Antiplatelet Drugs for Neurointerventions: Part 2 Clinical Applications

Endovascular techniques have expanded to include balloon and stent-assistance, flow diversion and individualized endovascular occlusion devices, to widen the treatment spectrum for more complex aneurysm morphologies. While usually well-tolerated by patients, endovascular treatment of intracranial aneurysms carries the risk of complications, with procedure-related ischemic complications being the most common. Several antiplatelet agents have been studied in a neurointerventional setting for both prophylaxis and in the setting of intraprocedural thrombotic complications. Knowledge of these antiplatelet agents, evidence for their use and common dosages is important for the practicing neurointerventionist to ensure the proper application of these agents.Part one of this two-part review focused on basic platelet physiology, pharmacology of common antiplatelet medications and future directions and therapies. Part two focuses on clinical applications and evidence based therapeutic regimens.

Abstract P73: Imaging Markers of Brain Frailty and Outcome in Patients With Acute Ischemic Stroke

Background and purpose: Functional outcome after stroke may be related to preexisting brain health. Several imaging markers of brain frailty have been described including brain atrophy and markers of small vessel disease. We investigated the association of these imaging markers with functional outcome after acute ischemic stroke.

Methods: We retrospectively studied patients with acute ischemic stroke enrolled in the AXIS-2 trial, an international, multicenter, randomized controlled clinical trial of Granulocyte Colony Stimulating Factor versus placebo. We assessed the ratio of brain parenchymal volume to total intracerebral volumes (i.e., the brain parenchymal fraction [BPF]) and total brain volumes from routine baseline MRI data obtained within 9 hours of symptom onset using the unified segmentation algorithm in SPM12. Enlarged perivascular spaces (EPVS), white matter hyperintensities (WMH), lacunes as well as a small vessel disease (SVD) burden were rated visually. Functional outcomes (modified Rankin Scale [mRS] score) at day 90 were determined. Logistic regression was used to test associations between brain imaging features and functional outcomes. As there was no significant effect of G-CSF on any outcomes in AXIS-2, placebo and active groups were combined for these analyses.

Results: We enrolled 259 patients with a mean age of 69±12 years and 46 % were female. Increased BPF was associated with higher odds of excellent outcome (OR per percent increase: 1.081, 95%CI: 1.012-1.155). Total brain volumes and SVD burden were not associated with functional outcome. An interaction between BPF and large vessel occlusion on excellent outcome was not observed.

Conclusions: Global brain health, as assessed by brain parenchymal fraction on magnetic resonance imaging, is associated with excellent functional outcome after ischemic stroke.

Clinical Trial Registration: URL: http://www.clinicaltrials.gov . Unique identifier: NCT00927836.

Abstract P370: Early Brain Volume Change After Stroke: Subgroup Analysis From the Axis-2 Trial

Objective: The timing of brain atrophy after stroke is not well understood. We investigated the associations between age and imaging features and brain volume change in the first month after stroke.

Methods: We retrospectively studied patients with acute ischemic stroke enrolled in the AXIS-2 trial. Total brain volume change from hyperacute MRI data to the first month after stroke was assessed using unified segmentation in SPM12. We hypothesized that age, ischemic brain lesion size and white matter changes were associated with larger brain volume change. Enlarged perivascular spaces (EPVS) and white matter hyperintensities (WMH) were rated visually and the presence of lacunes was assessed.

Results: We enrolled 173 patients with a mean age of 67±11 years, 44 % were female. There was a median 6 mL decrease in volume (25th percentile -1mL-75th percentile 21mL) over time, equivalent to a median 0.5% (IQR-0.07% - 1.4%), decrease in brain volume. Age was associated with larger brain volume loss (per 10 years of age, 5 mL 95% CI 2 mL-8 mL). Baseline DWI lesion volume was not associated with greater volume loss (per 10 mL of lesion volume, change by 0 mL (95% CI -0.1 mL-0.1mL). Increasing Fazekas scores of deep white matter hyperintensity were associated with greater tissue loss (5 mL, 95% CI 1 mL-10 mL). Brain volume change was associated with ordinal change on the modified Rankin scale at 90 days (per 10 ml, OR 1.085, 95% CI 1.031-1.141) but the association was not present when adjusting for age, baseline diffusion lesion volume and NIHSS score (OR 1.044, 95% CI 0.990-1.010).Interpretation-Global brain volume loss occurs over 1 month after stroke and is associated with age and deep white matter disease. We did not find evidence that more severe strokes lead to increased early tissue loss.

