Impact of Poverty on Stroke Recurrence: A Population-Based Study

BACKGROUND AND OBJECTIVES

Poverty is associated with greater stroke incidence. The relationship between poverty and stroke recurrence is less clear.

METHODS

In this population-based study, incident strokes within the Greater Cincinnati/Northern Kentucky region were ascertained during the 2015 study period and followed up for recurrence until December 31, 2018. The primary exposure was neighborhood socioeconomic status (nSES), defined by the percentage of households below the federal poverty line in each census tract in 4 categories (≤5%, >5%-10%, >10%-25%, >25%). Poisson regression models provided recurrence rate estimates per 100,000 residents using population data from the 2015 5-year American Community Survey, adjusting for age, sex, and race. In a secondary analysis, Cox models allowed for the inclusion of vascular risk factors in the assessment of recurrence risk by nSES among those with incident stroke.

RESULTS

Of 2,125 patients with incident stroke, 245 had a recurrent stroke during the study period. Poorer nSES was associated with increased stroke recurrence, with rates of 12.5, 17.5, 25.4, and 29.9 per 100,000 in census tracts with ≤5%, >5%-10%, >10%-25%, and >25% below the poverty line, respectively (p < 0.01). The relative risk (95% CI) for recurrent stroke among Black vs White individuals was 2.54 (1.91-3.37) before adjusting for nSES, and 2.00 (1.47-2.74) after adjusting for nSES, a 35.1% decrease. In the secondary analysis, poorer nSES (HR 1.74, 95% CI 1.10-2.76 for lowest vs highest category) and Black race (HR 1.31, 95% CI 1.01-1.70) were both independently associated with recurrence risk, though neither retained significance after full adjustment. Age, diabetes, and left ventricular hypertrophy were associated with increased recurrence risk in fully adjusted models.

DISCUSSION

Residents of poorer neighborhoods had a dose-dependent increase in stroke recurrence risk, and neighborhood poverty accounted for approximately one-third of the excess risk among Black individuals. These results highlight the importance of poverty, race, and the intersection of the 2 as potent drivers of stroke recurrence.

Racial Disparities in Blood Pressure at Time of Acute Ischemic Stroke Presentation: A Population Study

BACKGROUND

Hypertension is a stroke risk factor with known disparities in prevalence and management between Black and White patients. We sought to identify if racial differences in presenting blood pressure (BP) during acute ischemic stroke exist.

METHODS AND RESULTS

Adults with acute ischemic stroke presenting to an emergency department within 24 hours of last known normal during study epochs 2005, 2010, and 2015 within the Greater Cincinnati/Northern Kentucky Stroke Study were included. Demographics, histories, arrival BP, National Institutes of Health Stroke Scale score, and time from last known normal were collected. Multivariable linear regression was used to determine differences in mean BP between Black and White patients, adjusting for age, sex, National Institutes of Health Stroke Scale score, history of hypertension, hyperlipidemia, smoking, stroke, body mass index, and study epoch. Of 4048 patients, 853 Black and 3195 White patients were included. In adjusted analysis, Black patients had higher presenting systolic BP (161 mm Hg [95% CI, 159-164] versus 158 mm Hg [95% CI, 157-159], P<0.01), diastolic BP (86 mm Hg [95% CI, 85-88] versus 83 mm Hg [95% CI, 82-84], P<0.01), and mean arterial pressure (111 mm Hg [95% CI, 110-113] versus 108 mm Hg [95% CI, 107-109], P<0.01) compared with White patients. In adjusted subanalysis of patients <4.5 hours from last known normal, diastolic BP (88 mm Hg [95% CI, 86-90] versus 83 mm Hg [95% CI, 82-84], P<0.01) and mean arterial pressure (112 mm Hg [95% CI, 110-114] versus 108 mm Hg [95% CI, 107-109], P<0.01) were also higher in Black patients.

CONCLUSIONS

This population-based study suggests differences in presenting BP between Black and White patients during acute ischemic stroke. Further study is needed to determine whether these differences influence clinical decision-making, outcome, or clinical trial eligibility.

Trends Over Time in Stroke Incidence by Race in the Greater Cincinnati Northern Kentucky Stroke Study

BACKGROUND AND OBJECTIVES

Understanding the current status of and temporal trends of stroke epidemiology by age, race, and stroke subtype is critical to evaluate past prevention efforts and to plan future interventions to eliminate existing inequities. We investigated trends in stroke incidence and case fatality over a 22-year time period.

METHODS

In this population-based stroke surveillance study, all cases of stroke in acute care hospitals within a 5-county population of southern Ohio/northern Kentucky in adults aged ≥20 years were ascertained during a full year every 5 years from 1993 to 2015. Temporal trends in stroke epidemiology were evaluated by age, race (Black or White), and subtype (ischemic stroke [IS], intracranial hemorrhage [ICH], or subarachnoid hemorrhage [SAH]). Stroke incidence rates per 100,000 individuals from 1993 to 2015 were calculated using US Census data and age-standardized, race-standardized, and sex-standardized as appropriate. Thirty-day case fatality rates were also reported.

RESULTS

Incidence rates for stroke of any type and IS decreased in the combined population and among White individuals (any type, per 100,000, 215 [95% CI 204-226] in 1993/4 to 170 [95% CI 161-179] in 2015, p = 0.015). Among Black individuals, incidence rates for stroke of any type decreased over the study period (per 100,000, 349 [95% CI 311-386] in 1993/4 to 311 [95% CI 282-340] in 2015, p = 0.015). Incidence of ICH was stable over time in the combined population and in race-specific subgroups, and SAH decreased in the combined groups and in White adults. Incidence rates among Black adults were higher than those of White adults in all time periods, and Black:White risk ratios were highest in adults in young and middle age groups. Case fatality rates were similar by race and by time period with the exception of SAH in which 30-day case fatality rates decreased in the combined population and White adults over time.

DISCUSSION

Stroke incidence is decreasing over time in both Black and White adults, an encouraging trend in the burden of cerebrovascular disease in the US population. Unfortunately, however, Black:White disparities have not decreased over a 22-year period, especially among younger and middle-aged adults, suggesting the need for more effective interventions to eliminate inequities by race.

Using Epidemiological Data to Inform Clinical Trial Feasibility Assessments: A Case Study

BACKGROUND

Clinical trial enrollment and completion is challenging, with nearly half of all trials not being completed or not completed on time. In 2014, the National Institutes of Health StrokeNet in collaboration with stroke epidemiologists from GCNKSS (Greater Cincinnati/Northern Kentucky Stroke Study) began providing proposed clinical trials with formal trial feasibility assessments. Herein, we describe the process of prospective feasibility analyses using epidemiological data that can be used to improve enrollment and increase the likelihood a trial is completed.

METHODS

In 2014, DEFUSE 3 (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke 3) trialists, National Institutes of Health StrokeNet, and stroke epidemiologists from GCNKSS collaborated to evaluate the initial inclusion/exclusion criteria for the DEFUSE 3 study. Trial criteria were discussed and an assessment was completed to evaluate the percent of the stroke population that might be eligible for the study. The DEFUSE 3 trial was stopped early with the publication of DAWN (Thrombectomy 6 to 24 Hours After Stroke With a Mismatch Between Deficit and Infarct), and the Wilcoxon rank-sum statistic was used to analyze whether the trial would have been stopped had the proposed changes not been made, following the DEFUSE 3 statistical analysis plan.

RESULTS

After initial epidemiological analysis, 2.4% of patients with acute stroke in the GCNKSS population would have been predicted to be eligible for the study. After discussion with primary investigators and modifying 4 key exclusion criteria (upper limit of age increased to 90 years, baseline modified Rankin Scale broadened to 0-2, time since last well expanded to 16 hours, and decreased lower limit of National Institutes of Health Stroke Scale score to <6), the number predicted to be eligible for the trial increased to 4%. At the time of trial conclusion, 57% of the enrolled patients qualified only by the modified criteria, and the trial was stopped at an interim analysis that demonstrated efficacy. We estimated that the Wilcoxon rank-sum value for the unadjusted predicted enrollment would not have crossed the threshold for efficacy and the trial not stopped.

CONCLUSIONS

Objectively assessing trial inclusion/exclusion criteria using a population-based resource in a collaborative and iterative process including epidemiologists can lead to improved recruitment and can increase the likelihood of successful trial completion.

Trends in Disparities in Advanced Neuroimaging Utilization in Acute Stroke: A Population-Based Study

Background:

Our primary objective was to evaluate if disparities in race, sex, age, and socioeconomic status (SES) exist in utilization of advanced neuroimaging in year 2015 in a population-based study. Our secondary objective was to identify the disparity trends and overall imaging utilization as compared with years 2005 and 2010.

