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.

Intensive blood pressure reduction with intravenous thrombolysis therapy for acute ischaemic stroke (ENCHANTED): an international, randomised, open-label, blinded-endpoint, phase 3 trial

BACKGROUND

Systolic blood pressure of more than 185 mm Hg is a contraindication to thrombolytic treatment with intravenous alteplase in patients with acute ischaemic stroke, but the target systolic blood pressure for optimal outcome is uncertain. We assessed intensive blood pressure lowering compared with guideline-recommended blood pressure lowering in patients treated with alteplase for acute ischaemic stroke.

METHODS

We did an international, partial-factorial, open-label, blinded-endpoint trial of thrombolysis-eligible patients (age ≥18 years) with acute ischaemic stroke and systolic blood pressure 150 mm Hg or more, who were screened at 110 sites in 15 countries. Eligible patients were randomly assigned (1:1, by means of a central, web-based program) within 6 h of stroke onset to receive intensive (target systolic blood pressure 130-140 mm Hg within 1 h) or guideline (target systolic blood pressure <180 mm Hg) blood pressure lowering treatment over 72 h. The primary outcome was functional status at 90 days measured by shift in modified Rankin scale scores, analysed with unadjusted ordinal logistic regression. The key safety outcome was any intracranial haemorrhage. Primary and safety outcome assessments were done in a blinded manner. Analyses were done on intention-to-treat basis. This trial is registered with ClinicalTrials.gov, number NCT01422616.

FINDINGS

Between March 3, 2012, and April 30, 2018, 2227 patients were randomly allocated to treatment groups. After exclusion of 31 patients because of missing consent or mistaken or duplicate randomisation, 2196 alteplase-eligible patients with acute ischaemic stroke were included: 1081 in the intensive group and 1115 in the guideline group, with 1466 (67·4%) administered a standard dose among the 2175 actually given intravenous alteplase. Median time from stroke onset to randomisation was 3·3 h (IQR 2·6-4·1). Mean systolic blood pressure over 24 h was 144·3 mm Hg (SD 10·2) in the intensive group and 149·8 mm Hg (12·0) in the guideline group (p<0·0001). Primary outcome data were available for 1072 patients in the intensive group and 1108 in the guideline group. Functional status (mRS score distribution) at 90 days did not differ between groups (unadjusted odds ratio [OR] 1·01, 95% CI 0·87-1·17, p=0·8702). Fewer patients in the intensive group (160 [14·8%] of 1081) than in the guideline group (209 [18·7%] of 1115) had any intracranial haemorrhage (OR 0·75, 0·60-0·94, p=0·0137). The number of patients with any serious adverse event did not differ significantly between the intensive group (210 [19·4%] of 1081) and the guideline group (245 [22·0%] of 1115; OR 0·86, 0·70-1·05, p=0·1412). There was no evidence of an interaction of intensive blood pressure lowering with dose (low vs standard) of alteplase with regard to the primary outcome.

INTERPRETATION

Although intensive blood pressure lowering is safe, the observed reduction in intracranial haemorrhage did not lead to improved clinical outcome compared with guideline treatment. These results might not support a major shift towards this treatment being applied in those receiving alteplase for mild-to-moderate acute ischaemic stroke. Further research is required to define the underlying mechanisms of benefit and harm resulting from early intensive blood pressure lowering in this patient group.

FUNDING

National Health and Medical Research Council of Australia; UK Stroke Association; Ministry of Health and the National Council for Scientific and Technological Development of Brazil; Ministry for Health, Welfare, and Family Affairs of South Korea; Takeda.

Abstract TP432: Dilated Optic Nerve Sheath Diameter by Trans-Orbital Ultrasound Predicts Mortality Among Patients With Acute Intracerebral Hemorrhage

Introduction: Supratentorial Intracerebral hemorrhage (ICH) main prognostic factors on admission are age, Glasgow coma scale (GCS), ICH volume and ventricular hemorrhage. Subsequent ICH expansion and associated elevated intracranial pressure (ICP) have also been linked to poorer outcomes. Dilatation of optic nerve sheath diameter (ONSD) by trans-orbital ultrasound examination is an increasingly recognized marker of elevated ICP. We sought to evaluate whether increased ONSD at hospital admission could be associated with mortality among patients with supratentorial ICH.

Methods: Prospective cohort of consecutive acute supratentorial ICH patients admitted to a tertiary stroke center. Exclusion criteria: 1) last well seen > 24 hours; 2) immediate surgical intervention indicated by neurosurgery team; 3) Secondary ICH (anticoagulants and antiplatelets were allowed); 4) previous optic nerve pathology precluding accurate ONSD measurements. Ultrasound assessment and CT performed within the first hour after admission. Primary outcome was 90-days mortality. Multivariate logistic regression, ROC curve and c-statistics was used to identify independent predictors of mortality.

