Increased stroke severity and mortality in patients with SARS-CoV-2 infection: An analysis from the N3C database.

BACKGROUND: Studies from early in the COVID-19 pandemic showed that patients with ischemic stroke and concurrent SARS-CoV-2 infection had increased stroke severity. We aimed to test the hypothesis that this association persisted throughout the first year of the pandemic and that a similar increase in stroke severity was present in patients with hemorrhagic stroke. METHODS: Using the National Institute of Health National COVID Cohort Collaborative (N3C) database, we identified a cohort of patients with stroke hospitalized in the United States between March 1, 2020 and February 28, 2021. We propensity score matched patients with concurrent stroke and SARS-COV-2 infection and available NIH Stroke Scale (NIHSS) scores to all other patients with stroke in a 1:3 ratio. Nearest neighbor matching with a caliper of 0.25 was used for most factors and exact matching was used for race/ethnicity and site. We modeled stroke severity as measured by admission NIHSS and the outcomes of death and length of stay. We also explored the temporal relationship between time of SARS-COV-2 diagnosis and incidence of stroke. RESULTS: Our query identified 43,295 patients hospitalized with ischemic stroke (5765 with SARS-COV-2, 37,530 without) and 18,107 patients hospitalized with hemorrhagic stroke (2114 with SARS-COV-2, 15,993 without). Analysis of our propensity matched cohort revealed that stroke patients with concurrent SARS-COV-2 had increased NIHSS (Ischemic stroke: IRR=1.43, 95% CI:1.33-1.52, p<0.001; hemorrhagic stroke: IRR=1.20, 95% CI:1.08-1.33, p<0.001), length of stay (Ischemic stroke: estimate = 1.48, 95% CI: 1.37, 1.61, p<0.001; hemorrhagic stroke: estimate = 1.25, 95% CI: 1.06, 1.47, p=0.007) and higher odds of death (Ischemic stroke: OR 2.19, 95% CI: 1.79-2.68, p<0.001; hemorrhagic stroke: OR 2.19, 95% CI: 1.79-2.68, p<0.001). We observed the highest incidence of stroke diagnosis on the same day as SARS-COV-2 diagnosis with a logarithmic decline in counts. CONCLUSION: This retrospective observational analysis suggests that stroke severity in patients with concurrent SARS-COV-2 was increased throughout the first year of the pandemic.

Collateral status, hyperglycemia, and functional outcome after acute ischemic stroke.

BACKGROUND: Mixed data exist regarding the association between hyperglycemia and functional outcome after acute ischemic stroke when accounting for the impact of leptomeningeal collateral flow. We sought to determine whether collateral status modifies the association between treatment group and functional outcome in a subset of patients with large vessel occlusion enrolled in the Stroke Hyperglycemia Insulin Network Effort (SHINE) trial. METHODS: In this post-hoc analysis, we analyzed patients enrolled into the SHINE trial with anterior circulation large vessel occlusion who underwent imaging with CT angiography prior to glucose control treatment group assignment. The primary analysis assessed the degree to which collateral status modified the effect between treatment group and functional outcome as defined by the 90-day modified Rankin Scale score. Logistic regression was used to model the data, with adjustments made for thrombectomy status, age, post-perfusion thrombolysis in cerebral infarction (TICI) score, tissue plasminogen activator (tPA) use, and baseline National Institutes of Health Stroke Scale (NIHSS) score. Five SHINE trial centers contributed data for this analysis. Statistical significance was defined as a p-value < 0.05. RESULTS: Among the 1151 patients in the SHINE trial, 57 with angiographic data were included in this sub-analysis, of whom 19 had poor collaterals and 38 had good collaterals. While collateral status had no effect (p = 0.855) on the association between glucose control treatment group and functional outcome, patients with good collaterals were more likely to have a favorable functional outcome (p = 0.001, OR 5.02; 95% CI 1.37-16.0). CONCLUSIONS: In a post-hoc analysis using a subset of patients with angiographic data enrolled in the SHINE trial, collateral status did not modify the association between glucose control treatment group and functional outcome. However, consistent with prior studies, there was a significant association between good collateral status and favorable outcome in patients with large vessel occlusion stroke. TRIAL REGISTRATION: ClinicalTrials.gov Identifier is NCT01369069. Registration date is June 8, 2011.

