Should we adjudicate outcomes in stroke trials? A systematic review

BACKGROUND

Central adjudication of outcomes is common in randomized clinical trials in stroke. The rationale for adjudication is clear; centrally adjudicated outcomes should have less random and systematic errors than outcomes assessed locally by site investigators. However, adjudication brings added complexities to a clinical trial and can be costly.

AIM

To assess the evidence for outcome adjudication in stroke trials.

SUMMARY OF REVIEW

We identified 12 studies evaluating central adjudication in stroke trials. The majority of these were secondary analyses of trials, and the results of all of these would have remained unchanged had central adjudication not taken place, even for trials without sufficient blinding. The largest differences between site-assessed and adjudicator-assessed outcomes were between the most subjective outcomes, such as causality of serious adverse events. We found that the cost of adjudication could be upward of £100,000 for medium to large prevention trials. These findings suggest that the cost of central adjudication may outweigh the advantages it brings in many cases. However, through simulation, we found that only a small amount of bias is required in site investigators' outcome assessments before adjudication becomes important.

CONCLUSION

Central adjudication may not be necessary in stroke trials with blinded outcome assessment. However, for open-label studies, central adjudication may be more important.

Surgery for Malignant Acute Ischemic Stroke: A Narrative Review of the Knowns and Unknowns

Malignant acute ischemic stroke (AIS) is characterized by acute neurological deterioration caused by progressive space-occupying brain edema, often occurring in the first hours to days after symptom onset. Without any treatment, the result is often fatal. Despite advances in treatment for AIS, up to 80% of patients with a large hemispheric stroke or cerebellar stroke are at risk of poor outcome. Decompressive surgery can be life-saving in a subgroup of patients with malignant AIS, but uncertainties exist on patient selection, predictors of malignant infarction, perioperative management, and timing of intervention. Although survivors are left disabled, most agree with the original decision to undergo surgery and would make the same decision again. In this narrative review, we focus on the clinical and radiological predictors of malignant infarction in AIS and outline the technical aspects of decompressive surgery as well as duraplasty and cranioplasty. We discuss the current evidence and recommendations for surgery in AIS, highlighting gaps in knowledge, and suggest directions for future studies. KEY POINTS: · Acute ischemic stroke from occlusion of a proximal intracranial artery can progress quickly to malignant edema, which can be fatal in 80% of patients despite medical management.. · Decompression surgery is life-saving within 48 hours of stroke onset, but the benefits beyond this time and in the elderly are unknown.. · Decompressive surgery is associated with high morbidity, particularly in the elderly. The decision to operate must be made after considering the individual's preference and expectations of quality of life in the context of the clinical condition.. · Further studies are needed to refine surgical technique including value of duraplasty and understand the role monitoring intracranial pressure during and after decompressive surgery.. · More studies are needed on the pathophysiology of malignant cerebral edema, prediction models including imaging and biomarkers to identify which subgroup of patients will benefit from decompressive surgery.. · More research is needed on factors associated with morbidity and mortality after cranioplasty, safety and efficacy of implants, and comparisons between them.. · Further studies are needed to assess the long-term effects of physical disability and quality of life of survivors after surgery, particularly those with severe neurological deficits..

Indobufen versus aspirin in patients with acute ischaemic stroke in China (INSURE): a randomised, double-blind, double-dummy, active control, non-inferiority trial

BACKGROUND

Aspirin is recommended for secondary stroke prevention in patients with moderate-to-severe ischaemic stroke but can lead to gastrointestinal intolerance and bleeding. Indobufen is used as an alternative antiplatelet agent in some countries, despite an absence of large-scale clinical trials for this indication. We tested the hypothesis that indobufen is non-inferior to aspirin in reducing the risk of new stroke at 90 days in patients with moderate-to-severe ischaemic stroke.

METHODS

We conducted a randomised, double-blind, double-dummy, active control, non-inferiority trial at 163 tertiary and district general hospitals in China. Eligible participants were aged 18-80 years with acute moderate-to-severe ischaemic stroke (National Institutes of Health Stroke Scale score 4-18). We randomly assigned (1:1) participants within 72 h of the onset of symptoms to receive either indobufen (100 mg tablet twice per day) or aspirin (100 mg tablet once per day) for 90 days. The randomisation sequence was computer generated centrally and stratified by local participating centres. Masked local investigators assigned the random code to patients in ascending order and provided a treatment kit corresponding to the random code. The primary efficacy outcome was new stroke and the primary safety outcome was severe or moderate bleeding, both within 90 days. This primary efficacy outcome was assessed in all randomly assigned and consenting patients and in a per-protocol group (ie, all patients finishing the treatment without major violation of the trial protocol). Safety analyses were done in the safety-analysis population (ie, all patients who received at least one dose of the study drug and had a safety assessment available). We assessed the non-inferiority of indobufen versus aspirin using the one-sided upper limit of the 95% CI of the hazard ratio (HR) with a prespecified non-inferiority margin of 1·25. This trial is registered with ClinicalTrials.gov (NCT03871517).