Results: Between July 2014 and July 2017, 57 patients were evaluated. Among those, 13 were excluded and 44 were recruited into the trial. Their mean age was 62.3± 13.1 years and 32 (72.7%) were male. On univariate analysis, ICH volume on admission CT scan, ICH ipsilateral ONSD measurement on admission TCCD, diabetes and current smoking were predictors of mortality. After multivariate analysis, ipsilateral ONSD (OR:6.24;95CI%1.18-33.1;p=0.031) was an independent predictor of mortality, even after adjustment for ICH volume, age, GCS and intraventricular hemorrhage. The ONSD had an area under the curve (AUC) of 0.71 (p=0.021) for mortality at 3 months.

Conclusion: ONSD is a non-invasively, bedside, low cost technique that could be used to estimate increased ICP in patients with acute supratentorial ICH. Among these patients, increased ONSD is an independent predictor of mortality at 3 months.

Large Vessel Occlusion Score: A Screening Tool to Detect Large Vessel Occlusion in the Acute Stroke Setting

BACKGROUND

The results of recent trials of mechanical thrombectomy for acute ischemic stroke have increased the demand for identification of patients with large vessel occlusion (LVO) at the primary stroke center, where a prompt detection may expedite transfer to a comprehensive stroke center for endovascular treatment. However, in developing countries, a noncontrast computed tomography (NCCT) may be the only neuroimaging modality available at the primary stroke center scenario, what calls for a screening strategy accurate enough to avoid unnecessary transfers of noneligible patients for endovascular therapy. Algorithms based on National Institute of Health Stroke Scale (NIHSS) and NCCT findings can be used to screen for LVO in patients with anterior circulation stroke (ACS).

OBJECTIVE

To test the accuracy of a score based on NIHSS and NCCT to detect LVO in patients with ACS.

METHODS

We evaluated 178 patients from a prospective stroke registry of patients admitted to an academic tertiary emergency unit. NIHSS and vessel attenuation values of the middle cerebral artery on NCCT absolute vessel attenuation (VA) were collected by 2 investigators that were blind to CT angiography (CTA) findings. We used receiver operating characteristics curve analysis and C-statistics to predict LVO on CTA.

RESULTS

NIHSS and vessel attenuation were highly associated with LVO with an area under the curve (AUC) of .86 and .77. The LVO score, built by logistic regression coefficients of the NIHSS and VA, showed the highest accuracy for the presence of LVO on CTA (AUC of .91).

CONCLUSION

The LVO score may be a useful screening approach to identify LVO in patients with ACS.

New biomarker for acute ischaemic stroke: plasma glycogen phosphorylase isoenzyme BB

BACKGROUND

Glycogen phosphorylase is the key enzyme that breaks down glycogen to yield glucose-1-phosphate in order to restore depleted energy stores during cerebral ischaemia. We sought to determine whether plasma levels of glycogen phosphorylase BB (GPBB) isoform increased in patients with acute ischaemic stroke (AIS).

METHODS

We studied plasma GPBB levels within 12 hours and again at 48±24 hours of symptom onset in 172 patients with imaging-confirmed AIS and 133 stroke-free individuals. We determined the ability of plasma GPBB to discriminate between cases and controls and examined the predictive value of plasma GPBB for 90-day functional outcome, 90-day survival and acute lesion volumes on neuroimaging.

RESULTS

The mean (SD) GPBB levels were higher in cases (46.3±38.6 ng/mL at first measurement and 38.6±36.5 ng/mL at second measurement) than in controls (4.1±7.6 ng/mL, p<0.01 for both). The area under the receiver operating characteristic (ROC) curve for case-control discrimination based on first GPBB measurement was 0.96 (95% CI 0.93 to 0.98). The sensitivity and specificity based on optimal operating point on the ROC curve (7.0 ng/mL) were both 93%. GPBB levels increased in 90% of patients with punctate infarcts (<1.5 mL) and in all patients admitted within the first 4.5 hours of onset. There was no correlation between GPBB concentration and either clinical outcome or acute infarct volume.

CONCLUSION

GPBB demonstrates robust response to acute ischaemia and high sensitivity for small infarcts. If confirmed in more diverse populations that also include stroke mimics, GPBB could find utility as a stand-alone marker for acute brain ischaemia.

Abstract TMP88: High Accuracy of Auto-CPAP for Obstructive Sleep Apnea in Acute Stroke Patients

Background: Obstructive sleep apnea (OSA) is very common in acute stroke patients and has been associated with a poor short-term and long-term outcome. Polysomnography (PSG) is the gold standard diagnostic method for OSA, but it is not feasible as a routine for all acute stroke patients. Therefore, it is essential to validade alternative methods to accurately diagnose OSA in acute stroke patients. The newest generation of automatic continuous positive airway pressure (auto-CPAP) devices innovates by the possibility of detecting the different types of respiratory events. However, the accuracy of auto-CPAP devices for OSA diagnosis has never been tested in comparison to PSG in the acute stroke setting. The main objective of this study was to evaluate the accuracy of an auto-CPAP device to diagnose OSA and to validate its algorithm of respiratory events detection to diagnose OSA in patients during the acute phase of stroke.

Methods: A sleep study was performed with PSG and auto-CPAP device, simultaneously, within the first 48 hours after the acute stroke onset. The Receiver Operating Characteristic Curve (ROC), C-statistics, Spearman correlation coefficient, and intraclass correlation coefficient were analyzed.