Abstract P352: Reversible Relative FLAIR Signal Intensity Changes in the Penumbra Correlate With Severity of Hypoperfusion

In ischemic stroke, the study of edema, measurable as fluid attenuated inversion recovery (FLAIR) signal increase, has mainly focused on the ischemic core and less on the surrounding penumbra. To the naked eye, no FLAIR changes are present in the penumbra. However, changes in perfusion status could induce physiological changes resulting in subtle penumbral FLAIR signal alterations. To investigate penumbral FLAIR changes, we included subjects from the Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke (WAKE-UP) and Granulocyte Colony-Stimulating Factor in Patients With Acute Ischemic Stroke (AXIS 2) trial with perfusion- and diffusion-weighted imaging (PWI, DWI) and FLAIR at baseline. We used RAPID software to calculate the core and perfusion lesion on DWI and PWI and selected subjects with a minimal mismatch volume (15 ml) and ratio (1.2). We created voxel-based relative FLAIR signal intensity (rFLAIR SI) maps at baseline and follow up (FU) by calculating the ratio of the FLAIR intensity in one voxel and the median FLAIR intensity in a sphere with 15 mm radius around a contralateral homologues voxel. We studied rFLAIR SI in two regions of interest: the baseline penumbra (baseline perfusion lesion - [core lesion + voxels with apparent diffusion coefficient <620 10 -6 mm 2 /s]) and the non-infarcted penumbra (baseline perfusion lesion - FU FLAIR lesion) at 24 hours (WAKE-UP) or 30 days (AXIS 2). Severity of hypoperfusion was defined as the time to maximum of the residue function. In the baseline penumbra, rFLAIR SI was elevated (ratio=1.04, p=1.7*10 -13 , n=126) and correlated with severity of hypoperfusion (Pearson’s r 0.03, p<1.0*10 -4 , n=126). At 24 hours in a subgroup from WAKE-UP, rFLAIR SI in the non-infarcted penumbra further increased (ratio=1.05 at 24h vs 1.03 at baseline, p=7.1*10 -3 , n=43). In a different subgroup from AXIS 2, this increase in rFLAIR SI was reversible (ratio=1.02 at 30d vs 1.04 at baseline, p=1.5*10 -3 n=26) since it was no longer different from 1 at 30 days (ratio=1.01 at 30 days, p=0.099, n=26). Increases in rFLAIR SI, likely representing edema, are not restricted to the ischemic core and correlate with severity of hypoperfusion in the penumbra. They appear early after stroke onset, further increase at 24 hours and are reversible by 30 days.

Extent of FLAIR Hyperintense Vessels May Modify Treatment Effect of Thrombolysis: A Post hoc Analysis of the WAKE-UP Trial

Background and Aims: Fluid-attenuated inversion recovery (FLAIR) hyperintense vessels (FHVs) on MRI are a radiological marker of vessel occlusion and indirect sign of collateral circulation. However, the clinical relevance is uncertain. We explored whether the extent of FHVs is associated with outcome and how FHVs modify treatment effect of thrombolysis in a subgroup of patients with confirmed unilateral vessel occlusion from the randomized controlled WAKE-UP trial.

Methods: One hundred sixty-five patients were analyzed. Two blinded raters independently assessed the presence and extent of FHVs (defined as the number of slices with visible FHV multiplied by FLAIR slice thickness). Patients were then separated into two groups to distinguish between few and extensive FHVs (dichotomization at the median <30 or ≥30).

Results: Here, 85% of all patients (n = 140) and 95% of middle cerebral artery (MCA) occlusion patients (n = 127) showed FHVs at baseline. Between MCA occlusion patients with few and extensive FHVs, no differences were identified in relative lesion growth (p = 0.971) and short-term [follow-up National Institutes of Health Stroke Scale (NIHSS) score; p = 0.342] or long-term functional recovery [modified Rankin Scale (mRS) <2 at 90 days poststroke; p = 0.607]. In linear regression analysis, baseline extent of FHV (defined as a continuous variable) was highly associated with volume of hypoperfused tissue (β = 2.161; 95% CI 0.96–3.36; p = 0.001). In multivariable regression analysis adjusted for treatment group, stroke severity, lesion volume, occlusion site, and recanalization, FHV did not modify functional recovery. However, in patients with few FHVs, the odds for good functional outcome (mRS) were increased in recombinant tissue plasminogen activator (rtPA) patients compared to those who received placebo [odds ratio (OR) = 5.3; 95% CI 1.2–24.0], whereas no apparent benefit was observed in patients with extensive FHVs (OR = 1.1; 95% CI 0.3–3.8), p-value for interaction was 0.11.

Conclusion: While the extent of FHVs on baseline did not alter the evolution of stroke in terms of lesion progression or functional recovery, it may modify treatment effect and should therefore be considered relevant additional information in those patients who are eligible for intravenous thrombolysis.

Clinical Trial Registration: Main trial (WAKE-UP): ClinicalTrials.gov, NCT01525290; and EudraCT, 2011-005906-32. Registered February 2, 2012.

Feasibility trial of metformin XR in people with pre-diabetes and stroke (MIPPS)-randomised open blinded endpoint controlled trial

AIMS

Pre-diabetes is a common condition that affects about 16.4% of Australian adults. Hyperglycaemia is a strong risk factor for the development of stroke. Metformin XR is an approved medication to treat type 2 diabetes in Australia but not pre-diabetes. Additionally, whether it is tolerated following a stroke is unclear. In this pilot study, we aimed to assess the feasibility of Metformin XR in people with stroke and pre-diabetes.

