Endovascular Thrombectomy for Treatment of Acute Ischemic Stroke During Pregnancy and the Early Postpartum Period.

BACKGROUND AND PURPOSE: Acute ischemic stroke (AIS) is a rare occurrence during pregnancy and the postpartum period. Existing literature evaluating endovascular mechanical thrombectomy (MT) for this patient population is limited. METHODS: The National Inpatient Sample was queried from 2012 to 2018 to identify and characterize pregnant and postpartum patients (up to 6 weeks following childbirth) with AIS treated with MT. Complications and outcomes were compared with nonpregnant female patients treated with MT and to other pregnant and postpartum patients managed medically. Complex samples regression models and propensity score matching were implemented to assess adjusted associations and to address confounding by indication, respectively. RESULTS: Among 4590 pregnant and postpartum patients with AIS, 180 (3.9%) were treated with MT, and rates of utilization increased following the MT clinical trial era (2015-2018; 1.9% versus 5.3%, P=0.011). Compared with nonpregnant patients with AIS treated with MT, they experienced lower rates of intracranial hemorrhage (11% versus 24%, P=0.069) and poor functional outcome (50% versus 72%, P=0.003) at discharge. Pregnant/postpartum status was independently associated with a lower likelihood of development of intracranial hemorrhage (adjusted odds ratio, 0.26 [95% CI, 0.09-0.70]; P=0.008) following multivariable analysis adjusting for age, illness severity, and stroke severity. Following propensity score matching, pregnant and postpartum patients treated with MT and those medically managed differed in frequency of venous thromboembolism (17% versus 0%, P=0.001) and complications related to pregnancy (44% versus 64%, P=0.034), but not in functional outcome at discharge or hospital length of stay. Pregnant and postpartum women treated with MT did not experience mortality or miscarriage during hospitalization. CONCLUSIONS: This large-scale analysis utilizing national claims data suggests that MT is a safe and efficacious therapy for AIS during pregnancy and the postpartum period. In the absence of prospective clinical trials, population-based cross-sectional analyses such as the present study provide valuable clinical insight.

Association of Dexamethasone with Shunt Requirement, Early Disability, and Medical Complications in Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND AND PURPOSE: Current guidelines do not support the routine use of corticosteroids in patients with aneurysmal subarachnoid hemorrhage (aSAH). However, corticosteroids use in aSAH has been practiced at some centers by convention. The aim of the study was to determine the incidence of hydrocephalus requiring ventriculoperitoneal shunt (VPS) placement as well as functional outcome on discharge and adverse events attributed to corticosteroids in patients with aSAH treated with different dexamethasone (DXM) treatment schemes. METHODS: We retrospectively analyzed 206 patients with aSAH stratified to three groups based on the DXM treatment scheme: no corticosteroids, short course of DXM (S-DXM; 4 mg every 6 h for 1 day followed by a daily total dose reduction by 25% and then by 50% on last day), and long course of DXM (L-DXM; 4 mg every 6 h for 5-7 days followed by reduction by 50% every other day). The primary outcome measure was the placement of a VPS, and the secondary outcome was a good functional outcome [modified Rankin Scale (mRS) 0-3] at hospital discharge. Safety measures were the incidence of infection (pneumonia, urinary tract infection, ventriculitis, meningitis), presence of delirium, and hyperglycemia. RESULTS: There was no difference in the rate of external ventricular drain (EVD) (p = 0.164) and VPS placement (p = 0.792), nor in the rate of good outcome (p = 0.928) among three defined treatment regimens. Moreover, the median duration of treatment with EVD did not differ between subjects treated with no corticosteroids, S-DXM, and L-DXM (p = 0.905), and the probability of EVD removal was similar when stratified according to treatment regimens (log-rank; p = 0.256). Patients who received L-DXM had significantly more complications as compared to patients, who received no corticosteroids or S-DXM (78.4% vs. 58.6%; p = 0.005). After adjustment, L-DXM remained independently associated with increased risk of combined adverse events (OR = 2.72; 95%CI, 1.30-5.72; p = 0.008), infection (OR = 3.45; 95%CI, 1.63-7.30; p = 0.001) and hyperglycemia (OR = 2.05; 95%CI, 1.04-4.04; p = 0.039). CONCLUSIONS: DXM use among patients with aSAH did not relate to the rate of EVD and VPS placement, duration of EVD treatment, and functional disability at discharge but increased the risk of medical complications.

