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BACKGROUND AND OBJECTIVES: Intravenous alteplase improves functional outcome after acute ischemic stroke. However, little is known about the effects on self-reported health-related quality of life (HRQoL). METHODS: WAKE-UP was a multicenter, randomized, placebo-controlled trial of MRI-guided intravenous alteplase in stroke with unknown onset time. HRQoL was assessed using the EuroQol five-dimensional questionnaire (EQ-5D) at 90 days, comprising the EQ-5D index and the EQ visual analogue scale (VAS). Functional outcome was assessed by the modified Rankin Scale (mRS). We calculated the effect of treatment on EQ-5D index and EQ VAS using multiple linear regression models. Mediation analysis was performed on stroke survivors to explore the extent to which the effect of alteplase on HRQoL was mediated by functional outcome. RESULTS: Among 490 stroke survivors, the EQ-5D index was available for 452 (92.2%), of whom 226 (50%) were assigned to treatment with alteplase and 226 (50%) to placebo. At 90 days, mean EQ-5D index was higher, reflecting a better health state, in patients randomized to treatment with alteplase than with placebo (0.75 vs 0.67) with an adjusted mean difference of 0.07 (95% CI 0.02-0.12, p = 0.005). In addition, mean EQ VAS was higher with alteplase than with placebo (72.6 vs 64.9), with an adjusted mean difference of 7.6 (95% CI 3.9-11.8, p < 0.001). Eighty-five percent of the total treatment effect of alteplase on the EQ-5D index was mediated using the mRS score while there was no significant direct effect. By contrast, the treatment effect on the EQ VAS was mainly through the direct pathway (60%), whereas 40% was mediated by the mRS. DISCUSSION: Assessment of patient-reported outcome measures reveals a potential benefit of intravenous alteplase for HRQoL beyond improvement of functional outcome. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov number, NCT01525290; EudraCT number, 2011-005906-32.

BACKGROUND AND OBJECTIVES: Cerebral microbleeds (CMBs) are common in patients with acute ischemic stroke and are associated with increased risk of intracerebral hemorrhage (ICH) after intravenous thrombolysis. Whether CMBs modify the treatment effect of thrombolysis is unknown. METHODS: We performed a prespecified analysis of the prospective randomized controlled multicenter Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke (WAKE-UP) trial including patients with acute ischemic stroke with unknown time of symptom onset and diffusion-weighted imaging-fluid-attenuated inversion recovery mismatch on MRI receiving alteplase or placebo. Patients were screened and enrolled between September 2012 and June 2017 (with final follow-up in September 2017). Patients were randomized to treatment with IV thrombolysis with alteplase at 0.9 mg/kg body weight or placebo. CMB status (presence, number, and distribution) was assessed after study completion by 3 raters blinded to clinical information following a standardized protocol. Outcome measures were excellent functional outcome at 90 days, defined by modified Rankin Scale (mRS) score ≤1, and symptomatic ICH according to National Institutes of Neurological Disease and Stroke trial criteria 22 to 36 hours after treatment. RESULTS: Of 503 patients enrolled in the WAKE-UP trial, 459 (91.3%; 288 [63%] men) were available for analysis. Ninety-eight (21.4%) had at least 1 CMB on baseline imaging; 45 (9.8%) had exactly 1 CMB; 37 (8.1%) had 2 to 4 CMBs; and 16 (3.5%) had ≥5 CMBs. Presence of CMBs was associated with a nonsignificant increased risk of symptomatic ICH (11.2% vs 4.2%; adjusted odds ratio [OR] 2.32, 95% confidence interval [CI] 0.99-5.43, p = 0.052) but had no effect on functional outcome at 90 days (mRS score ≤1: 45.8% vs 50.7%; adjusted OR 0.99, 95% CI 0.59-1.64, p = 0.955). Patients receiving alteplase had better functional outcome (mRS score ≤1: 54.6% vs 44.6%, adjusted OR 1.61, 95% CI 1.07-2.43, p = 0.022) w

