Association of Assisted Reproductive Technology and Stroke During Hospitalization for Delivery in the United States.

INTRODUCTION: Infertility treatment with assisted reproductive technologies (ARTs) has been associated with adverse vascular events in some but not all previous studies. Endothelial damage, prothrombotic factor release, and a higher prevalence of cardiovascular risk factors in those receiving ART have been invoked to explain this association. We sought to explore the relationship between ART and stroke risk using population-level data. METHODS: We conducted a retrospective cohort study using data from the National Inpatient Sample registry from 2015 to 2020, including all delivery hospitalizations for patients aged 15 to 55 years. The study exposure was use of ART. The primary end point was any stroke defined as ischemic stroke, subarachnoid hemorrhage, intracerebral hemorrhage, or cerebral venous thrombosis during index delivery hospitalization. Individual stroke subtypes (ischemic stroke, subarachnoid hemorrhage, intracerebral hemorrhage, and cerebral venous thrombosis) were evaluated as secondary end points. Standard International Classification of Diseases, Tenth Revision, Clinical Modification algorithms were used to define study exposure, comorbidities, and prespecified end points. In addition to reporting population-level estimates, propensity score adjustment by inverse probability weighting was used to mimic the effects of randomization by balancing baseline clinical characteristics associated with stroke between ART and non-ART users. RESULTS: Among 19 123 125 delivery hospitalizations identified, patients with prior ART (n=202 815, 1.1%) experienced significantly higher rates of any stroke (27.1/100 000 versus 9.1/100 000), ischemic stroke (9.9/100 000 versus 3.3/100 000), subarachnoid hemorrhage (7.4/100 000 versus 1.6/100 000), intracerebral hemorrhage (7.4/100 000 versus 2.0/100 000), and cerebral venous thrombosis (7.4/100 000 versus 2.7/100 000) in comparison to non-ART users (all P<0.001 for all unadjusted comparisons). Following inverse probability weighting analysis, ART was associated with increased odds of any stroke (adjusted odds ratios, 2.14 (95% CI, 2.02-2.26); P<0.001). CONCLUSIONS: Using population-level data among patients hospitalized for delivery in the United States, we found an association between ART and stroke after adjustment for measured confounders.

Factors impacting D-dimer levels in patients with acute ischemic cerebrovascular events.

BACKGROUND AND OBJECTIVES: A better understanding of the factors influencing D-dimer levels in code stroke patients is needed to guide further investigations of concomitant thrombotic conditions. This study aimed to investigate the impact of time from symptom onset and other factors on D-dimer levels in patients with acute ischemic stroke (AIS) or transient ischemic attack (TIA). METHODS: Data on consecutive AIS and TIA patients treated at our tertiary-care stroke center between January 2015 and December 2020 were retrospectively assessed. Patients with available D-dimer levels were evaluated for eligibility. Multivariable non-linear regression analyses were performed. RESULTS: In total, 2467 AIS patients and 708 TIA patients were included. The median D-dimer levels differed between the AIS and TIA groups (746 µg/L [interquartile range 381-1468] versus 442 µg/L [interquartile range 244-800], p<0.001). In AIS patients, an early increase in D-dimer levels was demonstrated within the first 6 h (standardized beta coefficient [ß] 0.728; 95% confidence interval [CI] 0.324-1.121). This was followed by an immediate decrease (ß -13.022; 95% CI -20.401 to -5.643) and then by a second, late increase after 35 h (ß 11.750; 95% CI 4.71-18.791). No time-dependent fluctuation in D-dimer levels was observed in TIA patients. CONCLUSION: The time from symptom onset may affect D-dimer levels in patients with AIS but not those with TIA. Further studies confirming these findings and validating time-specific variations are needed to enable D-dimer levels to be used efficiently as an acute stroke and thrombotic risk biomarker.

Cost-Effectiveness of Smoking Cessation Interventions in Patients With Ischemic Stroke and Transient Ischemic Attack.

