Background and purpose: The current left atrial appendage (LAA) classification system (cLAA-CS) categorizes it into 4 morphologies: chicken wing (CW), windsock, cactus, and cauliflower, though there is limited data on either reliability or associations between different morphologies and stroke risk. We aimed to develop a simplified LAA classification system and to determine its relationship to embolic stroke subtypes. Methods: Consecutive patients with ischemic stroke from a prospective stroke registry who previously underwent a clinically-indicated chest CT were included. Stroke subtype was determined and LAA morphology was classified using the traditional system (in which CW = low risk) and a new system (LAA-H/L, in which low risk morphology (LAA-L) was defined as an acute angle bend or fold from the proximal/middle portion of the LAA and high risk morphology (LAA-H) was defined as all others). As a proof of concept study, we determined reliability for the two classification systems, and we assessed the associations between both classification systems with stroke subtypes in our cohort and previous studies. Results: We identified 329 ischemic stroke patients with a qualifying chest CT (126 cardioembolic subtype, 116 embolic stroke of undetermined source (ESUS), and 87 non-cardioembolic subtypes). Intra- and inter-rater agreements improved using the LAA-H/L (0.95 and 0.85, respectively) vs. cLAA-CS (0.50 and 0.40). The LAA-H/L led to classifying 69 LAA morphologies that met criteria for CW as LAA-H. In fully adjusted models, LAA-H was associated with cardioembolic stroke (OR 5.4, 95%CI 2.1-13.7) and ESUS (OR 2.8 95% CI 1.2-6.4). Non-CW morphology was also associated with embolic stroke subtypes, but the effect size was much less pronounced. Studies using the cLAA-CS yielded mixed results for inter- and infra-rater agreements but most showed an association between a non-CW morphology and stroke with no difference among the three non-CW subtypes. Conclusion: The LAA-H/L classification system is simple, has excellent infra and inter-rater agreements, and may help risk identify patients with cardioembolic stroke subtypes. Larger studies are needed to validate these findings.

Background and Purpose: Early neurologic improvement (ENI) in patients treated with alteplase has been shown to correlate with functional outcome. However, the definition of ENI remains controversial and has varied across studies. Current definitions take into account the absolute difference between the admission and 24-hour NIHSS but this difference is usually not reported as a function of the baseline NIHSS. We hypothesized that ENI defined as a percentage change in NIHSS (percent change NIHSS) at 24-hours would better correlate with favorable outcomes at 3 months than ENI defined as the change in NIHSS (delta NIHSS) at 24 hours. Methods: Retrospective analysis of prospectively collected single center quality improvement data was performed of all acute ischemic stroke (AIS) patients treated with alteplase. Delta NIHSS was defined as the difference in admission and 24-hour NIHSS. Percent change NIHSS was defined as delta NIHSS divided by the admission NIHSS. We examined delta NIHSS and percent change NIHSS in unadjusted and adjusted logistic regression models as predictors of a favorable outcome at 3 months (defined as mRS 0-1). Results: Among 586 patients with AIS treated with alteplase with admission NIHSS, 24-hour NIHSS, and 3-month mRS available, 194 (33.1%) had a favorable outcome at 3 months. The mean age was 65 years and 59% were men. In fully adjusted models, both delta NIHSS (OR per point decrease 1.27; 95% CI, 1.19– 1.36) and percent change NIHSS (OR per 10 percent decrease 1.17; 95% CI, 1.12-1.22) were associated with favorable functional outcome at 3 months. Receiver operating characteristic (ROC) curve comparison showed that the area under the ROC curve for percent change NIHSS (0.755) was greater than delta NIHSS (0.613) or admission NIHSS (0.694). Conclusion: Percentage change in NIHSS may be a better surrogate marker of ENI and functional outcome in AIS patients after receiving acute thrombolytic therapy. More studies are needed to confirm our findings.