Quantification of hematoma and perihematomal edema volumes in intracerebral hemorrhage study: Design considerations in an artificial intelligence validation (QUANTUM) study.

BACKGROUND: Hematoma and perihematomal edema volumes are important radiographic markers in spontaneous intracerebral hemorrhage. Accurate, reliable, and efficient quantification of these volumes will be paramount to their utility as measures of treatment effect in future clinical studies. Both manual and semi-automated quantification methods of hematoma and perihematomal edema volumetry are time-consuming and susceptible to inter-rater variability. Efforts are now underway to develop a fully automated algorithm that can replace them. A (QUANTUM) study to establish inter-quantification method measurement equivalency, which deviates from the traditional use of measures of agreement and a comparison hypothesis testing paradigm to indirectly infer quantification method measurement equivalence, is described in this article. The Quantification of Hematoma and Perihematomal Edema Volumes in Intracerebral Hemorrhage study aims to determine whether a fully automated quantification method and a semi-automated quantification method for quantification of hematoma and perihematomal edema volumes are equivalent to the hematoma and perihematomal edema volumes of the manual quantification method. METHODS/DESIGN: Hematoma and perihematomal edema volumes of supratentorial intracerebral hemorrhage on 252 computed tomography scans will be prospectively quantified in random order by six raters using the fully automated, semi-automated, and manual quantification methods. Primary outcome measures for hematoma and perihematomal edema volumes will be quantified via computed tomography scan on admission (<24 h from symptom onset) and on day 3 (72 ± 12 h from symptom onset), respectively. Equivalence hypothesis testing will be conducted to determine if the hematoma and perihematomal edema volume measurements of the fully automated and semi-automated quantification methods are within 7.5% of the hematoma and perihematomal edema volume measurements of the manual quantification reference method. DISCUSSION: By allowing direct equivalence hypothesis testing, the Quantification of Hematoma and Perihematomal Edema Volumes in Intracerebral Hemorrhage study offers advantages over radiology validation studies which utilize measures of agreement to indirectly infer measurement equivalence and studies which mistakenly try to infer measurement equivalence based on the failure of a comparison two-sided null hypothesis test to reach the significance level for rejection. The equivalence hypothesis testing paradigm applied to artificial intelligence application validation is relatively uncharted and warrants further investigation. The challenges encountered in the design of this study may influence future studies seeking to translate artificial intelligence medical technology into clinical practice.

Vertebral Artery Tortuosity and Morphometric Characteristics of Patients with Recurrent Cervical Artery Dissection.

BACKGROUND: Cervical Artery Dissection is an important cause of stroke in the young. Data on incidence and associations of recurrence in patients with cervical artery dissection are lacking. Increased Vertebral Artery Tortuosity Index has been reported in patients with cervical artery dissection and associated with earlier age of arterial dissection in patients with connective tissue disease. OBJECTIVE: To test the hypothesis that increased vertebral artery tortuosity is associated with recurrent cervical artery dissection. METHODS: We reviewed data from a single-center registry of cervical artery dissection patients enrolled between 2011-2021. CT angiography was reviewed for neck length, vertebral artery dominance, and vertebral artery tortuosity index. Incidence rate of recurrent dissection was calculated using Poisson regression. Differences between groups were analyzed using the Kruskal-Wallis rank sum test and Fisher's exact test. RESULTS: The cohort included 155 patients: women (56%), mean (SD) age 42 (±10) years, and 116 single and 39 multiple artery dissections. Eleven (7.1%) had a recurrence with an incidence rate (95% CI) of 1.91 (1.06, 3.44) per 100 person-years. Vertebral artery tortuosity did not differ significantly between single and recurrent groups (median (IQR) 46.81 (40.85, 53.91) vs 44.97 (40.68, 50.62) p = 0.388). Morphometric characteristics of height, neck length, and BMI were not associated with recurrence. There was no difference in vertebral artery tortuosity by dissection location (carotid vs vertebral). CONCLUSION: In this single center cohort of patients with cervical artery dissection, there was no difference in VTI between single and recurrent groups.