BACKGROUND: Smoking cessation rates after stroke and transient ischemic attack are suboptimal, and smoking cessation interventions are underutilized. We performed a cost-effectiveness analysis of smoking cessation interventions in this population. METHODS: We constructed a decision tree and used Markov models that aimed to assess the cost-effectiveness of varenicline, any pharmacotherapy with intensive counseling, and monetary incentives, compared with brief counseling alone in the secondary stroke prevention setting. Payer and societal costs of interventions and outcomes were modeled. The outcomes were recurrent stroke, myocardial infarction, and death using a lifetime horizon. Estimates and variance for the base case (35% cessation), costs and effectiveness of interventions, and outcome rates were imputed from the stroke literature. We calculated incremental cost-effectiveness ratios and incremental net monetary benefits. An intervention was considered cost-effective if the incremental cost-effectiveness ratio was less than the willingness-to-pay threshold of $100 000 per quality-adjusted life-year (QALY) or when the incremental net monetary benefit was positive. Probabilistic Monte Carlo simulations modeled the impact of parameter uncertainty. RESULTS: From the payer perspective, varenicline and pharmacotherapy with intensive counseling were associated with more QALYs (0.67 and 1.00, respectively) at less total lifetime costs compared with brief counseling alone. Monetary incentives were associated with 0.71 more QALYs at an additional cost of $120 compared with brief counseling alone, yielding an incremental cost-effectiveness ratio of $168/QALY. From the societal perspective, all 3 interventions provided more QALYs at less total costs compared with brief counseling alone. In 10 000 Monte Carlo simulations, all 3 smoking cessation interventions were cost-effective in >89% of runs. CONCLUSIONS: For secondary stroke prevention, it is cost-effective and potentially cost-saving to deliver smoking cessation therapy beyond brief counseling alone.

Prevalence of neurological complaints among emergency department patients with severe hypertension.

OBJECTIVE: Severe hypertension can accompany neurological symptoms without obvious signs of target organ damage. However, acute cerebrovascular events can also be a cause and consequence of severe hypertension. We therefore use US population-level data to determine prevalence and clinical characteristics of patients with severe hypertension and neurological complaints. METHODS: We used nationally representative data from the National Hospital Ambulatory Medical Care Survey (NHAMCS) collected in 2016-2019 to identify adult ED patients with severely elevated blood pressure (BP) defined as systolic BP ≥ 180 mmHg and/or diastolic BP ≥120 mmHg. We used ED reason for visit data fields to define neurological complaints and used diagnosis data fields to define acute target organ damage. We applied survey visit weights to obtain national estimates. RESULTS: Based on 5083 observations, an estimated 40.4 million patients (95% CI: 37.5-43.0 million) in EDs nationwide from 2016 to 2019 had severe hypertension, equating to 6.1% (95% CI: 5.7-6.5%) of all ED visits. Only 2.8% (95% CI: 2.0-3.9%) of ED patients with severe hypertension were diagnosed with acute cerebrovascular disease; hypertensive urgency was diagnosed in 92.0% (95% CI: 90.3-93.4%). Neurological complaints were frequent in both patients with (75.6%) and without (19.9%) cerebrovascular diagnoses. Hypertensive urgency patients with neurological complaints were more often older, female, had prior stroke/TIA, and had neuroimaging than patients without these complaints. Non-migraine headache and vertigo were the most common neurological complaints recorded. CONCLUSION: In a nationally representative survey, one-in-sixteen ED patients had severely elevated BP and one-fifth of those patients had neurological complaints.

Laparoscopically Confirmed Endometriosis and Risk of Incident Stroke: A Prospective Cohort Study.