FINDINGS

This trial took place between June 2, 2019, and Nov 28, 2021. Of 84 093 patients screened, 5438 patients were randomly assigned to receive either indobufen (n=2715) or aspirin (n=2723), all of whom were included in the primary analyses. Median age was 64·2 years (IQR 56·1-70·6); 1921 (35·3%) were women and 3517 (64·7%) were men. Stroke occurred within 90 days in 213 (7·9%) patients in the indobufen group versus 175 (6·4%) in the aspirin group (HR 1·23, 95% CI 1·01-1·50; pnon-inferiority=0·44). Moderate or severe bleeding occurred in 18 (0·7%) patients in the indobufen group and in 28 (1·0%) in the aspirin group (0·63, 95% CI 0·35 to 1·15; p=0·13). Adverse events within 90 days occurred in 666 (24·5%) patients in the indobufen group and 679 (24·9%) patients in the aspirin group (p=0·73).

INTERPRETATION

In patients with acute moderate-to-severe ischaemic stroke, indobufen was not non-inferior to aspirin because the upper limit of the 95% CI was greater than 1·25. Furthermore, indobufen seemed to be inferior to aspirin in reducing the risk of recurrent stroke at 90 days because the lower limit of the 95% CI was greater than 1·00. Although moderate or severe bleeding did not differ between groups, these findings do not support the use of indobufen for secondary stroke prevention in patients with moderate-to-severe ischaemic stroke.

FUNDING

Hangzhou Zhongmei Huadong Pharmaceutical and Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences.

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.

Applicability of ENCHANTED trial results to current acute ischemic stroke patients eligible for intravenous thrombolysis in England and Wales: Comparison with the Sentinel Stroke National Audit Programme registry

BACKGROUND

Randomized controlled trials provide high-level evidence, but the necessity to include selected patients may limit the generalisability of their results.

METHODS

Comparisons were made of baseline and outcome data between patients with acute ischemic stroke (AIS) recruited into the alteplase-dose arm of the international, multi-center, Enhanced Control of Hypertension and Thrombolysis Stroke study (ENCHANTED) in the United Kingdom (UK), and alteplase-treated AIS patients registered in the UK Sentinel Stroke National Audit Programme (SSNAP) registry, over the study period June 2012 to October 2015.

RESULTS

There were 770 AIS patients (41.2% female; mean age 72 years) included in ENCHANTED at sites in England and Wales, which was 19.5% of alteplase-treated AIS patients registered in the SSNAP registry. Trial participants were significantly older, had lower baseline neurological severity, less likely Asian, and had more premorbid symptoms, hypertension and atrial fibrillation. Although ENCHANTED participants had higher rates of symptomatic intracerebral hemorrhage than those in SSNAP, there were no differences in onset-to-treatment time, levels of disability (assessed by the modified Rankin scale) at hospital discharge, and mortality over 90 days between groups.

CONCLUSIONS

Despite the high level of participation, equipoise over the dose of alteplase among UK clinician investigators favored the inclusion of older, frailer, milder AIS patients in the ENCHANTED trial.

CLINICAL TRIAL REGISTRATION

Clinical Trial Registration-URL: http://www.clinicaltrials.gov . Unique identifier: NCT01422616.

Abstract 78: Predicting Ordinal Functional Outcome at 90-Days Post Intracerebral Hemorrhage

Introduction: There is substantial variability in current estimation and communication of stroke prognosis. Existing predictive models have focused on dichotomous outcomes (e.g. functional independence or not), though other outcomes may also be of importance to patients and families. Our objective was to create an ordinal prognostic model to predict the full range of functional outcome (modified Rankin Scale (mRS)) at 90 days after intracerebral hemorrhage.

Methods: We used anonymized data from the Virtual International Stroke Trials Archive (VISTA), comprising individuals from both clinical trials and registries. The 90-day mRS was modeled using a proportional odds model. Potential predictors were selected a priori from available data including age, sex, comorbidities, and initial stroke severity. The best model was chosen based on fit statistics using a stepwise selection approach, internally validated using bootstrapping procedures, and externally validated using a population-based sample of 126 ICH cases from southeast Texas.

Results: A total of 1097 ICH cases were used in model building, with 95% from clinical trials. Cases were 63% male, with an average age of 66.7 years (SD=12.0), a median stroke severity of 13 (NIHSS) and 23% had a history of stroke. The final predictive model included 6 variables (age, sex, NIHSS, AFIB, diabetes, and prior stroke) and discriminated well between mRS scores (c-statistic=0.743), with minor optimism after bootstrap resampling (corrected c-statistic=0.740). The model yielded good discrimination in the external data set (c-statistic=0.774). Examples of model output are shown in the Figure.