Care of the Patient With Acute Ischemic Stroke (Posthyperacute and Prehospital Discharge): Update to 2009 Comprehensive Nursing Care Scientific Statement: A Scientific Statement From the American Heart Association.

In 2009, the American Heart Association/American Stroke Association published a comprehensive scientific statement detailing the nursing care of the patient with an acute ischemic stroke through all phases of hospitalization. The purpose of this statement is to provide an update to the 2009 document by summarizing and incorporating current best practice evidence relevant to the provision of nursing and interprofessional care to patients with ischemic stroke and their families during the acute (posthyperacute phase) inpatient admission phase of recovery. Many of the nursing care elements are informed by nurse-led research to embed best practices in the provision and standard of care for patients with stroke. The writing group comprised members of the Stroke Nursing Committee of the Council on Cardiovascular and Stroke Nursing and the Stroke Council. A literature review was undertaken to examine the best practices in the care of the patient with acute ischemic stroke. The drafts were circulated and reviewed by all committee members. This statement provides a summary of best practices based on available evidence to guide nurses caring for adult patients with acute ischemic stroke in the hospital posthyperacute/intensive care unit. In many instances, however, knowledge gaps exist, demonstrating the need for continued nurse-led research on care of the patient with acute ischemic stroke.

Neuroprotective Therapies for Spontaneous Intracerebral Hemorrhage.

Patients who survive the initial ictus of spontaneous intracerebral hemorrhage (ICH) remain vulnerable to subsequent injury of the perilesional parenchyma by molecular and cellular responses to the hematoma. Secondary brain injury after ICH, which contributes to long-term functional impairment and mortality, has emerged as an attractive therapeutic target. This review summarizes preclinical and clinical evidence for neuroprotective therapies targeting secondary injury pathways following ICH. A focus on therapies with pleiotropic antiinflammatory effects that target thrombin-mediated chemotaxis and inflammatory cell migration has led to studies investigating statins, anticholinergics, sphingosine-1-phosphate receptor modulators, peroxisome proliferator activated receptor gamma agonists, and magnesium. Attempts to modulate ICH-induced blood-brain barrier breakdown and perihematomal edema formation has prompted studies of nonsteroidal antiinflammatory agents, matrix metalloproteinase inhibitors, and complement inhibitors. Iron chelators, such as deferoxamine and albumin, have been used to reduce the free radical injury that ensues from erythrocyte lysis. Stem cell transplantation has been assessed for its potential to enhance subacute neurogenesis and functional recovery. Despite promising preclinical results of numerous agents, their outcomes have not yet translated into positive clinical trials in patients with ICH. Further studies are necessary to improve our understanding of the molecular events that promote damage and inflammation of the perihematomal parenchyma after ICH. Elucidating the temporal and pathophysiologic features of this secondary brain injury could enhance the clinical efficacy of neuroprotective therapies for ICH.

Telestroke Across the Continuum of Care: Lessons from the COVID-19 Pandemic.

