHODS

Using CT from 9 stroke studies, we compared software with masked experts. As per indications for software use, we assessed e-ASPECTS results for patients with/without middle cerebral artery (MCA) ischemia but no other cause of stroke. In an analysis outside the intended use of the software, we enriched our dataset with non-MCA ischemia, hemorrhage, and mimics to simulate a representative "front door" hospital population. With final diagnosis as the reference standard, we tested the diagnostic accuracy of e-ASPECTS for identifying stroke features (ischemia, hyperattenuated arteries, and hemorrhage) in the representative population.

RESULTS

We included 4,100 patients (51% women, median age = 78 years, National Institutes of Health Stroke Scale [NIHSS] = 10, onset to scan = 2.5 hours). Final diagnosis was ischemia (78%), hemorrhage (14%), or mimic (8%). From 3,035 CTs with expert-rated ASPECTS, most (2084/3035, 69%) e-ASPECTS results were within one point of experts. In the representative population, the diagnostic accuracy of e-ASPECTS was 71% (95% confidence interval [CI] = 70-72%) for detecting ischemic features, 85% (83-86%) for hemorrhage. Software identified more false positive ischemia (12% vs 2%) and hemorrhage (14% vs <1%) than experts.

INTERPRETATION

On independent testing, e-ASPECTS provided moderate agreement with experts and overcalled stroke features. Therefore, future prospective trials testing impacts of artificial intelligence (AI) software on patient care and outcome are required before widespread implementation of stroke decision-support software. ANN NEUROL 2022;92:943-957.

Time intervals and distances travelled for prehospital ambulance stroke care: data from the randomised-controlled ambulance-based Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2)

OBJECTIVES

Ambulances offer the first opportunity to evaluate hyperacute stroke treatments. In this study, we investigated the conduct of a hyperacute stroke study in the ambulance-based setting with a particular focus on timings and logistics of trial delivery.

DESIGN

Multicentre prospective, single-blind, parallel group randomised controlled trial.

SETTING

Eight National Health Service ambulance services in England and Wales; 54 acute stroke centres.

PARTICIPANTS

Paramedics enrolled 1149 patients assessed as likely to have a stroke, with Face, Arm, Speech and Time score (2 or 3), within 4 hours of symptom onset and systolic blood pressure >120 mm Hg.

INTERVENTIONS

Paramedics administered randomly assigned active transdermal glyceryl trinitrate or sham.

PRIMARY AND SECONDARY OUTCOMES

Modified Rankin scale at day 90. This paper focuses on response time intervals, distances travelled and baseline characteristics of patients, compared between ambulance services.

RESULTS

Paramedics enrolled 1149 patients between September 2015 and May 2018.

FINAL DIAGNOSIS

intracerebral haemorrhage 13%, ischaemic stroke 52%, transient ischaemic attack 9% and mimic 26%. Timings (min) were (median (25-75 centile)): onset to emergency call 19 (5-64); onset to randomisation 71 (45-116); total time at scene 33 (26-46); depart scene to hospital 15 (10-23); randomisation to hospital 24 (16-34) and onset to hospital 97 (71-141). Ambulances travelled (km) 10 (4-19) from scene to hospital. Timings and distances differed between ambulance service, for example, onset to randomisation (fastest 53 min, slowest 77 min; p<0.001), distance from scene to hospital (least 4 km, most 20 km; p<0.001).

CONCLUSION

We completed a large prehospital stroke trial involving a simple-to-administer intervention across multiple ambulance services. The time from onset to randomisation and modest distances travelled support the applicability of future large-scale paramedic-delivered ambulance-based stroke trials in urban and rural locations.

TRIAL REGISTRATION NUMBER

ISRCTN26986053.

The Role of Oxidative Stress in Acute Ischemic Stroke-Related Thrombosis

Acute ischemic stroke is a serious life-threatening disease that affects almost 600 million people each year throughout the world with a mortality of more than 10%, while two-thirds of survivors remain disabled. However, the available treatments for ischemic stroke are still limited to thrombolysis and/or mechanical thrombectomy, and there is an urgent need for developing new therapeutic target. Recently, intravascular oxidative stress, derived from endothelial cells, platelets, and leukocytes, has been found to be tightly associated with stroke-related thrombosis. It not only promotes primary thrombus formation by damaging endothelial cells and platelets but also affects thrombus maturation and stability by modifying fibrin components. Thus, oxidative stress is expected to be a novel target for the prevention and treatment of ischemic stroke. In this review, we first discuss the mechanisms by which oxidative stress promotes stroke-related thrombosis, then summarize the oxidative stress biomarkers of stroke-related thrombosis, and finally put forward an antithrombotic therapy targeting oxidative stress in ischemic stroke.