Incidence of Neo-Intimal Hyperplasia in Anterior Circulation Aneurysms Following Pipeline Flow Diversion.

INTRODUCTION: Flow diversion of the distal anterior circulation cerebral vasculature may be used for management of wide necked aneurysms not amenable to other endovascular approaches. Follow-up angiography sometimes demonstrates neo-intimal hyperplasia within or adjacent to the stent, however there is limited evidence in the literature examining the incidence in MCA and ACA aneurysms. We present our experience with flow diversion of the distal vasculature and evaluate the incidence of neo-intimal hyperplasia. MATERIALS AND METHODS: Retrospective review of patients who underwent Pipeline embolization device (PED) treatment for ruptured and unruptured anterior circulation aneurysms. RESULTS: A total of 251 anterior circulation aneurysms were treated by pipeline flow diversion, of which 175 were ICA aneurysms, 14 were ACA aneurysms and 18 were MCA aneurysms. 6-month follow-up angiography was available in 207 patients. The incidence of neo-intimal hyperplasia was 15.9%, 21.4%, and 61.1% in ICA, ACA, and MCA aneurysms, respectively. MCA-territory aneurysms developed neo-intimal hyperplasia at a significantly higher rate than aneurysms in other vessel territories. Rates of aneurysmal occlusion did not significantly differ from those patients who did not exhibit intimal hyperplasia on follow-up angiography. CONCLUSION: In our experience, flow diversion of distal wide-necked MCA and ACA aneurysms is a safe and effective treatment strategy. The presence of neo-intimal hyperplasia at 6-month angiography is typically clinically asymptomatic. Given the statistically higher rate of neo-intimal hyperplasia in MCA aneurysms at 6-month angiography, we propose delaying initial follow-up angiography to 12-months and maintaining dual antiplatelet therapy during that time.

Cerebral Venous Sinus Thrombosis in COVID-19 Infection: A Case Series and Review of The Literature.

SARS-CoV-2, the virus responsible for novel Coronavirus (COVID-19) infection, has recently been associated with a myriad of hematologic derangements; in particular, an unusually high incidence of venous thromboembolism has been reported in patients with COVID-19 infection. It is postulated that either the cytokine storm induced by the viral infection or endothelial damage caused by viral binding to the ACE-2 receptor may activate a cascade leading to a hypercoaguable state. Although pulmonary embolism and deep venous thrombosis have been well described in patients with COVID-19 infection, there is a paucity of literature on cerebral venous sinus thrombosis (cVST) associated with COVID-19 infection. cVST is an uncommon etiology of stroke and has a higher occurrence in women and young people. We report a series of three patients at our institution with confirmed COVID-19 infection and venous sinus thrombosis, two of whom were male and one female. These cases fall outside the typical demographic of patients with cVST, potentially attributable to COVID-19 induced hypercoaguability. This illustrates the importance of maintaining a high index of suspicion for cVST in patients with COVID-19 infection, particularly those with unexplained cerebral hemorrhage, or infarcts with an atypical pattern for arterial occlusive disease.

Acute Cerebrovascular Disorders and Vasculopathies Associated with Significant Mortality in SARS-CoV-2 Patients Admitted to The Intensive Care Unit in The New York Epicenter.

The current Coronavirus pandemic due to the novel SARS-Cov-2 virus has proven to have systemic and multi-organ involvement with high acuity neurological conditions including acute ischemic strokes. We present a case series of consecutive COVID-19 patients with cerebrovascular disease treated at our institution including 3 cases of cerebral artery dissection including subarachnoid hemorrhage. Knowledge of the varied presentations including dissections will help treating clinicians at the bedside monitor and manage these complications preemptively.

