Ischemic Stroke and Reduced Left Ventricular Ejection Fraction: A Multidisciplinary Approach to Optimize Brain and Cardiac Health.

Reduced left ventricular ejection fraction ≤40%, a known risk factor for adverse cardiac outcomes and recurrent acute ischemic stroke, may be detected during an acute ischemic stroke hospitalization. A multidisciplinary care paradigm informed by neurology and cardiology expertise may facilitate the timely implementation of an array of proven heart failure-specific therapies and procedures in a nuanced manner to optimize brain and cardiac health.

Cerebrovascular Complications of COVID-19 and COVID-19 Vaccination.

The risk of stroke and cerebrovascular disease complicating infection with SARS-CoV-2 has been extensively reported since the onset of the pandemic. The striking efforts of many scientists in cooperation with regulators and governments worldwide have rapidly brought the development of a large landscape of vaccines against SARS-CoV-2. The novel DNA and mRNA vaccines have offered great flexibility in terms of antigen production and led to an unprecedented rapidity in effective and safe vaccine production. However, as mass vaccination has progressed, rare but catastrophic cases of thrombosis have occurred in association with thrombocytopenia and antibodies against PF4 (platelet factor 4). This catastrophic syndrome has been named vaccine-induced immune thrombotic thrombocytopenia. Rarely, ischemic stroke can be the symptom onset of vaccine-induced immune thrombotic thrombocytopenia or can complicate the course of the disease. In this review, we provide an overview of stroke and cerebrovascular disease as a complication of the SARS-CoV-2 infection and outline the main clinical and radiological characteristics of cerebrovascular complications of vaccinations, with a focus on vaccine-induced immune thrombotic thrombocytopenia. Based on the available data from the literature and from our experience, we propose a therapeutic protocol to manage this challenging condition. Finally, we highlight the overlapping pathophysiologic mechanisms of SARS-CoV-2 infection and vaccination leading to thrombosis.

Leveraging the Capabilities of AI: Novice Neurology-Trained Operators Performing Cardiac POCUS in Patients with Acute Brain Injury.

BACKGROUND: Cardiac point-of-care ultrasound (cPOCUS) can aid in the diagnosis and treatment of cardiac disorders. Such disorders can arise as complications of acute brain injury, but most neurologic intensive care unit (NICU) providers do not receive formal training in cPOCUS. Caption artificial intelligence (AI) uses a novel deep learning (DL) algorithm to guide novice cPOCUS users in obtaining diagnostic-quality cardiac images. The primary objective of this study was to determine how often NICU providers with minimal cPOCUS experience capture quality images using DL-guided cPOCUS as well as the association between DL-guided cPOCUS and change in management and time to formal echocardiograms in the NICU. METHODS: From September 2020 to November 2021, neurology-trained physician assistants, residents, and fellows used DL software to perform clinically indicated cPOCUS scans in an academic tertiary NICU. Certified echocardiographers evaluated each scan independently to assess the quality of images and global interpretability of left ventricular function, right ventricular function, inferior vena cava size, and presence of pericardial effusion. Descriptive statistics with exact confidence intervals were used to calculate proportions of obtained images that were of adequate quality and that changed management. Time to first adequate cardiac images (either cPOCUS or formal echocardiography) was compared using a similar population from 2018. RESULTS: In 153 patients, 184 scans were performed for a total of 943 image views. Three certified echocardiographers deemed 63.4% of scans as interpretable for a qualitative assessment of left ventricular size and function, 52.6% of scans as interpretable for right ventricular size and function, 34.8% of scans as interpretable for inferior vena cava size and variability, and 47.2% of scans as interpretable for the presence of pericardial effusion. Thirty-seven percent of screening scans changed management, most commonly adjusting fluid goals (81.2%). Time to first adequate cardiac images decreased significantly from 3.1 to 1.7 days (p < 0.001). CONCLUSIONS: With DL guidance, neurology providers with minimal to no cPOCUS training were often able to obtain diagnostic-quality cardiac images, which informed management changes and significantly decreased time to cardiac imaging.

Association Between Neutrophil-Lymphocyte Ratio and 30-Day Infection and Thrombotic Outcomes After Intraventricular Hemorrhage: A CLEAR III Analysis.