Methods:

This was a retrospective, population-based study that utilized the GCNKSS (Greater Cincinnati/Northern Kentucky Stroke Study) data. Patients with stroke and transient ischemic attack were identified in the years 2005, 2010, and 2015 in a metropolitan population of 1.3 million. The proportion of imaging use within 2 days of stroke/transient ischemic attack onset or hospital admission date was computed. SES determined by the percentage below the poverty level within a given respondent’s US census tract of residence was dichotomized. Multivariable logistic regression was used to determine the odds of advanced neuroimaging use (computed tomography angiogram/magnetic resonance imaging/magnetic resonance angiogram) for age, race, gender, and SES.

Results:

There was a total of 10 526 stroke/transient ischemic attack events in the combined study year periods of 2005, 2010, and 2015. The utilization of advanced imaging progressively increased (48% in 2005, 63% in 2010, and 75% in 2015 [ P <0.001]). In the combined study year multivariable model, advanced imaging was associated with age and SES. Younger patients (≤55 years) were more likely to have advanced imaging compared with older patients (adjusted odds ratio, 1.85 [95% CI, 1.62–2.12]; P <0.01), and low SES patients were less likely to have advanced imaging compared with high SES (adjusted odds ratio, 0.83 [95% CI, 0.75–0.93]; P <0.01). A significant interaction was found between age and race. Stratified by age, the adjusted odds of advanced imaging were higher for Black patients compared with White patients among older patients (>55 years; adjusted odds ratio, 1.34 [95% CI, 1.15–1.57]; P <0.01), but no racial differences among the young.

Conclusions:

Racial, age, and SES-related disparities exist in the utilization of advanced neuroimaging for patients with acute stroke. There was no evidence of a change in trend of these disparities between the study periods.

Changing Trends in Demographics, Risk Factors, and Clinical Features of Patients With Infective Endocarditis-Related Stroke, 2005-2015

BACKGROUND

There is a rising incidence of infective endocarditis-related stroke (IERS) in the United States attributed to the opioid epidemic. A contemporary epidemiologic description is necessary to understand the impact of the opioid epidemic on clinical characteristics of IERS. We describe and analyze trends in the demographics, risk factors, and clinical features of IERS.

METHODS

This is a retrospective cohort study within a biracial population of 1.3 million in the Greater Cincinnati/Northern Kentucky region. All hospitalized patients with hemorrhagic or ischemic stroke were identified and physician verified from the 2005, 2010, and 2015 calendar years using ICD-9 and -10 codes. IERS was defined as an acute stroke attributed to infective endocarditis meeting modified Duke Criteria for possible or definite endocarditis. Unadjusted comparison of demographics, risk factors, outcome, and clinical characteristics was performed between each study period for IERS and non-IERS. An adjusted model to compare trends used Cochran-Armitage test for categorical variables and a general linear model or a Kruskal-Wallis test for numerical variables. Examination for interaction of endocarditis status in trends was performed using a general linear or logistic model.

RESULTS

A total of 54 patients with IERS and 8204 without IERS were identified during the study periods. Between 2005 and 2015, there was a decline in rates of hypertension (91.7% vs 36.0%; p=0.0005) and increased intravenous drug users (IVDU) (8.3% vs 44.0%; p=0.02) in the IERS cohort. The remainder of the stroke population demonstrated a significant rise in hypertension, diabetes, atrial fibrillation, and peri-operative stroke. Infective endocarditis status significantly interacted with the trend in hypertension prevalence (p=0.001).

CONCLUSION

From 2005 to 2015, infective endocarditis-related stroke was increasingly associated with intravenous drug use and fewer risk factors, specifically hypertension. These trends likely reflect the demographics of the opioid epidemic, which has affected younger patients with fewer comorbidities.Non-standard Abbreviations and Acronyms IERS: infective endocarditis-related stroke; IVDU: intravenous drug users; GCNKSS: Greater Cincinnati Northern Kentucky Stroke Study; NIHSS: National Institute of Health Stroke Scale; tPA: tissue plasminogen activator.

Abstract WMP46: Impact Of Poverty On Stroke Incidence And Recurrence: A Population-based Study

Background: Poorer socioeconomic status (SES) is associated with higher stroke incidence. Less is known about SES and stroke recurrence. We sought to obtain updated estimates of stroke incidence stratified by aggregate measures of SES, and to explore the association between SES and stroke recurrence.

Methods: The Greater Cincinnati/Northern Kentucky region includes a population of 1.3 million, representative of the US population in terms of sociodemographics and percent black race. We ascertained all hospitalized strokes in the region in 2015 by screening ICD-9 codes 430-437 and ICD-10 codes I60-69, G45-46. Recurrent strokes were ascertained from 1/1/2015-12/31/2018. Patients’ home addresses were geocoded using DeGAUSS. Population estimates were obtained from the US Census Bureau using the 2015 5-year American Community Survey. Aggregate SES was estimated by percentage below poverty in each census tract. Regional incidence and recurrence rates were adjusted for age, sex, and race and calculated both with and without SES adjustment using Poisson regression models.

Results: Stroke incidence and recurrence rates stratified by SES are shown in the Table. Poorer SES was associated with greater stroke incidence (p<0.01) and recurrence (p<0.01) across races. The relative risk (95% CI) for first-ever stroke among black compared with nonblack individuals was 2.06 (1.79-2.38) before adjusting for SES, and 1.79 (1.54-2.08) after adjusting for SES. The relative risk (95% CI) for recurrent stroke among black compared with nonblack individuals was 2.54 (1.91-3.37) before adjusting for SES, and 2.00 (1.47-2.74) after adjusting for SES. There was no race by SES interaction.

Conclusions: Poorer SES was associated with increased risk for both incident and recurrent stroke across races. Of the excess risk for stroke incidence among black individuals, 25.5% was accounted for by SES, while 35.1% of the excess risk for recurrence was accounted for by SES.

Abstract WP176: Prior TIAs Among Patients With Ischemic Stroke In The Greater Cincinnati Northern Kentucky Stroke Study (GCNKSS)

Background: TIAs serve as an opportunity to identify and modify risk factors and to prevent future events. Given known epidemiologic differences in strokes by race and sex, our objective was to investigate the rates of prior TIAs among those with incident ischemic stroke (IS) in the GCNKSS.

Methods: We included all physician adjudicated, incident IS among adults age ≥20 years in the GCNKSS, a population-based stroke surveillance study in a 5-county region of southern Ohio/ northern Kentucky, in 2005, 2010, and 2015. We calculated the frequency of cases in which a TIA (sudden onset of focal neurologic symptoms lasting ≤ 24 hours) was documented in the 365 days prior to IS. Frequencies and proportions of prior TIA were compared by sex, race, and age, and location at which patients sought care for their TIA was described. Finally, multivariable logistic regression was performed to investigate demographic and clinical predictors of cases in which TIA preceded stroke; covariates were chosen a priori.

Results: We included 5310 IS events; mean age was 69.7 (SD 14.8) years, 54.7% were female, and 20.4% were Black. A total of 351 patients (6.6%) had a documented TIA the year preceding their IS. Overall, 42.2% did not seek care for their TIA, 21.6% called 911 and/or came to the ED, 6.0% saw a PCP, and 6.6% sought other care. In 22.5% of cases, location of care was unknown. In adjusted results, older age, female sex, history of hypertension, and CAD were associated with having had a prior TIA, while Black race was not. NIHSS was inversely associated with prior TIA (Table). Prior TIAs were similar between study years.

Conclusions: We conservatively estimate that ≥ 6% of patients with first-ever IS had a TIA in the preceding year, though underreporting is likely. Many patients did not report seeking care for the TIA, suggesting missed opportunities for risk factor modification. Further research is needed to understand the implications of sex and race differences in frequencies of prior TIA.

Abstract WP184: Identifying Optimal Cut Points Of National Institutes Of Health Stroke Scale To Predict Mortality: A Population-based Assessment

Background: Ischemic stroke is the 5 th leading cause of death in the US. As a measure of stroke severity, initial NIHSS has been used to predict clinical outcome. We sought to identify the optimal cut-points of NIHSS at initial presentation that are associated with higher 30-day mortality.

Methods: In 2005, 2010, and 2015 all hospitalized, first acute ischemic stroke events occurring within the Greater Cincinnati area were ascertained. Potential ischemic stroke cases underwent chart abstraction and physician adjudication, including retrospective NIHSS score (range 0 - 42) based on clinical findings at initial presentation. Descriptive statistics for NIHSS were estimated by study year, demographics, and medical history. Data regarding mortality was obtained from the National Death Index. The Contal and O’Quigley method based on a modified log-rank test statistic was used to determine cut-points of the NIHSS score associated with 30-day mortality, and hazard ratios were obtained from Cox models with adjustment for sex, race, and age.

Results: In 2005, 2010, and 2015 there were 1704, 1818 and 1852 ischemic stroke events with 30-day mortality rates of 10.5%, 9.6% and 9.0%, respectively. Optimal cut-points of NIHSS <9, 9-16 and >16 were identified. Across all 3 periods, 3431 (84.5%) cases had NIHSS 0-8, 352 (8.7%) had NIHSS 9-16 and 274 (6.8%) >16. Kaplan Meier Survival Curves for the 3 NIHSS groups are shown in the Figure. Strokes with NIHSS >16 at initial presentation were associated with a 15-fold (HR with 95% CI: 13, 19) increase in the risk of death at 30-days compared to those with NIHSS <9.