Mechanical Thrombectomy in Patients With Ischemic Stroke With Prestroke Disability.

Background and Purpose- We aimed to compare functional and procedural outcomes of patients with acute ischemic stroke with none-to-minimal (modified Rankin Scale [mRS] score, 0-1) and moderate (mRS score, 2-3) prestroke disability treated with mechanical thrombectomy. Methods- Consecutive adult patients undergoing mechanical thrombectomy for an anterior circulation stroke were prospectively identified at 2 comprehensive stroke centers from 2012 to 2018. Procedural and 90-day functional outcomes were compared among patients with prestroke mRS scores 0 to 1 and 2 to 3 using χ2, logistic, and linear regression tests. Primary outcome and significant differences in secondary outcomes were adjusted for prespecified covariates. Results- Of 919 patients treated with mechanical thrombectomy, 761 were included and 259 (34%) patients had moderate prestroke disability. Ninety-day mRS score 0 to 1 or no worsening of prestroke mRS was observed in 36.7% and 26.7% of patients with no-to-minimal and moderate prestroke disability, respectively (odds ratio, 0.63 [0.45-0.88], P=0.008; adjusted odds ratio, 0.90 [0.60-1.35], P=0.6). No increase in the disability at 90 days was observed in 22.4% and 26.7%, respectively. Rate of symptomatic intracerebral hemorrhage (7.3% versus 6.2%, P=0.65), successful recanalization (86.7% versus 83.8%, P=0.33), and median length of hospital stay (5 versus 5 days, P=0.06) were not significantly different. Death by 90 days was higher in patients with moderate prestroke disability (14.3% versus 40.3%; odds ratio, 4.06 [2.82-5.86], P<0.001; adjusted odds ratio, 2.83 [1.84, 4.37], P<0.001). Conclusions- One-third of patients undergoing mechanical thrombectomy had a moderate prestroke disability. There was insufficient evidence that functional and procedural outcomes were different between patients with no-to-minimal and moderate prestroke disability. Patients with prestroke disability were more likely to die by 90 days.

Cerebral Herniation Secondary to Stroke-Associated Hemorrhagic Transformation, Fulminant Cerebral Edema in Setting of COVID-19 Associated ARDS and Active Malignancy.

SARS-CoV-2 infection has been associated with ischemic stroke as well as systemic complications such as acute respiratory failure; cytotoxic edema is a well-known sequelae of acute ischemic stroke and can be worsened by the presence of hypercarbia induced by respiratory failure. We present the case of a very rapid neurologic and radiographic decline of a patient with an acute ischemic stroke who developed rapid fulminant cerebral edema leading to herniation in the setting of hypercarbic respiratory failure attributed to SARS-CoV-2 infection. Given the elevated incidence of cerebrovascular complications in patients with COVID-19, it is imperative for clinicians to be aware of the risk of rapidly progressive cerebral edema in patients who develop COVID-19 associated acute respiratory distress syndrome.

Reversible cerebral vasoconstriction syndrome and dissection in the setting of COVID-19 infection.

The current COVID-19 pandemic has recently brought to attention the myriad of neuro- logic sequelae associated with Coronavirus infection including the predilection for stroke, particularly in young patients. Reversible cerebral vasoconstriction syndrome (RCVS) is a well-described clinical syndrome leading to vasoconstriction in the intracra- nial vessels, and has been associated with convexity subarachnoid hemorrhage and oc- casionally cervical artery dissection. It is usually reported in the context of a trigger such as medications, recreational drugs, or the postpartum state; however, it has not been described in COVID-19 infection. We report a case of both cervical vertebral ar- tery dissection as well as convexity subarachnoid hemorrhage due to RCVS, in a pa- tient with COVID-19 infection and no other triggers.

Mechanical Thrombectomy in Ischemic Stroke Patients with Severe Pre-Stroke Disability.