The symptoms of acute ischemic stroke can be attributed to disruption of the brain network architecture. Systemic thrombolysis is an effective treatment that preserves structural connectivity in the first days after the event. Its effect on the evolution of global network organisation is, however, not well understood. We present a secondary analysis of 269 patients from the randomized WAKE-UP trial, comparing 127 imaging-selected patients treated with alteplase with 142 controls who received placebo. We used indirect network mapping to quantify the impact of ischemic lesions on structural brain network organisation in terms of both global parameters of segregation and integration, and local disruption of individual connections. Network damage was estimated before randomization and again 22 to 36 h after administration of either alteplase or placebo. Evolution of structural network organisation was characterised by a loss in integration and gain in segregation, and this trajectory was attenuated by the administration of alteplase. Preserved brain network organization was associated with excellent functional outcome. Furthermore, the protective effect of alteplase was spatio-topologically nonuniform, concentrating on a subnetwork of high centrality supported in the salvageable white matter surrounding the ischemic cores. This interplay between the location of the lesion, the pathophysiology of the ischemic penumbra, and the spatial embedding of the brain network explains the observed potential of thrombolysis to attenuate topological network damage early after stroke. Our findings might, in the future, lead to new brain network-informed imaging biomarkers and improved prognostication in ischemic stroke.

Thrombolysis with recombinant tissue plasminogen activator in acute ischemic stroke aims to restore compromised blood flow and prevent further neuronal damage. Despite the proven clinical efficacy of this treatment, little is known about the short-term effects of systemic thrombolysis on structural brain connectivity. In this secondary analysis of the WAKE-UP trial, we used MRI-derived measures of infarct size and estimated structural network disruption to establish that thrombolysis is associated not only with less infarct growth, but also with reduced loss of large-scale connectivity between grey-matter areas after stroke. In a causal mediation analysis, infarct growth mediated a non-significant 8.3% (CI95% [-8.0, 32.6]%) of the clinical effect of thrombolysis on functional outcome. The proportion mediated jointly through infarct growth and change of structural connectivity, especially in the border zone around the infarct core, however, was as high as 33.4% (CI95% [8.8, 77.4]%). Preservation of structural connectivity is thus an important determinant of treatment success and favourable functional outcome in addition to lesion volume. It might, in the future, serve as an imaging endpoint in clinical trials or as a target for therapeutic interventions.

INTRODUCTION: To assess the association between 24 h blood pressure variability (BPV) on functional outcome and treatment effect of intravenous alteplase in acute ischaemic stroke. PATIENTS AND METHODS: In all patients with acute ischaemic stroke of unknown onset randomised in the WAKE-UP (Efficacy and Safety of magnetic resonance imaging [MRI]-based Thrombolysis in Wake-Up Stroke) trial, blood pressure (BP) was measured before randomisation and after initiation of treatment at regular intervals up to 24 hours. Individual BPV was measured by coefficient of variation (CV) of all BP values. Primary outcome measure was favourable outcome defined by a modified Rankin Scale (mRS) score 0 or 1 at 90 days after stroke. RESULTS: BP measurements were available for 498 of 503 patients randomised (177 women [35.5%], mean age [SD] of 65.2 [11.5] years). Systolic BPV was not associated with the treatment effect of thrombolysis (test for interaction, p = 0.46). The adjusted odds ratio (aOR) for favourable outcome with alteplase, adjusted for age, stroke severity and baseline BP on admission, did not show an association across the quintiles of increasing systolic BPV with an aOR 1.89 (95% confidence interval [CI], 0.76-4.70) in the lowest quintile to aOR 1.05 (95% CI, 0.43-2.56) in the highest quintile. Higher mean systolic BP was associated with a smaller treatment effect of thrombolysis with a significant interaction (p = 0.033). The aOR for favourable outcome with alteplase decreased with quintiles of increasing mean systolic BP from aOR 3.16 (95% CI, 1.26-7.93) in the lowest quintile to aOR 0.84 (95% CI, 0.34-2.10) in in the highest quintile. CONCLUSIONS: There was a significant interaction between mean systolic BP and treatment effect of thrombolysis with higher mean systolic BP being associated with poorer outcome. BPV was not associated with outcome after thrombolysis.ClinicalTrials.gov identifier NCT01525290.