Prehospital transdermal glyceryl trinitrate in patients with presumed acute stroke (MR ASAP): an ambulance-based, multicentre, randomised, open-label, blinded endpoint, phase 3 trial

BACKGROUND

Pooled analyses of previous randomised studies have suggested that very early treatment with glyceryl trinitrate (also known as nitroglycerin) improves functional outcome in patients with acute ischaemic stroke or intracerebral haemorrhage, but this finding was not confirmed in a more recent trial (RIGHT-2). We aimed to assess whether patients with presumed acute stroke benefit from glyceryl tr initrate started within 3 h after symptom onset.

METHODS

MR ASAP was a phase 3, randomised, open-label, blinded endpoint trial done at six ambulance services serving 18 hospitals in the Netherlands. Eligible participants (aged ≥18 years) had a probable diagnosis of acute stroke (as assessed by a paramedic), a face-arm-speech-time test score of 2 or 3, systolic blood pressure of at least 140 mm Hg, and could start treatment within 3 h of symptom onset. Participants were randomly assigned (1:1) by ambulance personnel, using a secure web-based electronic application with random block sizes stratified by ambulance service, to receive either transdermal glyceryl trinitrate 5 mg/day for 24 h plus standard care (glyceryl trinitrate group) or to standard care alone (control group) in the prehospital setting. Informed consent was deferred until after arrival at the hospital. The primary outcome was functional outcome assessed with the modified Rankin Scale (mRS) at 90 days. Safety outcomes included death within 7 days, death within 90 days, and serious adverse events. Analyses were based on modified intention to treat, and treatment effects were expressed as odds ratios (ORs) or common ORs, with adjustment for baseline prognostic factors. We separately analysed the total population and the target population (ie, patients with intracerebral haemorrhage, ischaemic stroke, or transient ischaemic attack). The target sample size was 1400 patients. The trial is registered as ISRCTN99503308.

FINDINGS

On June 24, 2021, the MR ASAP trial was prematurely terminated on the advice of the data and safety monitoring board, with recruitment stopped because of safety concerns in patients with intracerebral haemorrhage. Between April 4, 2018, and Feb 12, 2021, 380 patients were randomly allocated to a study group. 325 provided informed consent or died before consent could be obtained, of whom 170 were assigned to the glyceryl trinitrate group and 155 to the control group. These patients were included in the total population. 201 patients (62%) had ischaemic stroke, 34 (10%) transient ischaemic attack, 56 (17%) intracerebral haemorrhage, and 34 (10%) a stroke-mimicking condition. In the total population (n=325), the median mRS score at 90 days was 2 (IQR 1-4) in both the glyceryl trinitrate and control groups (adjusted common OR 0·97 [95% CI 0·65-1·47]). In the target population (n=291), the 90-day mRS score was 2 (2-4) in the glyceryl trinitrate group and 3 (1-4) in the control group (0·92 [0·59-1·43]). In the total population, there were no differences between the two study groups with respect to death within 90 days (adjusted OR 1·07 [0·53-2·14]) or serious adverse events (unadjusted OR 1·23 [0·76-1·99]). In patients with intracerebral haemorrhage, 12 (34%) of 35 patients allocated to glyceryl trinitrate versus two (10%) of 21 allocated to the control group died within 7 days (adjusted OR 5·91 [0·78-44·81]); death within 90 days occurred in 16 (46%) of 35 in the glyceryl trinitrate group and 11 (55%) of 20 in the control group (adjusted OR 0·87 [0·18-4·17]).

INTERPRETATION

We found no sign of benefit of transdermal glyceryl trinitrate started within 3 h of symptom onset in the prehospital setting in patients with presumed acute stroke. The signal of potential early harm of glyceryl trinitrate in patients with intracerebral haemorrhage suggests that glyceryl trinitrate should be avoided in this setting.