Background: Predictors of alteplase associated symptomatic intracranial hemorrhage (sICH) have been identified but there are very limited data on predictors of delayed sICH (> 24 hours from infusion). We hypothesize that asymptomatic hemorrhage on 24 hour brain imaging predicts delayed sICH and that delaying antithrombotic treatment in these patients reduces this risk. Methods: This is a retrospective analysis of a prospective quality improvement database of a comprehensive stroke center. We included all patients with a discharge diagnosis of ischemic stroke who received alteplase. Patients with sICH occurring within 24 hours from alteplase and those whose code status was changed to comfort measures only were excluded. Delayed sICH was defined as any hemorrhage causing neurological deterioration. We compared baseline characteristics, asymptomatic hemorrhage on 24 hour brain imaging, and median time to initiating antithrombotic therapy between patients with and without delayed sICH. Results: Among 606 patients who met our inclusion criteria; mean age was 70 years and 52% were men; 23.8% had asymptomatic hemorrhage on 24 hour brain imaging (CT or MRI) and 12 patients (2%) had delayed sICH. Aspirin was the most common initial antithrombotic (91.2%) followed by plavix (2.6%), and others (3.8%). After adjusting for confounders, asymptomatic hemorrhage on 24 hour brain imaging was associated with increased odds of delayed sICH (OR 5.5, 95% CI 1.52 - 19.87, p = 0.009) but the median time (days) to starting antithrombotic therapy did not differ between those with asymptomatic hemorrhage who developed delayed sICH vs. those who did not [2 (3) vs. 3 (5), p = 0.447). Conclusion: Delayed sICH in patients receiving alteplase is uncommon and asymptomatic hemorrhage is a strong predictor. Delaying initiation of antithrombotic treatment in patients with asymptomatic hemorrhage on 24 hour imaging was not associated with reduced delayed sICH risk. It is possible that other factors such as reperfusion and blood brain barrier disruption are more important determinants of delayed sICH risk as opposed to timing of antithrombotic therapy initiation.

Background and Purpose: While studies have stratified cardioembolic (CE) stroke risk by qualitative left atrial appendage (LAA) morphology and biomarkers of atrial dysfunction, the quantitative properties that underlie these observations are not well established. Accordingly, we hypothesized that LAA volume and contrast density (attenuation) on computerized tomography (CT) may capture the structural and hemodynamic processes that underlie CE stroke risk. Methods: Data were collected from a single center prospective ischemic stroke database over 18 months and included all patients with ischemic stroke who previously underwent routine, non-gated, contrast enhanced thin-slice (≤2.5 mm) chest CT. Stroke subtype was determined based on the inpatient diagnostic evaluation. LAA volume and attenuation were determined from CT studies performed for various clinically appropriate indications. Univariate and multivariable analyses were performed to determine factors associated with ischemic stroke subtype, including known risk factors and biomarkers, as well as LAA density and morphologic measures. Results: We identified 311 patients with a qualifying chest CT (119 CE subtype, 109 ESUS, and 83 non-CE). In unadjusted models, there was an association between CE (vs. non-CE) stroke subtype and LAA volume (OR per mL increase 1.15, 95% CI 1.07-1.24, p<0.001) and LAA density (4 th quartile vs. 1 st quartile; OR 2.95, 95% CI 1.28-6.80, p=0.011), but not with ESUS (vs. non-CE) subtype. In adjusted models, only the association between LAA density and CE stroke subtype persisted (adjusted OR 3.71, 95% CI 1.37-10.08, p=0.010). Conclusion: The LAA volume and density values on chest CT are associated with CE stroke subtype but not ESUS subtype. Patients with ESUS and increased LAA volume or attenuation may be a subgroup where the mechanism is cardioembolic and anticoagulation can be tested for secondary stroke prevention.