Frequency and outcomes of mechanical thrombectomy (MT) in clinical practice for patients with severe pre-stroke disability are largely unknown. In this case series, we aim to describe the disability make-up and outcomes of 33 patients with severe pre-stroke disability undergoing MT. Patients with a permanent, severe, pre-stroke disability (modified Rankin Score, mRS, 4-5) were identified from a prospectively-maintained database of consecutive, MT-treated, anterior circulation acute ischemic stroke patients at two comprehensive stroke centers in the United States. We present details on the cause of disability and socio-demographic status as well as procedural and functional outcomes. This study, despite the lack of inferential testing due to limited sample size, provides insight into demographics and outcomes of MT-treated patients with severe pre-stroke disability. Rate of return to functional baseline as well as rates of procedural success and complications were comparable to that reported in the literature for patients without any pre-existing disability.

Blood Pressure after Endovascular Therapy for Ischemic Stroke (BEST): A Multicenter Prospective Cohort Study.

Background and Purpose- To identify the specific post-endovascular stroke therapy (EVT) peak systolic blood pressure (SBP) threshold that best discriminates good from bad functional outcomes (a priori hypothesized to be 160 mm Hg), we conducted a prospective, multicenter, cohort study with a prespecified analysis plan. Methods- Consecutive adult patients treated with EVT for an anterior ischemic stroke were enrolled from November 2017 to July 2018 at 12 comprehensive stroke centers accross the United States. All SBP values within 24 hours post-EVT were recorded. Using Youden index, the threshold of peak SBP that best discriminated primary outcome of dichotomized 90-day modified Rankin Scale score (0-2 versus 3-6) was identified. Association of this SBP threshold with the outcomes was quantified using multiple logistic regression. Results- Among 485 enrolled patients (median age, 69 [interquartile range, 57-79] years; 51% females), a peak SBP of 158 mm Hg was associated with the largest difference in the dichotomous modified Rankin Scale score (absolute risk reduction of 19%). Having a peak SBP >158 mm Hg resulted in an increased likelihood of modified Rankin Scale score 3 to 6 (odds ratio, 2.24 [1.52-3.29], P<0.01; adjusted odds ratio, 1.29 [0.81-2.06], P=0.28, after adjustment for prespecified variables). Conclusions- A peak post-EVT SBP of 158 mm Hg was prospectively identified to best discriminate good from bad functional outcome. Those with a peak SBP >158 had an increased likelihood of having a bad outcome in unadjusted, but not in adjusted analysis. The observed effect size was similar to prior studies. This finding should undergo further testing in a future randomized trial of goal-targeted post-EVT antihypertensive treatment.

Predicting symptomatic intracranial haemorrhage after mechanical thrombectomy: the TAG score.

BACKGROUND: There is limited data on predictors of symptomatic intracranial haemorrhage (sICH) in patients who underwent mechanical thrombectomy. In this study, we aim to determine those predictors with external validation. METHODS: We evaluated mechanical thrombectomy in a derivation cohort of patients at a comprehensive stroke centre over a 30-month period. Clinical and radiographic data on these patients were obtained from the prospective quality improvement database. sICH was defined using the European Cooperative Acute Stroke Study III. We compared clinical and radiographic characteristics between patients with and without sICH using χ2 and t tests to identify independent predictors of sICH with p<0.1. Significant variables were then combined in a multivariate logistic regression model to derive an sICH prediction score. This score was then validated using data from the Blood Pressure After Endovascular Treatment multicentre prospective registry. RESULTS: We identified 578 patients with acute ischaemic stroke who received thrombectomy, 19 had sICH (3.3%). Predictive factors of sICH were: thrombolysis in cerebral ischaemia (TICI) score, Alberta stroke program early CT score (ASPECTS), and glucose level, and from these predictors, we derived the weighted TICI-ASPECTS-glucose (TAG) score, which was associated with sICH in the derivation (OR per unit increase 1.98, 95% CI 1.48 to 2.66, p<0.001, area under curve ((AUC)=0.79) and validation (OR per unit increase 1.48, 95% CI 1.22 to 1.79, p<0.001, AUC=0.69) cohorts. CONCLUSION: High TAG scores are associated with sICH in patients receiving mechanical thrombectomy. Larger studies are needed to validate this scoring system and test strategies to reduce sICH risk and make thrombectomy safer in patients with elevated TAG scores.