While use of telemedicine to guide emergent treatment of ischemic stroke is well established, the COVID-19 pandemic motivated the rapid expansion of care via telemedicine to provide consistent care while reducing patient and provider exposure and preserving personal protective equipment. Temporary changes in re-imbursement, inclusion of home office and patient home environments, and increased access to telehealth technologies by patients, health care staff and health care facilities were key to provide an environment for creative and consistent high-quality stroke care. The continuum of care via telestroke has broadened to include prehospital, inter-facility and intra-facility hospital-based services, stroke telerehabilitation, and ambulatory telestroke. However, disparities in technology access remain a challenge. Preservation of reimbursement and the reduction of regulatory burden that was initiated during the public health emergency will be necessary to maintain expanded patient access to the full complement of telestroke services. Here we outline many of these initiatives and discuss potential opportunities for optimal use of technology in stroke care through and beyond the pandemic.

Pandemic Guidance for Stroke Centers Aiding COVID-19 Treatment Teams.

The coronavirus disease 2019 (COVID-19) pandemic has in some regions overwhelmed the capacity and staffing needs of healthcare systems, necessitating the provision of resources and staff from different disciplines to aid COVID treatment teams. Stroke centers have multidisciplinary clinical and procedural expertise to support COVID treatment teams. Staff safety and patient safety are essential, as are open lines of communication between stroke center leaders and hospital leadership in a pandemic where policies and procedures can change or evolve rapidly. Support needs to be allocated in a way that allows for the continued operation of a fully capable stroke center, with the ability to adjust if stroke center volume or staff attrition requires.

Prehospital Triage of Acute Stroke Patients During the COVID-19 Pandemic.

The coronavirus disease 2019 (COVID-19) pandemic has broad implications on stroke patient triage. Emergency medical services providers have to ensure timely transfer of patients while minimizing the risk of infectious exposure for themselves, their co-workers, and other patients. This statement paper provides a conceptual framework for acute stroke patient triage and transfer during the COVID-19 pandemic and similar healthcare emergencies in the future.

Fully Automated Segmentation Algorithm for Perihematomal Edema Volumetry After Spontaneous Intracerebral Hemorrhage.

Background and Purpose- Perihematomal edema (PHE) is a promising surrogate marker of secondary brain injury in patients with spontaneous intracerebral hemorrhage, but it can be challenging to accurately and rapidly quantify. The aims of this study are to derive and internally validate a fully automated segmentation algorithm for volumetric analysis of PHE. Methods- Inpatient computed tomography scans of 400 consecutive adults with spontaneous, supratentorial intracerebral hemorrhage enrolled in the Intracerebral Hemorrhage Outcomes Project (2009-2018) were separated into training (n=360) and test (n=40) datasets. A fully automated segmentation algorithm was derived from manual segmentations in the training dataset using convolutional neural networks, and its performance was compared with that of manual and semiautomated segmentation methods in the test dataset. Results- The mean volumetric dice similarity coefficients for the fully automated segmentation algorithm were 0.838±0.294 and 0.843±0.293 with manual and semiautomated segmentation methods as reference standards, respectively. PHE volumes derived from the fully automated versus manual (r=0.959; P<0.0001), fully automated versus semiautomated (r=0.960; P<0.0001), and semiautomated versus manual (r=0.961; P<0.0001) segmentation methods had strong between-group correlations. The fully automated segmentation algorithm (mean 18.0±1.8 seconds/scan) quantified PHE volumes at a significantly faster rate than both of the manual (mean 316.4±168.8 seconds/scan; P<0.0001) and semiautomated (mean 480.5±295.3 seconds/scan; P<0.0001) segmentation methods. Conclusions- The fully automated segmentation algorithm accurately quantified PHE volumes from computed tomography scans of supratentorial intracerebral hemorrhage patients with high fidelity and greater efficiency compared with manual and semiautomated segmentation methods. External validation of fully automated segmentation for assessment of PHE is warranted.

Delay to Tissue Plasminogen Activator in Hypertensive Stroke Patients: An Analysis of Delay Duration Across Agents.