Objective: Clinical predictors of ischemic stroke in the setting of atrial fibrillation (AF) have been identified, but there is limited data on predictors in the context of abnormal flow originating from the left atrial appendage. We hypothesize that reduced LAA flow velocity is associated with cerebrovascular ischemic events in patients with AF. Methods: We investigated consecutive patients with AF evaluated for ablation. Peak flow velocities at the orifice of the left atrial appendage (LAA) were obtained by transeosphageal echocardiography (TEE) studies, and elevated velocities were defined as greater than 40 cm/sec, in line with prior studies. The primary outcome was defined as the presence of any of the following: history of stroke/transient ischemic event, or non-lacunar brain infarct on brain imaging performed before the TEE. Univariate and multivariable analyses were performed to determine the association between LAA peak flow and the primary outcome, adjusting for CHADS2Vasc score. Results: We identified 322 patients with TEE performed. The mean age was 62.1 years and 24.5% men. Patients with LAA-flow velocity < 40 cm/sec were more likely to have the primary outcome (10.7% vs 4.3%, p=0.023). This association persisted after adjusting for CHADS2VASc (OR, 2.62; 95% CI, 1.09-6.33, p = 0.032). Conclusion: Low velocity in the LAA is associated with cerebrovascular ischemic events in patients with AF. More studies are needed to deterine whether LAA flow velocity can help risk stratify “low risk” patients with AF.

Background: White matter disease (WMD) and microhemorrhages (MH) present at the time of stroke have been linked to outcome, yet few have investigated changes in the time leading up to stroke. Magnetic Resonance Imaging (MRI) characteristics before a stroke may shed light on the severity of outcomes following stroke. Methods: We retrospectively identified patients admitted to our institution for ischemic stroke between 5/16-12/17 who had an MRI in the 1-24 months prior to their stroke. After collecting clinical and demographic data, automatic segmentations of gray and white matter volumes and manual segmentation of WMD and MH (size<10mm) were completed using 3D Slicer 4.5 and 4.9, respectively. Groups were created based on modified Rankin Scale score (mRS) at 90 days; an mRS of 3-6 was considered a poor outcome. Univariate analyses and multivariate regression models were performed to determine factors associated with poor outcome. Results: Among the 48 patients in our study (mean age 68, 50% female), 29 patients (60%) had poor outcome. Poor outcome was associated with pre-existing WMD volume (21.9+/-23.6 vs 6.1+/-5.7mL, p= 0.002), and WMD volume at time of stroke (26.4+/-24.9 vs 8.8+/-6.0mL, p=0.001). There was a trend towards poor outcome in older patients (p=0.073), women (p=0.075), higher NIHSS score (p=0.066), and need for thrombectomy (p=0.065). History of prior stroke was not associated with poor outcome (p=0.74), larger pre-existing WMD volumes (14.3+/-19.3 vs 19.5+/-22.6mL, p=0.47) or larger WMD volumes at time of stroke (18.7±22.5 vs 21.5±18.8mL, p=0.67). After adjusting for confounders, pre-existing WMD volume showed a trend to predict poor outcome (adjusted OR 1.086 per one point increase, 95% CI 0.987-1.195, p=0.09), as did WMD volume at the time of stroke (adjusted OR 1.103 per one point increase, 95% CI 0.992-1.226, p=0.07). Conclusions: Greater volume of WMD at time of and prior to admission for stroke may be independent predictors of poor outcome. These results should be validated in subsequent studies.

ABSTRACTBACKGROUND AND PURPOSEThere is evidence suggesting that Los Angeles Motor Scale (LAMS) ≥ 4 predicts large vessel occlusion (LVO). We aim to determine whether atrial fibrillation (AF) can improve the ability of LAMS in predicting LVO.METHODSWe included consecutive patients with a discharge diagnosis of ischemic stroke admitted within 24 hours from last known normal time who underwent emergent vascular imaging using a computerized tomography angiography (CTA) of the head and neck. LVO was defined as intracranial internal carotid artery, proximal middle cerebral artery (M1 or proximal M2 segment), or basilar occlusion. LAMS was determined in the emergency department upon arrival. Univariate and multivariable models were performed to identify predictors of LVO and to determine whether AF improves the ability of LAMS to predict LVO.RESULTSAmong 1,234 patients admitted with ischemic stroke, 862 underwent emergent vascular imaging (69.8%) out of which 374 (43.4%) had evidence of LVO and 207 (24%) underwent mechanical thrombectomy. In multivariable models, predictors of LVO were LAMS (OR 1.42 per one point increase 95% CI 1.29‐1.57) and AF (OR 1.95 95% CI 1.26‐3.02, P < .001). We developed the LAMS‐AF that includes the LAMS score and adds two points if AF is present. In this analysis, LAMS‐AF (AUC .78) had improved prediction over LAMS (AUC .76) in predicting LVO and lead to reclassification of 8/68 patients (11.8%) with LAMS = 3 group into the high‐risk LVO group.CONCLUSIONIn patients with LAMS = 3, using the LAMS‐AF score may improve the ability of LAMS in predicting LVO. Larger studies are needed to confirm our findings.