BACKGROUND: Serum neutrophil-lymphocyte ratio (NLR) is a surrogate marker for the inflammatory response after intracerebral hemorrhage (ICH) and is associated with perihematomal edema and long-term functional outcomes. Whether NLR is associated with short-term ICH complications is poorly understood. We hypothesized that NLR is associated with 30-day infection and thrombotic events after ICH. METHODS: We performed a post hoc exploratory analysis of the Clot Lysis: Evaluating Accelerated Resolution of Intraventricular Hemorrhage III trial. The study exposure was the serum NLR obtained at baseline and on days 3 and 5. The coprimary outcomes, ascertained at 30 days, were any infection and a thrombotic event, defined as composite of cerebral infarction, myocardial infarction, or venous thromboembolism; both infection and thrombotic event were determined through adjudicated adverse event reporting. Binary logistic regression was used to study the relationship between NLR and outcomes, after adjustment for demographics, ICH severity and location, and treatment randomization. RESULTS: Among the 500 patients enrolled in the Clot Lysis: Evaluating Accelerated Resolution of Intraventricular Hemorrhage III trial, we included 303 (60.6%) without missing data on differential white blood cell counts at baseline. There were no differences in demographics, comorbidities, or ICH severity between patients with and without data on NLR. In adjusted logistic regression models, NLR ascertained at baseline (odds ratio [OR] 1.03; 95% confidence interval [CI] 1.01-1.07, p = 0.03) and NLR ascertained at day 3 were associated with infection (OR 1.15; 95% CI 1.05-1.20, p = 0.001) but not with thrombotic events. Conversely, NLR at day 5 was associated with thrombotic events (OR 1.07, 95% CI 1.01-1.13, p = 0.03) but not with infection (OR 1.13; 95% CI 0.76-1.70, p = 0.56). NLR at baseline was not associated with either outcome. CONCLUSIONS: Serum NLR ascertained at baseline and on day 3 after randomization was associated with 30-day infection, whereas NLR obtained on day 5 was associated with thrombotic events after ICH, suggesting that NLR could be a potential early biomarker for ICH-related complications.

Smoking Cessation in Stroke Survivors in the United States: A Nationwide Analysis.

BACKGROUND: Continued smoking after stroke is associated with a high risk of stroke recurrence and other cardiovascular disease. We sought to comprehensively understand the epidemiology of smoking cessation in stroke survivors in the United States. Furthermore, we compared smoking cessation in stroke and cancer survivors because cancer is another smoking-related condition in which smoking cessation is prioritized. METHODS: We performed a cross-sectional analysis of data from the Centers for Disease Control and Prevention Behavioral Risk Factor Surveillance System, an annual, nationally representative health survey. Using pooled data from 2013 to 2019, we identified stroke and cancer survivors with a history of smoking. We used survey procedures to estimate frequencies and summarize quit ratios with attention to demographic and geographic (state-wise and rural-urban) factors for stroke survivors. The quit ratio is conventionally defined as the proportion of ever smokers who have quit. Then, we used multivariable logistic regression to compare quit ratios in stroke and cancer survivors while adjusting for demographics and smoking-related comorbidities. RESULTS: Among 4 434 604 Americans with a history of stroke and smoking, the median age was 68 years (interquartile range, 59-76), and 45.4% were women. The overall quit ratio was 60.8% (95% CI, 60.1%-61.6%). Quit ratios varied by age group, sex, race and ethnicity, and several geographic factors. There was marked geographic variation in quit ratios, ranging from 48.3% in Kentucky to 71.5% in California. Furthermore, compared with cancer survivors, stroke survivors were less likely to have quit smoking (odds ratio, 0.72 [95% CI, 0.67-0.79]) after accounting for differences in demographics and smoking-related comorbidities. CONCLUSIONS: There were considerable demographic and geographic disparities in smoking quit ratios in stroke survivors, who were less likely to have quit smoking than cancer survivors. A targeted initiative is needed to improve smoking cessation for stroke survivors.

Early Deterioration, Hematoma Expansion, and Outcomes in Deep Versus Lobar Intracerebral Hemorrhage: The FAST Trial.