Results: We prospectively evaluated 31 adult patients with acute stroke. The mean age was 59.7 ± 12 years and 60% were males. All patients used auto-CPAP for longer than 4 hours. The PSG revealed an apnea-hypopnea index (AHI) mean of 34 ± 41 events/h, and the auto-CPAP showed an AHI of 18 ± 16 events/h. The area under the ROC curve for OSA diagnosis by the auto-CPAP was above 0.90, with sensitivity and specificity above 80% for each AHI value. The Spearman correlation coefficients (rs) of the AHI, of the hypopnea index, of the obstructive apnea index and of the central apnea index were 0.92; 0.89; 0.63 and 0.62, respectively. The intraclass correlation coefficients between device-detected and PSG manually scored events were 0.60 for AHI, 0.64 for hypopnea index, and 0.45 for apnea index.

Conclusion: The auto-CPAP showed an excellent accuracy for the diagnosis of OSA and it was well tolerated by acute stroke patients. Our results suggest that auto-CPAP should be considered as the preferred diagnostic tool for OSA diagnosis during the acute phase of stroke.

Abstract TP422: Cerebral Perfusion, Functional Connectivity and Cognitive Profile of Patients With Assymptomatic Carotid Stenosis

Introduction: Patients with carotid stenosis, without history of stroke or transient ischemic attack are considered to be asymptomatic. However, many of those patients might have some degree of cognitive decline, changes in perfusion and functional connectivity that may precede clinical events suggesting a high risk for stroke. In this study, we aimed to evaluate the frequency and severity of cerebral blood flow (CBF), functional connectivity (FC) and cognitive performance abnormalities in patients with severe “asymptomatic” carotid artery stenosis (aCAS).

Methods: Fifteen patients with aCAS >70% and 15 controls were evaluated with 3T MRI, including BOLD-FMRI, Pseudo-continuous Arterial Spin Labeling and Resting-State Brain Networks. The cognitive assessment included tests for executive function, psychomotor speed, attention and memory. We used Mann-Whitney U Test to compare cognition and CBF between groups; Wilcoxon test for intragroup CBF differences; Spearman Correlation Coefficient for associations between CBF, FC and cognition.

Results: CBF maps in patients with aCAS revealed reduction in blood flow in the gray matter of temporal lobes and internal structures when compared to controls (p<0.05). The cognitive performance of patients with aCAS was lower than the control group for all measures, with significant differences in attention, mnemonic process and executive functions (p<0.05). Patients presented decreased connectivity for the fronto-temporal, salience and dorsal attentional networks (p-FDR<0.01). Additionally, we observed significant correlations (p<0.01) between salience network and the cognitive measures performed in this study.

Conclusions: Subjects with aCAS showed less expressive networks and significantly lower cognitive performance, indicating deficits in fundamental networks for the identification of relevant stimuli, neural resource coordination, and information processing. We identified preclinical abnormalities in CBF, FC and cognitive performance of patients with aCAS, suggesting that neuroimaging markers in MRI, combined with cognitive assessment, have a great potential to identify the profile of patients with high risk of stroke and cognitive decline.

Abstract WP22: Collateral Score and Outcome After Endovascular Treatment for Basilar Occlusion

Introduction: Basilar artery occlusion (BAO) is a rare stroke subtype with high morbidity and mortality rates. Best reperfusion strategy is still somewhat controversial and is currently under investigation in multicenter randomized trials. We aim to describe outcomes of BAO patients submitted to mechanical thrombectomy in a comprehensive stroke center in Brazil and analyze which previous published computed tomography angiography (CTA) collateral score better predicts functional outcomes.

Methods: Retrospective analysis of consecutive BAO patients from a prospective stroke registry. BAO was diagnosed through CTAs, which were also used to evaluate the Posterior Circulation Collateral Score (PC-CS), the Basilar Artery on Computed Tomography Angiography (BATMAN) scores and also for the presence of both posterior communicating arteries. A favorable outcome was defined as a mRS ≤3 at 90 days. After univariate analyses, multivariate logistic regression was used to identify if any collateral score independently predicts a favorable outcome. We also used ROC curves and C-statistics for score comparisons.

Results: Between January/2011 and April/2017, 27 (85% male) BAO patients with median NIHSS of 26 (IQR:15-32) were identified. Twenty-five (93%) patients were treated with a stent-retriever or an aspiration device, and only 2 (7%) patients were treated with basilar artery angioplasty and stenting. Recanalization rate was 85% and only 1 (3.7%) patient had a symptomatic hemorrhagic transformation. Favorable outcomes were reached in 10 (37%) patients at 90-days and mortality rate was 37%. In univariate analysis, female sex, NIHSS, onset-to-groin time and PC-CS predict favorable outcomes. In multivariate analysis, only PC-CS (OR=1.69;95%CI:1.10-2.60;p=0.016) and the baseline NIHSS (OR=0.84;95%CI:0.77-0.93;p=0.001) remained as independent predictors of favorable outcomes. The PC-CS AUC for favorable outcome was 0.80 (95%CI:0.62-0.98;p=0.012).