Conclusions: This calibrated, internally and externally validated ordinal prognostic model to predict the full range of 90-day functional outcome will be tested as a part of an ongoing study to develop an educational decision support tool for stroke surrogate decision makers (NCT0342764).

Analysis of endothelial progenitor cell subtypes as clinical biomarkers for elderly patients with ischaemic stroke

Endothelial progenitor cells (EPCs), expressing markers for stemness (CD34), immaturity (CD133) and endothelial maturity (KDR), may determine the extent of post-stroke vascular repair. Given the prevalence of stroke in elderly, this study explored whether variations in plasmatic availability of certain EPC subtypes could predict the severity and outcome of disease in older patients. Blood samples were collected from eighty-one consented patients (≥ 65 years) at admission and days 7, 30 and 90 post-stroke. EPCs were counted with flow cytometry. Stroke severity and outcome were assessed using the National Institutes of Health Stroke Scale, Barthel Index and modified Rankin Scale. The levels of key elements known to affect EPC characteristics were measured by ELISA. Diminished total antioxidant capacity and CD34 + KDR + and CD133 + KDR + counts in early phases of stroke were associated with disease severity and worse functional outcome at day 90 post-stroke. Baseline levels of angiogenic agent PDGF-BB, but not VEGF, positively correlated with CD34 + KDR + numbers at day 90. Baseline LDL-cholesterol levels were inversely correlated with CD34 + KDR+, CD133 + KDR + and CD34 + CD133 + KDR + numbers at day 90. Close correlation between baseline CD34 + KDR + and CD133 + KDR + counts and the outcome of stroke proposes these particular EPC subtypes as potential prognostic markers for ischaemic stroke.

Relationship between nitrate headache and outcome in patients with acute stroke: results from the efficacy of nitric oxide in stroke (ENOS) trial

INTRODUCTION

Nitrate-induced headache is common and may signify responsive cerebral vasculature. We assessed the relationship between nitrate headache and outcome in patients with acute stroke.

MATERIALS AND METHODS

Patients were those randomised to glyceryl trinitrate (GTN) versus no GTN in the efficacy of nitric oxide in stroke trial. Development of headache by end of treatment (day 7), and functional outcome (modified Rankin Scale, primary outcome) at day 90, were assessed. Analyses are adjusted for baseline prognostic factors and give OR and mean difference (MD) with 95% CI.

RESULTS

In 4011 patients, headache was more common in GTN than control (360, 18.0% vs 170, 8.5%; p<0.001). Nitrate-related headache was associated with: younger age, female sex, higher diastolic blood pressure, non-total anterior circulation syndrome, milder stroke and absence of dysphasia (p<0.05). Nitrate headache was not associated with improved functional outcome (OR 0.90, 95% CI 0.73 to 1.10, p=0.30) or death (day 90) (HR 0.64, 95% CI 0.40 to 1.02, p=0.062), but reduced death or deterioration (day 7) (OR 0.45, 95% CI 0.25 to 0.82), death in hospital (OR 0.44, 95% CI 0.22 to 0.88) and improved activities of daily living (Barthel index, MD 3.7, 95% CI 0.3 to 7.1) and cognition (telephone interview cognitive screen, MD 2.0, 95% CI 0.7 to 3.3) (day 90). Non-nitrate headache was not associated with death, disability or cognition.

DISCUSSION AND CONCLUSION

Development of a nitrate headache by day 7 after stroke may be associated with improved activities of daily living and cognitive impairment at day 90, which was not seen with non-nitrate headache.

Dietary nitrate supplementation for preventing and reducing the severity of winter infections, including COVID-19, in care homes (BEET-Winter): a randomised placebo-controlled feasibility trial

PURPOSE

Infections cause considerable care home morbidity and mortality. Nitric oxide (NO) has broad-spectrum anti-viral, bacterial and yeast activity in vitro. We assessed the feasibility of supplementing dietary nitrate (NO substrate) intake in care home residents.

METHODS

We performed a cluster-randomised placebo-controlled trial in UK residential and nursing care home residents and compared nitrate containing (400 mg) versus free (0 mg daily) beetroot juice given for 60 days. Outcomes comprised feasibility of recruitment, adherence, salivary and urinary nitrate, and ordinal infection/clinical events.