Discussion: NIH Stroke Scale scores are a reliable predictor of mortality, with higher NIHSS scores having higher risk of death. The cut points reported identify subgroups of stroke patients with dramatically different prognoses. Future studies should assess if this excess mortality risk among severe strokes persists after the more widespread implementation of thrombectomy beyond 2015.

Abstract 71: Temporal Trends In 30-day And 5-year Stroke Case Fatality Rates

Background: Previous studies spanning the 1990s-2010s have inconsistently identified a decline in 30-day stroke case-fatality rate (CFR), and little is known about trends in longer term stroke CFR over that period. We studied temporal trends in 30-day and 5-year CFRs in the well-defined Greater Cincinnati/Norther Kentucky (GCNK) stroke population.

Methods: The NIH-funded GCNK Stroke Study is a population-based study conducted in a 5-county region that is representative of the USA in terms of Black race, income, and education. The study ascertained all strokes in 1993/4, 1999, 2005, 2010, and 2015 using well-validated methods. All stroke subtypes were included: ischemic strokes (IS), intracerebral hemorrhages (ICH), and subarachnoid hemorrhages (SAHs). Deaths were identified via the National Death Index. Cox proportional hazards models were used to assess all-cause fatality, by subtype, to examine temporal trends adjusting for age, sex, and race.

Results: A total of 10372 stroke cases were ascertained over the five study periods (8428 IS, 443 SAH, and 1501 ICH). IS patients did not demonstrate a decline in 30-day CFRs over time, but did show a nonsignificant decrease in 5-year CFR. Among IS patients, female sex was associated with a lower 5-year CFR, whereas Black individuals had a lower 30-day CFR but a higher 5-year CFR. For ICH, there was a small increase in both 30-day and 5-year CFR in later study periods, although this did not reach significance in all years. SAH showed a lower 30-day CFR over time but no change in 5-year CFR. Older age was associated with a higher 30-day and 5-year CFR in all subtypes.

Discussion: Despite widespread advances in post-stroke care, adjusted 5-year CFR has not clearly improved for any stroke subtype and may have slightly worsened for ICH. 30-day CFR has shown a modest improvement among SAH patients. Future studies should investigate why Black individuals with IS experience lower early CFR but a higher late CFR.

Abstract 68: Socioeconomic Factors Associated With Ems-documented Stroke Chief Complaints In The Greater Cincinnati Northern Kentucky Stroke Study (GCNKSS)

Background: Accurate identification of stroke by EMS is necessary for triage and pre-notification within stroke systems of care. Our objective was to describe disparities in the documentation of stroke as the patient’s chief complaint (CC) by EMS in a large population-based stroke study.

Methods: We included physician-adjudicated strokes and TIAs occurring among adults ≥18 years old in 2015 in the GCNKSS study population, based in a 5-county area of Southern Ohio/Northern Kentucky. Strokes in which EMS was not used and events occurring in the hospital, during EMS transport, at an unknown location, or outside the study region were excluded. The documented CC by EMS (stroke/CVA, MI, seizure, fall, weakness/numbness, headache, or other) were compared between race/sex subgroups. Sequential multivariable logistic regression was performed to identify associations between race, sex, and social determinants of health with an EMS-documented stroke CC. Social determinants included living arrangement and census tract social deprivation index (SDI).

Results: A total of 1451 stroke/TIA events were included. White women had the highest proportion of EMS-documented stroke CCs (56%), more than Black women (48%), White men (45%), and Black men (42%), (p=0.02). Black race was inversely associated with an EMS-documented stroke CC in initial models but was collinear with SDI and no longer significant when SDI was included. In the full model, age, previous stroke, and living with others were associated with an EMS-documented stroke CC, while SDI and CAD were inversely associated with EMS-documented stroke CCs. (Table)

Conclusion: Patients living in census tracts characterized by social deprivation were less likely to have EMS-documented stroke CCs, suggesting differences in either patient or EMS recognition of stroke. Further work is needed to explore potential confounders including EMS protocols and to improve identification of stroke by patients and EMS providers.

Abstract WP43: Characteristics And Management Of Hospitalized Retinal Artery Occlusion Patients In The Era Of Updated Guidelines: A Population-based Study

Background: Retinal artery occlusion (RAO) is a stroke equivalent that causes significant morbidity. There has been growing emphasis on urgent in-hospital evaluation of these patients, both to facilitate potential thrombolytic therapy and expedite workup; however, little is known regarding its effect on systems of care. We thus examined presenting characteristics and management of hospitalized RAO patients using the Greater Cincinnati Northern Kentucky Stroke Study (GCNKSS).

Methods: The GCNKSS is a population-based study of stroke in a 5-county region with a population of 1.3 million representative of the USA in terms of Black race, income, and education. All cases of RAO among Black individuals from July 2019-December 2020 and among White individuals from 2020 were chart abstracted using ICD codes. All cases underwent physician adjudication. Demographic and clinical data were recorded.

Results: We identified 57 hospitalizations with acute RAO among 55 patients. Characteristics of their hospitalization and demographics are shown (Table). Notably, 19% (11/57) of patients presented in a thrombolytic window of ≤3.5 and average time from symptom onset to evaluation was 17 hours. Most patients initially interacted with a subspecialist (53%) and presented to the ED in delayed fashion. One patient received thrombolytic therapy, four (7%) patients underwent carotid revascularization, and no patients had newly identified atrial fibrillation, cardiac thrombus, or endocarditis.

Discussion: Our population-based study found only a minority of patients presented within a thrombolytic window, suggesting that systems of care need to promote more rapid evaluation of these patients. Very few patients received select intervention, but the high impact of carotid revascularization may warrant urgent evaluation of even low risk patients. Further study of long-term outcomes in this patient population is called for.

Abstract TP161: Predictors Of Undiagnosed Risk Factors For Cerebrovascular Ischemic Events: A Population-based Study

Introduction: Primary prevention reduces the burden of acute ischemic stroke (AIS), yet cerebrovascular risk factors (RF) remain underdiagnosed in certain populations. We aimed to identify predictors of undiagnosed RF among patients with cerebrovascular ischemic events in a large bi-racial population.

Methods: Individuals 20 years and older with an incident TIA or AIS from the population-based Greater Cincinnati/Northern Kentucky 2015 stroke study period were screened for inclusion. We included all hospital ascertained, physician-verified cases of AIS and TIAs. Outpatient and ED-only cases were excluded. Abstracted medical record data included determination of newly diagnosed hypertension (HTN), diabetes mellitus (DM), hyperlipidemia (HLD) or atrial fibrillation (AF). Multivariable models were used to identify predictors for each undiagnosed RF. Model variables included: age, sex, race, insurance status and number of cerebrovascular RF (additionally including coronary artery disease and smoking).

Results: A total of 1604 ischemic events were included (1485 stroke, 119 TIA) with 52.9% female; 22.4% Black; median age 70 (IQR 59, 82)). Only 6% (n=102) had no history of RF. The prevalence of each undiagnosed RF was: HTN 4.1%; HLD 7.9%; DM 3.1%; AF 3.2%. In unadjusted bivariate analysis, uninsured/unknown status was predictive of undiagnosed HTN (OR = 3.97, 95% CI 1.48, 10.68; p =.006) and HLD (OR=5.53, 95% CI 2.68, 11.4; p <.0001). After adjustment, insurance status remained a predictor for only undiagnosed HLD ( Table 1 ). No relationship was found with race.

Conclusions: The most consistent predictor for an undiagnosed RF was absence of other RF and lack of insurance, both suggestive of suboptimal cardiovascular screening in this population. Further studies assessing known but undertreated RF and socioeconomic factors could be of benefit.

Co-Occurrence of Sj/ITPR1 and NMDA Antibodies: A Case Report

Objective

To highlight a case of concurrent anti-SJ/ITPR1 and anti-NMDA encephalitis.

Background

The anti-Sj/inositol 1,4,5-trisphosphate receptor (ITPR1) has been associated with autoimmune cerebellar ataxia and malignancy. Reports of patients with anti-Sj/ITPR1 describe isolated cerebellar ataxia as well as various manifestations throughout the central and peripheral nervous system. Anti-NMDA encephalitis presents with subacute decline, seizures, movement disorder, alterations in behavior and cognition, autonomic dysfunction, and central hypoventilation but is rarely associated with cerebellar ataxia in adults.

Design/Methods

NA.

Results

A 28-year-old female with no relevant medical history presented to an outside hospital with acute onset headache, diplopia, nystagmus, and vertigo. MRI and MRV were unremarkable. CSF analysis showed a lymphocytic pleocytosis. She was empirically treated with acyclovir, although viral serologies were negative. On initial assessment in our clinic, neurologic exam showed square wave jerks, ataxic eye movements, resting tremor, appendicular and gait ataxia. She progressively declined with gait instability, autonomic dysfunction, neuropsychiatric symptoms, and significant weight gain from compulsive hyperphagia. Her course was complicated by respiratory failure and tracheostomy was placed for mechanical ventilation. Malignancy screening with mammogram, CT, and full body PET was negative. Transvaginal ultrasound was nondiagnostic. Serum paraneoplastic autoantibody panel was negative. EEG showed severe generalized slowing. Repeat CSF studies were positive for anti-SJ/ITPR1 and anti-NMDA. She was treated with high-dose IV methylprednisolone, plasmapheresis, and rituximab. She has residual moderate/severe ataxia, but is now conversant, without trach dependence, and ambulates with assistance.