BACKGROUND: In patients with intracerebral hemorrhage (ICH), it is unclear whether early neurological deterioration, hematoma expansion (HE), and outcome vary by supratentorial ICH location (deep versus lobar). Herein, we assessed these relationships in a clinical trial cohort that underwent brain imaging early after symptom onset. We hypothesized that HE would occur more frequently, and outcome would be worse in patients with deep ICH. METHODS: We performed a post hoc analysis of the FAST (Factor-VII-for-Acute-Hemorrhagic-Stroke-Treatment) trial including all patients with supratentorial hemorrhage. Enrolled patients underwent brain imaging within 3 hours of symptom onset and 24 hours after randomization. Multivariable regression was used to test the association between ICH location and 3 outcomes: HE (increase of ≥33% or 6mL), early neurological deterioration (decrease in Glasgow Coma Scale score ≥2 points or increase in National Institutes of Health Stroke Scale ≥4 points within 24 hours of admission), and 90-day outcome (modified Rankin Scale). RESULTS: Of 841 FAST trial patients, we included 728 (mean age 64 years, 38% women) with supratentorial hemorrhages (deep n=623, lobar n=105). HE (44 versus 27%, P=0.001) and early neurological deterioration (31 versus 17%, P=0.001) were more common in lobar hemorrhages. Deep hemorrhages were smaller than lobar hemorrhages at baseline (12 versus 35mL, P<0.001) and 24 hours (14 versus 38mL, P<0.001). Unadjusted 90-day outcome was worse in lobar compared with deep ICH (median modified Rankin Scale score 5 versus 4, P=0.03). However, when adjusting for variables included in the ICH score including ICH volume, deep location was associated with worse and lobar location with better outcome (odds ratio lobar location, 0.58 [95% CI, 0.38-0.89]; P=0.01). CONCLUSIONS: In this secondary analysis of randomized trial patients, lobar ICH location was associated with larger ICH volume, more HE and early neurological deterioration, and worse outcome than deep ICH. After adjustment for prognostic variables, however, deep ICH was associated with worse outcome, likely due to their proximity to eloquent brain structures.

Risk of Stroke After Posterior Reversible Encephalopathy Syndrome.

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) can cause short-term cerebrovascular complications, such as brain infarction and hemorrhage. We hypothesized that PRES is also associated with an increased long-term risk of stroke. METHODS: We performed a retrospective cohort study in the United States using statewide all-payer claims data from 2016 to 2018 on all admissions to nonfederal hospitals in 11 states. Adults with PRES were compared with adults with renal colic (negative control) and transient ischemic attack (TIA; positive control). Any stroke and the secondary outcomes of ischemic and hemorrhagic stroke were ascertained using International Classification of Diseases, Tenth Revision, Clinical Modification codes. We excluded prevalent stroke. We used time-to-event statistics to calculate incidence rates and Cox proportional hazards analyses to evaluate the association between PRES and stroke, adjusting for demographics and stroke risk factors. In a sensitivity analysis, outcomes within 2 weeks of index admission were excluded. RESULTS: We identified 1606 patients with PRES, 1192 with renal colic, and 38 216 with TIA. Patients with PRES had a mean age of 56±17 years; 72% were women. Over a median follow-up of 0.9 years, the stroke incidence per 100 person-years was 6.1 (95% CI, 5.0-7.4) after PRES, 1.0 (95% CI, 0.62-1.8) after renal colic, and 9.7 (95% CI, 9.4-10.0) after TIA. After statistical adjustment for patient characteristics and risk factors, patients with PRES had an elevated risk of stroke compared with renal colic (hazard ratio [HR], 2.3 [95% CI, 1.7-3.0]), but lower risk than patients with TIA (HR, 0.67 [95% CI, 0.54-0.82]). In secondary analyses, compared with TIA, PRES was associated with hemorrhagic stroke (HR, 2.0 [95% CI, 1.4-2.9]). PRES was associated with ischemic stroke when compared with renal colic (HR, 1.9 [95% CI, 1.4-2.7]) but not when compared with TIA (HR, 0.49 [95% CI, 0.38-0.63]). Results were similar with 2-week washout. CONCLUSIONS: Patients with PRES had an elevated risk of incident stroke.

Acute Ischemic Stroke, Depressed Left Ventricular Ejection Fraction, and Sinus Rhythm: Prevalence and Practice Patterns.

BACKGROUND: There are limited data about the epidemiology and secondary stroke prevention strategies used for patients with depressed left ventricular ejection fraction (LVEF) and sinus rhythm following an acute ischemic stroke (AIS). We sought to describe the prevalence of LVEF ≤40% and sinus rhythm among patients with AIS and antithrombotic treatment practice in a multi-center cohort from 2002 to 2018. METHODS: This was a multi-center, retrospective cohort study comprised of patients with AIS hospitalized in the Greater Cincinnati Northern Kentucky Stroke Study and 4 academic, hospital-based cohorts in the United States. A 1-stage meta-analysis of proportions was undertaken to calculate a pooled prevalence. Univariate analyses and an adjusted multivariable logistic regression model were performed to identify demographic, clinical, and echocardiographic characteristics associated with being prescribed an anticoagulant upon AIS hospitalization discharge. RESULTS: Among 14 338 patients with AIS with documented LVEF during the stroke hospitalization, the weighted pooled prevalence of LVEF ≤40% and sinus rhythm was 5.0% (95% CI, 4.1-6.0%; I2, 84.4%). Of 524 patients with no cardiac thrombus and no prior indication for anticoagulant who survived postdischarge, 200 (38%) were discharged on anticoagulant, 289 (55%) were discharged on antiplatelet therapy only, and 35 (7%) on neither. There was heterogeneity by site in the proportion discharged with an anticoagulant (22% to 45%, P<0.0001). Cohort site and National Institutes of Health Stroke Severity scale >8 (odds ratio, 2.0 [95% CI, 1.1-3.8]) were significant, independent predictors of being discharged with an anticoagulant in an adjusted analysis. CONCLUSIONS: Nearly 5% of patients with AIS have a depressed LVEF and are in sinus rhythm. There is significant variation in the clinical practice of antithrombotic therapy prescription by site and stroke severity. Given this clinical equipoise, further study is needed to define optimal antithrombotic treatment regimens for secondary stroke prevention in this patient population.