RESULTS

Of 30 targeted care homes in late 2020, 16 expressed interest and only 6 participated. 49 residents were recruited (median 8 [interquartile range 7-12] per home), mean (standard deviation) age 82 (8) years, with proxy consent 41 (84%), advance directive for hospital non-admission 8 (16%) and ≥ 1 doses of COVID-19 vaccine 37 (82%). Background dietary nitrate was < 30% of acceptable daily intake. 34 (76%) residents received > 50% of juice. Residents randomised to nitrate vs placebo had higher urinary nitrate levels, median 50 [18-175] v 18 [10-50] mg/L, difference 25 [0-90]. Data paucity precluded clinical between-group comparisons; the outcome distribution was as follows: no infection 32 (67%), uncomplicated infection 0, infection requiring healthcare support 11 (23%), all-cause hospitalisation 5 (10%), all-cause mortality 0. Urinary tract infections were most common.

CONCLUSIONS

Recruiting UK care homes during the COVID-19 pandemic was partially successful. Supplemented dietary nitrate was tolerated and elevated urinary nitrate. Together, infections, hospitalisations and deaths occurred in 33% of residents over 60 days. A larger trial is now required.

TRIAL REGISTRATION

ISRCTN51124684. Application date 7/12/2020; assignment date 13/1/2021.

Remote platelet function testing using P-selectin expression in patients with recent cerebral ischaemia on clopidogrel

Background

Antiplatelet agents reduce recurrence after cerebral ischaemia but are not effective in all patients, in part because of treatment resistance. The primary aim was to assess the proportion of patients who are insensitive to clopidogrel. The secondary aim was to assess the association between insensitivity to clopidogrel and recurrent cerebrovascular events.

Methods

Following written informed consent, independent patients with a recent non-cardioembolic ischaemic stroke or transient ischaemic attack, and taking clopidogrel, were enrolled. Platelet function was assessed with remote measurement of surface expression of P-selectin (CD62P) using commercial kits sensitive to aspirin or clopidogrel. Participants’ general practitioners provided details on recurrent vascular events at least 90 days later. Data are mean (SD) and median [IQR]. Resistance was defined as: aspirin median fluorescence (MF) >500 units, clopidogrel MF >860 units. Non-parametric descriptors and tests were used.

Results

63 patients were recruited: mean age 64 (13.7) years, women 47%. At baseline, 59 (95%) patients were taking clopidogrel alone with 3 (5%) on combined clopidogrel and aspirin. Assessment of platelet surface P-selectin revealed: aspirin test 528 [317, 834], >500 54.8%; clopidogrel test 429 [303, 656], >860 11.3%. No participants on aspirin and clopidogrel showed aspirin resistance. Thirteen (20.6%) patients had a recurrent cerebrovascular event; those with an ischaemic stroke had a non-significantly higher baseline P-selectin using the clopidogrel test as compared with those with no recurrence: 626 [380, 801] versus 406 [265, 609], p=0.08.

Conclusions

Remote measurement of platelet function assessed using the platelet surface expression of P-selectin is feasible. 11% of patients taking clopidogrel showed resistance. No significant associations were noted between clopidogrel resistance and recurrent ischaemic events.

Brief Consent Methods Enable Rapid Enrollment in Acute Stroke Trial: Results From the TICH-2 Randomized Controlled Trial

BACKGROUND

Seeking consent rapidly in acute stroke trials is crucial as interventions are time sensitive. We explored the association between consent pathways and time to enrollment in the TICH-2 (Tranexamic Acid in Intracerebral Haemorrhage-2) randomized controlled trial.

METHODS

Consent was provided by patients or by a relative or an independent doctor in incapacitated patients, using a 1-stage (full written consent) or 2-stage (initial brief consent followed by full written consent post-randomization) approach. The computed tomography-to-randomization time according to consent pathways was compared using the Kruskal-Wallis test. Multivariable logistic regression was performed to identify variables associated with onset-to-randomization time of ≤3 hours.

RESULTS

Of 2325 patients, 817 (35%) gave self-consent using 1-stage (557; 68%) or 2-stage consent (260; 32%). For 1507 (65%), consent was provided by a relative (1 stage, 996 [66%]; 2 stage, 323 [21%]) or a doctor (all 2-stage, 188 [12%]). One patient did not record prerandomization consent, with written consent obtained subsequently. The median (interquartile range) computed tomography-to-randomization time was 55 (38-93) minutes for doctor consent, 55 (37-95) minutes for 2-stage patient, 69 (43-110) minutes for 2-stage relative, 75 (48-124) minutes for 1-stage patient, and 90 (56-155) minutes for 1-stage relative consents (P<0.001). Two-stage consent was associated with onset-to-randomization time of ≤3 hours compared with 1-stage consent (adjusted odds ratio, 1.9 [95% CI, 1.5-2.4]). Doctor consent increased the odds (adjusted odds ratio, 2.3 [1.5-3.5]) while relative consent reduced the odds of randomization ≤3 hours (adjusted odds ratio, 0.10 [0.03-0.34]) compared with patient consent. Only 2 of 771 patients (0.3%) in the 2-stage pathways withdrew consent when full consent was sought later. Two-stage consent process did not result in higher withdrawal rates or loss to follow-up.