Conclusions

There is no definite current evidence for the pathogenicity of the ITPR1 antibody. Given the rarity of cerebellar ataxia in anti-NMDA encephalitis in adults, one could argue for a pathogenic role of ITPR1 in our case. No underlying malignancy was identified in our patient. We will continue surveillance since the clinical syndrome may precede tumor identification by several years.

Substance Use and Performance of Toxicology Screens in the Greater Cincinnati Northern Kentucky Stroke Study

BACKGROUND

Though stroke risk factors such as substance use may vary with age, less is known about trends in substance use over time or about performance of toxicology screens in young adults with stroke.

METHODS

Using the Greater Cincinnati Northern Kentucky Stroke Study, a population-based study in a 5-county region comprising 1.3 million people, we reported the frequency of documented substance use (cocaine/marijuana/opiates/other) obtained from electronic medical record review, overall and by race/gender subgroups among physician-adjudicated stroke events (ischemic and hemorrhagic) in adults 20 to 54 years of age. Secondary analyses included heavy alcohol use and cigarette smoking. Data were reported for 5 one-year periods spanning 22 years (1993/1994-2015), and trends over time were tested. For 2015, to evaluate factors associated with performance of toxicology screens, multiple logistic regression was performed.

RESULTS

Overall, 2152 strokes were included: 74.5% were ischemic, mean age was 45.7±7.6, 50.0% were women, and 35.9% were Black. Substance use was documented in 4.4%, 10.4%, 19.2%, 24.0%, and 28.8% of cases in 1993/1994, 1999, 2005, 2010, and 2015, respectively (Ptrend<0.001). Between 1993/1994 and 2015, documented substance use increased in all demographic subgroups. Adjusting for gender, comorbidities, and National Institutes of Health Stroke Scale, predictors of toxicology screens included Black race (adjusted odds ratio, 1.58 [95% CI, 1.02-2.45]), younger age (adjusted odds ratio, 0.70 [95% CI, 0.53-0.91], per 10 years), current smoking (adjusted odds ratio, 1.62 [95% CI, 1.06-2.46]), and treatment at an academic hospital (adjusted odds ratio, 1.80 [95% CI, 1.14-2.84]). After adding chart-reported substance use to the model, only chart-reported substance abuse and age were significant.

CONCLUSIONS

In a population-based study of young adults with stroke, documented substance use increased over time, and documentation of substance use was higher among Black compared with White individuals. Further work is needed to confirm race-based disparities and trends in substance use given the potential for bias in screening and documentation. Findings suggest a need for more standardized toxicology screening.

Racial Disparities in Stroke Recurrence: A Population-Based Study

BACKGROUND

There are significant racial disparities in stroke in the United States, with Black individuals having a higher risk of incident stroke even when adjusted for traditional stroke risk factors. It is unknown whether Black individuals are also at a higher risk of recurrent stroke.

METHODS

Over an 18-month period spanning 2014-2015, we ascertained index stroke cases within the Greater Cincinnati/Northern Kentucky population of 1.3 million. We then followed all patients for 3 years and determined the risk of recurrence. Multivariable survival analysis was performed to determine the effect of Black race on recurrence.

RESULTS

There were 3816 patients with index stroke/TIA events in our study period, and 476 patients had a recurrent event within three years. The Kaplan-Meier estimate of 3-year recurrence rate was 15.4%. Age- and sex-adjusted stroke recurrence rate was higher in Black individuals (HR 1.34, 95% CI 1.1-1.6; p=0.003); however, when adjusted for traditional stroke risk factors including hypertension, diabetes, smoking status, age, and left ventricular hypertrophy, the association between Black race and recurrence was significantly attenuated and became nonsignificant (HR 1.1, 95% CI 0.9-1.36, p=0.32). At younger ages, Black race was more strongly associated with recurrence and this effect may not be fully attenuated by traditional stroke risk factors.

CONCLUSIONS

Recurrent stroke was more common among Black individuals, but the magnitude of the racial difference was substantially attenuated and became nonsignificant when adjusted for traditional stroke risk factors. Interventions targeting these risk factors could reduce disparities in stroke recurrence.

Abstract 113: Duration Between Stroke Onset And Presentation Over Time: A Population-based Study

Background: In acute stroke, reducing delays between symptom onset and treatment can improve outcomes. While in-hospital delays have been successfully reduced, pre-hospital delays have persisted. Public health campaigns have attempted to reduce these delays by increasing stroke symptom awareness, but it is unknown whether these efforts have improved the percentage of patients presenting early after symptom onset.

Methods: We performed an analysis of the Greater Cincinnati/Northern Kentucky Stroke Study, a population-based study of all stroke patients in a large geographic area. We looked at the 2010 and 2015 study years. All stroke cases (ischemic and hemorrhagic) presenting to the 16 regional EDs were included. We examined the time between symptom onset and ED arrival times, dichotomized into ≤3.5 hours and >3.5 hours. In cases without a clear onset, estimates were derived using wake-up or last known well times. Comparisons were made using multivariable logistic regression.

Results: Among 4633 total stroke patients, 1359 patients presented early (29%). Results of the multivariable analysis are shown in the Table . There was no improvement the rate of early presentation in 2015 (aOR 1.01, 95% CI 0.89-1.16). EMS utilization, night arrival, higher NIHSS scores, and better premorbid function were associated with early arrival. Patients who lived alone were less likely to arrive early.

Conclusion: We found no evidence for improvement in the rate of early presentation over the years studied. Work is needed to address other barriers to early hospital arrival, including underutilization of EMS.

Abstract 93: Utility Of Routine Inpatient Echocardiography In Acute Ischemic Stroke Patients With Established Stroke Etiology: A Population Study

Background: Acute ischemic stroke (AIS) remains a leading cause of mortality and disability worldwide, with stroke etiology having an important role in work-up, management, and prognosis. The current AHA/ASA guidelines cite routine echocardiography as reasonable but not mandatory for the work-up of ischemic stroke. We sought to identify how often transthoracic echocardiogram (TTE) results would show a potentially treatment-altering finding.

Methods: Using the Greater Cincinnati/Northern Kentucky Stroke Study (GCNKSS) for years 2005, 2010, and 2015, we selected patients with a new diagnosis of AIS using ICD-9/10 codes in adults ≥18yrs of age presenting to the emergency department and who had a TTE with stroke etiology of Cardioembolic, Small Vessel, or Large Vessel. All cases were physician reviewed and stroke etiology determined based on our epidemiologic criteria. Demographic information, medical history, electrocardiograms with atrial fibrillation (Afib), and TTE features were collected for each patient and compared across stroke etiology groups using Wilcoxon rank sum test and chi-square test, or Fisher’s exact test, as appropriate.

Results: There were 5,490 patients presenting with AIS in the GCNKSS in 2005, 2010, and 2015 and 3,984 (73%) had a TTE performed. Of those with TTE, 2,422 (61%) had a presumed etiology of Small Vessel, Large Artery Atherosclerosis (LAA), or Cardioembolic (120 identified as “Other,” 1442 identified as “Undetermined”). Potential findings of TTE that could change management were 1% in Small Vessel, 2% in LAA, and 7% in Cardioembolic etiology strokes.

Conclusion: In patients presenting with Small Vessel or LAA stroke etiologies, routine inpatient TTE rarely had management-changing findings. Future studies are needed in order to assess cost effective use of TTE in patients with established stroke etiology.

Abstract WP192: Ischemic Stroke Mechanisms By Sex And Race Over Time In The Greater Cincinnati Northern Kentucky Stroke Study

Background: Identifying the mechanism of acute ischemic stroke (AIS) is critical to determining secondary stroke prevention strategies. As past data conflict on sex and race differences in stroke mechanism, we aimed to describe stroke mechanisms by sex and race over time in a population-based study of AIS cases with a focus on strokes with unknown mechanism.

Methods: We included physician adjudicated, hospital ascertained incident AIS among adults over five study periods (1993/4, 1999, 2005, 2010, 2015) from the Greater Cincinnati Northern Kentucky Stroke Study. Stroke mechanisms were adjudicated by trained study physicians and included: small vessel disease, cardioembolic, large artery disease, other, and unknown. The percentage of AIS cases in each of the 5 categories was reported by sex and race in each of our five 1-year study periods, and trends over time by subgroup were tested using the Cochran-Armitage trend test.