BackgroundThe aetiology of wall motion abnormalities (WMA) in patients with ischaemic stroke is unclear. We hypothesised that WMAs on transthoracic echocardiography (TTE) in the setting of ischaemic stroke mostly reflect pre-existing coronary heart disease rather than simply an isolated neurocardiogenic phenomenon.MethodsData were retrospectively abstracted from a prospective ischaemic stroke database over 18 months and included patients with ischaemic stroke who underwent a TTE. Coronary artery disease was defined as history of myocardial infarction (MI), coronary intervention or ECG evidence of prior MI. The presence (vs absence) of WMA was abstracted. Multivariable logistic regression was used to determine the association between coronary artery disease and WMA in models adjusting for potential confounders.ResultsWe identified 1044 patients who met inclusion criteria; 139 (13.3%, 95% CI 11.2% to 15.4%) had evidence of WMA of whom only 23 (16.6%, 95% CI 10.4% to 22.8%) had no history of heart disease or ECG evidence of prior MI. Among these 23 patients, 12 had a follow-up TTE after the stroke and WMA persisted in 92.7% (11/12) of patients. In fully adjusted models, factors associated with WMA were older age (OR per year increase 1.03, 95% 1.01 to 1.05, p=0.009), congestive heart failure (OR 4.44, 95% CI 2.39 to 8.33, p<0.001), history of coronary heart disease or ECG evidence prior MI (OR 27.03, 95% CI 14.93 to 50.0, p<0.001) and elevated serum troponin levels (OR 2.00, 95% CI 1.06 to 3.75, p=0.031).ConclusionIn patients with ischaemic stroke, WMA on TTE may reflect underlying cardiac disease and further cardiac evaluation may be considered.

Background and Purpose: Early neurologic improvement (ENI) in patients treated with alteplase has been shown to correlate with functional outcome. However, the definition of ENI remains controversial and has varied across studies. We hypothesized that ENI defined as a percentage change in the National Institute of Health Stroke Scale (NIHSS) score (percent change NIHSS score) at 24-hours would better correlate with favorable outcomes at 3 months than ENI defined as the change in NIHSS score (delta NIHSS score) at 24 hours. Methods: Retrospective analysis of prospectively collected single-center quality improvement data was performed of all acute ischemic stroke (AIS) patients treated with alteplase. We examined delta NIHSS score and percent change NIHSS score in unadjusted and adjusted logistic regression models as predictors of a favorable outcome at 3 months (defined as mRS 0-1). Results: Among 586 patients who met the inclusion criteria, 194 (33.1%) had a favorable outcome at 3 months. In fully adjusted models, both delta NIHSS score (OR per point decrease 1.27; 95% confidence interval [CI] 1.19-1.36) and percent change NIHSS score (OR per 10 percent decrease 1.17; 95% CI 1.12-1.22) were associated with favorable functional outcome at 3 months. Receiver operating characteristic (ROC) curve comparison showed that the area under the ROC curve for percent change NIHSS score (.755) was greater than delta NIHSS score (.613) or admission NIHSS (.694). Conclusions: Percentage change in NIHSS score may be a better surrogate marker of ENI and functional outcome in AIS patients after receiving acute thrombolytic therapy. More studies are needed to confirm our findings.