CONCLUSIONS

The use of initial brief consent was associated with shorter times to enrollment, while maintaining good participant retention. Seeking written consent from relatives was associated with significant delays.

REGISTRATION

URL: https://www.isrctn.com; Unique identifier: ISRCTN93732214.

Desmopressin for reversal of Antiplatelet drugs in Stroke due to Haemorrhage (DASH): protocol for a phase II double-blind randomised controlled feasibility trial

INTRODUCTION

Intracerebral haemorrhage (ICH) can be devastating and is a common cause of death and disability worldwide. Pre-ICH antiplatelet drug use is associated with a 27% relative increase in 1 month case fatality compared with patients not using antithrombotic drugs. We aim to assess the feasibility of conducting a randomised controlled testing the safety and efficacy of desmopressin for patients with antiplatelet-associated ICH.

METHODS AND ANALYSIS

We aim to include 50 patients within 24 hours of spontaneous ICH onset, associated with oral antiplatelet drug(s) use in at least the preceding 7 days. Patients will be randomised (1:1) to receive intravenous desmopressin 20 µg in 50 mL sodium chloride 0.9% infused over 20 min or matching placebo. We will mask participants, relatives and outcome assessors to treatment allocation. Feasibility outcomes include proportion of patients approached being randomised, number of patients receiving allocated treatment, rate of recruitment and adherence to treatment and follow-up. Secondary outcomes include change in ICH volume at 24 hours; hyponatraemia at 24 hours, length of hospital stay, discharge destination, early death less than 28 days, death or dependency at day 90, death up to day 90, serious adverse events (including thromboembolic events) up to day 90; disability (Barthel index, day 90), quality of life (EuroQol 5D (EQ-5D), day 90), cognition (telephone mini-mental state examination day 90) and health economic assessment (EQ-5D).

ETHICS AND DISSEMINATION

The Desmopressin for reversal of Antiplatelet drugs in Stroke due to Haemorrhage (DASH) trial received ethical approval from the East Midlands-Nottingham 2 research ethics committee (18/EM/0184). The DASH trial is funded by National Institute for Health and Care Research RfPB grant: PB-PG-0816-20011. Trial results will be published in a peer reviewed academic journal and disseminated through academic conferences and through patient stroke support groups. Reporting will be in compliance with Consolidated Standards of Reporting Trials recommendations.

TRIAL REGISTRATION NUMBERS

NCT03696121; ISRCTN67038373; EudraCT 2018-001904-12.

Abstract 103: Intensive versus Guideline Antiplatelet Therapy in Patients With Transient Ischaemic Attack: Data From the Triple Antiplatelets for Reducing Dependency in Ischaemic Stroke (TARDIS) Trial

Background: The risk of recurrence following an ischaemic stroke (IS) or transient ischaemic attack (TIA) is high, especially immediately after the event. Intensive treatment might be more effective in preventing recurrence than guideline therapy providing bleeding does not become excessive. We tested this in a subgroup of patients enrolled with TIA into the TARDIS trial.

Methods: TARDIS was an international multicentre prospective randomised open-label blinded-endpoint controlled trial. Patients with acute non-cardioembolic IS or TIA were randomised to intensive antiplatelet therapy (combined aspirin, clopidogrel and dipyridamole) or guideline antiplatelets (clopidogrel alone, or combined aspirin and dipyridamole) given for one month. The primary outcome was recurrent cerebral events and their severity (using modified Rankin Scale) at 3 months. Data are number (%), mean (standard deviation, SD) or odds ratio (OR) with 95% confidence interval (CI).

Results: Of 3,096 patients, 953 (30.8%; intensive 480, guideline 473) were enrolled with TIA. At baseline: mean age 70 (SD 10); male 62%; onset to randomisation <12 hours 17%, <24 hours 48%. By day 90, no differences were present between the two treatment groups for the primary outcome, death or other functional outcomes. However, patients in the intensive arm were less likely to suffer a recurrent TIA than those on guideline treatment (OR 0.48, 95% CI 0.25-0.93).

Conclusion: Patients with a qualifying event of TIA were less likely to suffer a recurrent TIA if they received intensive treatment rather than guideline. However, no differences were present for recurrent stroke events.

Abstract 140: Incidence of Stroke in and Around Pregnancy: A UK Population-based Cohort Study

Introduction: There are very few population-based studies on the incidence of stroke in women of childbearing age, stratifying by stroke types and pregnancy-related periods.