Results: We included 8349 AIS over 5 study periods: 4693 (56%) were women, 1607 (19%) were Black, mean age was 70.5 (14.3). Over the 22-year time period, the proportion of strokes whose mechanism was ‘unknown’ decreased in women (46.1%, 1993/4 to 38.5%, 2015 , p<0.0001), men (46.2%, 1993/4 to 33.9%, 2015, p<0.0001), Black (51.8%, 1993/4 to 40.7%, 2015, p=0.004), and White (45.0%, 1993/4 to 40.7%, 2015, p<0.0001) patients. The proportion of small vessel strokes increased over time in men, strokes of ‘other’ mechanisms increased in all subgroups, and cardioembolic strokes increased in women and White individuals only (Figure).

Conclusions: In a large population-based stroke study, the proportion of AIS with an unknown mechanism has decreased over time in all demographic groups, while trends in those categorized as cardioembolic or small vessel disease varied by sex and/or race. As changes in imaging utilization may be a contributor to our findings, future work investigating possible sex and race differences in diagnostic evaluations of AIS is warranted.

Abstract WP199: Disparities In Post-stroke Evaluation And Treatment According To Pre-stroke Functional Status

Introduction: Stroke patients with a pre-existing disability are less likely to receive acute stroke treatments compared to those without a pre-existing disability. Using the Greater Cincinnati Northern Kentucky (GCNK) Stroke Study, we aimed to understand the disparities in inpatient and outpatient continuum of stroke care according to the patients’ pre-stroke functional status.

Methods: We ascertained all hospitalized stroke patients ≥18 years old in year 2015 using ICD-9 430-436; ICD-10 I60-I67, G45-G46 within GCNK population; all cases were physician-reviewed. Per-stroke functional status was ascertained by trained research nurses during medical record review. We compared rates of in-hospital rehabilitative therapies, initiation of stroke prevention treatments, inpatient stroke workup (cardiac/vessel imaging), in-hospital and post-discharge rehabilitative therapies between ischemic stroke patients with pre-stroke modified Rankin score (mRS) 0-1 vs ≥2. Logistic regression was used to evaluate the association between pre-stroke mRS and these outcomes adjusting for age, presenting NIHSS, and insurance status.

Results: Of 2476 patients with ischemic stroke in the GCNK population during 2015, 1326 (53%) had a pre-stroke mRS ≥2. Compared to those with pre-stroke mRS 0-1, these patients were less likely to receive complete stroke workup (aOR 0.86 [0.71-1.04]) and certain stroke prevention treatments (aOR 0.46[0.26-0.81], p<0.01), but more likely to require in-hospital and post-discharge rehabilitative therapies (aOR 2.6[2.11-3.21] and 2.27[1.86-2.77], p<0.01, respectively).

Conclusions: Ischemic stroke patients with pre-stroke disability were less likely to receive complete in-hospital stroke workup and initiation of certain stroke preventive treatments. Further research into factors driving medical decision-making for stroke patients with a pre-stroke disability is urgently needed to ensure optimal continuum of stroke care.

Abstract TP136: Disparities In Care Of Patients With Intracerebral Hemorrhage According To Baseline Functional Status

Introduction: Disparities exist in acute ischemic stroke care according to patients’ pre-stroke functional status. However, the effects of baseline disability on the presentation and care of patients with intracerebral hemorrhage (ICH) are unknown. We aimed to understand this using the Greater Cincinnati Northern Kentucky (GCNK) Stroke Study.

Methods: We ascertained all hospitalized ICH patients ≥18 years old in 2015 using ICD-9 430-436; ICD-10 I60-I67, G45-G46 GCNK) population; all cases were physician-reviewed. Per-stroke functional status was ascertained by medical record review. Baseline NIHSS, Glasgow coma scale (GCS), imaging modalities (CT/MRI), in-hospital rehabilitative therapies (rate and frequency), initiation of antihypertensive treatment, and discharge disposition between patients with pre-ICH mRS 0-1 vs ≥2 were compared using Wilcoxon rank-sum or chi-square tests. Logistic regression was used to evaluate the association between pre-stroke mRS and in-hospital therapy, post-discharge therapy, and ICH workup adjusting for age, Glasgow score, insurance status, and ICH location.

Results: Of 350 patients with ICH, 187 (53%) had a pre-ICH mRS ≥2. Compared to those with pre-stroke mRS 0-1, these patients had more severe clinical presentation as measured by NIHSS and GCS (table). Among patients who were not made comfort care, no association between pre-ICH mRS and performance of inpatient MRI or in-hospital and post-discharge rehabilitative therapies was found in adjusted analyses.

Conclusions: Patients with pre-ICH mRS >2 were made comfort care at a higher rate, but for those not made comfort care there were no post-ICH disparities of care seen in the 2015 GCNK population-based cohort of 350 patients.

Abstract TP220: Clinical And Demographic Characteristics Associated With Poor Posterior Circulation Stroke Outcomes: Greater Cincinnati/Northern Kentucky Stroke Study

Background: Posterior circulation strokes (PCS) make up 20% of all strokes, yet there is poor understanding of what factors contribute to poor clinical outcomes. We investigated clinical and demographic characteristics associated with poor clinical outcomes in PCS using a population-based biracial cohort.

Methods: Greater Cincinnati Northern Kentucky Stroke Study (GSNKSS) 2010 and 2015 data was utilized to identify 1842 patients who were >20 years old with MRI-proven PCS. Eligible patients were then stratified based on functional outcomes (modified Rankin Scale<3 vs >/= 3, with >= 3 considered poor) according to demographics, stroke risk factors, tPA treatment, stroke location, and stroke mechanism. A multivariable logistic model was used to identify the predictors for poor functional outcomes.

Results: Age, higher NIHSS, higher baseline mRS, hypertension, temporal, thalamus, and brainstem location, and cardioembolic mechanism were associated with poor clinical outcomes (Table). After multivariable analysis, age, higher NIHSS, higher baseline mRS, hypertension, temporal, thalamus, and brainstem location, and cardioembolic mechanism remained associated with poor outcomes.

Conclusion: Understanding these factors associated with poor prognosis after posterior circulation stroke will allow for better prognostication and family counseling.

Abstract WP206: Temporal Trends In Stroke Patients Who Had Prior Transient Ischemic Attack And Did Not Present To The Emergency Room: A Population Study

Background: Acute ischemic stroke (AIS) is a leading cause of disability worldwide, with up to 30% of cases preceded by transient ischemic attack (TIA). Urgent evaluation of TIA symptoms is recommended to reduce risk of stroke, but not all patients with TIA symptoms seek evaluation. Our goal was to assess temporal trends in the demographics of such patients.

Methods: Using the Greater Cincinnati/Northern Kentucky Stroke Study (GCNKSS) for years 2005, 2010, and 2015, we selected patients with a diagnosis of AIS using ICD-9/10 codes in adults ≥18yrs of age presenting to the ED. We identified patients who had a preceding TIA based on symptoms within 60 days of presentation, as judged by an adjudicating physician. Demographics, histories, and proportion of patients with TIA were compared across study years using Wilcoxon rank sum test or chi-square test.

Results: We identified 5977 patients presenting with AIS across three epochs. Of these 207 (3%) had prior suspected TIA and did not seek immediate medical attention; 56/1790 (3%) in 2005, 62/1993 (3%) in 2010, and 70/2194 (3%) in 2015 (p-value=0.99). Patients with suspected TIA had increasing rates of previously diagnosed HLD and DM over the three time periods. No other risk factors or demographics showed a change over time. Known HTN was consistently prevalent across epochs (Table 2).

Conclusion: Over the three epochs, 3% of AIS patients consistently did not seek emergent medical attention for a recent preceding TIA. A substantial proportion of these patients were increasingly already diagnosed with DM and HLD over the study periods, and the majority were persistently diagnosed with HTN. This is an opportune cohort for future targeted outreach.

Abstract 132: Projections Of Endovascular Therapy-eligible Patients For The Us Population In 2021

Introduction: Endovascular (EVT) eligibility estimates using population-based, NIH-funded Greater Cincinnati Northern Kentucky (GCNK) Stroke Study 2010 data have been reported. Given the evolving EVT landscape, we present updated estimates of annual EVT eligibility using the 2015 GCNK epidemiological data and extrapolate to the 2021 US census. We project the potential increase in eligible patients in the US for each possible expanded indication with a randomized trial currently planned/underway.

Methods: We ascertained all hospitalized AIS patients ≥18 years old in 2015 using ICD-9 430-436; ICD-10 I60-I67, G45-G46 within GCNK population; all cases were physician-reviewed. Patients presenting within 0-5 hrs of last known well (LKW) were considered EVT eligible if they had a pre-stroke mRS<2, NIHSS ≥6 and ASPECTS ≥6. Those within 5-23 hrs of LKW were considered EVT-eligible if they had a pre-stroke mRS <3, NIHSS≥6, and favorable perfusion imaging. Expanded EVT eligible patients were defined as those with NIHSS <6, and pre-stroke mRS >1 (for 0-5 hrs) or ≥2 (for 5-23 hrs), or larger core. Estimates of vessel occlusion and favorable imaging were applied based on literature review and expert opinions. The derived estimates were age, race and sex-adjusted to the 2015 US adult population and extrapolated to 2021 population.