Long-Term Risk of Ischemic Stroke among Elderly Survivors of Non-Traumatic Subarachnoid Hemorrhage.

INTRODUCTION: Non-traumatic subarachnoid hemorrhage (SAH) is associated with poor long-term functional outcomes, but the risk of ischemic stroke among SAH survivors is poorly understood. OBJECTIVES: The aim of this study was to evaluate the risk of ischemic stroke among survivors of SAH. METHODS: We performed a retrospective cohort study using claims data from Medicare beneficiaries from 2008 to 2015. The exposure was a diagnosis of SAH, while the outcome was an acute ischemic stroke, both identified using previously validated ICD-9-CM diagnosis codes. We used Cox regression analysis adjusting for demographics and stroke risk factors to evaluate the association between SAH and long-term risk of ischemic stroke. RESULTS: Among 1.7 million Medicare beneficiaries, 912 were hospitalized with non-traumatic SAH. During a median follow-up of 5.2 years (IQR, 2.7-6.7), the cumulative incidence of ischemic stroke was 22 per 1,000 patients per year among patients with SAH, and 7 per 1,000 patients per year in those without SAH. In adjusted Cox models, SAH was associated with an increased risk of ischemic stroke (HR, 2.0; 95% confidence interval, 1.4-2.8) as compared to beneficiaries without SAH. Similar results were obtained in sensitivity analyses, when treating death as a competing risk (sub HR, 3.0; 95% CI, 2.8-3.3) and after excluding ischemic stroke within 30 days of SAH discharge (HR, 1.5; 95% CI, 1.1-2.3). CONCLUSIONS: In a large, heterogeneous national cohort of elderly patients, survivors of SAH had double the long-term risk of ischemic stroke. SAH survivors should be closely monitored and risk stratified for ischemic stroke.

Evidence-based cardiovascular magnetic resonance cost-effectiveness calculator for the detection of significant coronary artery disease.

BACKGROUND: Although prior reports have evaluated the clinical and cost impacts of cardiovascular magnetic resonance (CMR) for low-to-intermediate-risk patients with suspected significant coronary artery disease (CAD), the cost-effectiveness of CMR compared to relevant comparators remains poorly understood. We aimed to summarize the cost-effectiveness literature on CMR for CAD and create a cost-effectiveness calculator, useable worldwide, to approximate the cost-per-quality-adjusted-life-year (QALY) of CMR and relevant comparators with context-specific patient-level and system-level inputs. METHODS: We searched the Tufts Cost-Effectiveness Analysis Registry and PubMed for cost-per-QALY or cost-per-life-year-saved studies of CMR to detect significant CAD. We also developed a linear regression meta-model (CMR Cost-Effectiveness Calculator) based on a larger CMR cost-effectiveness simulation model that can approximate CMR lifetime discount cost, QALY, and cost effectiveness compared to relevant comparators [such as single-photon emission computed tomography (SPECT), coronary computed tomography angiography (CCTA)] or invasive coronary angiography. RESULTS: CMR was cost-effective for evaluation of significant CAD (either health-improving and cost saving or having a cost-per-QALY or cost-per-life-year result lower than the cost-effectiveness threshold) versus its relevant comparator in 10 out of 15 studies, with 3 studies reporting uncertain cost effectiveness, and 2 studies showing CCTA was optimal. Our cost-effectiveness calculator showed that CCTA was not cost-effective in the US compared to CMR when the most recent publications on imaging performance were included in the model. CONCLUSIONS: Based on current world-wide evidence in the literature, CMR usually represents a cost-effective option compared to relevant comparators to assess for significant CAD.

Short-term stroke risk after emergency department treat-and-release headache visit.