Lesion analysis is a fundamental and classical approach for inferring the causal contributions of brain regions to brain function. However, many studies have been limited by the shortcomings of methodology or clinical data. Aiming to overcome these limitations, we here use an objective multivariate approach based on game theory, Multi-perturbation Shapley value Analysis, in conjunction with data from a large cohort of 394 acute stroke patients, to derive causal contributions of brain regions to four principal functional components of the widely used National Institutes of Health Stroke Score measure. The analysis was based on a high-resolution parcellation of the brain into 294 grey and white matter regions. Through initial lesion symptom mapping for identifying all potential candidate regions and repeated iterations of the game-theoretical approach to remove non-significant contributions, the analysis derived the smallest sets of regions contributing to each of the four principal functional components as well as functional interactions among the regions. Specifically, the factor 'language and consciousness' was related to contributions of cortical regions in the left hemisphere, including the prefrontal gyrus, the middle frontal gyrus, the ventromedial putamen and the inferior frontal gyrus. Right and left motor functions were associated with contributions of the left and right dorsolateral putamen and the posterior limb of the internal capsule, correspondingly. Moreover, the superior corona radiata and the paracentral lobe of the right hemisphere as well as the right caudal area 23 of the cingulate gyrus were mainly related to left motor function, while the prefrontal gyrus, the external capsule and the sagittal stratum fasciculi of the left hemisphere contributed to right motor function. Our approach demonstrates a practically feasible strategy for applying an objective lesion inference method to a high-resolution map of the human brain and distilling a small, ch

BACKGROUND AND PURPOSE: The aim was to study the effect of intravenous alteplase on the development of post-stroke depression (PSD) in acute stroke patients, and to identify predictors of PSD. METHODS: This post hoc analysis included patients with unknown onset stroke randomized to treatment with alteplase or placebo in the WAKE-UP trial (ClinicalTrials.gov number, NCT01525290), in whom a composite end-point of PSD was defined as a Beck Depression Inventory ≥10, medication with an antidepressant, or depression recorded as an adverse event. Multiple logistic regression was used to identify predictors of PSD at 90 days. Structural equation modelling was applied to assess the indirect effect of thrombolysis on PSD mediated by the modified Rankin Scale. RESULTS: Information on the composite end-point was available for 438 of 503 randomized patients. PSD was present in 96 of 224 (42.9%) patients in the alteplase group and 115 of 214 (53.7%) in the placebo group (odds ratio 0.63; 95% confidence interval 0.43-0.94; p = 0.022; adjusted for age and National Institutes of Health Stroke Scale at baseline). Prognostic factors associated with PSD included baseline medication with antidepressants, higher lesion volume, history of depression and assignment to placebo. While 65% of the effect of thrombolysis on PSD were caused directly, 35% were mediated by an improvement of the mRS. CONCLUSIONS: Treatment with alteplase in patients with acute stroke resulted in lower rates of depression at 90 days, which were only partially explained by reduced functional disability. Predictors of PSD including history and clinical characteristics may help in identifying patients at risk of PSD.

Stroke has a deleterious impact on quality of life. However, it is less well known if stroke lesions in different brain regions are associated with reduced quality of life (QoL). We therefore investigated this association by multivariate lesion-symptom mapping. We analyzed magnetic resonance imaging and clinical data from the WAKE-UP trial. European Quality of Life 5 Dimensions (EQ-5D) 3 level questionnaires were completed 90 days after stroke. Lesion symptom mapping was performed using a multivariate machine learning algorithm (support vector regression) based on stroke lesions 22-36 h after stroke. Brain regions with significant associations were explored in reference to white matter tracts. Of 503 randomized patients, 329 were included in the analysis (mean age 65.4 years, SD 11.5; median NIHSS = 6, IQR 4-9; median EQ-5D score 90 days after stroke 1, IQR 0-4, median lesion volume 3.3 ml, IQR 1.1-16.9 ml). After controlling for lesion volume, significant associations between lesions and EQ-5D score were detected for the right putamen, and internal capsules of both hemispheres. Multivariate lesion inference analysis revealed an association between injuries of the cortico-spinal tracts with worse self-reported quality of life 90 days after stroke in comparably small stroke lesions, extending previous reports of the association of striato-capsular lesions with worse functional outcome. Our findings are of value to identify patients at risk of impaired QoL after 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.