Results: Among the 1.3 million total (1.05m adult) GCNK population in 2015, 2741 adults had an ischemic stroke and 2176 had data available for this analysis. A total of 1978 presented within 23 hrs of LKW, and 1233 within 0-5 hrs of LKW. Further results are outlined in the figure.

Conclusions: It is estimated 18,484 adult patients in the US in 2021 meet strict EVT eligibility criteria. An estimated 15,699 patients with low NIHSS, 9621 with unfavorable imaging, and 28,107 with pre-stroke disability may become eligible for EVT in the future annually. US stroke systems should be optimized to handle all EVT-eligible stroke patients both now and in the future.

Abstract WMP12: Disparities In Acute Stroke Care According To Pre-stroke Functional Status

Introduction: Disparities in acute ischemic stroke (IS) care due to patients’ pre-stroke disabilities remain understudied. Using the Greater Cincinnati Northern Kentucky (GCNK) Stroke Study, we aimed to understand the differences in acute stroke presentation and care according to patients’ pre-stroke functional status.

Methods: We ascertained all hospitalized IS patients ≥18 years old presenting to emergency departments in the GCNK region in 2015 using ICD-9 430-436; ICD-10 I60-I67, G45-G46; all cases were physician-reviewed. Trained nurses ascertained pre-stroke functional status from the medical record. Acute IS presentation, time metrics, and treatment were compared between patients with pre-stroke mRS 0-1 vs ≥2 using Wilcoxon rank-sum or chi-square tests. Logistic regression was used to evaluate the association between pre-stroke mRS and intravenous thrombolysis (IVT) and endovascular treatment adjusting for age, presenting NIHSS, time to presentation, and baseline anticoagulation use.

Results: Of 2191 patients with IS, 1134 had a pre-stroke mRS ≥2. Patients in the latter group were older, more likely be female, had higher rates of medical comorbidities, had higher presenting NIHSS (3[1-8] vs 2[1-5], p<0.01, Table). They were less likely to receive IVT (aOR 0.43[0.28-0.68], p<0.01, for patients presenting within 0-4 hours) and EVT (aOR 0.32[0.13-0.78], p=0.01, for patients presenting within 0-23.5 hours). They had a higher rate of presentation via EMS, but the time from stroke onset to ED presentation was longer.

Conclusions: Acute IS patients with pre-stroke disability presented later, with more severe strokes, and were less likely to receive reperfusion treatments. Further research into factors driving acute stroke medical decision-making for patients with a pre-stroke disability is needed to ensure optimal acute neurovascular care for all IS patients across the nation and worldwide.

Abstract WP177: Trends In The Clinical Phenotype Of Infective Endocarditis Related Stroke From 2005-2015: A Population-Based Study Of The Greater Cincinnati/ Northern Kentucky Region

Background: Prior studies have demonstrated a rising incidence of infective endocarditis related stroke (IERS) in the US due to the opioid epidemic. The Greater Cincinnati/Northern Kentucky (GCNK) region has one of the highest opioid abuse rates in the nation. A modern epidemiologic description is necessary to understand the impact of the opioid epidemic on the clinical phenotype of IERS.

Methods: Using the GCNK Stroke Study, all patients hospitalized with IERS in 2005, 2010, and 2015 were abstracted and physician reviewed. IERS was defined as an acute stroke clinically attributed to infective endocarditis in patients meeting modified Duke Criteria for possible or definite endocarditis. Comparison between years were by chi-square or Fisher’s exact test for categorical variables; ANOVA or Kruskal-Wallis test for numerical variables. Cochran-Armitage test was used to examine trend. Secondary analysis compared characteristics between intravenous drug users (IVDU) and non-IVDU.

Results: A total of 54 patients with IERS were identified in 2005, 2010, and 2015. Over the period, there was a significant decline in hypertension (91.7% in 2005, 36.0% in 2015; p=0.0005) and increase in IVDU (8.3% in 2005, 44.0% in 2015; p=0.02). They trended towards increased white race, younger age, and fewer vascular risk factors. Compared to non-IVDU, IVDU were significantly younger (41.1±14.1vs 63.1±14.3 years; p<0.001), less often female (12.5% vs 47.4%; p=0.02), had higher rates of sepsis (50% vs 18.4%; p=0.04), less atrial fibrillation (0% vs 31.6%; p=0.01), and less renal disease (0% vs 23.7%; p=0.045). The incidence of IERS per 100,000 increased from 1.31 (CI: 0.56-2.06) in 2005, to 1.66 (CI: 0.87-2.45) in 2010, and to 2.41(CI:1.46-3.36) in 2015.

Conclusion: From 2005 to 2015, IERS was increasingly associated with IVDU and an absence of hypertension. These trends likely reflect the demographics of the opioid epidemic, which has affected younger patients with less comorbidities.

Abstract WMP77: Anticoagulation-Associated Intracerebral Hemorrhage Incidence Rates: A Longitudinal Population-Based Assessment

Background: Anticoagulant-associated intracerebral hemorrhage (AA-ICH) quintupled in the Greater Cincinnati/Northern Kentucky (GC/NK) region from 1988 to 1999 in association with increasing warfarin use. Direct-acting oral anticoagulants (DOACs), available in 2010, have evidence of less bleeding risk, while atrial fibrillation detection rates have increased. We sought to determine if rates of AA-ICH continued to increase in the last decade within a large, bi-racial population.

Methods: We identified all patients, 20 years or older, hospitalized with first-ever intracerebral hemorrhage (ICH) in GC/NK region in 1993/4, 1999, 2005, 2010 and 2015. AA-ICH was defined as ICH in patients prescribed warfarin, heparin or low molecular weight heparin, or a DOAC at the time of their ICH. Incidence rates were age-, sex- and race-adjusted to the 2010 US population. Change over time was tested using regression. All-cause case fatality was adjusted for age, sex and race and trend over time evaluated using a general linear model.

Results: There was no significant change over time in the incidence rate for total ICH or AA-ICH from 1993 through 2015 (Table). As compared to ICH patients without anticoagulant use, patients with AA-ICH were more likely to be older, white, have hypertension, diabetes mellitus, hyperlipidemia, prior ischemic stroke and atrial fibrillation, but less likely to smoke. The age-, sex- and race-adjusted 30-day case fatality for ICH overall and AA-ICH also did not change significantly from 1993/4 to 2015 (Table). Warfarin utilization increased in our ICH population from 1993/4 (7.6%) to 2005 (17.7%), then decreased through 2015 (11.8%/DOAC 6.4%); p<0.0001.

Conclusion: Despite increased incidence rates of AA-ICH in the late 1980s to 1990s, we observed no overall change in incidence or case-fatality rate from AA-ICH over the full 20-year period despite higher rates of atrial fibrillation detection which may be explained by higher rates of DOAC (vs warfarin) use.

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.

Feasibility of Nurse-Led Multidimensional Outcome Assessments in the Neuroscience Intensive Care Unit

BACKGROUND

The outcome focus for survivors of critical care has shifted from mortality to patient-centered outcomes. Multidimensional outcome assessments performed in critically ill patients typically exclude those with primary neurological injuries.

OBJECTIVE

To determine the feasibility of measurements of physical function, cognition, and quality of life in patients requiring neurocritical care.

METHODS

This evaluation of a quality improvement initiative involved all patients admitted to the neuroscience intensive care unit at the University of Cincinnati Medical Center.

INTERVENTIONS

Telephone assessments of physical function (Glasgow Outcome Scale-Extended and modified Rankin Scale scores), cognition (modified Telephone Interview for Cognitive Status), and quality of life (5-level EQ-5D) were conducted between 3 and 6 months after admission.

RESULTS

During the 2-week pilot phase, the authors contacted and completed data entry for all patients admitted to the neuroscience intensive care unit over a 2-week period in approximately 11 hours. During the 18-month implementation phase, the authors followed 1324 patients at a mean (SD) time of 4.4 (0.8) months after admission. Mortality at follow-up was 38.9%; 74.8% of these patients underwent withdrawal of care. The overall loss to follow-up rate was 23.6%. Among all patients contacted, 94% were available by the second attempt to interview them by telephone.

CONCLUSIONS

Obtaining multidimensional outcome assessments by telephone across a diverse population of neurocritically ill patients was feasible and efficient. The sample was similar to those in other cohort studies in the neurocritical care population, and the loss to follow-up rate was comparable with that of the general critical care population.

Abstract P264: Trends in Diagnostic Testing and Mechanism of Stroke Determination

Introduction: A main goal for hospital admission following acute ischemic stroke (AIS) is to establish the mechanism of stroke (MoS) allowing for patient specific secondary prevention of stroke interventions. We previously reported on diagnostic testing trends and MoS determination from 1993 through 2010. We updated this analysis with 2015 data to better understand the effects of trends in diagnostic testing on MoS determination.