METHODS

In this PROBE design trial, people who had recent stroke (within 3 months) with pre-diabetes were randomized to either the active arm (n = 13) receiving usual care plus Metformin XR (500 mg daily increased to a total daily dose of 1500 mg) or the control group receiving only usual care (n = 13). At baseline & after four months of intervention, clinical and biomedical characteristics, cardiovascular risk factors and medication data were recorded. At one month and 2.5 months into the study, compliance rateandside effects were determined.

RESULTS

This trial showed that it is feasible to recruit, retain and monitor participants. However, the compliance rate was low. Adherence to metformin XR was 52% (IQR:42% to 61%) based on the remaining tablets in the container after 4 months of intervention. None of the reported side effects were deemed to be related to the study treatment and no significant differences were observed between the metformin XR and the control group.

CONCLUSION

Treatment with Metformin XR in participants admitted with stroke and with pre-diabetes is feasible and safe. Strategies are needed to improve adherence in future trials.

Association of Reperfusion After Thrombolysis With Clinical Outcome Across the 4.5- to 9-Hours and Wake-up Stroke Time Window: A Meta-Analysis of the EXTEND and EPITHET Randomized Clinical Trials

Importance

Intravenous alteplase reduces disability after ischemic stroke in patients 4.5 to 9 hours after onset and with wake-up onset stroke selected using perfusion imaging mismatch. However, whether the benefit is consistent across the 4.5- to 6-hours, 6- to 9-hours, and wake-up stroke epochs is uncertain.

Objective

To examine the association of reperfusion with reduced disability, including by onset-to-randomization time strata in the Extending the Time for Thrombolysis in Emergency Neurological Deficits (EXTEND) and Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET) randomized clinical trials.

Design, Setting, and Participants

Individual patient meta-analysis of randomized clinical trials performed from August 2001 to June 2018 with 3-month follow-up. Patients had acute ischemic stroke with 4.5-to 9-hours poststroke onset or with wake-up stroke were randomized to alteplase or placebo after perfusion mismatch imaging. Analysis began July 2019 and ended May 2020.

Exposures

Reperfusion was defined as more than 90% reduction in time to maximum of more than 6 seconds' lesion volume at 24- to 72-hour follow-up.

Main Outcomes and Measures

Ordinal logistic regression adjusted for baseline age and National Institutes of Health Stroke Scale score was used to analyze functional improvement in day 90 modified Rankin Scale score overall, including a reperfusion × time-to-randomization multiplicative interaction term, and in the 4.5- to 6-hours, 6- to 9-hours, and wake-up time strata. Symptomatic hemorrhage was defined as large parenchymal hematoma with a National Institutes of Health Stroke Scale score increase of 4 points or more.

Results

Reperfusion was assessable in 270 of 295 patients (92%), 68 of 133 (51%) in the alteplase group, and 38 of 137 (28%) in the placebo reperfused group (P < .001). The median (interquartile range) age was 76 (66-81) years in the reperfusion group vs 74 (64.5-81.0) years in the group with no reperfusion. The median (interquartile range) baseline National Institutes of Health Stroke Scale score was 10 (7-15) in the reperfusion group vs 12 (8.0-17.5) in the no reperfusion group. Overall, reperfusion was associated with improved functional outcome (common odds ratio, 7.7; 95% CI, 4.6-12.8; P < .001). Reperfusion was associated with significantly improved functional outcome in each of the 4.5- to 6-hours, 6- to 9-hours, and wake-up time strata, with no evidence of association between time to randomization and beneficial effect of reperfusion (P = .63). Symptomatic hemorrhage, assessed in all 294 patients, occurred in 3 of 51 (5.9%) in the 4.5- to 6-hours group, 2 of 28 (7.1%) in the 6- to 9-hours group, and 4 of 73 (5.5%) in the wake-up stroke in patients treated with alteplase (Fisher P = .91).

Conclusions and Relevance

Strong benefits of reperfusion in all time strata without differential risk in symptomatic hemorrhage support the consistent treatment effect of alteplase in perfusion mismatch-selected patients throughout the 4.5- to 9-hours and wake-up stroke time window.

Imaging Markers of Brain Frailty and Outcome in Patients With Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Functional outcome after stroke may be related to preexisting brain health. Several imaging markers of brain frailty have been described including brain atrophy and markers of small vessel disease. We investigated the association of these imaging markers with functional outcome after acute ischemic stroke.

METHODS

We retrospectively studied patients with acute ischemic stroke enrolled in the AXIS-2 trial (AX200 in Ischemic Stroke Trial), a randomized controlled clinical trial of granulocyte colony-stimulating factor versus placebo. We assessed the ratio of brain parenchymal volume to total intracerebral volumes (ie, the brain parenchymal fraction) and total brain volumes from routine baseline magnetic resonance imaging data obtained within 9 hours of symptom onset using the unified segmentation algorithm in SPM12. Enlarged perivascular spaces, white matter hyperintensities, lacunes, as well as a small vessel disease burden, were rated visually. Functional outcomes (modified Rankin Scale score) at day 90 were determined. Logistic regression was used to test associations between brain imaging features and functional outcomes.