Methods: We used an open cohort study design including all women aged 15-49 years from UK linked primary (Clinical Practice Research Datalink) and secondary (Hospital Episode Statistics) care records in 1997-2014. The exposure of our study was pregnancy resulting in a live or a stillbirth and associated antenatal and postpartum periods. The outcome of the study was the first ever stroke diagnosis, defined using ICD-10 codes (I60-I64, O22.5 and O87.3) or relevant Read codes, and classified as having ischaemic stroke (IS), intracerebral haemorrhage (ICH), subarachnoid haemorrhage (SAH) or unspecified. We calculated the absolute rates of stroke per 100,000 person-years and 95% confidence intervals (95%CI) for different exposure periods. We stratified the analysis by maternal age and types of stroke.

Results: Of 2,047,858 women, we identified 336,957 women with 453,776 deliveries. There were totally 2,526 women with a first incidence of stroke: IS 1,140 (45.1%), SAH 684 (27.1%), ICH 368 (14.6%) and unspecified 334 (13.2%). The overall incidence rate of stroke was 24.9 (95%CI 23.6-26.2) per 100,000 person-years in the non-pregnant period (IS 11.2 [10.4-12.1], ICH 3.6 [3.2-4.2], SAH 6.8 [6.2-7.5] and unspecified 3.3 [2.9-3.8]). The incidence was however higher around delivery (281.9 [141.6-561.2]) and in the first six weeks postpartum (43.8 [25.3-75.9]) and the rate ratios compared to the non-pregnant period after adjusting for age were 19.2 (9.6-38.3) and 3.0 (1.7-5.2) respectively.

Conclusions: Although the incidence of stroke for young women was relatively low, the incidence around delivery or in the early postpartum was significantly higher compared to other periods, regardless of maternal age.

Abstract TP47: Infarct Growth Does Not Predict Functional Outcome For Small Vessel Stroke

Introduction: Infarct growth has been shown to be a predictor of clinical outcome following ischemic stroke and has been used as a surrogate in reperfusion studies. There are no data whether the association of infarct growth and clinical outcome depends on stroke etiology. Furthermore, there is uncertainty on how to handle small volume infarcts with some studies excluding them from analyses. We studied the relationship between infarct growth and functional outcome in stroke patients with small volume infarcts for subgroups with small and non-small vessel etiologies.

Methods: We studied 37 patients in the MRI substudy of the Efficacy of Nitric Oxide in Stroke (ENOS) trial with baseline infarct volumes of ≤5ml. None of the patients were treated with reperfusion strategies. Brain MRI was performed serially at baseline within 48 hours of onset, on days 7 and 90. Infarct growth was measured as the volume difference between final T2 and baseline DWI lesions. Good functional outcome was defined as day 90 modified Rankin score ≤2 and poor as >2.

Results: Among the 26 patients with underlying small vessel etiology, there was no difference between those with good and poor outcomes in terms of absolute [median 0.0 (IQR -0.4 to 1.1) vs 0.1 (-0.7 to 0.2) mL, p=0.802] and relative infarct growth [median -3 (-27 to 81) vs 8 (-46 to 10) %, p=0.802]. However, in the 11 patients with etiologies other than small vessel disease, patients with good outcome had less absolute [median -0.9 (-1.6 to 0.7) vs 3.2 (0.2 to 9.1) mL, p=0.033] and relative infarct growth [median -59 (-81 to 9) vs 154 (35 to 292) %, p=0.019] compared to those with poor outcome.

Discussion: In small volume strokes, infarct growth was not associated with functional outcome for small vessel stroke although there was a significant association for other stroke etiologies. This novel finding in this small sample should be confirmed in larger studies. Our findings are expected as small vessel stroke involves occlusion of penetrating arterioles which supply small, limited yet strategically important brain regions. Thus, while infarct growth may be a suitable surrogate for clinical outcomes for small volume infarcts due to non-small vessel disease, but it may not be for small vessel strokes.

Cigarette smoking sensitizes and desensitizes impedance-measured ADP-induced platelet aggregation in whole blood