Methods: Patients with AIS aged > 20 years from all study time periods (Table) of the population based GCNKSS were included. Charts were abstracted in a systematic way for tests performed during the hospital stay. Only first-ever ischemic stroke cases, evaluated in an emergency department were used for this analysis. Stroke experts reviewed these events and adjudicated the mechanism of stroke according to modified TOAST criteria. We looked at and compared trends for testing and MoS.

Results: Our analysis included 7226 patients. Basic patient demographics, MoS categories and tests across study periods are detailed in the Table. There were significant increases in EKG (7%), TTE (35%), TEE (7%), HCT (4%), brain MRI (65%), MRA (30%) and CTA (28%). Across study periods, cardioembolic (4.1%), small vessel disease (3%), large artery disease (0.9%) and other (1.5%) MoS increased while unknown MoS decreased (-9.5%).

Discussion: From 1993/1994 to 2015 there has been a significant increase of in-hospital testing in AIS and decreases in undetermined MoS. Cardioembolic and small vessel disease MoS categories increased the most. Despite a significant increase in vessel imaging, large artery disease and “other determined” MoS categories are largely unchanged. Further research is required to elucidate the occult MoS underlying the undetermined category. Based on our analysis it appears unlikely to be significantly associated with our current definition of stroke associated with large artery disease defined as ≥ 50% ipsilateral stenosis.

Abstract P224: Management of TIA Over Time in the Greater Cincinnati Northern Kentucky Stroke Study

Introduction: The availability of rapid tissue and vessel imaging for TIA has increased, but the utilization rates of these and other diagnostic and management strategies for TIA over time are unknown.

Objective: To investigate trends in TIA diagnostic and management strategies over time in the Greater Cincinnati Northern Kentucky Stroke Study (GCNKSS).

Methods: The GCNKSS is a population-based study of 1.3 million people living in a 5-county area of southern Ohio and Northern Kentucky. For this study, all physician-adjudicated, first-ever cases of TIA (defined clinically as sudden onset of focal symptoms lasting < 24 hours) presenting to an emergency department over five study periods (1993/4, 1999, 2005, 2010, 2015) were included. Use of AHA-recommended aspects of TIA management as well as disposition of TIA patients (admission to hospital or discharge from ED) and length of stay were compared across study periods. Rates of acute infarct on MRI were also reported. Trends were examined using the Cochran-Armitage test for trend.

Results: In total, over all study periods, there were 2251 first-ever TIAs. Overall, 14% (n=311) occurred in Black individuals, and 57% (n=1275) occurred in women. Utilization of diagnostic modalities [non-contrast CT brain, vascular imaging (CTA, MRA, or carotid dopplers), tissue imaging (MRI), and echocardiogram] increased significantly over time (all p<0.0001). In terms of management, both admission to the hospital and discharge from the hospital on an antiplatelet agent increased over time (both p<0.0001; Table).

Conclusions: The management of TIA has changed significantly over time. Utilization of tissue and vessel imaging as well as echocardiogram during the hospital stay has increased; in 2015, the vast majority of patients with TIA in this population-based study received each of these testing modalities and were admitted to a hospital for TIA work-up. Further work is needed to understand the best practices for work-up of suspected TIA.

Abstract P244: Association Between Diagnostic Work-Up and Outcomes of TIA in the Greater Cincinnati Northern Kentucky Stroke Study

Background: Substantial practice variability exists with respect to the diagnostic workup and disposition of patients with TIA. Identifying the workup needed to prevent adverse outcomes is critical. We aimed to determine whether there is an association between specific elements of TIA management and outcomes.

Methods: The GCNKSS is a population-based study of 1.3 million people living in a 5-county area of southern Ohio/ Northern Kentucky. For this study, all physician adjudicated, first-ever TIAs (clinically defined as sudden onset, focal neurologic symptoms lasting < 24 hours, with or without MRI correlate) presenting to the ED during 2015 were included; those with prior stoke or TIA were excluded. Multivariable logistic regression was performed to investigate associations between specific aspects of TIA management and an adverse outcome, defined as stroke, recurrent TIA, or all-cause mortality within 30 days, adjusted for demographics, co-morbidities, and symptom type and length as classified in the ABCD2 score.

Results: In 2015, there were 477 adjudicated first ever TIA events presenting to the ED. Overall, 13% (n=62) occurred in Black individuals and 51% (n=243) in women. Regarding outcomes, 3% (n=16) had a stroke within 30 days, 6% (n=30) had a recurrent TIA within 30 days, and 1% (n=4) died within 30 days (all-cause mortality). 16.4% had acute infarct on MRI. In multivariable analysis, having an MRI was associated with reduced risk of adverse outcome, while performance of vessel imaging, echocardiogram, or admission to hospital were not significantly associated with outcomes (Table).

Conclusions: Among common diagnostic and management strategies for TIA, only performance of MRI was associated with a lower likelihood of having an adverse outcome within 30 days. Possible contributors include variability in care between hospitals with differing MRI performance rates and changes in management of risk factors based on MRI results, though further work is needed.

Abstract 19: Prehospital Identification of Acute Ischemic Stroke is Associated With Faster and More Frequent Thrombolysis

Background: Functional outcomes are improved when AIS patients receive faster treatment. The first medical contact for many AIS patients is with emergency medical services (EMS) providers. We hypothesize that AIS treatment is faster when EMS providers suspect stroke.

Methods: We performed a retrospective analysis of the Greater Cincinnati/Northern Kentucky Stroke Study, a comprehensive study of stroke patients in a large geographical area with 1.3 million inhabitants whose demographics are representative of the United States. We compared AIS patients age ≥18 years transported by EMS in 2015 with an EMS impression of “stroke” or “weakness/numbness” to those with other EMS impressions. Primary outcome was thrombolysis rate, and secondary outcomes were times from EMS scene arrival to ED arrival, CT, and treatment and times from ED arrival to CT and treatment. Chi-square and Mann-Whitney U-tests were used to compare treatment rates and times, respectively. Logistic regression (for rates) and median regression (for times) adjusted for NIHSS, GCS, age, sex, race, and prior stroke history.

Results: Among 2,486 confirmed AIS patients from 1/1/2015-12/31/2015, 868 were transported by EMS, including 595 (69%) with EMS suspected stroke. Compared to EMS non-suspected strokes, patients with EMS suspected stroke patients were more likely to receive thrombolysis (18% vs 8%; OR 2.67, 95% CI 1.63-4.47) and had faster prehospital transport (30 vs 32 min, p=0.02), ED arrival to CT (27 vs 46 min, p<0.01) and thrombolysis (64 vs 83 min, p=0.03), and EMS scene arrival to thrombolysis (91 vs 118 min, p=0.03) and EVT (164 vs 250 min, p=0.03). Findings were maintained in the adjusted models except for EMS arrival to EVT (Table).

Conclusions: In a large population-based study, EMS stroke identification is associated with a higher rate of and faster thrombolysis. Efforts to increase accuracy of EMS stroke identification is likely to have significant clinical impact by shortening treatment times.

Abstract P602: Stroke Risk Factors Among the Young Over Time in the GCNKSS

Background: Data from the Greater Cincinnati Northern Kentucky Stroke Study (GCNKSS) have demonstrated stable or increasing stroke incidence rates in young adults with differences by sex and race, suggesting the need for targeted approaches to stroke prevention in the young. We aimed to describe trends over time in prevalence of stroke risk factors among adults ages 20-54 with stroke by sex and race.

Methods: Cases of incident stroke (IS, ICH, SAH) occurring in those 20-54 years old and living in a 5-county area of southern Ohio/northern Kentucky were ascertained during 5 study periods (1993-1994, 1999, 2005, 2010, 2015). All physician-adjudicated inpatient events and a sampling of outpatient events were included, excluding nursing home events. Data on risk factors (hypertension, diabetes, obesity (BMI≥30), and high cholesterol) diagnosed prior to stroke were abstracted from medical records, and prevalence of each risk factor was reported over time in race/sex groups. Trends over time were examined using the Cochran-Armitage test.

Results: Over the 5 study periods, 1204 incident strokes were included; 49% were women, 33% were black, and mean age was 46 (SD 7) years. Premorbid hypertension increased over time in Black women (48% in 1993/4 to 76% in 2015, p=0.005) but not in any other race/sex group (all p>0.05). Premorbid high cholesterol increased significantly in all race/sex groups (Figure, all p<0.05) except for White men (p=0.06). There were no significant trends over time in pre-stroke diagnoses of diabetes or obesity in any of the race/sex groups (Figure).

Conclusions: Among patients aged 20-54 with incident stroke in a large population-based study, the change in the prevalence of hypertension and high cholesterol differed by sex and race, while obesity and diabetes were stable over time in all race/sex groups. Future research is needed to address risk factor control at a population level and to understand the role of undiagnosed pre-stroke risk factors in the young.

Abstract P716: Factors Associated With Functional Dependence at Hospital Discharge in Patients With Low NIHSS Strokes Who Do Not Receive Intravenous Alteplase

Introduction: Patients without prior functional deficits who suffer mild stroke (NIHSS <6) have a 20-30% likelihood of disability (mRS ≥2). Predictors of disability have been described mostly in clinical trials and single center registries. We identified variables associated with functional dependence (mRS ≥3) in mild stroke using a retrospective population-based sample.