RESULTS

We enrolled 259 patients with a mean age of 69±12 years and 46 % were female. Increased brain parenchymal fraction was associated with higher odds of excellent outcome (odds ratio per percent increase, 1.078 [95% CI, 1.008-1.153]). Total brain volumes and small vessel disease burden were not associated with functional outcome. An interaction between brain parenchymal fraction and large vessel occlusion on excellent outcome was not observed.

CONCLUSIONS

Global brain health, as assessed by brain parenchymal fraction on magnetic resonance imaging, is associated with excellent functional outcome after ischemic stroke. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00927836.

Occlusive Disease and Upright Activity in Acute Ischemic Stroke

The impact of out-of-bed upright activity on outcomes in ischemic stroke patients with severe extra- and intracranial stenosis or occlusion is unknown. Using ultrasound findings from a cohort recruited to A Very Early Rehabilitation Trial (AVERT) which compared higher dose very early mobilisation (VEM) to usual care (UC), we aimed to explore the association between occlusive disease and 3-month outcomes and occlusive disease-by-mobilisation treatment interactions. Participants with ischemic stroke, with carotid and transcranial Doppler ultrasounds performed ≤1 week after admission, were included in this single centre substudy in Melbourne, Australia. Reports were retrospectively reviewed to determine the degree of stenosis or presence of occlusion in the relevant arterial territory. Stenosis ≥70% extracranial or ≥50% intracranial were classified as severe or occlusion. Overall, 19% (n = 36/191) had occlusive disease in the affected circulation. About 40% (n = 14/36) with occlusive disease and 51% (n = 79/155) without had a 3-month favourable outcome (mRS 0-2) (adjusted OR0.53, CI0.17-1.67). Fourteen percent (n = 5) with occlusive disease and 4% (n = 6) without died by 3 months (adjusted OR2.52, CI0.6-10.7). Fifty percent (n = 11/22) of UC (adjusted OR0.86, CI0.23-3.2) and 21% (n = 3/14) of VEM participants (adjusted OR0.16, CI0.01-2.7) with occlusive disease had a favourable outcome. Almost 30% (n = 4) VEM participants with occlusive disease died (adjusted OR3.99, CI0.69-22.9) compared to 5% (n = 1) UC participants with occlusive disease (adjusted OR0.45, CI0.02-8.6), however numbers were small. No stenosis-by-treatment interactions were found. High quality prospective studies are needed to help guide decision making about when patients with occlusive disease should commence upright activity in acute stroke.

Review of deep learning algorithms for the automatic detection of intracranial hemorrhages on computed tomography head imaging

Artificial intelligence is a rapidly evolving field, with modern technological advances and the growth of electronic health data opening new possibilities in diagnostic radiology. In recent years, the performance of deep learning (DL) algorithms on various medical image tasks have continually improved. DL algorithms have been proposed as a tool to detect various forms of intracranial hemorrhage on non-contrast computed tomography (NCCT) of the head. In subtle, acute cases, the capacity for DL algorithm image interpretation support might improve the diagnostic yield of CT for detection of this time-critical condition, potentially expediting treatment where appropriate and improving patient outcomes. However, there are multiple challenges to DL algorithm implementation, such as the relative scarcity of labeled datasets, the difficulties in developing algorithms capable of volumetric medical image analysis, and the complex practicalities of deployment into clinical practice. This review examines the literature and the approaches taken in the development of DL algorithms for the detection of intracranial hemorrhage on NCCT head studies. Considerations in crafting such algorithms will be discussed, as well as challenges which must be overcome to ensure effective, dependable implementations as automated tools in a clinical setting.

Postoperative Atrial Fibrillation and Long-Term Risk of Stroke in Patients Undergoing Liver Transplantation

BACKGROUND AND PURPOSE

Postoperative atrial fibrillation (POAF) is the commonest cardiovascular complication following liver transplantation (LT). This study sought to assess a possible association of POAF with subsequent thromboembolic events in patients undergoing LT.

METHODS

A retrospective cohort study of consecutive adults undergoing LT between 2010 and 2018 was undertaken. Patients were classified as POAF if atrial fibrillation (AF) was documented within 30 days of LT without a prior history of AF. Cases of ischemic stroke or systemic embolism were adjudicated by a panel of 2 independent physicians.