FUNDING

The Collaboration for New Treatments of Acute Stroke consortium, the Brain Foundation Netherlands, the Ministry of Economic Affairs, Stryker, Medtronic, Cerenovus, and the Dutch Heart Foundation.

Measures of intracranial compartments in acute intracerebral haemorrhage: data from the Rapid Intervention with Glyceryl Trinitrate in Hypertensive Stroke-2 Trial (RIGHT-2)

BACKGROUND AND PURPOSE

Intracerebral haemorrhage volume (ICHV) is prognostically important but does not account for intracranial volume (ICV) and cerebral parenchymal volume (CPV). We assessed measures of intracranial compartments in acute ICH using computerised tomography scans and whether ICHV/ICV and ICHV/CPV predict functional outcomes. We also assessed if cistern effacement, midline shift, old infarcts, leukoaraiosis and brain atrophy were associated with outcomes.

METHODS

Data from 133 participants from the Rapid Intervention with Glyceryl Trinitrate in Hypertensive Stroke-2 Trial trial were analysed. Measures included ICHV (using ABC/2) and ICV (XYZ/2) (by independent observers); ICHV, ICV and CPV (semiautomated segmentation, SAS); atrophy (intercaudate distance, ICD, Sylvian fissure ratio, SFR); midline shift; leukoaraiosis and cistern effacement (visual assessment). The effects of these measures on death at day 4 and poor functional outcome at day 90 (modified Rankin scale, mRS of >3) was assessed.

RESULTS

ICV was significantly different between XYZ and SAS: mean (SD) of 1357 (219) vs 1420 (196), mean difference (MD) 62 mL (p<0.001). There was no significant difference in ICHV between ABC/2 and SAS. There was very good agreement for ICV measured by SAS, CPV, ICD, SFR, leukoaraiosis and cistern score (all interclass correlations, n=10: interobserver 0.72-0.99, intraobserver 0.73-1.00). ICHV/ICV and ICHV/CPV were significantly associated with mRS at day 90, death at day 4 and acute neurological deterioration (all p<0.05), similar to ICHV. Midline shift and cistern effacement at baseline were associated with poor functional outcome but old infarcts, leukoaraiosis and brain atrophy were not.

CONCLUSIONS

Intracranial compartment measures and visual estimates are reproducible. ICHV adjusted for ICH and CPV could be useful to prognosticate in acute stroke. The presence of midline shift and cistern effacement may predict outcome but the mechanisms need validation in larger studies.

Brain Bioenergetics in Chronic Hypertension: Risk Factor for Acute Ischemic Stroke

Chronic hypertension is one of the key modifiable risk factors for acute ischemic stroke, also contributing to determine greater neurological deficits and worse functional outcome when an acute cerebrovascular event would occur. A tight relationship exists between cerebrovascular autoregulation, neuronal activity and brain bioenergetics. In chronic hypertension, progressive adaptations of these processes occur as an attempt to cope with the demanding necessity of brain functions, creating a new steady-state homeostatic condition. However, these adaptive modifications are insufficient to grant an adequate response to possible pathological perturbations of the established fragile hemodynamic and metabolic homeostasis. In this narrative review, we will discuss the main mechanisms by which alterations in brain bioenergetics and mitochondrial function in chronic hypertension could lead to increased risk of acute ischemic stroke, stressing the interconnections between hemodynamic factors (i.e. cerebral autoregulation and neurovascular coupling) and metabolic processes. Both experimental and clinical pieces of evidence will be discussed. Moreover, the potential role of mitochondrial dysfunction in determining, or at least sustaining, the pathogenesis and progression of chronic neurogenic hypertension will be considered. In the perspective of novel therapeutic strategies aiming at improving brain bioenergetics, we propose some determinant factors to consider in future studies focused on the cause-effect relationships between chronic hypertension and brain bioenergetic abnormalities (and vice versa), so to help translational research in this so-far unfilled gap.

Endothelial NO synthase 786T/T polymorphism increases hemorrhagic transformation after endovascular thrombectomy

BACKGROUND AND PURPOSE

This study examined whether the 786 NOS3 polymorphism is associated with the risk of hemorrhagic transformation (HT) in stroke patients with anterior large vessel occlusion (ALVO) treated using endovascular thrombectomy (EVT).