Background and Purpose- Left atrial enlargement has been shown to be associated with ischemic stroke, but the association with embolic stroke mechanisms remains unknown. We aim to study the associations between left atrial volume index (LAVI) and embolic stroke subtypes and atrial fibrillation (AF) detection on cardiac event monitoring in patients with embolic stroke of unknown source. Methods- Data were collected from a prospective cohort of consecutive patients with ischemic stroke admitted to a comprehensive stroke center over 18 months. Stroke subtype was classified into cardioembolic stroke, noncardioembolic stroke of determined mechanism (NCE), or embolic stroke of undetermined source (ESUS). Univariate and prespecified multivariable analyses were performed to assess associations between LAVI and stroke subtype and AF detection in patients with ESUS. Results- Of 1224 consecutive patients identified during the study period, 1020 (82.6%) underwent transthoracic echocardiography and had LAVI measurements. LAVI was greater in patients with cardioembolic stroke than NCE (41.4 mL/m2±18.0 versus 28.6 mL/m2±12.2; P<0.001) but not in ESUS versus NCE (28.9 mL/m2±12.6 versus 28.6 mL/m2±12.2; P=0.61). In multivariable logistic regression models, LAVI was greater in cardioembolic stroke versus NCE (adjusted odds ratio per mL/m2, 1.07; 95% CI, 1.05-1.09; P<0.001) but not in ESUS versus NCE (adjusted odds ratio per mL/m2, 1.00; 95% CI, 0.99-1.02; P=0.720). Among 99 patients with ESUS who underwent cardiac monitoring, 18.2% had AF detected; LAVI was independently associated with AF detection in ESUS (adjusted odds ratio per mL/m2, 1.09; 95% CI, 1.02-1.15; P=0.007). Conclusions- LAVI is associated with cardioembolic stroke as well as AF detection in patients with ESUS, 2 subsets of ischemic stroke that benefit from anticoagulation therapy. Patients with increased LAVI may be a subgroup where anticoagulation may be tested for stroke prevention.

Background: Patients are more likely to develop white matter disease (WMD) and microhemorrhage (MH) after ischemic stroke. Little is known about whether stroke patients had an increased prevalence of these findings before a stroke compared to patients who did not go on to develop a stroke. Methods: We retrospectively identified patients admitted to our institution with ischemic stroke between 5/16 - 12/17 who had magnetic resonance imaging (MRI) of the brain between 30 days-2 years prior to their stroke. Age and gender-matched controls for the initial MRI were identified for pair-wise comparison. Automatic segmentations of gray and white matter volumes and manual segmentation of WMD and MH (size<10mm) were completed using 3D Slicer 4.5 and 4.9, respectively. Univariate analyses and multivariate models were performed to determine factors associated with stroke. This included demographic factors and traditional vascular risk factors. Results: Among the 96 patients in our study, stroke patients (n=48, mean age 68, 50% female) had lower rates of cancer (p=0.03) but higher rates of hyperlipidemia (p=0.024) compared to controls. Stroke patients exhibited greater WMD volume (15.7±20.2 vs 7.3±10.4 mL, p= 0.012) compared to controls, but not MH number (p=0.29) or total MH volume (p=0.26). Although history of stroke was associated with new presentation of stroke (72.9% vs 22.9%, p<0.001), prior stroke was not linked to an overall difference in WMD volume (13.7±17.6 vs 9.4±15.3mL, p=0.20), gray to white matter ratio (1.27±0.54 vs 1.21±0.74 mL, p=0.68), MH number (p=0.36) or total MH volume (p=0.39). After adjusting for confounders, pre-existing WMD volume remained an independent predictor of stroke (adjusted OR 1.042 per one point increase, 95% CI 1.001-1.086, p=0.046). Conclusion: Increased volume of white matter disease correlates with a greater risk of future ischemic stroke. These results should be validated in subsequent studies.