BACKGROUND: Prior research suggests that women with endometriosis are at greater risk of coronary heart disease. Therefore, our objective was to prospectively investigate the association between laparoscopically confirmed endometriosis and risk of incident stroke during 28 years of follow-up. METHODS: Participants in the NHSII cohort study (Nurses' Health Study II) were followed from 1989 when they were between the ages of 25 to 42 until 2017 for development of incident stroke (ischemic and hemorrhagic). Cox proportional hazard models were used to calculate hazard ratios and 95% CI, with adjustment for potential confounding variables (alcohol intake, body mass index at age 18, current body mass index, age at menarche, menstrual cycle pattern in adolescence, current menstrual cycle pattern, parity, oral contraceptive use history, smoking history, diet quality, physical activity, NSAID use, aspirin use, race/ethnicity, and income). We estimated the proportion of the total association mediated by history of hypertension, hypercholesterolemia, hysterectomy/oophorectomy, and hormone therapy. We also tested for effect modification by age (<50, ≥50 years), infertility history, body mass index (<25, ≥25 kg/m2), and menopausal status. RESULTS: We documented 893 incident cases of stroke during 2 770 152 person-years of follow-up. Women with laparoscopically confirmed endometriosis had a 34% greater risk of stroke in multivariable-adjusted models (hazard ratio, 1.34 [95% CI, 1.10-1.62]), compared to those without a history of endometriosis. Of the total association of endometriosis with risk of stroke, the largest proportion was attributed to hysterectomy/oophorectomy (39% mediated [95% CI, 14%-71%]) and hormone therapy (16% mediated [95% CI, 5%-40%]). We observed no differences in the relationship between endometriosis and stroke by age, infertility history, body mass index, or menopausal status. CONCLUSIONS: We observed that women with endometriosis were at elevated risk of stroke. Women and their health care providers should be aware of endometriosis history, maximize primary cardiovascular prevention, and discuss signs and symptoms of cardiovascular disease.

Direct Oral Anticoagulants Versus Warfarin in the Treatment of Cerebral Venous Thrombosis (ACTION-CVT): A Multicenter International Study.

BACKGROUND: A small randomized controlled trial suggested that dabigatran may be as effective as warfarin in the treatment of cerebral venous thrombosis (CVT). We aimed to compare direct oral anticoagulants (DOACs) to warfarin in a real-world CVT cohort. METHODS: This multicenter international retrospective study (United States, Europe, New Zealand) included consecutive patients with CVT treated with oral anticoagulation from January 2015 to December 2020. We abstracted demographics and CVT risk factors, hypercoagulable labs, baseline imaging data, and clinical and radiological outcomes from medical records. We used adjusted inverse probability of treatment weighted Cox-regression models to compare recurrent cerebral or systemic venous thrombosis, death, and major hemorrhage in patients treated with warfarin versus DOACs. We performed adjusted inverse probability of treatment weighted logistic regression to compare recanalization rates on follow-up imaging across the 2 treatments groups. RESULTS: Among 1025 CVT patients across 27 centers, 845 patients met our inclusion criteria. Mean age was 44.8 years, 64.7% were women; 33.0% received DOAC only, 51.8% received warfarin only, and 15.1% received both treatments at different times. During a median follow-up of 345 (interquartile range, 140-720) days, there were 5.68 recurrent venous thrombosis, 3.77 major hemorrhages, and 1.84 deaths per 100 patient-years. Among 525 patients who met recanalization analysis inclusion criteria, 36.6% had complete, 48.2% had partial, and 15.2% had no recanalization. When compared with warfarin, DOAC treatment was associated with similar risk of recurrent venous thrombosis (aHR, 0.94 [95% CI, 0.51-1.73]; P=0.84), death (aHR, 0.78 [95% CI, 0.22-2.76]; P=0.70), and rate of partial/complete recanalization (aOR, 0.92 [95% CI, 0.48-1.73]; P=0.79), but a lower risk of major hemorrhage (aHR, 0.35 [95% CI, 0.15-0.82]; P=0.02). CONCLUSIONS: In patients with CVT, treatment with DOACs was associated with similar clinical and radiographic outcomes and favorable safety profile when compared with warfarin treatment. Our findings need confirmation by large prospective or randomized studies.

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.

Biomarkers of Coagulation and Inflammation in COVID-19-Associated Ischemic Stroke.

[Figure: see text].

Anticoagulation Timing in Cardioembolic Stroke and Recurrent Event Risk.