RESULTS

Among the 461 patients included, POAF occurred in 47 (10.2%) a median of 3 days following transplantation. Independent predictors of POAF included advancing age, postoperative sepsis and left atrial enlargement. Over a median follow-up of 4.9 (interquartile range, 2.9-7.2) years, 21 cases of stroke and systemic embolism occurred. Rates of thromboembolic events were significantly higher in patients with POAF (17.0% versus 3.1%; P<0.001). After adjustment, POAF remained a strong independent predictor of thromboembolic events (hazard ratio, 8.36 [95% CI, 2.34-29.79]). Increasing CHA₂DS₂VASc score was also an independent predictor of thromboembolic events (hazard ratio, 1.58 [95% CI, 1.02-2.46]). A model using POAF and a CHA₂DS₂VASc score ≥2 alone yielded a C statistic of 0.77, with appropriate calibration for the prediction of thromboembolic events. However, POAF was not an independent predictor of long-term mortality.

CONCLUSIONS

POAF following LT is associated with an 8-fold increased risk of thromboembolic events and the use of the CHA₂DS₂VASc score may facilitate risk stratification of these patients. Prospective studies are warranted to assess whether the use of oral anticoagulants can reduce the risk of thromboembolism following LT.

High Frequency of Anticoagulation Management Errors Preceding Ischemic Strokes in Atrial Fibrillation

BACKGROUND AND AIMS

Anticoagulants are recommended to prevent cardioembolic stroke in most patients with atrial fibrillation (AF). Management errors with anticoagulation and use of aspirin instead of anticoagulants have been documented worldwide, especially with vitamin K antagonists. We assessed the rate of anticoagulant mismanagement errors in patients admitted with ischemic stroke, and the clinical correlates with stroke outcomes in the era of non-vitamin K oral anticoagulants.

METHODS

We performed a retrospective analysis of patients admitted with ischemic stroke and history of AF to a single-centre tertiary hospital stroke unit in Melbourne, Australia, between January 2016 and June 2019. We assessed management errors as defined using European Heart Rhythm Association criteria with anticoagulation in the two weeks prior to the index stroke.

RESULTS

A total of 306 patients with AF and ischemic stroke were included, of whom 196 (64%) had management errors. Patients with management errors were older (median age 84 versus 81 years [p=0.002]) and more often female (53% verse 38% [p=0.02]). Of those with management errors, 74 (37%) were not prescribed any anticoagulation despite increased stroke risk and absence of contraindications and 40 (20%) had anticoagulation inappropriately ceased. Mortality at 3-months was 32% in those with management errors, compared to 17% in the appropriately anticoagulated group (p=0.005).

CONCLUSIONS

Inappropriate management of anticoagulants is present in the majority of acute ischemic stroke in the 2 weeks preceding the event and is linked to higher mortality. Improved anticoagulation practice has the potential to substantially reduce stroke rates in patients with AF. This article is protected by copyright. All rights reserved.

Safety and efficacy of intravenous thrombolysis in stroke patients on prior antiplatelet therapy in the WAKE-UP trial

Background

One quarter to one third of patients eligible for systemic thrombolysis are on antiplatelet therapy at presentation. In this study, we aimed to assess the safety and efficacy of intravenous thrombolysis in stroke patients on prescribed antiplatelet therapy in the WAKE-UP trial.

Methods

WAKE-UP was a multicenter, randomized, double-blind, placebo-controlled clinical trial to study the efficacy and safety of MRI-guided intravenous thrombolysis with alteplase in patients with an acute stroke of unknown onset time. The medication history of all patients randomized in the WAKE-UP trial was documented. The primary safety outcome was any sign of hemorrhagic transformation on follow-up MRI. The primary efficacy outcome was favorable functional outcome defined by a score of 0–1 on the modified Rankin scale at 90 days after stroke, adjusted for age and baseline stroke severity. Logistic regression models were fitted to study the association of prior antiplatelet treatment with outcome and treatment effect of intravenous alteplase.

Results

Of 503 randomized patients, 164 (32.6%) were on antiplatelet treatment. Patients on antiplatelet treatment were older (70.3 vs. 62.8 years, p <  0.001), and more frequently had a history of hypertension, atrial fibrillation, diabetes, hypercholesterolemia, and previous stroke or transient ischaemic attack. Rates of symptomatic intracranial hemorrhage and hemorrhagic transformation on follow-up imaging did not differ between patients with and without antiplatelet treatment. Patients on prior antiplatelet treatment were less likely to achieve a favorable outcome (37.3% vs. 52.6%, p = 0.014), but there was no interaction of prior antiplatelet treatment with intravenous alteplase concerning favorable outcome (p = 0.355). Intravenous alteplase was associated with higher rates of favorable outcome in patients on prior antiplatelet treatment with an adjusted odds ratio of 2.106 (95% CI 1.047–4.236).

Conclusions

Treatment benefit of intravenous alteplase and rates of post-treatment hemorrhagic transformation were not modified by prior antiplatelet intake among MRI-selected patients with unknown onset stroke. Worse functional outcome in patients on antiplatelets may result from a higher load of cardiovascular co-morbidities in these patients.

Screening for Fabry Disease in Young Strokes in the Australian Stroke Clinical Registry (AuSCR)

Introduction: Fabry disease (FD) is an X-linked lysosomal storage disorder characterized by a deficiency or absence of alpha-galactosidase A (α-GAL A) enzyme, where stroke can be a serious complication. The aim of this study is to determine the feasibility of centralized screening for FD, among young stroke adults registered in the national Australian Stroke Clinical Registry (AuSCR).