Cardiac Biomarkers Predict Large Vessel Occlusion in Patients with Ischemic Stroke.

BACKGROUND AND PURPOSE: Cardiac biomarkers may help identify stroke mechanisms and may aid in improving stroke prevention strategies. There is limited data on the association between these biomarkers and acute ischemic stroke (AIS) caused by large vessel occlusion (LVO). We hypothesized that cardiac biomarkers (cardiac troponin and left atrial diameter [LAD]) would be associated with the presence of LVO. METHODS: Data were abstracted from a single center prospective AIS database over 18 months and included all patients with AIS with CT angiography of the head and neck. The presence of LVO was defined as proximal LVO of the internal carotid artery terminus, middle cerebral artery (M1 or proximal M2), or basilar artery. Univariate analyses and predefined multivariable models were performed to determine the association between cardiac biomarkers (positive troponin [troponin ≥0.1 ng/mL] and LAD on transthoracic echocardiogram) and LVO adjusting for demographic factors (age and sex), risk factors (hypertension, diabetes, hyperlipidemia, history of stroke, congestive heart failure, coronary heart disease, and smoking), and atrial fibrillation (AF). RESULTS: We identified 1234 patients admitted with AIS; 886 patients (71.8%) had vascular imaging to detect LVO. Of those with imaging available, 374 patients (42.2%) had LVO and 207 patients (23.4%) underwent thrombectomy. There was an association between positive troponin and LVO after adjusting for age, sex and other risk factors (adjusted OR 1.69 [1.08-2.63], P = .022) and this association persisted after including AF in the model (adjusted OR 1.60 [1.02-2.53], P = 0.043). There was an association between LAD and LVO after adjusting for age, sex, and risk factors (adjusted OR per mm 1.03 [1.01-1.05], P = 0.013) but this association was not present when AF was added to the model (adjusted OR 1.01 [0.99-1.04], P = .346). Sensitivity analyses using thrombectomy as an outcome yielded similar findings. CONCLUSIONS: Cardiac biomarkers, particularly serum troponin levels, are associated with acute LVO in patients with ischemic stroke. Prospective studies are ongoing to confirm this association and to test whether anticoagulation reduces the risk of recurrent embolism in this patient population.

Serum Troponin Level in Acute Ischemic Stroke Identifies Patients with Visceral Infarcts.

BACKGROUND AND PURPOSE: Patients with ischemic stroke of cardioembolic origin are at risk of visceral (renal or splenic) infarction. We hypothesized that serum troponin level at time of ischemic stroke would be associated with presence of visceral infarction. METHODS: Data were abstracted from a single center prospective stroke database over 18 months and included all patients with ischemic stroke who underwent contrast-enhanced computerized tomography (CT) of the abdomen and pelvis for clinical purposes within 1 year of stroke. The primary predictor was troponin concentration ≥.1ng/mL. The primary outcome was visceral infarct (renal and/or splenic) on CT abdomen and pelvis. Univariate and multivariable logistic regression models were used to estimate the odds ratio and 95% confidence intervals (OR, 95% CI) for the association of troponin with visceral infarction. RESULTS: Of 1233 patients with ischemic stroke, 259 patients had a qualifying visceral CT. Serum troponin level on admission was measured in 237 of 259 patients (93.3%) and 41 of 237 (17.3%) had positive troponin. There were 25 patients with visceral infarcts: 16 renal, 7 splenic, and 2 both. In univariate models, patients with a positive troponin level (versus negative) were more likely to have visceral infarcts (39.1% [9/23] versus 15.0% [32/214], P = .008) and this association persisted in multivariable models (adjusted OR 3.83; 95% CI 1.42-10.31, P = .006). CONCLUSIONS: In ischemic stroke patients, elevated serum troponin levels may help identify patients with visceral infarcts. This suggests that troponin in the acute stroke setting is a biomarker of embolic risk. Larger studies with systematic visceral imaging are needed to confirm our findings.

Troponin Improves the Yield of Transthoracic Echocardiography in Ischemic Stroke Patients of Determined Stroke Subtype.