Conclusions: Mechanical thrombectomy seems to be a promising strategy for patients with acute BAO. Collateral flow assessment using the PC-CS is an independent predictor of favorable outcomes among acute BAO patients treated with mechanical thrombectomy.

Low-Dose vs Standard-Dose Alteplase for Patients With Acute Ischemic Stroke: Secondary Analysis of the ENCHANTED Randomized Clinical Trial

Importance

A lower dose of intravenous alteplase appears to be a safer treatment option than the standard dose, reducing the risk of symptomatic intracerebral hemorrhage. There is uncertainty, however, over how this effect translates into an overall clinical benefit for patients with acute ischemic stroke (AIS).

Objective

To assess whether older, Asian, or severely affected patients with AIS who are considered at high risk of thrombolysis may benefit more from low-dose rather than standard-dose alteplase treatment.

Design, Setting, and Participants

This study is a prespecified secondary analysis of the Enhanced Control of Hypertension and Thrombolysis Stroke Study (ENCHANTED), an international, randomized, open-label, blinded, end-point clinical trial of low-dose vs standard-dose intravenous alteplase for patients with AIS. From March 1, 2012, to August 31, 2015, a total of 3310 patients who had a clinical diagnosis of AIS as confirmed by brain imaging and who fulfilled the local criteria for thrombolysis treatment were included in the alteplase-dose arms. Patients were randomly assigned to receive low-dose (0.6 mg/kg; 15% as bolus and 85% as infusion over 1 hour) or standard-dose (0.9 mg/kg; 10% as bolus and 90% as infusion over 1 hour) alteplase. Of the 3310 randomized patients, 13 patients were excluded for missing consent, mistaken randomization, and duplicate randomization numbers. This secondary analysis was conducted between May 1, 2016, and April 28, 2017.

Main Outcomes and Measures

The primary end point was a poor outcome defined by the combination of death and any disability as scored by the modified Rankin Scale (scores range from 2 to 6, with the highest score indicating death) at 90 days.

Results

Of the 3297 patients included in the analysis, 1248 (37.9%) were women, and the mean (SD) age was 67 (13) years. No significant differences in the treatment effects were observed between low- and standard-dose alteplase for poor outcomes (death or disability) by age, ethnicity, or severity (all P > .37 for interaction). Similarly, the treatment effects of low- vs standard-dose alteplase on function outcome (ordinal shift of the modified Rankin Scale) in Asians (odds ratio, 1.05; 95% CI, 0.90-1.22) was consistent with non-Asians (odds ratio, 0.93; 95% CI, 0.76-1.14) (P = .32 for interaction). There were generally consistent reductions in rates of symptomatic intracerebral hemorrhage with low-dose alteplase, although this reduction was not statistically significant by age, ethnicity, or severity.

Conclusions and Relevance

This analysis found that the effects of low-dose alteplase were not clearly superior to the effects of standard-dose alteplase on death or disability in key demographic subgroups of patients with AIS. Further investigation is required to identify patients with AIS who may benefit from low-dose alteplase.

Trial Registration

clinicaltrials.gov Identifier: NCT01422616.

Hyper-attenuating brain lesions on CT after ischemic stroke and thrombectomy are associated with final brain infarction

Purpose Hyper-attenuating lesions, or contrast staining, on a non-contrast brain computed tomography (NCCT) scan have been investigated as a predictor for hemorrhagic transformation after endovascular treatment of acute ischemic stroke (AIS). However, the association of hyper-attenuating lesions and final ischemic areas are poorly investigated in this setting. The aim of the present study was to assess correlations between hyper-attenuating lesions and final brain infarcted areas after thrombectomy for AIS. Methods Data from patients with AIS of the anterior circulation who underwent endovascular treatment were retrospectively assessed. Images of the brain NCCT scans were analyzed in the first hours and late after treatment. The hyper-attenuating areas were compared to the final ischemic areas using the Alberta Stroke Program Early CT Score (ASPECTS). Results Seventy-one of the 123 patients (65.13%) treated were included. The association between the hyper-attenuating region in the post-thrombectomy CT scan and final brain ischemic area were sensitivity (58.3% to 96.9%), specificity (42.9% to 95.6%), positive predictive values (71.4% to 97.7%), negative predictive values (53.8% to 79.5%), and accuracy values (68% to 91%). The highest sensitivity values were found for the lentiform (96.9%) and caudate nuclei (80.4%) and for the internal capsule (87.5%), and the lowest values were found for the M1 (58.3%) and M6 (66.7%) cortices. Conclusions Hyper-attenuating lesions on head NCCT scans performed after endovascular treatment of AIS may predict final brain infarcted areas. The prediction appears to be higher in the deep brain regions compared with the cortical regions.

Assessment of the Predictive Validity of Etiologic Stroke Classification

Importance

The ability of present-day etiologic stroke classification systems to generate subtypes with discrete stroke characteristics is not known.

Objective

To test the hypothesis that etiologic stroke subtyping identifies different disease processes that can be recognized through their different clinical courses.