OBJECTIVE: Guidelines recommend initiating anticoagulation within 4 to 14 days after cardioembolic stroke. Data supporting this did not account for key factors potentially affecting the decision to initiate anticoagulation, such as infarct size, hemorrhagic transformation, or high-risk features on echocardiography. METHODS: We pooled data from stroke registries of 8 comprehensive stroke centers across the United States. We included consecutive patients admitted with ischemic stroke and atrial fibrillation. The primary predictor was timing of initiating anticoagulation (0-3 days, 4-14 days, or >14 days), and outcomes were recurrent stroke/transient ischemic attack/systemic embolism, symptomatic intracerebral hemorrhage (sICH), and major extracranial hemorrhage (ECH) within 90 days. RESULTS: Among 2,084 patients, 1,289 met the inclusion criteria. The combined endpoint occurred in 10.1% (n = 130) subjects (87 ischemic events, 20 sICH, and 29 ECH). Overall, there was no significant difference in the composite endpoint between the 3 groups (0-3 days: 10.3%, 64/617; 4-14 days: 9.7%, 52/535; >14 days: 10.2%, 14/137; p = 0.933). In adjusted models, patients started on anticoagulation between 4 and 14 days did not have a lower rate of sICH (vs 0-3 days; odds ratio [OR] = 1.49, 95% confidence interval [CI] = 0.50-4.43), nor did they have a lower rate of recurrent ischemic events (vs >14 days; OR = 0.76, 95% CI = 0.36-1.62, p = 0.482). INTERPRETATION: In this multicenter real-world cohort, the recommended (4-14 days) time frame to start oral anticoagulation was not associated with reduced ischemic and hemorrhagic outcomes. Randomized trials are required to determine the optimal timing of anticoagulation initiation. ANN NEUROL 2020;88:807-816.

Ischaemic stroke on anticoagulation therapy and early recurrence in acute cardioembolic stroke: the IAC study.

BACKGROUND AND PURPOSE: A subset of ischaemic stroke patients with atrial fibrillation (AF) have ischaemic stroke despite anticoagulation. We sought to determine the association between prestroke anticoagulant therapy and recurrent ischaemic events and symptomatic intracranial haemorrhage (sICH). METHODS: We included consecutive patients with acute ischaemic stroke and AF from the Initiation of Anticoagulation after Cardioembolic stroke (IAC) study from eight comprehensive stroke centres in the USA. We compared recurrent ischaemic events and delayed sICH risk using adjusted Cox regression analyses between patients who were prescribed anticoagulation (ACp) versus patients who were naïve to anticoagulation therapy prior to the ischaemic stroke (anticoagulation naïve). RESULTS: Among 2084 patients in IAC, 1518 had prior anticoagulation status recorded and were followed for 90 days. In adjusted Cox hazard models, ACp was associated with some evidence of a higher risk higher risk of 90-day recurrent ischaemic events only in the fully adjusted model (adjusted HR 1.50, 95% CI 0.99 to 2.28, p=0.058) but not increased risk of 90-day sICH (adjusted HR 1.08, 95% CI 0.46 to 2.51, p=0.862). In addition, switching anticoagulation class was not associated with reduced risk of recurrent ischaemic events (adjusted HR 0.41, 95% CI 0.12 to 1.33, p=0.136) nor sICH (adjusted HR 1.47, 95% CI 0.29 to 7.50, p=0.641). CONCLUSION: AF patients with ischaemic stroke despite anticoagulation may have higher recurrent ischaemic event risk compared with anticoagulation-naïve patients. This suggests differing underlying pathomechanisms requiring different stroke prevention measures and identifying these mechanisms may improve secondary prevention strategies.

Statistical insights for crude-rate-based operational measures of misdiagnosis-related harms.