OBJECTIVE: To evaluate whether patients discharged to home after an emergency department (ED) visit for headache face a heightened short-term risk of stroke. BACKGROUND: Stroke hospitalizations that occur soon after ED visits for headache complaints may reflect diagnostic error. METHODS: We conducted a retrospective cohort study using statewide administrative claims data for all ED visits and admissions at nonfederal hospitals in Florida 2005-2018 and New York 2005-2016. Using standard International Classification of Diseases (ICD) codes, we identified adult patients discharged to home from the ED (treat-and-release visit) with a benign headache diagnosis (cohort of interest) as well as those with a diagnosis of renal colic or back pain (negative controls). The primary study outcome was hospitalization within 30 days for stroke (ischemic or hemorrhagic) defined using validated ICD codes. We assess the relationship between index ED visit discharge diagnosis and stroke hospitalization adjusting for patient demographics and vascular comorbidities. RESULTS: We identified 1,502,831 patients with an ED treat-and-release headache visit; mean age was 41 (standard deviation: 17) years and 1,044,520 (70%) were female. A total of 2150 (0.14%) patients with headache were hospitalized for stroke within 30 days. In adjusted analysis, stroke risk was higher after headache compared to renal colic (hazard ratio [HR]: 2.69; 95% confidence interval [CI]: 2.29-3.16) or back pain (HR: 4.0; 95% CI: 3.74-4.3). In the subgroup of 26,714 (1.78%) patients with headache who received brain magnetic resonance imaging at index ED visit, stroke risk was only slightly elevated compared to renal colic (HR: 1.47; 95% CI: 1.22-1.78) or back pain (HR: 1.49; 95% CI: 1.24-1.80). CONCLUSION: Approximately 1 in 700 patients discharged to home from the ED with a headache diagnosis had a stroke in the following month. Stroke risk was three to four times higher after an ED visit for headache compared to renal colic or back pain.

Risk Stratification Models for Stroke in Patients Hospitalized with COVID-19 Infection.

OBJECTIVES: To derive models that identify patients with COVID-19 at high risk for stroke. MATERIALS AND METHODS: We used data from the AHA's Get With The Guidelines® COVID-19 Cardiovascular Disease Registry to generate models for predicting stroke risk among adults hospitalized with COVID-19 at 122 centers from March 2020-March 2021. To build our models, we used data on demographics, comorbidities, medications, and vital sign and laboratory values at admission. The outcome was a cerebrovascular event (stroke, TIA, or cerebral vein thrombosis). First, we used Cox regression with cross validation techniques to identify factors associated with the outcome in both univariable and multivariable analyses. Then, we assigned points for each variable based on corresponding coefficients to create a prediction score. Second, we used machine learning techniques to create risk estimators using all available covariates. RESULTS: Among 21,420 patients hospitalized with COVID-19, 312 (1.5%) had a cerebrovascular event. Using traditional Cox regression, we created/validated a COVID-19 stroke risk score with a C-statistic of 0.66 (95% CI, 0.60-0.72). The CANDLE score assigns 1 point each for prior cerebrovascular disease, afebrile temperature, no prior pulmonary disease, history of hypertension, leukocytosis, and elevated systolic blood pressure. CANDLE stratified risk of an acute cerebrovascular event according to low- (0-1: 0.2% risk), medium- (2-3: 1.1% risk), and high-risk (4-6: 2.1-3.0% risk) groups. Machine learning estimators had similar discriminatory performance as CANDLE: C-statistics, 0.63-0.69. CONCLUSIONS: We developed a practical clinical score, with similar performance to machine learning estimators, to help stratify stroke risk among patients hospitalized with COVID-19.

Association between Pregnancy and Cervical Artery Dissection.

OBJECTIVE: We wanted to determine whether pregnancy is associated with cervical artery dissection. METHODS: We performed a case-control study using claims data from all nonfederal emergency departments and acute care hospitals in New York and Florida between 2005 and 2015. Cases were women 12-42 years of age hospitalized with cervical artery dissection, defined using validated diagnosis codes for carotid/vertebral artery dissection. Controls were women 12-42 years of age with a primary diagnosis of renal colic. Cases and controls were matched 1:1 on age, race, insurance, income, state, and visit year. The exposure variable was pregnancy, defined as labor and delivery within 90 days before or 6 months after the index visit. Logistic regression was used to compare the odds of pregnancy between cases and controls. We performed a secondary cohort-crossover study comparing the risk of cervical artery dissection during pregnancy versus the same time period 1 year later. RESULTS: Pregnancy was twice as common among 826 women with cervical artery dissection compared with the 826 matched controls with renal colic (odds ratio, 2.5; 95% confidence interval [CI], 1.3-4.7). In our secondary analysis, pregnancy was associated with a higher risk of cervical artery dissection (incidence rate ratio [IRR], 2.2; 95% CI, 1.3-3.5), with the heightened risk limited to the postpartum period (IRR, 5.5; 95% CI, 2.6-11.7). INTERPRETATION: Pregnancy, specifically the postpartum period, was associated with hospitalization for cervical artery dissection. Although these findings might in part reflect ascertainment bias, our results suggest that arterial dissection is one mechanism by which pregnancy can lead to stroke. ANN NEUROL 2020;88:596-602.