BACKGROUND AND PURPOSE: A subset of ischemic stroke patients present with blood pressures above that considered safe for thrombolytic administration, requiring antihypertensive therapy. Guideline statements are ambivalent regarding which antihypertensive agent should be used to obtain a satisfactory blood pressure < 185/110 mm Hg prior to alteplase. METHODS: We reviewed data from consecutive patients at a single institution treated with alteplase from January 2014 to January 2019, collecting door-to-needle times, antihypertensive agent (if used), and antihypertensive-to-needle times. Patients were grouped by initial agent administered. We assessed for differences in door-to-needle times between those needing antihypertensive(s) and those who did not. Antihypertensive-to-needle times were compared across 3 antihypertensive groups (labetalol, nicardipine, and hydralazine). RESULTS: Analysis included 239 patients: 177 receiving no antihypertensive, 44 labetalol, 13 nicardipine, and 5 hydralazine. Those not administered an antihypertensive prior to alteplase had shorter door-to-needle times (52.6 minutes versus 62.1 minutes, P = .016). We found no statistical differences when comparing door-to-needle times across all groups (no med 52.6 minutes, labetalol 64.3 minutes, nicardipine 53.0 minutes, hydralazine 67.4 minutes, P = .052). No differences were found in antihypertensive-to-needle amongst the 3 antihypertensive groups (labetalol 18.75 minutes, nicardipine 12.15 minutes, hydralazine 25.40 minutes, P = .239). CONCLUSIONS: Patients requiring antihypertensives experienced slower door-to-needle times. No statistically significant changes were observed in door-to-needle times by antihypertensive used, however these results may have clinical importance. This study is limited by relatively small sample size. Pooling data from multiple institutions could provide more robust assessment and inform clinical practice.

Cigarette Smoking History and Functional Outcomes After Spontaneous Intracerebral Hemorrhage.

Background and Purpose- Although cigarette use may be a risk for intracerebral hemorrhage (ICH), animal models suggest that nicotine has a potential neuroprotective effect. The aim of this multicenter study is to determine the effect of smoking history on outcome in ICH patients. Methods- We analyzed prospectively collected data from the Ethnic/Racial Variations of Intracerebral Hemorrhage study and included patients with smoking status data in the analysis. Patients were dichotomized into nonsmokers versus ever-smokers, and the latter group was further categorized as former (>30 days before ICH) or current (≤30 days before ICH) smokers. The primary outcome was 90-day modified Rankin Scale score shift analysis. Secondary outcomes were in-hospital mortality and mortality, Barthel Index, and self-reported health status measures at 90 days. Results- The overall study cohort comprised 1509 nonsmokers and 1423 ever-smokers (841 former, 577 current, 5 unknown). No difference in primary outcome was observed between nonsmokers versus ever-smokers (adjusted odds ratio [aOR], 1.041; 95% CI, 0.904-1.199; P=0.577). No differences in primary outcome were observed between former (aOR, 0.932; 95% CI, 0.791-1.178; P=0.399) or current smokers (aOR, 1.178; 95% CI, 0.970-1.431; P=0.098) versus nonsmokers. Subgroup analyses by race/ethnicity demonstrated no differences in primary outcome when former and current smokers were compared with nonsmokers. Former, but not current, smokers had a lower in-hospital mortality rate (aOR, 0.695; 95% CI, 0.500-0.968; P=0.031), which was only observed in Hispanics (aOR, 0.533; 95% CI, 0.309-0.921; P=0.024). Differences in self-reported health status measures were only observed in whites. Conclusions- Cigarette smoking history does not seem to provide a beneficial effect on 90-day functional outcome in patients with ICH.

Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association.