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.

Early Elevated Troponin Levels After Ischemic Stroke Suggests a Cardioembolic Source.

BACKGROUND AND PURPOSE: Elevated cardiac troponin is a marker of cardiac disease and has been recently shown to be associated with embolic stroke risk. We hypothesize that early elevated troponin levels in the acute stroke setting are more prevalent in patients with embolic stroke subtypes (cardioembolic and embolic stroke of unknown source) as opposed to noncardioembolic subtypes (large-vessel disease, small-vessel disease, and other). METHODS: We abstracted data from our prospective ischemic stroke database and included all patients with ischemic stroke during an 18-month period. Per our laboratory, we defined positive troponin as ≥0.1 ng/mL and intermediate as ≥0.06 ng/mL and <0.1 ng/mL. Unadjusted and adjusted regression models were built to determine the association between stroke subtype (embolic stroke of unknown source and cardioembolic subtypes) and positive and intermediate troponin levels, adjusting for key confounders, including demographics (age and sex), clinical characteristics (hypertension, hyperlipidemia, diabetes mellitus, renal function, coronary heart disease, congestive heart failure, current smoking, and National Institutes of Health Stroke Scale score), cardiac variables (left atrial diameter, wall-motion abnormalities, ejection fraction, and PR interval on ECG), and insular involvement of infarct. RESULTS: We identified 1234 patients, of whom 1129 had admission troponin levels available; 10.0% (113/1129) of these had a positive troponin. In fully adjusted models, there was an association between troponin positivity and embolic stroke of unknown source subtype (adjusted odds ratio, 4.46; 95% confidence interval, 1.03-7.97; P=0.003) and cardioembolic stroke subtype (odds ratio, 5.00; 95% confidence interval, 1.83-13.63; P=0.002). CONCLUSIONS: We found that early positive troponin after ischemic stroke may be independently associated with a cardiac embolic source. Future studies are needed to confirm our findings using high-sensitivity troponin assays and to test optimal secondary prevention strategies in patients with embolic stroke of unknown source and positive troponin.

Left Atrial Enlargement and Anticoagulation Status in Patients with Acute Ischemic Stroke and Atrial Fibrillation.

BACKGROUND: Despite anticoagulation therapy, ischemic stroke risk in atrial fibrillation (AF) remains substantial. We hypothesize that left atrial enlargement (LAE) is more prevalent in AF patients admitted with ischemic stroke who are therapeutic, as opposed to nontherapeutic, on anticoagulation. METHODS: We included consecutive patients with AF admitted with ischemic stroke between April 1, 2015, and December 31, 2016. Patients were divided into two groups based on whether they were therapeutic (warfarin with an international normalized ratio ≥ 2.0 or non-vitamin K oral anticoagulant with uninterrupted use in the prior 2 weeks) versus nontherapeutic on anticoagulation. Univariable and multivariable models were used to estimate associations between therapeutic anticoagulation and clinical factors, including CHADS2 score and LAE (none/mild versus moderate/severe). RESULTS: We identified 225 patients during the study period; 52 (23.1%) were therapeutic on anticoagulation. Patients therapeutic on anticoagulation were more likely to have a larger left atrial diameter in millimeters (45.6 ± 9.2 versus 42.3 ± 8.6, P = .032) and a higher CHADS2 score (2.9 ± 1.1 versus 2.4 ± 1.1, P = .03). After adjusting for the CHADS2 score, patients who had a stroke despite therapeutic anticoagulation were more likely to have moderate to severe LAE (odds ratio, 2.05; 95% confidence interval, 1.01-4.16). CONCLUSION: LAE is associated with anticoagulation failure in AF patients admitted with an ischemic stroke. This provides indirect evidence that LAE may portend failure of anticoagulation therapy in patients with AF; further studies are needed to delineate the significance of this association and improve stroke prevention strategies.

A Simple Score That Predicts Paroxysmal Atrial Fibrillation on Outpatient Cardiac Monitoring after Embolic Stroke of Unknown Source.

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 1.79-12.12) 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.