Design, Setting, and Participants

We performed a head-to-head evaluation of the ability of the Causative Classification of Stroke (CCS), Trial of Org 10172 in Acute Stroke Treatment (TOAST), and ASCO (A for atherosclerosis, S for small-vessel disease, C for cardiac source, and O for other cause) classification systems to generate etiologic subtypes with different clinical, imaging, and prognostic characteristics in 1816 patients with ischemic stroke. This study included 2 cohorts recruited at separate periods; the first cohort was recruited between April 2003 and June 2006 and the second between June 2009 and December 2011. Data analysis was performed between June 2014 and May 2016.

Main Outcomes and Measures

Separate teams of stroke-trained neurologists performed CCS, TOAST, and ASCO classifications based on information available at the time of hospital discharge. We assessed the association between etiologic subtypes and stroke characteristics by computing receiver operating characteristic curves for binary variables (90-day stroke recurrence and 90-day mortality) and by calculating the ratio of between-category to within-category variability from the analysis of variance for continuous variables (admission National Institutes of Health Stroke Scale score and acute infarct volume).

Results

Among the 1816 patients included, the median age was 70 years (interquartile range, 58-80 years) (830 women [46%]). The classification systems differed in their ability to assign stroke etiologies into known subtypes; the size of the undetermined category was 33% by CCS, 53% by TOAST, and 42% by ASCO (P < .001 for all binary comparisons). All systems provided significant discrimination for the validation variables tested. For the primary validation variable (90-day recurrence), the area under the receiver operating characteristic curve was 0.71 (95% CI, 0.66-0.75) for CCS, 0.61 (95% CI, 0.56-0.67) for TOAST, and 0.66 (95% CI, 0.60-0.71) for ASCO (P = .01 for CCS vs ASCO; P < .001 for CCS vs TOAST; P = .13 for ASCO vs TOAST). The classification systems exhibited similar discrimination for 90-day mortality. For admission National Institutes of Health Stroke Scale score and acute infarct volume, CCS generated more distinct subtypes with higher between-category to within-category variability than TOAST and ASCO.

Conclusions and Relevance

Our findings suggest that the major etiologic stroke subtypes are distinct categories with different stroke characteristics irrespective of the classification system used to identify them. We further show that CCS generates discrete etiologic categories with more diverse clinical, imaging, and prognostic characteristics than either TOAST or ASCO.

Abstract TP371: Monitoring a Large-scale International Cluster Stroke Trial: Lessons From Head Position in Stroke Trial

Background and Purpose: There is limited evidence on head positioning in acute ischemic stroke (AIS) or intracerebral hemorrhage (ICH). Potential benefits for lying flat (0°) include improved collateral blood flow in AIS and for head up (30°) reduced cerebral oedema in ICH. The Head Positioning in Stroke Trial (HeadPoST) aims to provide reliable evidence on the optimum head position in acute stroke.

Methods: HeadPoST is a prospective, cluster randomised, crossover, blinded outcome assessed, clinical trial with consecutive patient recruitment who were positioned within 24 hours of admission. Hospitals were randomised to service organisation to compare lying flat vs. sitting up (≥30°) head positioning of stroke patients. An innovative centralized remote monitoring system was used to assess data quality across participating countries.

Results: Over a 30 month study period, 10,000+ patients were recruited across 114 hospitals in 9 countries. A web-based monitoring system provided alerts for cross-over time points and achievement of cluster balance. Centralised reports included serious adverse events, protocol deviations, forms completion, data queries, entry delays and data validation, which were distributed to regional co-ordinating centres for action. Details of these procedures are outlined.

Conclusions: Reliable, complete, and high quality data were required for this pragmatic international nursing care clinical trial, which used a novel cluster cross-over design.

Low-Dose versus Standard-Dose Intravenous Alteplase in Acute Ischemic Stroke

BACKGROUND

Thrombolytic therapy for acute ischemic stroke with a lower-than-standard dose of intravenous alteplase may improve recovery along with a reduced risk of intracerebral hemorrhage.

METHODS

Using a 2-by-2 quasi-factorial open-label design, we randomly assigned 3310 patients who were eligible for thrombolytic therapy (median age, 67 years; 63% Asian) to low-dose intravenous alteplase (0.6 mg per kilogram of body weight) or the standard dose (0.9 mg per kilogram); patients underwent randomization within 4.5 hours after the onset of stroke. The primary objective was to determine whether the low dose would be noninferior to the standard dose with respect to the primary outcome of death or disability at 90 days, which was defined by scores of 2 to 6 on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]). Secondary objectives were to determine whether the low dose would be superior to the standard dose with respect to centrally adjudicated symptomatic intracerebral hemorrhage and whether the low dose would be noninferior in an ordinal analysis of modified Rankin scale scores (testing for an improvement in the distribution of scores). The trial included 935 patients who were also randomly assigned to intensive or guideline-recommended blood-pressure control.