Background and Purpose- The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations in a single document for clinicians caring for adult patients with acute arterial ischemic stroke. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators. These guidelines supersede the 2013 Acute Ischemic Stroke (AIS) Guidelines and are an update of the 2018 AIS Guidelines. Methods- Members of the writing group were appointed by the American Heart Association (AHA) Stroke Council's Scientific Statements Oversight Committee, representing various areas of medical expertise. Members were not allowed to participate in discussions or to vote on topics relevant to their relations with industry. An update of the 2013 AIS Guidelines was originally published in January 2018. This guideline was approved by the AHA Science Advisory and Coordinating Committee and the AHA Executive Committee. In April 2018, a revision to these guidelines, deleting some recommendations, was published online by the AHA. The writing group was asked review the original document and revise if appropriate. In June 2018, the writing group submitted a document with minor changes and with inclusion of important newly published randomized controlled trials with >100 participants and clinical outcomes at least 90 days after AIS. The document was sent to 14 peer reviewers. The writing group evaluated the peer reviewers' comments and revised when appropriate. The current final document was approved by all members of the writing group except when relationships with industry precluded members from voting and by the governing bodies of the AHA. These guidelines use the American College of Cardiology/AHA 2015 Class of Recommendations and Level of Evidence and the new AHA guidelines format. Results- These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks. The guidelines support the overarching concept of stroke systems of care in both the prehospital and hospital settings. Conclusions- These guidelines provide general recommendations based on the currently available evidence to guide clinicians caring for adult patients with acute arterial ischemic stroke. In many instances, however, only limited data exist demonstrating the urgent need for continued research on treatment of acute ischemic stroke.

First International Consensus on the diagnosis and management of fibromuscular dysplasia.

This article is a comprehensive document on the diagnosis and management of fibromuscular dysplasia (FMD), which was commissioned by the working group 'Hypertension and the Kidney' of the European Society of Hypertension (ESH) and the Society for Vascular Medicine (SVM). This document updates previous consensus documents/scientific statements on FMD published in 2014 with full harmonization of the position of European and US experts. In addition to practical consensus-based clinical recommendations, including a consensus protocol for catheter-based angiography and percutaneous angioplasty for renal FMD, the document also includes the first analysis of the European/International FMD Registry and provides updated data from the US Registry for FMD. Finally, it provides insights on ongoing research programs and proposes future research directions for understanding this multifaceted arterial disease.

2018 Guidelines for the Early Management of Patients With Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association.

BACKGROUND AND PURPOSE: The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations for clinicians caring for adult patients with acute arterial ischemic stroke in a single document. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators. These guidelines supersede the 2013 guidelines and subsequent updates. METHODS: Members of the writing group were appointed by the American Heart Association Stroke Council's Scientific Statements Oversight Committee, representing various areas of medical expertise. Strict adherence to the American Heart Association conflict of interest policy was maintained. Members were not allowed to participate in discussions or to vote on topics relevant to their relations with industry. The members of the writing group unanimously approved all recommendations except when relations with industry precluded members voting. Prerelease review of the draft guideline was performed by 4 expert peer reviewers and by the members of the Stroke Council's Scientific Statements Oversight Committee and Stroke Council Leadership Committee. These guidelines use the American College of Cardiology/American Heart Association 2015 Class of Recommendations and Levels of Evidence and the new American Heart Association guidelines format. RESULTS: These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks. The guidelines support the overarching concept of stroke systems of care in both the prehospital and hospital settings. CONCLUSIONS: These guidelines are based on the best evidence currently available. In many instances, however, only limited data exist demonstrating the urgent need for continued research on treatment of acute ischemic stroke.

Cervical Artery Dissection in Patients of African Ancestry.