Gastrointestinal Disorders and Risk of First-Ever Ischemic Stroke.

BACKGROUND AND PURPOSE: Recent studies suggest that alteration of the normal gut microbiome contributes to atherosclerotic burden and cardiovascular disease. While many gastrointestinal diseases are known to cause disruption of the normal gut microbiome in humans, the clinical impact of gastrointestinal diseases on subsequent cerebrovascular disease remains unknown. We conducted an exploratory analysis evaluating the relationship between gastrointestinal diseases and ischemic stroke. METHODS: We performed a retrospective cohort study using claims between 2008 and 2015 from a nationally representative 5% sample of Medicare beneficiaries. We included only beneficiaries ≥66 years of age. We used previously validated diagnosis codes to ascertain our primary outcome of ischemic stroke. In an exploratory manner, we categorized gastrointestinal disorders by anatomic location, disease chronicity, and disease mechanism. We used Cox proportional hazards models to examine associations of gastrointestinal disorder categories and ischemic stroke with adjustment for demographics and established vascular risk factors. RESULTS: Among a mean of 1 725 246 beneficiaries in each analysis, several categories of gastrointestinal disorders were associated with an increased risk of ischemic stroke after adjustment for established stroke risk factors. The most notable positive associations included disorders of the stomach (hazard ratio, 1.17 [95% CI, 1.15-1.19]) and functional (1.16 [95% CI, 1.15-1.17]), inflammatory (1.13 [95% CI, 1.12-1.15]), and infectious gastrointestinal disorders (1.13 [95% CI, 1.12-1.15]). In contrast, we found no associations with stroke for diseases of the anus and rectum (0.97 [95% CI, 0.94-1.00]) or neoplastic gastrointestinal disorders (0.97 [95% CI, 0.94-1.00]). CONCLUSIONS: In exploratory analyses, several categories of gastrointestinal disorders were associated with an increased risk of future ischemic stroke after adjustment for demographics and established stroke risk factors.

Trends in Active Cigarette Smoking Among Stroke Survivors in the United States, 1999 to 2018.

Background and Purpose- Patients who continue to smoke after a stroke face a higher risk of recurrent stroke. While several effective drugs for smoking cessation became available over the past 2 decades, whether active smoking has decreased among stroke survivors is unknown. We, therefore, evaluated trends in active smoking among stroke survivors during this period. Methods- We performed trends analyses using cross-sectional data collected every 1 to 2 years from 2 US health surveys spanning 1999 to 2018. In the National Health and Nutrition Examination Survey (NHANES) and the Behavioral Risk Factor Surveillance System (BRFSS) survey, participants were asked about prior stroke and active tobacco smoking. In NHANES, serum cotinine levels were available as a secondary measure of active smoking. We used multivariable logistic regression models for survey data to assess trends in active smoking among participants with and without prior stroke. Results- Among 49 375 participants in NHANES during 1999 to 2016 and 3 621 741 participants in BRFSS during 2011 to 2018, the prevalence of stroke was ≈3%. The overall prevalence of active smoking among stroke survivors was 24% in NHANES and 23% in BRFSS. Among individuals without prior stroke, the odds of smoking decreased over time in both NHANES (odds ratio, 0.95 per 2 years [95% CI, 0.93-0.96]) and BRFSS (odds ratio, 0.96 per year [95% CI, 0.96-0.96]). In contrast, there was no decrease in smoking among stroke survivors in NHANES (odds ratio, 1.00 [95% CI, 0.93-1.07]) or BRFSS (odds ratio, 0.99 [95% CI, 0.98-1.004]). Results were consistent in secondary analysis using biochemical ascertainment of active smoking in NHANES and in sensitivity analyses accounting for potential demographic changes in stroke epidemiology. Conclusions- In contrast to the general population, the prevalence of active smoking among stroke survivors has not decreased during the past 2 decades.

Reclassification of Ischemic Stroke Etiological Subtypes on the Basis of High-Risk Nonstenosing Carotid Plaque.