RESULTS

The primary outcome occurred in 855 of 1607 participants (53.2%) in the low-dose group and in 817 of 1599 participants (51.1%) in the standard-dose group (odds ratio, 1.09; 95% confidence interval [CI], 0.95 to 1.25; the upper boundary exceeded the noninferiority margin of 1.14; P=0.51 for noninferiority). Low-dose alteplase was noninferior in the ordinal analysis of modified Rankin scale scores (unadjusted common odds ratio, 1.00; 95% CI, 0.89 to 1.13; P=0.04 for noninferiority). Major symptomatic intracerebral hemorrhage occurred in 1.0% of the participants in the low-dose group and in 2.1% of the participants in the standard-dose group (P=0.01); fatal events occurred within 7 days in 0.5% and 1.5%, respectively (P=0.01). Mortality at 90 days did not differ significantly between the two groups (8.5% and 10.3%, respectively; P=0.07).

CONCLUSIONS

This trial involving predominantly Asian patients with acute ischemic stroke did not show the noninferiority of low-dose alteplase to standard-dose alteplase with respect to death and disability at 90 days. There were significantly fewer symptomatic intracerebral hemorrhages with low-dose alteplase. (Funded by the National Health and Medical Research Council of Australia and others; ENCHANTED ClinicalTrials.gov number, NCT01422616.).

Trends of Stroke Incidence from 1995 to 2013 in Joinville, Brazil

BACKGROUND

Temporal trends on the incidence of stroke and its subtypes could help assess on-going public health policies and point to further targets for action among middle- and low-income countries, where the stroke burden is very high. This study aimed at evaluating longitudinal trends of stroke incidence in Joinville, Brazil.

METHODS

We ascertained the incidence of all first-ever strokes occurred in 1995, 2005-2006 and 2012-2013, which were extracted from Joinville Stroke Registry, a prospective epidemiological data bank, launched in 1995.

RESULTS

From 1995 to 2013, the age-adjusted incidence of all strokes decreased 37% (95% CI 32-42). From 2005 to 2013, the haemorrhagic stroke (HS) incidence decreased 60% (95% CI 13-86), ischemic stroke (IS) incidence decreased 15% (95% CI 1-28), and subarachnoid haemorrhage incidence remained stable. The proportion of IS and HS patients with regularly treated hypertension increased by 60% (p = 0.01) and 33% (p = 0.01), respectively. The proportion of IS and HS patients that quit smoking increased 8% (p = 0.03) and 17% (p = 0.03), respectively.

CONCLUSIONS

Stroke incidence has been decreasing in Joinville over the last 18 years, more so for HS than IS. Better control of hypertension and tobacco use might explain these findings.

Polarity-Dependent Misperception of Subjective Visual Vertical during and after Transcranial Direct Current Stimulation (tDCS)

Pathologic tilt of subjective visual vertical (SVV) frequently has adverse functional consequences for patients with stroke and vestibular disorders. Repetitive transcranial magnetic stimulation (rTMS) of the supramarginal gyrus can produce a transitory tilt on SVV in healthy subjects. However, the effect of transcranial direct current stimulation (tDCS) on SVV has never been systematically studied. We investigated whether bilateral tDCS over the temporal-parietal region could result in both online and offline SVV misperception in healthy subjects. In a randomized, sham-controlled, single-blind crossover pilot study, thirteen healthy subjects performed tests of SVV before, during and after the tDCS applied over the temporal-parietal region in three conditions used on different days: right anode/left cathode; right cathode/left anode; and sham. Subjects were blind to the tDCS conditions. Montage-specific current flow patterns were investigated using computational models. SVV was significantly displaced towards the anode during both active stimulation conditions when compared to sham condition. Immediately after both active conditions, there were rebound effects. Longer lasting after-effects towards the anode occurred only in the right cathode/left anode condition. Current flow models predicted the stimulation of temporal-parietal regions under the electrodes and deep clusters in the posterior limb of the internal capsule. The present findings indicate that tDCS over the temporal-parietal region can significantly alter human SVV perception. This tDCS approach may be a potential clinical tool for the treatment of SVV misperception in neurological patients.

Abstract TP46: A Score to Detect Proximal Artery Occlusion in Patients With Acute Ischemic Stroke of the Anterior Circulation Based on NIHSS and Non-contrast Brain CT: the PAO Score

Introduction: After the results of the new endovascular trials that demonstrated a robust effect of endovascular treatment for acute ischemic stroke (AIS), early detection of proximal artery occlusion (PAO) has become a fundamental task during the initial assessment of acute stroke patients at the emergency department. Nevertheless, an accurate identification of PAO may be particularly challenging in smaller hospitals and in developing countries, areas with restricted assess to vascular neuroimaging modalities such as CTA and MRA.

Hypothesis: Algorithms based on NIHSS and non-contrasted CT (NCCT) findings can be accurately used to detect PAO in patients with AIS of the anterior circulation.

Method: We retrospectively evaluated 194 consecutive patients with AIS of the anterior circulation from a prospective stroke registry of patients admitted to an academic tertiary emergency unit in Brazil during 2014 that had a NCCT and a CTA at admission. NIHSS scores and attenuation of major intracranial arteries of the anterior circulation on NCCT were collected by two experienced investigators that were blind to the CT angiography findings. We used a ratio between two ROIs (rVA) that were drawn on NCCT blinded to CT angiography: (i) on the region of highest vessel attenuation ipsilateral to the involved hemisphere and (ii) mirror ROI on the corresponding vessel segment of the contralateral hemisphere. We used ROC curve analysis and C-statistics to predict CT angiography PAO.