In longitudinal event data, a crude rate is a simple quantification of the event rate, defined as the number of events during an evaluation window, divided by the at-risk population size at the beginning or mid-time point of that window. The crude rate recently received revitalizing interest from medical researchers who aimed to improve measurement of misdiagnosis-related harms using administrative or billing data by tracking unexpected adverse events following a "benign" diagnosis. The simplicity of these measures makes them attractive for implementation and routine operational monitoring at hospital or health system level. However, relevant statistical inference procedures have not been systematically summarized. Moreover, it is unclear to what extent the temporal changes of the at-risk population size would bias analyses and affect important conclusions concerning misdiagnosis-related harms. In this article, we present statistical inference tools for using crude-rate based harm measures, as well as formulas and simulation results that quantify the deviation of such measures from those based on the more sophisticated Nelson-Aalen estimator. Moreover, we present results for a generalized multibin version of the crude rate, for which the usual crude rate is a single-bin special case. The generalized multibin crude rate is more straightforward to compute than the Nelson-Aalen estimator and can reduce potential biases of the single-bin crude rate. For studies that seek to use multibin measures, we provide simulations to guide the choice regarding number of bins. We further bolster these results using a worked example of stroke after "benign" dizziness from a large data set.

Factors associated with hospitalization for ischemic stroke and TIA following an emergency department headache visit.

BACKGROUND: Misdiagnosis of cerebrovascular disease among Emergency Department (ED) patients with headache has been reported. We hypothesized that markers of substandard diagnostic processes would be associated with subsequent ischemic cerebrovascular events among patients discharged from the ED with a headache diagnosis even after adjusting for demographic variables and medical history. METHODS: We conducted a case-control study of adult ED patients diagnosed with a primary headache disorder at Montefiore Medical Center from 9/1/2013-9/1/2018. Cases were defined as patients hospitalized for an ischemic stroke or TIA within 365 days of their index ED visit. Control patients were defined as those who lacked a subsequent hospitalization for cerebrovascular disease. Pre-specified demographic, clinical, and diagnostic process factors were compared between groups; conditional logistic regression was used to assess the separate and joint influence of baseline features on risk of cerebral ischemia. RESULTS: A total of 93 consecutive headache patients with a subsequent ischemic stroke/TIA hospitalization were matched to 93 controls (n = 186). Cases were older than controls and more likely to have traditional cerebrovascular risk factors. Neurological consultation was obtained more often for cases (13% vs. 4%; P = 0.03), cases were in the ED for longer (6 vs. 5 h, P = 0.03), and more frequently received neuroimaging (80% vs. 48%; P < 0.0001). Rates of neurological examination, documented differential diagnoses, and clear discharge follow up plans were similar between cases and controls. In our conditional logistic regression model, only history of prior stroke/TIA was associated with increased odds of subsequent cerebral ischemia. CONCLUSION: Factors associated with diagnostic process failures did not increase the odds of subsequent ischemic stroke/TIA hospitalization following ED headache visit in our study.

Under Treatment of High-Risk TIA Patients with Clopidogrel-Aspirin in the Emergency Setting.

BACKGROUND: Treating high-risk transient ischemic attack (TIA) with dual antiplatelet therapy (DAPT) reduces subsequent ischemic stroke risk yet current rates of clopidogrel-aspirin treatment are uncertain. MATERIALS AND METHODS: We conducted a retrospective cohort study of consecutive TIA patients who presented to any of the four emergency departments (ED) of a single urban health system from 1/1/2018-3/1/2020. Medical record review was used to describe the cohort and assess clopidogrel-aspirin treatment. Patient eligibility for clopidogrel-aspirin was determined using relevant criteria from the Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) Trial. Comparisons among eligible patients who received versus did not receive clopidogrel-aspirin were conducted using t-test, chi-squared, and Mann-Whitney as indicated. RESULTS: We identified 248 TIA patients of whom 95 met eligibility criteria for clopidogrel-aspirin treatment. Among these 95 patients, mean age was 69.5 (SD: 12), 68.4% were women, and median ABCD2 score was 5 (IQR: 4-6). A total of 26/95 (27.4%) eligible patients received clopidogrel-aspirin within 24 hours of symptom onset. Appropriate clopidogrel-aspirin use was associated with having a stroke code called upon ED arrival (88.5% vs. 34.8%; P<0.001), being evaluated by a vascular neurologist (88.5% vs. 21.1%; P<0.001), and not presenting to the community ED site wherein only a single patient received clopidogrel-aspirin. CONCLUSIONS: In a multisite, single health system study, nearly three-fourths of high-risk TIA patients eligible for clopidogrel-aspirin treatment did not receive it. Appropriate clopidogrel-aspirin use was highest among patients seen by vascular neurologists and lowest at the community ED, though under treatment was evident at all sites.