Background and Purpose— Transthoracic echocardiography (TTE) is widely used in the ischemic stroke setting. In this study, we aim to investigate the yield of TTE in patients with ischemic stroke and known subtype and whether the admission troponin level improves the yield of TTE. Methods— Data were abstracted from a single-center prospective ischemic stroke database for 18 months and included all patients with ischemic stroke whose etiologic subtype could be obtained without the need of TTE. Unadjusted and adjusted regression models were built to determine whether positive cardiac troponin levels (≥0.1 ng/mL) improve the yield of TTE, adjusting for demographic and clinical characteristics. Results— We identified 578 patients who met the inclusion criteria. TTE changed clinical management in 64 patients (11.1%), but intracardiac thrombus was detected in only 4 patients (0.7%). In multivariable models, there was an association between TTE changing management and positive serum troponin level (adjusted odds ratio, 4.26; 95% CI, 2.17–8.34; P <0.001). Conclusions— In patients with ischemic stroke, TTE might lead to a change in clinical management in ≈1 of 10 patients with known stroke subtype before TTE but changed acute treatment decisions in <1 percent of patients. Serum troponin levels improved the yield of TTE in these patients.

Background: Recent studies have shown that outpatient cardiac monitoring for 30 days or longer increases detection rate of paroxysmal atrial fibrillation (AF) after Embolic Stroke of Unknown Source (ESUS). For patients with AF detected on monitoring, anticoagulation can be initiated to reduce risk of recurrent stroke. In this study, we aim to compare characteristics between patients who received cardiac monitoring and those who did not to further elucidate trends in the use of prolonged outpatient cardiac monitoring following ESUS. Methods: We analyzed a retrospective cohort of patients discharged with a diagnosis of ESUS over a period of 18 months in whom outpatient cardiac monitoring was ordered. Patients who were deceased or without follow-up at 90 days were excluded. Patients were divided into two groups based on whether or not they received outpatient cardiac monitoring. We compared demographic data, clinical risk factors, and NIHSS between the two groups. Results: Out of 282 patients with ESUS, 189 (67.0%) patients had 90 day follow-up data available; 118 (62.4%) underwent cardiac monitoring and 71 (37.6%) did not undergo cardiac monitoring. Of the patients who were monitored, 81.4% (96/118) received a 30 day non-invasive monitor and 43.2% (51/118) patients had an ICM implanted. There were no significant differences in baseline characteristics among patients who underwent cardiac monitoring versus those who did not. Conclusion: More than one-third of patients with ESUS for whom outpatient cardiac monitoring was recommended and ordered did not actually receive it. This finding supports the need for more convenient, effective processes by which patients can follow through with outpatient cardiac monitoring which could perhaps be initiated at discharge.

Background Large vessel disease stroke subtype carries the highest risk of early recurrent stroke. In this study we aim to look at the association between impaired perfusion and early stroke recurrence in patients with intracranial atherosclerotic disease or total cervical carotid occlusion. Methods This is a retrospective study from a comprehensive stroke center where we included consecutive patients 18 years or older with intracranial atherosclerotic disease or total cervical carotid occlusion admitted with a diagnosis of ischemic stroke within 24 h from symptom onset with National Institute Health Stroke Scale < 15, between 1 December 2016 and 30 June 2017. Patients with (1) evidence of ≥ 50% stenosis of a large intracranial artery or total carotid artery occlusion, (2) symptoms referable to the territory of the affected artery, and (3) perfusion imaging data using the RAPID processing software were included. The primary predictor was unfavorable perfusion imaging defined as Tmax > 6 s mismatch volume (penumbra volume-infarct volume) of 15 ml or more. The outcome was recurrent cerebrovascular events at 90 days defined as worsening or new neurological symptoms in the absence of a nonvascular cause attributable to the decline, or new infarct or infarct extension in the territory of the affected artery. We used Cox proportional hazards models to determine the association between impaired perfusion and recurrent cerebrovascular events. Results Sixty-two patients met our inclusion criteria; mean age 66.4 ± 13.1 years, 64.5% male (40/62) and 50.0% (31/62) with intracranial atherosclerotic disease. When compared to patients with favorable perfusion pattern, patients with unfavorable perfusion pattern were more likely to have recurrent cerebrovascular events (55.6% (10/18) versus 9.1% (4/44), p < 0.001). This association persisted after adjusting for potential confounders (adjusted hazard ratio 10.44, 95% confidence interval 2.30-47.42, p = 0.002). Conclusion Perfusion mismatch predicts recurrent cerebrovascular events in patients with ischemic stroke due to intracranial atherosclerotic disease or total cervical carotid occlusion. Studies are needed to determine the utility of revascularization strategies in this patient population.