METHODS

We performed an observational cohort study that included 118 patients with ALVO who underwent EVT. HT was assessed in follow-up CT and MRI. HT and non-HT patients were compared in terms of the 786 NOS3 polymorphism, flow mediated dilation (FMD) values within 3 days after the stroke, and collateral status based on three grading scales. Demographics, vascular risk factors, additional radiological data including ASPECT score, thrombus length and infarct size, and EVT procedure and outcome variables were also included.

RESULTS

Radiological HT occurred in 55 (46.6%) patients and the 786T/T NOS3 polymorphism was associated with HT (unadjusted OR of 2.33, 95%CI: 1.05-5.20, adjusted OR of 3.14, 95%CI: 1.16-8.54). Collateral status and systemic endothelial function assessed by FMD were not mediators of this relationship as no differences were seen in the median FMD percentage values or collateral status between NOS3 genotypes.

CONCLUSIONS

Our results suggest that genetic variations affecting the NO pathway, such as the 786 NOS3 polymorphism, may contribute to individual variability in the occurrence of HT and these results support involvement of this pathway in the pathogenesis of ischemia-reperfusion injury after EVT.

Nitroglycerin Use in the Emergency Department: Current Perspectives

Nitroglycerin, a fast-acting vasodilator, is commonly used as a first-line agent for angina in the emergency department and to manage chest pain due to acute coronary syndromes. It is also a treatment option for other disease states such as acute heart failure, pulmonary edema, and aortic dissection. Nitroglycerin is converted to nitric oxide, a potent vasodilator, in the body, leading to venodilation at lower dosages and arteriodilation at higher dosages that results in both preload and afterload reduction, respectively. Although nitroglycerin has historically been administered as a sublingual tablet and/or spray, it is often given intravenously in the emergency department as this enables titration to effect with predictable pharmacokinetics. In this review article, we outline the indications, mechanism of action, contraindications, and adverse effects of nitroglycerin as well as review relevant literature and make general recommendations regarding the use of nitroglycerin in the emergency department.

Effect of Hypertension on Efficacy and Safety of Ticagrelor-Aspirin Versus Clopidogrel-Aspirin in Minor Stroke or Transient Ischemic Attack

BACKGROUND

Hypertension is a risk factor of poor stroke outcomes and associated with antiplatelet resistance. This study aimed to explore the efficacy and safety of ticagrelor-aspirin versus clopidogrel-aspirin in patients with different hypertension status, using randomized trial data from the CHANCE-2 trial (Clopidogrel in High-Risk Patients With Acute Nondisabling Cerebrovascular Events-II).

METHODS

A total of 6412 patients with minor stroke or transient ischemic attack who carried CYP2C19 loss-of-function alleles were enrolled and randomized to either ticagrelor-aspirin or clopidogrel-aspirin group. Hypertension status were classified into no, newly diagnosed, and previously diagnosed hypertension according to medical history, blood pressure, and antihypertensive medications during hospitalization. The primary efficacy and safety outcomes were stroke recurrence and moderate to severe bleeding risk within 90-day follow-up.

RESULTS

Ticagrelor-aspirin was associated with reduced risk of new stroke in patients without hypertension (32 [4.8%] versus 60 [7.2%]; hazard ratio, 0.55 [95% CI, 0.35-0.86]), but not in those with a newly diagnosed hypertension (20 [5.3%] versus 36 [9.1%]; hazard ratio 0.59 [95% CI, 0.33-1.07]), or those with a previously diagnosed hypertension (139 [7.0%] versus 147 [7.4%]; hazard ratio, 0.93 [95% CI, 0.74-1.18]) compared with clopidogrel-aspirin (P=0.04 for interaction). The risk of bleeding for ticagrelor-aspirin was not associated with hypertension status (0.1% versus 0.4%; 0.3% versus 0.5%, 0.4% versus 0.3%, P=0.50 for interaction). All the efficacy and safety outcomes between treatments did not differ by blood pressure levels on admission.

CONCLUSIONS

In the CHANCE-2 trial, patients without hypertension received a significantly greater benefit from ticagrelor- aspirin than those with previous hypertension after minor stroke or transient ischemic attack, and a similar benefit trend was observed in those with newly diagnosed hypertension.