Background and Purpose- Carotid artery plaque with <50% luminal stenosis may be an underappreciated stroke mechanism. We assessed how many stroke causes might be reclassified after accounting for nonstenosing plaques with high-risk features. Methods- We included patients enrolled in the Cornell Acute Stroke Academic Registry from 2011 to 2015 who had anterior circulation infarction, magnetic resonance imaging of the brain, and magnetic resonance angiography of the neck. High-risk plaque was identified by intraplaque hemorrhage ascertained from routine neck magnetic resonance angiography studies using validated methods. Infarct location was determined from diffusion-weighted imaging. Intraplaque hemorrhage and infarct location were assessed separately in a blinded fashion by a neuroradiologist. We used the McNemar test for matched data to compare the prevalence of intraplaque hemorrhage ipsilateral versus contralateral to brain infarction. We reclassified stroke subtypes by including large-artery atherosclerosis as a cause if there was intraplaque hemorrhage ipsilateral to brain infarction, regardless of the degree of stenosis. Results- Among the 1721 acute ischemic stroke patients registered in the Cornell Acute Stroke Academic Registry from 2011 to 2015, 579 were eligible for this analysis. High-risk plaque was more common ipsilateral versus contralateral to brain infarction in large-artery atherosclerotic (risk ratio [RR], 3.7 [95% CI, 2.2-6.1]), cryptogenic (RR, 2.1 [95% CI, 1.4-3.1]), and cardioembolic strokes (RR, 1.7 [95% CI, 1.1-2.4]). There were nonsignificant ipsilateral-contralateral differences in high-risk plaque among lacunar strokes (RR, 1.2 [95% CI, 0.4-3.5]) and strokes of other determined cause (RR, 1.5 [95% CI, 0.7-3.3]). After accounting for ipsilateral high-risk plaque, 88 (15.2%) patients were reclassified: 38 (22.6%) cardioembolic to multiple potential etiologies, 6 (8.5%) lacunar to multiple, 3 (15.8%) other determined cause to multiple, and 41 (20.8%) cryptogenic to large-artery atherosclerosis. Conclusions- High-risk carotid plaque was more prevalent ipsilateral to brain infarction across several ischemic stroke subtypes. Accounting for such plaques may reclassify the etiologies of up to 15% of cases in our sample.

Risk of Arterial Ischemic Events After Intracerebral Hemorrhage.

Background and Purpose- The risk of arterial ischemic events after intracerebral hemorrhage (ICH) is poorly understood given the lack of a control group in prior studies. This study aimed to evaluate the risk of acute ischemic stroke and myocardial infarction (MI) among patients with and without ICH. Methods- We performed a retrospective cohort study using claims data from Medicare beneficiaries from 2008 to 2014. Our exposure was acute ICH, identified using validated International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes. Our primary outcome was a composite of acute ischemic stroke and MI, whereas secondary outcomes were ischemic stroke alone and MI alone. We used Cox regression analysis to compute hazard ratios during 1-month intervals after ICH. Sensitivity analyses entailed exclusion of patients with atrial fibrillation and valvular heart disease. Results- Among 1 760 439 Medicare beneficiaries, 5924 had ICH. The 1-year cumulative incidence of an arterial ischemic event was 5.7% (95% CI, 4.8-6.8) in patients with ICH and 1.8% (95% CI, 1.7-1.9) in patients without ICH. After adjusting for potential confounders, the risk of an arterial ischemic event remained significantly increased for the first 6 months after ICH and was especially high in the first month (hazard ratio, 6.7 [95% CI, 5.0-8.6]). In secondary analysis, the risk of ischemic stroke was increased in the first 6 months after ICH (hazard ratio, 6.1 [95% CI, 3.5-9.3]) but the risk of MI was not (hazard ratio, 1.6 [95% CI, 0.3-2.9]). In sensitivity analyses excluding patients with atrial fibrillation and valvular heart disease, the association between ICH and arterial ischemic events was similar to that of the primary analysis. Conclusions- In a large population-based cohort, we found that elderly patients with ICH had a substantially increased risk of ischemic stroke in the first 6 months after diagnosis. Further exploration of this risk is needed to determine optimal secondary prevention strategies for these patients.

Misdiagnosis of Cervicocephalic Artery Dissection in the Emergency Department.

Background and Purpose- Cervicocephalic artery dissection is an important cause of stroke. The clinical presentation of dissection can resemble that of benign neurological conditions leading to delayed or missed diagnosis. Methods- We performed a retrospective cohort study using statewide administrative claims data from all Emergency Department visits and admissions at nonfederal hospitals in Florida from 2005 to 2015 and New York from 2006 to 2015. Using validated International Classification of Diseases, Ninth Revision, CM codes, we identified adult patients hospitalized for cervicocephalic artery dissection. We defined probable misdiagnosis of dissection as having an Emergency Department treat-and-release visit for symptoms or signs of dissection, including headache, neck pain, and focal neurological deficits in the 14 days before dissection diagnosis. Multivariable logistic regression was used to compare adverse clinical outcomes in patients with and without probable misdiagnosis. Results- Among 7090 patients diagnosed with a dissection (mean age 52.7 years, 44.9% women), 218 (3.1% [95% CI, 2.7%-3.5%]) had a preceding probable Emergency Department misdiagnosis. After adjustment for demographics and vascular risk factors, there were no differences in rates of stroke (odds ratio, 0.82 [95% CI, 0.62-1.09]) or in-hospital death (odds ratio, 0.26 [95% CI, 0.07-1.08]) between dissection patients with and without a probable misdiagnosis at index hospitalization. Conclusions- We found that ≈1 in 30 dissection patients was probably misdiagnosed in the 2 weeks before their diagnosis.