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.

Redefined Measure of Early Neurological Improvement Shows Treatment Benefit of Alteplase Over Placebo.

Background and Purpose- The first of the 2 NINDS (National Institute of Neurological Disorders and Stroke) Study trials did not show a significant increase in early neurological improvement, defined as National Institutes of Health Stroke Scale (NIHSS) improvement by ≥4, with alteplase treatment. We hypothesized that early neurological improvement defined as a percentage change in NIHSS (percent change NIHSS) at 24 hours is superior to other definitions in predicting 3-month functional outcomes and using this definition there would be treatment benefit of alteplase over placebo at 24 hours. Methods- We analyzed the NINDS rt-PA Stroke Study (Parts 1 and 2) trial data. Percent change NIHSS was defined as ([admission NIHSS score-24-hour NIHSS score]×100/admission NIHSS score] and delta NIHSS as (admission NIHSS score-24-hour NIHSS score). We compared early neurological improvement using these definitions between alteplase versus placebo patients. We also used receiver operating characteristic curve to determine the predictive association of early neurological improvement with excellent 3-month functional outcomes (Barthel Index score of 95-100 and modified Rankin Scale score of 0-1), good 3-month functional outcome (modified Rankin Scale score of 0-2), and 3-month infarct volume. Results- There was a significantly greater improvement in the 24-hour median percent change NIHSS among patients treated with alteplase compared with the placebo group (28% versus 15%; P=0.045) but not median delta NIHSS (3 versus 2; P=0.471). Receiver operating characteristic curve comparison showed that percent change NIHSS (ROCpercent) was better than delta NIHSS (ROCdelta) and admission NIHSS (ROCadmission) with regards to excellent 3-month Barthel Index (ROCpercent, 0.83; ROCdelta, 0.76; ROCadmission, 0.75), excellent 3-month modified Rankin Scale (ROCpercent, 0.83; ROCdelta, 0.74; ROCadmission, 0.78), and good 3-month modified Rankin Scale (ROCpercent, 0.83; ROCdelta, 0.76; ROCadmission, 0.78). Conclusions- In the NINDS rt-PA trial, alteplase was associated with a significant percent change improvement in NIHSS at 24 hours. Percent change in NIHSS may be a better surrogate marker of thrombolytic activity and 3-month outcomes.

Anticoagulation Type and Early Recurrence in Cardioembolic Stroke: The IAC Study.

BACKGROUND AND PURPOSE: In patients with acute ischemic stroke and atrial fibrillation, treatment with low molecular weight heparin increases early hemorrhagic risk without reducing early recurrence, and there is limited data comparing warfarin to direct oral anticoagulant (DOAC) therapy. We aim to compare the effects of the treatments above on the risk of 90-day recurrent ischemic events and delayed symptomatic intracranial hemorrhage. METHODS: We included consecutive patients with acute ischemic stroke and atrial fibrillation from the IAC (Initiation of Anticoagulation after Cardioembolic) stroke study pooling data from stroke registries of 8 comprehensive stroke centers across the United States. We compared recurrent ischemic events and delayed symptomatic intracranial hemorrhage between each of the following groups in separate Cox-regression analyses: (1) DOAC versus warfarin and (2) bridging with heparin/low molecular weight heparin versus no bridging, adjusting for pertinent confounders to test these associations. RESULTS: We identified 1289 patients who met the bridging versus no bridging analysis inclusion criteria and 1251 patients who met the DOAC versus warfarin analysis inclusion criteria. In adjusted Cox-regression models, bridging (versus no bridging) treatment was associated with a high risk of delayed symptomatic intracranial hemorrhage (hazard ratio, 2.74 [95% CI, 1.01-7.42]) but a similar rate of recurrent ischemic events (hazard ratio, 1.23 [95% CI, 0.63-2.40]). Furthermore, DOAC (versus warfarin) treatment was associated with a lower risk of recurrent ischemic events (hazard ratio, 0.51 [95% CI, 0.29-0.87]) but not delayed symptomatic intracranial hemorrhage (hazard ratio, 0.57 [95% CI, 0.22-1.48]). CONCLUSIONS: Our study suggests that patients with ischemic stroke and atrial fibrillation would benefit from the initiation of a DOAC without bridging therapy. Due to our study limitations, these findings should be interpreted with caution pending confirmation from large prospective studies.