REGISTRATION

URL: http://www.

CLINICALTRIALS

gov; Unique identifier: NCT04078737.

2022 Guidelines of the Taiwan Society of Cardiology and the Taiwan Hypertension Society for the Management of Hypertension

Hypertension is the most important modifiable cause of cardiovascular (CV) disease and all-cause mortality worldwide. Despite the positive correlations between blood pressure (BP) levels and later CV events since BP levels as low as 100/60 mmHg have been reported in numerous epidemiological studies, the diagnostic criteria of hypertension and BP thresholds and targets of antihypertensive therapy have largely remained at the level of 140/90 mmHg in the past 30 years. The publication of both the SPRINT and STEP trials (comprising > 8,500 Caucasian/African and Chinese participants, respectively) provided evidence to shake this 140/90 mmHg dogma. Another dogma regarding hypertension management is the dependence on office (or clinic) BP measurements. Although standardized office BP measurements have been widely recommended and adopted in large-scale CV outcome trials, the practice of office BP measurements has never been ideal in real-world practice. Home BP monitoring (HBPM) is easy to perform, more likely to be free of environmental and/or emotional stress, feasible to document long-term BP variations, of good reproducibility and reliability, and more correlated with hypertension-mediated organ damage (HMOD) and CV events, compared to routine office BP measurements. In the 2022 Taiwan Hypertension Guidelines of the Taiwan Society of Cardiology (TSOC) and the Taiwan Hypertension Society (THS), we break these two dogmas by recommending the definition of hypertension as ≥ 130/80 mmHg and a universal BP target of < 130/80 mmHg, based on standardized HBPM obtained according to the 722 protocol. The 722 protocol refers to duplicate BP readings taken per occasion ("2"), twice daily ("2"), over seven consecutive days ("7"). To facilitate implementation of the guidelines, a series of flowcharts encompassing assessment, adjustment, and HBPM-guided hypertension management are provided. Other key messages include that: 1) lifestyle modification, summarized as the mnemonic S-ABCDE, should be applied to people with elevated BP and hypertensive patients to reduce life-time BP burden; 2) all 5 major antihypertensive drugs (angiotensin-converting enzyme inhibitors [A], angiotensin receptor blockers [A], β-blockers [B], calcium-channel blockers [C], and thiazide diuretics [D]) are recommended as first-line antihypertensive drugs; 3) initial combination therapy, preferably in a single-pill combination, is recommended for patients with BP ≥ 20/10 mmHg above targets; 4) a target hierarchy (HBPM-HMOD- ambulatory BP monitoring [ABPM]) should be considered to optimize hypertension management, which indicates reaching the HBPM target first and then keeping HMOD stable or regressed, otherwise ABPM can be arranged to guide treatment adjustment; and 5) renal denervation can be considered as an alternative BP-lowering strategy after careful clinical and imaging evaluation.

Nitric oxide: Clinical applications in critically ill patients

Inhaled nitric oxide (iNO) acts as a selective pulmonary vasodilator and it is currently approved by the FDA for the treatment of persistent pulmonary hypertension of the newborn. iNO has been demonstrated to effectively decrease pulmonary artery pressure and improve oxygenation, while decreasing extracorporeal life support use in hypoxic newborns affected by persistent pulmonary hypertension. Also, iNO seems a safe treatment with limited side effects. Despite the promising beneficial effects of NO in the preclinical literature, there is still a lack of high quality evidence for the use of iNO in clinical settings. A variety of clinical applications have been suggested in and out of the critical care environment, aiming to use iNO in respiratory failure and pulmonary hypertension of adults or as a preventative measure of hemolysis-induced vasoconstriction, ischemia/reperfusion injury and as a potential treatment of renal failure associated with cardiopulmonary bypass. In this narrative review we aim to present a comprehensive summary of the potential use of iNO in several clinical conditions with its suggested benefits, including its recent application in the scenario of the COVID-19 pandemic. Randomized controlled trials, meta-analyses, guidelines, observational studies and case-series were reported and the main findings summarized. Furthermore, we will describe the toxicity profile of NO and discuss an innovative proposed strategy to produce iNO. Overall, iNO exhibits a wide range of potential clinical benefits, that certainly warrants further efforts with randomized clinical trials to determine specific therapeutic roles of iNO.

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.