The effect of smoking on platelet aggregation appears to produce conflicting results, with some studies indicating an enhancement and others a decrease of aggregation. This epidemiological study of 120 male smokers, a subset of the Caerphilly Heart Disease Study, examined the relationship of two dimensions of smoking (time proximity of last cigarette before venepuncture and serum nicotine concentration) with threshold dose of adenosine diphosphate (ADP) necessary to induce platelet aggregation in whole blood. Means (range) of ADP threshold dose and nicotine concentration were 1.66 (0.5-2.5, censored) microM and 12.2 (0-35.2) ng/ml. Men smoking within 30 min of venepuncture demonstrated lower ADP threshold doses (-0.48 microM lower [95% C.I.: -0.95, -0.02])--reflecting increased sensitivity. Men with higher nicotine concentration had higher ADP threshold doses (Regression Coefficient: +0.032 microM per ng/ml [95% C.I.: 0.003, 0.062])--reflecting decreased sensitivity. Men smoking 30 min or more before venepuncture who also had high nicotine concentration (25-30 ng/ml) demonstrated the highest ADP threshold doses compared to never smokers and to men smoking the previous day (approximately 2.20 vs 1.86 and 1.81 microM). Relations involving nicotine concentration do not necessarily reflect a pharmacological effect although the potential for a short term nicotine mediated tolerance effect cannot be dismissed. These observations support an hypothesis suggesting a temporal sequence of platelet sensitization and desensitization during smoking.

The medical management of stroke

The management of stroke, so long a 'Cinderella' condition, is changing rapidly as new developments appear for acute treatment, rehabilitation and secondary prevention. Most patients with acute stroke now need rapid assessment at hospital following the onset of symptoms. Those needing admission should be managed on an acute stroke unit for stabilisation, CT scanning and other investigation, and diagnosis, and then referred, as appropriate, to a specialist stroke rehabilitation unit. Aspirin is now the recognised treatment for acute ischaemic stroke (once primary intracerebral haemorrhage has been excluded), and can be continued for secondary prevention. Attention should be paid to risk factors to prevent recurrence, especially treatment of hypertension, atrial fibrillation, and severe ipsilateral carotid stenosis. Patients with mild cerebrovascular disease should be managed in a specialist stroke/TIA clinic. Stroke is no longer an untreatable or unpreventable condition, and it is vital that hospitals design appropriate systems to manage patients in an interdisciplinary environment.

Antiplatelet treatment for acute secondary prevention of non-cardioembolic minor stroke / transient ischaemic attack: an update for the acute physician

Acute stroke is the leading cause of disability in the UK and a leading cause of mortality worldwide. The majority of patients with ischaemic stroke present with minor deficits or transient ischaemic attack (TIA), and are often first seen by patient-facing clinicians. Urgent evaluation and treatment are important as many patients are at high risk of major vascular events and death within hours to days after the index event. This narrative review summarises the evidence on four antiplatelet treatments for non-cardioembolic stroke prevention: aspirin, clopidogrel, dipyridamole and ticagrelor. Each of these drugs has a unique mechanism and has been tested as a single agent or in combination. Aspirin, when given early is beneficial and short-term treatment with aspirin and clopidogrel has been shown to be more effective in high-risk TIA / minor stroke. This review concludes by highlighting gaps in evidence, including scope for future trials that could potentially change clinical practice.

Predictors of pharyngeal electrical stimulation treatment success in tracheotomised stroke patients with dysphagia: Secondary analysis from PHADER cohort study

Pharyngeal electrical stimulation (PES) has emerged as a promising intervention for neurogenic dysphagia, with potential benefits in reducing dysphagia severity in stroke patients. PES may facilitate decannulation in tracheotomised stroke patients with dysphagia, yet the predictive factors for treatment success have not been investigated in detail. This study used data from the PHAryngeal electrical stimulation for treatment of neurogenic Dysphagia European Registry (PHADER) study to identify predictive factors for PES treatment success among patients with post stroke dysphagia who required mechanical ventilation and tracheotomy. Multiple linear regression was performed to predict treatment success, as measured in improvement in dysphagia severity rating scale (DSRS), accounting for age, sex, stroke type, lesion location, baseline National Institutes of Health Stroke Scale (NIHSS) score, feeding status, time from stroke onset to PES, PES perceptual threshold and PES stimulation intensity at the first session. Cox regression was conducted to identify the predictors for decannulation for all participants. Ninety-eight participants (mean [SD] age ​= ​66.6 [13.0]; male 73.5%) were included in the analyses. Regression analyses showed that early intervention (p ​= ​0.004) and younger age (p ​= ​0.049) were significant predictors for treatment success. For participants who received PES during tracheotomy (n ​= ​60; mean [SD] age ​= ​66.6 [11.2]; male 73.3%), supratentorial stroke (p ​= ​0.033) and feeding status at baseline (p ​= ​0.025) were predictors of treatment success. Among all participants, early intervention was associated with higher likelihood of decannulation (p ​= ​0.026). These results highlight the importance of timely intervention, age and stroke location in PES treatment success for stroke patients with mechanical ventilation and tracheotomy.