Results: NIHSS and vessel attenuation values were highly associated with the PAO with an area under the curve (AUC) of 0.88 (p < 0,001) and 0.83 (p < 0,001), respectively. An NIHSS of 10 at admission had a sensitivity, and negative predictive value of 97% and 97%, respectively. The rVA ≥ 1.50 had a specificity and positive predictive value 96% and 85%, respectively. The POA score was then built by logistic regression from NIHSS and rVA and showed even higher accuracy for the presence of POA on CTA, with an AUC of 0.93 (p < 0,001).

Conclusion: The PAO score based on admission NIHSS and proximal vessel attenuation on NCCT can be accurately used to detect PAO in patients with AIS of the anterior circulation. Further studies are necessary to validate this score in a multicenter setting.

Rationale, Design, and Progress of the ENhanced Control of Hypertension ANd Thrombolysis Stroke Study (ENCHANTED) Trial: An International Multicenter 2 × 2 Quasi-Factorial Randomized Controlled Trial of Low- vs. Standard-Dose rt-PA and Early Intensive vs. Guideline-Recommended Blood Pressure Lowering in Patients with Acute Ischaemic Stroke Eligible for Thrombolysis Treatment

Rationale

Controversy exists over the optimal dose of intravenous (iv) recombinant tissue plasminogen activator (rt-PA) and degree of blood pressure (BP) control in acute ischaemic stroke (AIS). Asian studies suggest low-dose (0·6 mg/kg) is more efficacious than standard-dose (0·9 mg/kg) iv rt-PA, and guidelines recommend reducing systolic BP to <185 mmHg before and <180 mmHg after use of iv rt-PA, despite observational studies indicating better outcomes at much lower (<140 mmHg) systolic BP levels in this patient group.

Aims

The study aims to assess in thrombolysis-eligible AIS patients whether: (i) low-dose (0·6 mg/kg body weight; maximum 60 mg) iv rt-PA has non-inferior efficacy and lower risk of symptomatic intracerebral haemorrhage (sICH) compared to standard-dose (0·9 mg/kg body weight; maximum 90 mg) iv rt-PA; and (ii) early intensive BP lowering (systolic target 130–140 mmHg) has superior efficacy and lower risk of any ICH compared to guideline-recommended BP control (systolic target < 180 mmHg).

Design

The ENhanced Control of Hypertension And Thrombolysis strokE stuDy (ENCHANTED) trial is an independent, 2 × 2 quasi-factorial, active-comparison, prospective, randomized, open blinded endpoint (PROBE), clinical trial that is evaluating Arm [A] ‘rt-PA dose’ and/or Arm [B] ‘BP control’, using central Internet randomization and data collection in patients fulfilling local criteria for thrombolysis and clinician uncertainty over the study treatments. The treatment arms will be analyzed separately.

Study outcomes

The primary study outcome in both trial Arms is death or disability according to the modified Rankin scale (mRS, scores 2–6) assessed at 90 days. Secondary outcomes include sICH, any ICH, a shift (‘improvement’) in function across mRS scores, separately on death and disability, early neurological deterioration, recurrent major vascular events, health-related quality of life, length of hospital stay, need for permanent residential care, and health care costs.

Results

Following launch of the trial in February 2012, the study has recruited more than 2500 patients across a global network of approximately 100 sites in 15 countries. The required sample sizes are 3300 for Arm [A] and 2300 for Arm [B], which will provide >90% power to detect non-inferiority of low-dose iv rt-PA and superiority of intensive BP lowering on the primary clinical outcome, respectively.

Conclusions

Low-dose iv rt-PA and early intensive BP lowering could provide more affordable and safer use of thrombolysis treatment for patients with AIS worldwide.

Validation of a structured interview for telephone assessment of the modified Rankin Scale in Brazilian stroke patients

BACKGROUND

The modified Rankin Scale (mRS) is a commonly used scale to assess the functional outcome after stroke. Several studies on mRS showed good reliability, feasibility, and interrater agreement of this scale using a face-to-face assessment. However, telephone assessment is a more time-efficient way to obtain an mRS grade than a face-to-face interview. The aim of this study was to validate the telephone assessment of mRS among the Portuguese using a structured interview in a sample of Brazilian stroke patients.

METHODS

We evaluated 50 stroke outpatients twice. The first interview was face-to-face and the second was made by telephone and the time between the two assessments ranged between 7 and 14 days. Four certified raters evaluated the patients using a structured interview based on a questionnaire previously published in the literature. Raters were blinded for the Rankin score given by the other rater. For both assessments, the rater could also interview a caregiver if necessary.

RESULTS

The patients' mean age was 62.8 ± 14.7, mean number of years of study 5.2 ± 3.4, 52% were males, 55.2% of patients needed a caregiver's help to answer the questions. The majority of caregivers were female (85%), mean age 49.1 ± 15, and mean number of years of study 8.3 ± 3.4. Perfect agreement between the telephone and face-to-face assessments was obtained for 27 (54%) patients, corresponding to an unweighted Kappa of 0.44 (95% CI 0.27-0.61) and a weighted Kappa of 0.89. The median of telephone assessment mRS was 3.5 (interquartile range = 2-4) and of face-to-face assessment was 4 (interquartile range = 2-5). There was no difference between the two assessments (Wilcoxon test, p = 0.35).