Methods: The study was conducted in young (age 18 – 55 years) survivors of acute stroke of unknown etiology registered in AuSCR at hospitals in Queensland, Tasmania, New South Wales, and Victoria during 2014 – 2015; and who, at the 3-month outcome assessment, agreed to be re-contacted for future research. Descriptive analyses of case identification from responses and specific enzyme and DNA sequencing analyses were conducted for α-galactosidase A (α-GLA) from dried blood spot (DBS) testing.

Results: Of 326 AuSCR-identified patients invited to participate, 58 (18%) provided consent but six were subsequently unable to provide a blood sample and two later withdrew consent to use their data. Among the remaining 50 participants (median age 53 years [48 – 56 years]; 47% female), 67% had experienced an acute ischemic stroke. All males (n = 27) had an initial screen for α-GLA enzyme activity of whom seven with low enzyme levels had normal secondary α-GLA gene analysis. All females (n = 23) had genetic analysis, with one shown to have a pathogenic c.352C>T p.(Arg118Cys) missense mutation of the α-GLA gene for FD.

Conclusions: These findings provide logistical data for embedding a process of automated central stroke registry screening for an additional case-finding tool in FD.

Symptoms and probabilistic anatomical mapping of lacunar infarcts

Background

The anatomical distribution of acute lacunar infarcts has mainly been studied for supratentorial lesions. In addition, little is known about the association with distinct stroke symptoms, not summarized as classical lacunar syndromes. We aimed to describe the spatial lesion distribution of acute supra- and infratentorial lacunar infarcts and their association with stroke symptoms in patients eligible for thrombolysis.

Methods

All patients enrolled in the WAKE-UP trial (efficacy and safety of magnetic resonance imaging [MRI]-based thrombolysis in wake-up stroke) were screened for lacunar infarcts on diffusion-weighted imaging (DWI). The relationship between the anatomical distribution of supra- and infratentorial lacunar infarcts, their demographic characteristics and acute stroke symptoms, defined by the National Institutes of Health Stroke Scale (NIHSS) score, were correlated and compared.

Results

Maps of lesion distribution from 224 lacunar infarct patients (76 [33.9%] females, mean age [standard deviation] of 63.4 [11.5] years) were generated using computational image mapping methods. Median infarct volume was 0.73 ml (interquartile range [IQR] 0.37–1.15 ml). Median NIHSS sum score on hospital arrival was 4 (IQR 3–6). 165 (73.7%) patients had lacunar infarcts in the supratentorial deep white or grey matter, while 59 (26.3%) patients had infratentorial lacunar infarcts. Patients with supratentorial lacunar infarcts presented with a significantly lower occurrence of deficits in the NIHSS items gaze (p < 0.001) and dysarthria (p = 0.008), but had more often a paresis of the left arm (p = 0.009) and left leg (p = 0.068) compared to patients with infratentorial infarcts.

Conclusions

The anatomical lesion distribution of lacunar infarcts reveals a distinct pattern and supports an association of localization with different stroke symptoms.

Trial registration

NCT01525290.

Value of treatment by comprehensive stroke services for the reduction of critical gaps in acute stroke care in Europe

Stroke is the second leading cause of death and dependency in Europe and costs the European Union more than €30bn, yet significant gaps in the patient pathway remain and the cost-effectiveness of comprehensive stroke care to meet these needs is unknown. The European Brain Council Value of Treatment Initiative combined patient representatives, stroke experts, neurological societies and literature review to identify unmet needs in the patient pathway according to Rotterdam methodology. The cost-effectiveness of comprehensive stroke services was determined by a Markov model, using UK cost data as an exemplar and efficacy data for prevention of death and dependency from published systematic reviews and trials, expressing effectiveness as quality-adjusted life-years (QALYs). Model outcomes included total costs, total QALYs, incremental costs, incremental QALYs and the incremental cost-effectiveness ratio (ICER). Key unmet needs in the stroke patient pathway included inadequate treatment of atrial fibrillation (AF), access to neurorehabilitation and implementation of comprehensive stroke services. In the Markov model, full implementation of comprehensive stroke services was associated with a 9.8% absolute reduction in risk of death of dependency, at an intervention cost of £9566 versus £6640 for standard care, and long-term care costs of £35 169 per 5.1251 QALYS vs. £32 347.40 per 4.5853 QALYs, resulting in an ICER of £5227.89. Results were robust in one-way and probabilistic sensitivity analyses. Implementation of comprehensive stroke services is a cost-effective approach to meet unmet needs in the stroke patient pathway, to improve acute stroke care and support better treatment of AF and access to neurorehabilitation.

Intravenous alteplase for stroke with unknown time of onset guided by advanced imaging: systematic review and meta-analysis of individual patient data

BACKGROUND

Patients who have had a stroke with unknown time of onset have been previously excluded from thrombolysis. We aimed to establish whether intravenous alteplase is safe and effective in such patients when salvageable tissue has been identified with imaging biomarkers.