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 wa

OBJECTIVE: To explore the prevalence of the perfusion-weighted imaging (PWI)-diffusion-weighted imaging (DWI) mismatch and response to intravenous thrombolysis in the WAKE-UP trial. METHODS: We performed a prespecified post hoc analysis of ischemic stroke patients screened for DWI-fluid-attenuated inversion recovery (FLAIR) mismatch in WAKE-UP who underwent PWI. We defined PWI-DWI mismatch as ischemic core volume < 70ml, mismatch volume > 10ml, and mismatch ratio > 1.2. Primary efficacy end point was a modified Rankin Scale score of 0-1 at 90 days, adjusted for age and symptom severity. RESULTS: Of 1,362 magnetic resonance imaging-screened patients, 431 underwent PWI. Of these, 57 (13%) had a double mismatch, 151 (35%) only a DWI-FLAIR mismatch, and 54 (13%) only a PWI-DWI mismatch. DWI-FLAIR mismatch was more prevalent than PWI-DWI mismatch (48%, 95% confidence interval [CI] = 43-53% vs 26%, 95% CI = 22-30%; p < 0.0001). Screening for either one of the mismatch profiles resulted in a yield of 61% (95% CI = 56-65%). Prevalence of PWI-DWI mismatch was similar in patients with (27%) or without (24%) DWI-FLAIR mismatch (p = 0.52). In an exploratory analysis in the small subgroup of 208 randomized patients with PWI, PWI-DWI mismatch status did not modify the treatment response (p for interaction = 0.73). INTERPRETATION: Evaluating both the DWI-FLAIR and PWI-DWI mismatch patterns in patients with unknown time of stroke onset will result in the highest yield of thrombolysis treatment. The treatment benefit of alteplase in patients with a DWI-FLAIR mismatch seems to be driven not merely by the presence of a PWI-DWI mismatch, although this analysis was underpowered. ANN NEUROL 2020;87:931-938.

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 assoc

PURPOSE: Lacunar infarcts are thought to result from occlusion of small penetrating arteries due to microatheroma and lipohyalinosis, pathognomonic for cerebral small vessel disease (CSVD). Concurrent embolic ischemic lesions indicate a different stroke mechanism. The purpose of this study was to examine the clinical characteristics and outcome of patients with lacunar infarcts and concurrent embolic infarcts on diffusion-weighted imaging (DWI). METHODS: All patients screened for the WAKE-UP trial (ClinicalTrials.gov number, NCT01525290) were reviewed for acute lacunar infarcts and concurrent embolic lesions on baseline DWI. Clinical characteristics and outcome were compared between lacunar infarct patients with and without concurrent embolic lesions. RESULTS: Of 244 patients with an acute lacunar infarct, 20 (8.2%) had concurrent acute embolic infarcts. Compared to patients with a lacunar infarct only, patients with concurrent embolic infarcts were older (mean age 69 years vs. 63 years; p = 0.031), more severely affected (median National Institutes of Health Stroke Scale [NIHSS] score 5 vs. 4; p = 0.046), and-among those randomized-had worse functional outcome at 90 days (median modified Rankin Scale [mRS] 3 vs. 1; p = 0.011). CONCLUSION: Approximately 8% of lacunar infarct patients show concurrent embolic lesions suggesting a stroke etiology other than CSVD. These patients are more severely affected and have a worse functional outcome illustrating the need for a thorough diagnostic work-up of possible embolic sources even in patients with an imaging-defined diagnosis 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.

Background and Purpose- Relative signal intensity of acute ischemic stroke lesions in fluid-attenuated inversion recovery (fluid-attenuated inversion recovery relative signal intensity [FLAIR-rSI]) magnetic resonance imaging is associated with time elapsed since stroke onset with higher intensities signifying longer time intervals. In the randomized controlled WAKE-UP trial (Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke Trial), intravenous alteplase was effective in patients with unknown onset stroke selected by visual assessment of diffusion weighted imaging fluid-attenuated inversion recovery mismatch, that is, in those with no marked fluid-attenuated inversion recovery hyperintensity in the region of the acute diffusion weighted imaging lesion. In this post hoc analysis, we investigated whether quantitatively measured FLAIR-rSI modifies treatment effect of intravenous alteplase. Methods- FLAIR-rSI of stroke lesions was measured relative to signal intensity in a mirrored region in the contralesional hemisphere. The relationship between FLAIR-rSI and treatment effect on functional outcome assessed by the modified Rankin Scale (mRS) after 90 days was analyzed by binary logistic regression using different end points, that is, favorable outcome defined as mRS score of 0 to 1, independent outcome defined as mRS score of 0 to 2, ordinal analysis of mRS scores (shift analysis). All models were adjusted for National Institutes of Health Stroke Scale at symptom onset and stroke lesion volume. Results- FLAIR-rSI was successfully quantified in stroke lesions in 433 patients (86% of 503 patients included in WAKE-UP). Mean FLAIR-rSI was 1.06 (SD, 0.09). Interaction of FLAIR-rSI and treatment effect was not significant for mRS score of 0 to 1 (P=0.169) and shift analysis (P=0.086) but reached significance for mRS score of 0 to 2 (P=0.004). We observed a smooth continuing trend of decreasing treatment effects in relation to clinical end points with increasing F

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 i