Background: Occult paroxysmal atrial fibrillation (AF) is detected in 16%-30% of patients with embolic stroke of unknown source (ESUS). The identification of AF predictors on outpatient cardiac monitoring can help guide clinicians decide on a duration or method of cardiac monitoring after ESUS. Methods: We included all patients with ESUS who underwent an inpatient diagnostic evaluation and outpatient cardiac monitoring between January 1, 2013, and December 31, 2016. Patients were divided into 2 groups based on detection of AF or atrial flutter during monitoring. We compared demographic data, clinical risk factors, and cardiac biomarkers between the 2 groups. Multivariable logistic regression was used to determine predictors of AF. Results: We identified 296 consecutive patients during the study period; 38 (12.8%) patients had AF detected on outpatient cardiac monitoring. In a multivariable regression analysis, advanced age (ages 65-74: odds ratio [OR] 2.36, 95% confidence interval [CI].85-6.52; ages 75 or older: OR 4.08, 95% CI 1.58-10.52) and moderate-to-severe left atrial enlargement (OR 4.66, 95% CI 1.7912.12) were predictors of AF on outpatient monitoring. We developed the Brown ESUS-AF score: age (65-74 years: 1 point, 75 years or older: 2 points) and left atrial enlargement (moderate or severe: 2 points) with good prediction of AF (area under the curve.725) and was internally validated using bootstrapping. The percentage of patients with AF detected in each score category were as follows: 0: 4.2%; 1: 14.8%; 2: 20.8%; 3: 22.2%; 4: 55.6%. Conclusions: The Brown ESUS-AF score predicts AF on prolonged outpatient monitoring after ESUS. More studies are needed to externally validate our findings.

Importance: Large vessel disease (LVD) stroke subtype carries the highest risk of early recurrent stroke, reaching up to 30% in the first few days. Predictors of early recurrence have been previously described, but less is known regarding infarct expansion and other causes of neurological worsening. We aim to determine the association between impaired perfusion and neurological decline in patients with LVD subtype. Methods: This is a single center retrospective cohort study of all consecutive patients 18 years or older with LVD admitted with a diagnosis of ischemic stroke within 24 hours from symptom onset (12/1/2016 to 3/31/2017). Patients with 1) evidence of ≥ 50% stenosis of a large intra- or extracranial artery on computerized tomography angiography (CTA); 2) symptoms referable to the territory of the affected artery and NIHSS < 15 and 3) perfusion imaging data using the RAPID processing software were included. The primary predictor was unfavorable mismatch volume ≥15 mL, defined as perfusion deficit of Tmax > 6sec volume minus infarct volume similar to neuro-interventional trials. The outcome was recurrent cerebrovascular events (RCVE) at 90 days (adjudicated independently by two vascular neurologists) defined as a decline in neurologic function in the absence of a medical cause, or new infarct or infarct extension in the territory of the affected artery. We estimated the hazard ratio (HR) and 95% confidence interval (CI) for unfavorable perfusion imaging as predictor of RCVE using univariable and multivariable Cox proportional hazards models. Results: Sixty-eight patients met our inclusion criteria (mean age 64.7 years; 61.8% male; 58.8% intracranial LVD). When compared to patients without RCVE, patients with RCVE were more likely to have unfavorable mismatch volume [71.4% vs. 14.8%, p<0.001]. This association persisted after adjusting for sex, dual antiplatelet therapy, initial stroke severity, and intracranial location of LVD (adjusted HR 15.6, 95% CI 3.7-66.7, p<0.001). Conclusion: Perfusion mismatch is associated with RCVE in patients with ischemic stroke due to LVD. Pursuit of more aggressive treatment and management strategies may be warranted in this population.