Dysphagia after stroke: research advances in treatment interventions

After a stroke, most patients have dysphagia, which can lead to aspiration pneumonia, malnutrition, and adverse functional outcomes. Protective interventions aimed at reducing these complications remain the cornerstone of treatment. Dietary adjustments and oral hygiene help mitigate the risk of aspiration pneumonia, and nutritional supplementation, including tube feeding, might be needed to prevent malnutrition. Rehabilitative interventions aim to enhance swallowing function, with different behavioural strategies showing promise in small studies. Investigations have explored the use of pharmaceutical agents such as capsaicin and other Transient-Receptor-Potential-Vanilloid-1 (TRPV-1) sensory receptor agonists, which alter sensory perception in the pharynx. Neurostimulation techniques, such as transcranial direct current stimulation, repetitive transcranial magnetic stimulation, and pharyngeal electrical stimulation, might promote neuroplasticity within the sensorimotor swallowing network. Further advancements in the understanding of central and peripheral sensorimotor mechanisms in patients with dysphagia after a stroke, and during their recovery, will contribute to optimising treatment protocols.

The Effect of Tranexamic Acid on Neurosurgical Intervention in Spontaneous Intracerebral Hematoma: Data From 121 Surgically Treated Participants From the Tranexamic Acid in IntraCerebral Hemorrhage-2 Randomized Controlled Trial

BACKGROUND AND OBJECTIVES

An important proportion of patients with spontaneous intracerebral hemorrhage (ICH) undergo neurosurgical intervention to reduce mass effect from large hematomas and control the complications of bleeding, including hematoma expansion and hydrocephalus. The Tranexamic acid (TXA) for hyperacute primary IntraCerebral Hemorrhage (TICH-2) trial demonstrated that tranexamic acid (TXA) reduces the risk of hematoma expansion. We hypothesized that TXA would reduce the frequency of surgery (primary outcome) and improve functional outcome at 90 days in surgically treated patients in the TICH-2 data set.

METHODS

Participants enrolled in TICH-2 were randomized to placebo or TXA. Participants randomized to either TXA or placebo were analyzed for whether they received neurosurgery within 7 days and their characteristics, outcomes, hematoma volumes (HVs) were compared. Characteristics and outcomes of participants who received surgery were also compared with those who did not.

RESULTS

Neurosurgery was performed in 5.2% of participants (121/2325), including craniotomy (57%), hematoma drainage (33%), and external ventricular drainage (21%). The number of patients receiving surgery who received TXA vs placebo were similar at 4.9% (57/1153) and 5.5% (64/1163), respectively (odds ratio [OR] 0.893; 95% CI 0.619-1.289; P -value = .545). TXA did not improve outcome compared with placebo in either surgically treated participants (OR 0.79; 95% CI 0.30-2.09; P = .64) or those undergoing hematoma evacuation by drainage or craniotomy (OR 1.19 95% 0.51-2.78; P -value = .69). Postoperative HV was not reduced by TXA (mean difference -8.97 95% CI -23.77, 5.82; P -value = .45).

CONCLUSION

TXA was not associated with less neurosurgical intervention, reduced HV, or improved outcomes after surgery.

Abstract TMP13: Individual Patient Data Meta-analysis of Hypothermia for Acute Ischaemic Stroke

Background: It remains unclear whether inducing hypothermia is safe and effective for improving outcome after hyperacute ischaemic stroke. An individual patient data meta-analysis of completed trials was performed.

Methods: Following electronic searches for trials comparing hypothermia to control, Chief Investigators were approached to share individual patient data (IPD). Odds ratios (OR, 95% confidence intervals, 95% CI) were analysed with ordinal logistic regression and binary logistic regression with adjustment for trial, cooling method (endovascular, surface or unknown) and age.

Results: Data were obtained for 10 trials (320 participants): COAST-I, COAST-II, COOL AID pilot, COOL AID, COOLIST, HAIS-SE, ICTuS-L, ICTuS-2, MASCOT and MHAIS; IPD were not available for two studies. Trial designs varied and most had a small sample size, mean (SD) age 66 (11.5) years, female 42%, NIHSS 13.4 (5.3), time to treatment 4.5 (1.2) hours, thrombolysis 53%. In patients whose temperature was recorded (n=74), the lowest achieved temperature was in the hypothermia arm: 34.3 o C vs. 36.6 o C (p<0.001). Functional outcome (modified Rankin Scale) at day 90 did not differ between cooling vs. no cooling: n=297 OR 0.93 (95% CI 0.63-1.39, p=0.74). Serious adverse events (n=287) were increased in the cooling arm: 81.5% vs. 65.5% (p<0.001); pneumonia: 30.2% vs. 10.9% (p<0.001) and aspiration: 13.3% vs. 3.5% (p=0.004). There was no difference in death: 17.2% vs. 13.6% (p=0.21).

Conclusion: Hypothermia lowered temperature by 2.3 C, did not alter functional outcome or mortality, but was associated with more SAEs. Larger trials are needed to assess hypothermia in hyperacute stroke.