METHODS

We did a systematic review and meta-analysis of individual patient data for trials published before Sept 21, 2020. Randomised trials of intravenous alteplase versus standard of care or placebo in adults with stroke with unknown time of onset with perfusion-diffusion MRI, perfusion CT, or MRI with diffusion weighted imaging-fluid attenuated inversion recovery (DWI-FLAIR) mismatch were eligible. The primary outcome was favourable functional outcome (score of 0-1 on the modified Rankin Scale [mRS]) at 90 days indicating no disability using an unconditional mixed-effect logistic-regression model fitted to estimate the treatment effect. Secondary outcomes were mRS shift towards a better functional outcome and independent outcome (mRS 0-2) at 90 days. Safety outcomes included death, severe disability or death (mRS score 4-6), and symptomatic intracranial haemorrhage. This study is registered with PROSPERO, CRD42020166903.

FINDINGS

Of 249 identified abstracts, four trials met our eligibility criteria for inclusion: WAKE-UP, EXTEND, THAWS, and ECASS-4. The four trials provided individual patient data for 843 individuals, of whom 429 (51%) were assigned to alteplase and 414 (49%) to placebo or standard care. A favourable outcome occurred in 199 (47%) of 420 patients with alteplase and in 160 (39%) of 409 patients among controls (adjusted odds ratio [OR] 1·49 [95% CI 1·10-2·03]; p=0·011), with low heterogeneity across studies (I²=27%). Alteplase was associated with a significant shift towards better functional outcome (adjusted common OR 1·38 [95% CI 1·05-1·80]; p=0·019), and a higher odds of independent outcome (adjusted OR 1·50 [1·06-2·12]; p=0·022). In the alteplase group, 90 (21%) patients were severely disabled or died (mRS score 4-6), compared with 102 (25%) patients in the control group (adjusted OR 0·76 [0·52-1·11]; p=0·15). 27 (6%) patients died in the alteplase group and 14 (3%) patients died among controls (adjusted OR 2·06 [1·03-4·09]; p=0·040). The prevalence of symptomatic intracranial haemorrhage was higher in the alteplase group than among controls (11 [3%] vs two [<1%], adjusted OR 5·58 [1·22-25·50]; p=0·024).

INTERPRETATION

In patients who have had a stroke with unknown time of onset with a DWI-FLAIR or perfusion mismatch, intravenous alteplase resulted in better functional outcome at 90 days than placebo or standard care. A net benefit was observed for all functional outcomes despite an increased risk of symptomatic intracranial haemorrhage. Although there were more deaths with alteplase than placebo, there were fewer cases of severe disability or death.

FUNDING

None.

Polypharmacy, functional outcome and treatment effect of intravenous alteplase for acute ischaemic stroke

BACKGROUND AND PURPOSE

Polypharmacy is an important challenge in clinical practice. Our aim was to determine the effect of polypharmacy on functional outcome and treatment effect of alteplase in acute ischaemic stroke.

METHODS

This was a post hoc analysis of the randomized, placebo-controlled WAKE-UP trial of magnetic resonance imaging guided intravenous alteplase in unknown onset stroke. Polypharmacy was defined as an intake of five or more medications at baseline. Comorbidities were assessed by the Charlson Comorbidity Index (CCI). The primary efficacy variable was favourable outcome defined by a score of 0-1 on the modified Rankin Scale at 90 days. Logistic regression analysis was used to test for an association of polypharmacy with functional outcome, and for interaction of polypharmacy and the effect of thrombolysis.

RESULTS

Polypharmacy was present in 133/503 (26%) patients. Patients with polypharmacy were older (mean age 70 vs. 64 years; p < 0.0001) and had a higher score on the National Institutes of Health Stroke Scale at baseline (median 7 vs. 5; p = 0.0007). A comorbidity load defined by a CCI score ≥ 2 was more frequent in patients with polypharmacy (48% vs. 8%; p < 0.001). Polypharmacy was associated with lower odds of favourable outcome (adjusted odds ratio 0.50, 95% confidence interval 0.30-0.85; p = 0.0099), whilst the CCI score was not. Treatment with alteplase was associated with higher odds of favourable outcome in both groups, with no heterogeneity of treatment effect (test for interaction of treatment and polypharmacy, p = 0.29).

CONCLUSION

In stroke patients, polypharmacy is associated with worse functional outcome after intravenous thrombolysis independent of comorbidities. However, polypharmacy does not interact with the beneficial effect of alteplase.

Tranexamic acid in patients with intracerebral haemorrhage (STOP-AUST): a multicentre, randomised, placebo-controlled, phase 2 trial

BACKGROUND

Despite intracerebral haemorrhage causing 5% of deaths worldwide, few evidence-based therapeutic strategies other than stroke unit care exist. Tranexamic acid decreases haemorrhage in conditions such as acute trauma and menorrhoea. We aimed to assess whether tranexamic acid reduces intracerebral haemorrhage growth in patients with acute intracerebral haemorrhage.