BACKGROUND AND PURPOSE: The majority of published data in cervical artery dissection (CeAD), a common cause of stroke in young adults, derive from populations of European ancestry (EA), including a recent genome-wide study identifying an association with the rs9349379 polymorphism of the PHACTR1 gene. Little is known about CeAD in individuals of African ancestry (AA) despite robust epidemiological data showing increased risk of stroke at younger ages. We hypothesize that AA patients with CeAD have different epidemiology and clinical profiles compared to those of EA, and a different genetic architecture related to rs9349379 of the PHACTR1 gene. METHODS: We searched a single-center database of CeAD to identify AA and EA patients. We compared differential prevalence of CeAD versus all young stroke between AA and EA patients. We characterized clinical profiles via electronic medical record review. Data include descriptive statistics reported as medians or percentages. We also obtained publicly available allele frequencies of rs9349379 in AA and EA populations. RESULTS: AA patients comprise 7% of CeAD cases and 27% of young stroke cases while EA patients comprise 90% of CeAD cases and 70% of young stroke cases. Prevalence of hypertension, diabetes mellitus, and hyperlipidemia were 74, 30, and 50%, respectively, in AA patients compared to 37, 6, and 25% in EA patients. Allele frequencies for the CeAD risk allele, rs9349379(A), are higher in AA populations compared to EA populations. CONCLUSION: AA patients represent a smaller proportion of CeAD cases compared to young stroke cases at our center. AA patients suffering CeAD have higher prevalence of both vascular risk factors and frequency of the CeAD risk allele compared to EA patients. These findings suggest a complex interplay between traditional vascular risk factors and genetic predisposition underlying CeAD pathogenesis. Further prospective research is needed to clarify these associations and disparities.

Ischemic Stroke Secondary to Paradoxical Embolism Through a Pulmonary Arteriovenous Malformation: Case Report and Review of the Literature.

Paradoxical embolism due to isolated pulmonary arteriovenous malformation (AVM) is an uncommon cause of ischemic stroke, with the majority occurring in patients who have not yet been diagnosed with their malformation. We report a 32-year-old man who presented with an abrupt onset of right facial weakness and expressive aphasia. Brain magnetic resonance imaging revealed an acute infarct in the left middle cerebral artery territory and chronic infarcts in the bilateral cerebellar hemispheres. A cardioembolic mechanism was initially considered in the setting of perimyocarditis diagnosed a few months earlier. Transthoracic and transesophageal echocardiograms revealed high volume right to left shunting, but no septal defects. A pulmonary AVM was confirmed with computed tomography angiography and fistualization was successfully treated with embolization. This report highlights a case of undiagnosed pulmonary AVM leading to recurrent paradoxical emboli to the brain. We review the epidemiology, pathophysiology, and management of pulmonary AVMs in relation to stroke risk.

Genetic Drivers of von Willebrand Factor Levels in an Ischemic Stroke Population and Association With Risk for Recurrent Stroke.

BACKGROUND AND PURPOSE: von Willebrand factor (vWF) plays an important role in thrombus formation during cerebrovascular damage. We sought to investigate the potential role of circulating vWF in recurrent cerebrovascular events and identify genetic contributors to variation in vWF level in an ischemic stroke population. METHODS: We analyzed the effect of circulating vWF on risk of recurrent stroke using survival models in the VISP trial (Vitamin Intervention for Stroke Prevention) and the use of vWF in reclassification over traditional factors. We conducted a genome-wide association study) with imputation, based on 1000 Genomes Project data, for circulating vWF levels and then interrogated loci previously associated with vWF levels. We performed expression quantitative trait locus analysis for vWF across different tissues. RESULTS: Elevated vWF levels were associated with increased risk for recurrent stroke in VISP. Adding vWF to traditional clinical parameters also improved recurrent stroke risk prediction. We identified single-nucleotide polymorphisms significantly associated with circulating vWF at the ABO locus (P<5×10-8) and replicated findings from previous genetic associations of vWF levels in humans. Expression quantitative trait locus analyses demonstrate that most associated ABO single-nucleotide polymorphisms were also associated with vWF gene expression. CONCLUSIONS: Elevated vWF levels are associated with recurrent stroke in VISP. In the VISP population, genetic determinants of vWF levels that impact vWF gene expression were identified. These data add to our knowledge of the pathophysiologic and genetic basis for recurrent stroke risk and may have implications for clinical care decision making.