Differences in Admission Blood Pressure Among Causes of Intracerebral Hemorrhage.

Background and Purpose- It is unknown whether admission systolic blood pressure (SBP) differs among causes of intracerebral hemorrhage (ICH). We sought to elucidate an association between admission BP and ICH cause. Methods- We compared admission SBP across ICH causes among patients in the Cornell Acute Stroke Academic Registry, which includes all adults with ICH at our center from 2011 through 2017. Trained analysts prospectively collected demographics, comorbidities, and admission SBP, defined as the first recorded value in the emergency department or on transfer from another hospital. ICH cause was adjudicated by a panel of neurologists using the SMASH-U criteria. We used ANOVA to compare mean admission SBP among ICH causes. We used multiple linear regression to adjust for age, sex, race, Glasgow Coma Scale score, and hematoma size. In secondary analyses, we compared hourly SBP measurements during the first 72 hours after admission, using mixed-effects linear models adjusted for the covariates above plus antihypertensive agents. Results- Among 484 patients with ICH, admission SBP varied significantly across ICH causes, ranging from 138 (±24) mm Hg in those with structural vascular lesions to 167 (±35) mm Hg in those with hypertensive ICH (P<0.001). The mean admission SBP in hypertensive ICH was 17 (95% CI, 11-24) mm Hg higher than in ICH of all other causes combined. These differences remained significant after adjustment for age, sex, race, Glasgow Coma Scale score, and hematoma size (P<0.001), and this persisted throughout the first 72 hours of hospitalization (P<0.001). Conclusions- In a single-center ICH registry, SBP varied significantly among ICH causes, both on admission and during hospitalization. Our results suggest that BP in the acute post-ICH setting is at least partly associated with ICH cause rather than simply representing a physiological reaction to the ICH itself.

Machine Learning Prediction of Stroke Mechanism in Embolic Strokes of Undetermined Source.

BACKGROUND AND PURPOSE: One-fifth of ischemic strokes are embolic strokes of undetermined source (ESUS). Their theoretical causes can be classified as cardioembolic versus noncardioembolic. This distinction has important implications, but the categories' proportions are unknown. METHODS: Using data from the Cornell Acute Stroke Academic Registry, we trained a machine-learning algorithm to distinguish cardioembolic versus non-cardioembolic strokes, then applied the algorithm to ESUS cases to determine the predicted proportion with an occult cardioembolic source. A panel of neurologists adjudicated stroke etiologies using standard criteria. We trained a machine learning classifier using data on demographics, comorbidities, vitals, laboratory results, and echocardiograms. An ensemble predictive method including L1 regularization, gradient-boosted decision tree ensemble (XGBoost), random forests, and multivariate adaptive splines was used. Random search and cross-validation were used to tune hyperparameters. Model performance was assessed using cross-validation among cases of known etiology. We applied the final algorithm to an independent set of ESUS cases to determine the predicted mechanism (cardioembolic or not). To assess our classifier's validity, we correlated the predicted probability of a cardioembolic source with the eventual post-ESUS diagnosis of atrial fibrillation. RESULTS: Among 1083 strokes with known etiologies, our classifier distinguished cardioembolic versus noncardioembolic cases with excellent accuracy (area under the curve, 0.85). Applied to 580 ESUS cases, the classifier predicted that 44% (95% credibility interval, 39%-49%) resulted from cardiac embolism. Individual ESUS patients' predicted likelihood of cardiac embolism was associated with eventual atrial fibrillation detection (OR per 10% increase, 1.27 [95% CI, 1.03-1.57]; c-statistic, 0.68 [95% CI, 0.58-0.78]). ESUS patients with high predicted probability of cardiac embolism were older and had more coronary and peripheral vascular disease, lower ejection fractions, larger left atria, lower blood pressures, and higher creatinine levels. CONCLUSIONS: A machine learning estimator that distinguished known cardioembolic versus noncardioembolic strokes indirectly estimated that 44% of ESUS cases were cardioembolic.