CONCLUSIONS

Despite the low education level of our sample, the telephone assessment of functional impairment of stroke patients using a translated and culturally adapted Brazilian Portuguese version of the mRS showed good validity and reliability. Therefore, the telephone assessment of mRS can be used in clinical practice and scientific studies in Brazil.

Abstract T MP13: Chagas Disease Related Stroke: Safety of Intravenous Thrombolysis and Endovascular Treatment

Background: AND AIM: Chagas disease (CD) is a common cause of stroke in undeveloped countries and has become more frequent in the US, where it is largely underestimated. CD related strokes are believed to be mainly cardioembolic but some studies have suggested concomitant cerebral vasculitis. Data on the safety of recanalization therapies in patients with acute stroke related to CD is still restricted to single case reports. We aimed to assess the rate of symptomatic intracranial hemorrhage (SIH) in a group of patients with CD-related stroke treated with intravenous tissue plasminogen activator (IV TPA) and/or endovascular therapy.

METHODS: We performed a retrospective analysis of a prospective, single-center, hospital-based registry of acute stroke patients treated with IV TPA and/or endovascular therapy and routinely tested for CD. Demographics, medical history and clinical data were obtained from the registry. CT scans at admission and after 24-48 hours were blindly reviewed by two experienced stroke neurologists, who rated the presence of hemorrhage transformation according to the European Cooperative Acute Stroke Study criteria.

RESULTS: From 2001 to 2012, 197 patients met the inclusion criteria for this study. CD was diagnosed in 30 patients (15.2%). Patients with CD had higher admission scores on the National Institute of Health Stroke Scale [median: 19; interquartile range (IR): 16-22; no CD: 14; IR: 9-19; P<0.01]. Among patients treated with IV TPA, the rate of SIH was similar among patients with CD (1/24; 4.2%) and patients without CD (8/150; 5.3%; OR: 0.77, 95% CI: 0.09-6.46; P=0.99). Among those treated with rescue endovascular treatment, SIH occurred in 2/6 (33.3%) patients with CD and in 3/17 (17.6%) patients without CD (OR: 2.33, 95%CI: 0.28-19.17, P=0.58). Overall, there was no difference in mortality between groups [CD: 6 (20%); no CD: 24 (14.4%); OR: 1.49; 95% CI: 0.55-4.0; P=0.42].

CONCLUSIONS: In the largest series of patients with acute stroke related to CD treated with recanalization therapies ever reported, we found that IV TPA appears to be safe in these patients. Further studies are necessary to confirm the safety and efficacy of endovascular recanalization strategies in patients with CD.

Abstract W P224: SOS Score: an Optimized Score to Screen Acute Stroke Patients for Obstructive Sleep Apnea

Background: Obstructive sleep apnea (OSA) is frequent in acute stroke patients and is associated with increased mortality and poor functional outcome. Polysomnography (PSG) is the gold standard diagnostic method for OSA, but it is impracticable as a routine for all acute stroke patients. We evaluated how OSA screening tools such as the Berlin Questionnaire (BQ) and the Epworth Sleepiness Scale (ESS) would perform when administered to relatives of stroke patients in the acute setting, and compared these individual tools against a combined screening score (SOS score).

Methods: Ischemic stroke patients were submitted to a full PSG at the first night after symptoms onset. OSA severity was measured by apnea-hypopnea index (AHI). BQ and ESS were administered to relatives of stroke patients before the PSG. We combined elements of the BQ and ESS to create a new screening tool for OSA named Sleep Obstructive apnea score optimized for Stroke (SOS score).

Results: Thirty-nine consecutives ischemic stroke patients were enrolled in our study. The mean age was 62.3 ±12.2 years. Age was significantly different between those with and without OSA (p=0.02). The mean body mass index and neck circumference were 26.7 ± 4.7 and 38.9 ± 4.0cm, respectively. OSA (AHI ≥ 10) was present in 76.9%. The area under the curve for SOS score (AUC:0.812; p=0.005) was superior to BQ (AUC:0.567; p=0.549) and also to ESS (AUC:0.646; p=0.119 vs. AUC:0.686; p=0.048) for severe OSA (IAH ≥ 30). The threshold of SOS ≤ 10 (present in 20.5% of patients) showed high sensitivity (90%) and negative predictive value (96.2%) for OSA; SOS ≥20 (17.9% of patients) showed high specificity (100%) and positive predictive value (92.5%) for severe OSA. Using SOS as a screening approach would decrease by around 40% the demand for PSG during the acute stroke setting.

Conclusions: The SOS score when administered to relatives of stroke patients appears to be an appropriate tool to screen acute stroke patients for OSA, while decreasing the need for a formal sleep study during the acute stroke setting. The new derived SOS score is superior to BQ and ESS for identifying patients with OSA and Severe OSA during the acute phase of stroke.