METHODS

We did a prospective, double-blind, randomised, placebo-controlled, investigator-led, phase 2 trial at 13 stroke centres in Australia, Finland, and Taiwan. Patients were eligible if they were aged 18 years or older, had an acute intracerebral haemorrhage fulfilling clinical criteria (eg, Glasgow Coma Scale score of >7, intracerebral haemorrhage volume <70 mL, no identified or suspected secondary cause of intracerebral haemorrhage, no thrombotic events within the previous 12 months, no planned surgery in the next 24 h, and no use of anticoagulation), had contrast extravasation on CT angiography (the so-called spot sign), and were treatable within 4·5 h of symptom onset and within 1 h of CT angiography. Patients were randomly assigned (1:1) to receive either 1 g of intravenous tranexamic acid over 10 min followed by 1 g over 8 h or matching placebo, started within 4·5 h of symptom onset. Randomisation was done using a centralised web-based procedure with randomly permuted blocks of varying size. All patients, investigators, and staff involved in patient management were masked to treatment. The primary outcome was intracerebral haemorrhage growth (>33% relative or >6 mL absolute) at 24 h. The primary and safety analyses were done in the intention-to-treat population. The trial is registered at ClinicalTrials.gov (NCT01702636).

FINDINGS

Between March 1, 2013, and Aug 13, 2019, we enrolled and randomly assigned 100 participants to the tranexamic acid group (n=50) or the placebo group (n=50). Median age was 71 years (IQR 57-79) and median intracerebral haemorrhage volume was 14·6 mL (7·9-32·7) at baseline. The primary outcome was not different between the two groups: 26 (52%) patients in the placebo group and 22 (44%) in the tranexamic acid group had intracerebral haemorrhage growth (odds ratio [OR] 0·72 [95% CI 0·32-1·59], p=0·41). There was no evidence of a difference in the proportions of patients who died or had thromboembolic complications between the groups: eight (16%) in the placebo group vs 13 (26%) in the tranexamic acid group died and two (4%) vs one (2%) had thromboembolic complications. None of the deaths was considered related to study medication.

INTERPRETATION

Our study does not provide evidence that tranexamic acid prevents intracerebral haemorrhage growth, although the treatment was safe with no increase in thromboembolic complications. Larger trials of tranexamic acid, with simpler recruitment methods and an earlier treatment window, are justified.

FUNDING

National Health and Medical Research Council, Royal Melbourne Hospital Foundation.

Clinical Characteristics and Outcome of Patients With Hemorrhagic Transformation After Intravenous Thrombolysis in the WAKE-UP Trial

Background: Hemorrhagic transformation (HT) is an important complication of intravenous thrombolysis with alteplase. HT can show a wide range from petechiae to parenchymal hematoma with mass effect with varying clinical impact. We studied clinical and imaging characteristics of patients with HT and evaluated whether different types of HT are associated with functional outcome.

Methods: We performed a post-hoc analysis of WAKE-UP, a multicenter, randomized, placebo-controlled trial of MRI-guided intravenous alteplase in unknown onset stroke. HT was assessed on follow-up MRI or CT and diagnosed as hemorrhagic infarction type 1 and type 2 (HI1 and HI2, combined as HI), and parenchymal hemorrhage type 1 and type 2 (PH1 and PH2, combined as PH). Severity of stroke symptoms was assessed using the National Institutes of Health Stroke Scale (NIHSS) at baseline. Stroke lesion volume was measured on baseline diffusion weighted imaging (DWI). Primary endpoint was a favorable outcome defined as a modified Rankin Scale score 0–1 at 90 days.

Results: Of 483 patients included in the analysis, 95 (19.7%) showed HI and 21 (4.4%) had PH. Multiple logistic regression analysis identified treatment with alteplase (OR, 2.08 [95% CI, 1.28–3.40]), baseline NIHSS score (OR, 1.11 [95% CI, 1.05–1.17]), DWI lesion volume (OR, 1.03 [95% CI, 1.01–1.05]), baseline glucose levels (OR, 1.01 [95% CI, 1.00–1.01]) and atrial fibrillation (OR, 3.02 [95% CI, 1.57–5.80]) as predictors of any HT. The same parameters predicted HI. Predictors of PH were baseline NIHSS score (OR, 1.11 [95% CI, 1.01–1.22]) and as a trend treatment with alteplase (OR, 2.40 [95% CI, 0.93–6.96]). PH was associated with lower odds of favorable outcome (OR 0.25, 95% [CI 0.05–0.86]), while HI was not.

Conclusion: Our results indicate that HI is associated with stroke severity, cardiovascular risk factors and thrombolysis. PH is a rare complication, more frequent in severe stroke and with thrombolysis. In contrast to HI, PH is associated with worse functional outcome. The impact of HT after MRI-guided intravenous alteplase for unknown onset stroke on clinical outcome is similar as in the trials of stroke thrombolysis within a known early time-window.