Early ischaemic and haemorrhagic complications after atrial fibrillation-related ischaemic stroke: analysis of the IAC study.

INTRODUCTION: Predictors of long-term ischaemic and haemorrhagic complications in atrial fibrillation (AF) have been studied, but there are limited data on predictors of early ischaemic and haemorrhagic complications after AF-associated ischaemic stroke. We sought to determine these predictors. METHODS: The Initiation of Anticoagulation after Cardioembolic stroke study is a multicentre retrospective study across that pooled data from consecutive patients with ischaemic stroke in the setting of AF from stroke registries across eight comprehensive stroke centres in the USA. The coprimary outcomes were recurrent ischaemic event (stroke/TIA/systemic arterial embolism) and delayed symptomatic intracranial haemorrhage (d-sICH) within 90 days. We performed univariate analyses and Cox regression analyses including important predictors on univariate analyses to determine independent predictors of early ischaemic events (stroke/TIA/systemic embolism) and d-sICH. RESULTS: Out of 2084 patients, 1520 patients qualified; 104 patients (6.8%) had recurrent ischaemic events and 23 patients (1.5%) had d-sICH within 90 days from the index event. In Cox regression models, factors associated with a trend for recurrent ischaemic events were prior stroke or transient ischemic attack (TIA) (HR 1.42, 95% CI 0.96 to 2.10) and ipsilateral arterial stenosis with 50%-99% narrowing (HR 1.54, 95% CI 0.98 to 2.43). Those associated with sICH were male sex (HR 2.68, 95% CI 1.06 to 6.83), history of hyperlipidaemia (HR 2.91, 95% CI 1.08 to 7.84) and early haemorrhagic transformation (HR 5.35, 95% CI 2.22 to 12.92). CONCLUSION: In patients with ischaemic stroke and AF, predictors of d-sICH are different than those of recurrent ischaemic events; therefore, recognising these predictors may help inform early stroke versus d-sICH prevention strategies.

Multiple Administrations of Intravenous Thrombolytic Therapy to a Stroke Mimic.

BACKGROUND: Patients who present emergently with focal neurological deficits concerning for acute ischemic stroke can be extremely challenging to diagnose and treat. Unnecessary administration of thrombolytics to potential stroke patients whose symptoms are not caused by an acute ischemic stroke-stroke mimics-may result in patient harm, although the overall risk of hemorrhagic complications among stroke mimics is low. CASE REPORT: We present a case of a stroke mimic patient with underlying psychiatric disease who was treated with intravenous alteplase on four separate occasions in four different emergency departments in the same city. Although he did not suffer hemorrhagic complications, this case highlights the importance of rapid exchange of health information across institutions to improve diagnostic quality and safety. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Increased awareness of stroke mimics by emergency physicians may improve diagnostic safety for a subset of high-risk patients. Establishing rapid cross-institutional communication pathways that are integrated into provider's workflows to convey essential patient health information has potential to improve stroke diagnostic decision-making and thus represents an important topic for health systems research in emergency medicine.

Factors associated with therapeutic anticoagulation status in patients with ischemic stroke and atrial fibrillation.

BACKGROUND AND PURPOSE: Understanding factors associated with ischemic stroke despite therapeutic anticoagulation is an important goal to improve stroke prevention strategies in patients with atrial fibrillation (AF). We aim to determine factors associated with therapeutic or supratherapeutic anticoagulation status at the time of ischemic stroke in patients with AF. METHODS: The Initiation of Anticoagulation after Cardioembolic stroke (IAC) study is a multicenter study pooling data from stroke registries of eight comprehensive stroke centers across the United States. Consecutive patients hospitalized with acute ischemic stroke in the setting of AF were included in the IAC cohort. For this study, we only included patients who reported taking warfarin at the time of the ischemic stroke. Patients not on anticoagulation and patients who reported use of a direct oral anticoagulant were excluded. Analyses were stratified based on therapeutic (INR ≥2) versus subtherapeutic (INR <2) anticoagulation status. We used binary logistic regression models to determine factors independently associated with anticoagulation status after adjustment for pertinent confounders. In particular, we sought to determine whether atherosclerosis with 50% or more luminal narrowing in an artery supplying the infarct (a marker for a competing atherosclerotic mechanism) and small stroke size (≤ 10 mL; implying a competing small vessel disease mechanism) related to anticoagulant status. RESULTS: Of the 2084 patients enrolled in the IAC study, 382 patients met the inclusion criteria. The mean age was 77.4 ± 10.9 years and 52.4% (200/382) were women. A total of 222 (58.1%) subjects presented with subtherapeutic INR. In adjusted models, small stroke size (OR 1.74 95% CI 1.10-2.76, p = 0.019) and atherosclerosis with 50% or more narrowing in an artery supplying the infarct (OR 1.96 95% CI 1.06-3.63, p = 0.031) were independently associated with INR ≥2 at the time of their index stroke. CONCLUSION: Small stroke size (≤ 10 ml) and ipsilateral atherosclerosis with 50% or more narrowing may indicate a competing stroke mechanism. There may be important opportunities to improve stroke prevention strategies for patients with AF by targeting additional ischemic stroke mechanisms to improve patient outcomes.

Is the Cost-Effectiveness of Stroke Thrombolysis Affected by Proportion of Stroke Mimics?

Background and Purpose- Differentiating ischemic stroke patients from stroke mimics (SM), nonvascular conditions which simulate stroke, can be challenging in the acute setting. We sought to model the cost-effectiveness of treating suspected acute ischemic stroke patients before a definitive diagnosis could be made. We hypothesized that we would identify threshold proportions of SM among suspected stroke patients arriving to an emergency department above which administration of intravenous thrombolysis was no longer cost-effective. Methods- We constructed a decision-analytic model to examine various emergency department thrombolytic treatment scenarios. The main variables were proportion of SM to true stroke patients, time from symptom onset to treatment, and complication rates. Costs, reimbursement rates, and expected clinical outcomes of ischemic stroke and SM patients were estimated from published data. We report the 90-day incremental cost-effectiveness ratio of administering intravenous thrombolysis compared with no acute treatment from a healthcare sector perspective, as well as the cost-reimbursement ratio from a hospital-level perspective. Cost-effectiveness was defined as a willingness to pay <$100 000 USD per quality adjusted life year gained and high cost-reimbursement ratio was defined as >1.5. Results- There was an increase in incremental cost-effectiveness ratios as the proportion of SM cases increased in the 3-hour time window. The threshold proportion of SM above which the decision to administer thrombolysis was no longer cost-effective was 30%. The threshold proportion of SM above which the decision to administer thrombolysis resulted in high cost-reimbursement ratio was 75%. Results were similar for patients arriving within 0 to 90 minutes of symptom onset as compared with 91 to 180 minutes but were significantly affected by cost of alteplase in sensitivity analyses. Conclusions- We identified thresholds of SM above which thrombolysis was no longer cost-effective from 2 analytic perspectives. Hospitals should monitor SM rates and establish performance metrics to prevent rising acute stroke care costs and avoid potential patient harms.