Methods: Hospitalized strokes from the Greater Cincinnati Northern Kentucky Stroke Study were used. Included patients had an initial NIHSS <6 and baseline mRS 0, both extrapolated from chart review. To minimize the inclusion of patients with disabling symptoms, tPA treatment was excluded. Demographic and clinical characteristics were analyzed by discharge disability status. A multivariable logistic model with least absolute shrinkage and selection operator (lasso) regression analysis identified independent predictors of disability.

Results: Of 1268 ischemic strokes, 353 (28%) were functionally dependent at discharge. Increased baseline NIHSS was associated with worse outcome on the mRS. Leg, LOC questions, and sensation NIHSS subscores were the best predictors of outcome. Multivariable analysis identified age, race, hypertension, chronic kidney disease, heart failure, and post-stroke dysphagia as independently associated with discharge mRS ≥3.

Discussion: Our results agree with and complement the results of prior studies. They are not limited by inclusion/exclusion criteria or referral bias. Rather, our major limitation is the retrospective estimation of NIHSS and mRS based on physician descriptive documentation rather than direct score assessment. Our results may allow for modeling to better predict outcome which in turn can inform clinical decision making and trial design.

Abstract P593: Association Between Troponin and Ischemic Stroke Recurrence in the Greater Cincinnati/Northern Kentucky Stroke Study

Introduction: Elevations in troponin (cTn) are common in patients with acute ischemic stroke, yet their significance remains uncertain.

Hypothesis: Elevated cTn at the time of acute ischemic stroke is associated with ischemic stroke recurrence.

Methods: We included all adult patients with acute ischemic stroke who were residents of the Greater Cincinnati/Northern Kentucky region and who presented to an emergency department (ED) in 2015 and who had a cTn measured within 24 hours of ED arrival. Our exposure variable was an elevated cTn, defined as a value exceeding the laboratory’s 99 th percentile. Our primary outcome was ischemic stroke recurrence, defined as a new ischemic stroke with radiographic confirmation in the 3 years following the index ischemic stroke event. Cox proportional hazards model was used to evaluate the association between elevated cTn and ischemic stroke recurrence while adjusting for demographics, vascular risk factors, and stroke severity. In a secondary analysis, we excluded patients with a concomitant adjudicated myocardial infarction (MI) at the time of the index ischemic stroke.

Results: Among 2,334 patients with acute ischemic stroke, 1,992 (85%) had a cTn assay within 24 hours of ED arrival and were included in the analysis. 402 (20%) patients had an elevated cTn and 259 (13%) patients had a recurrent ischemic stroke. 66 (3%) patients had an elevated cTn and a concomitant acute MI and 336 (17%) patients had an elevated cTn without a concomitant acute MI. After adjustment for demographics, vascular risk factors, and stroke severity, we found

an association between elevated cTn and recurrent ischemic stroke (hazards ratio [HR], 1.5; 95% CI, 1.1-2.0). Our results were unchanged after excluding patients with a concomitant adjudicated MI (HR 1.4; 95% CI, 1.03-2.0).

Conclusions: Among patients with acute ischemic stroke, elevated cTn even in the absence of concomitant adjudicated MI, was associated with ischemic stroke recurrence. Further mechanistic studies are necessary to explore the underlying etiology of hypertroponinemia among patients with acute ischemic stroke in order to guide targeted therapies to reduce stroke recurrence.

Abstract P638: Racial Disparities in Blood Pressure at Time of Acute Ischemic Stroke Emergency Department Presentation Within a Population

Background: Hypertension is an important risk factor in the development of acute ischemic stroke (AIS). African American (AA) race is strongly associated with both hypertension and uncontrolled hypertension despite treatment, yet little is known about racial differences in presenting blood pressure (BP) in AIS. This study sought to describe differences in presenting BP and acute antihypertensive treatment between AA and white AIS patients who received and did not receive alteplase within a population.

Methods: Using the Greater Cincinnati/Northern Kentucky Stroke Study (GCNKSS) database for years 2005, 2010 and 2015, we selected patients with a diagnosis of AIS using ICD-9/10 codes in adults ≥ 18 yrs of age presenting to a local ED within 4.5 hrs of symptom onset. Candidates were stratified by race and alteplase use. Socio-demographics, stroke risk factors, stroke severity, BP on arrival, and acute BP treatment were compared using chi-square, t-tests or Wilcoxon rank sum test, as appropriate.

Results (Table 1): Of 1838 AIS patients included in the analysis, 392 (21%) received IV alteplase. AA patients were younger in both groups who received and did not receive alteplase. On presentation, AA stroke patients had higher diastolic BP. AA patients were more likely to receive 2 or more BP lowering medications compared to white patients in the alteplase treated group and the untreated group.

Conclusion: AA patients presenting within 4.5 hours of AIS symptom onset are more likely to have elevated diastolic BP and to receive multiple BP lowering medications compared to white patients. These findings were significant regardless of alteplase treatment. To our knowledge, we report the first population-based distribution of BP, and medical treatment of BP, upon presentation to an ED in AIS. Further study is needed to determine if these racial differences in elevated BP and refractoriness of BP and/or aggressive treatment contribute to outcome differences.

Racial Differences in Atrial Cardiopathy Phenotypes in Patients With Ischemic Stroke

OBJECTIVE

To test the hypothesis that thrombogenic atrial cardiopathy may be relevant to stroke-related racial disparities, we compared atrial cardiopathy phenotypes between Black vs White patients with ischemic stroke.

METHODS

We assessed markers of atrial cardiopathy in the Greater Cincinnati/Northern Kentucky Stroke Study, a study of stroke incidence in a population of 1.3 million. We obtained ECGs and reports of echocardiograms performed during evaluation of stroke during the 2010/2015 study periods. Patients with atrial fibrillation (AF) or flutter (AFL) were excluded. Investigators blinded to patients' characteristics measured P-wave terminal force in ECG lead V1 (PTFV1), a marker of left atrial fibrosis and impaired interatrial conduction, and abstracted left atrial diameter from echocardiogram reports. Linear regression was used to examine the association between race and atrial cardiopathy markers after adjustment for demographics, body mass index, and vascular comorbidities.

RESULTS

Among 3,426 ischemic stroke cases in Black or White patients without AF/AFL, 2,391 had a left atrial diameter measurement (mean, 3.65 ± 0.70 cm). Black race was associated with smaller left atrial diameter in unadjusted (β coefficient, -0.11; 95% confidence interval [CI], -0.17 to -0.05) and adjusted (β, -0.15; 95% CI, -0.21 to -0.09) models. PTFV1 measurements were available in 3,209 patients (mean, 3,434 ± 2,525 μV*ms). Black race was associated with greater PTFV1 in unadjusted (β, 1.59; 95% CI, 1.21-1.97) and adjusted (β, 1.45; 95% CI, 1.00-1.80) models.

CONCLUSIONS

We found systematic Black-White racial differences in left atrial structure and pathophysiology in a population-based sample of patients with ischemic stroke.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that atrial cardiopathy phenotypes differ in Black people with acute stroke compared to White people.

The Experience of a Neurocritical Care Admission and Discharge for Patients and Their Families: A Qualitative Analysis

INTRODUCTION

A qualitative assessment of discharge resource needs is important for developing evidence-based care improvements in neurocritically ill patients.

METHODS

We conducted a quality improvement initiative at an academic hospital and included all patients admitted to the neuroscience intensive care unit (ICU) during an 18-month period. Telephone assessments were made at 3 to 6 months after admission. Patients or caregivers were asked whether they had adequate resources upon discharge and whether they had any unanswered questions. The content of responses was reviewed by a neurointensivist and a neurocritical care nurse practitioner. A structured codebook was developed, organized into themes, and applied to the responses.

RESULTS

Sixty-one patients or caregivers responded regarding access to resources at discharge with 114 individual codable responses. Responses centered around 5 themes with 23 unique codes: satisfied, needs improvement, dissatisfied, poor post-ICU care, and poor health. The most frequently coded responses were that caregivers believed their loved one had experienced an unclear discharge (n = 11) or premature discharge (n = 12). Two hundred four patients or caregivers responded regarding unanswered questions or additional comments at follow-up, with 516 codable responses. These centered around 6 themes with 26 unique codes: positive experience, negative experience, neutral experience, medical questions, ongoing medical care or concern, or remembrance of time spent in the ICU. The most frequent response was that caregivers or patients stated that they received good care (n = 115). Multiple concerns were brought up, including lack of follow-up after hospitalization (n = 15) and dissatisfaction with post-ICU care (n = 15).

CONCLUSIONS

Obtaining qualitative responses after discharge provided insight into the transition from critical care. This could form the basis for an intervention to provide a smoother transition from the ICU to the outpatient setting.

Temporal Trends in Stroke Incidence Over Time by Sex and Age in the GCNKSS

Background and Purpose- Sex differences in stroke incidence over time were previously reported from the GCNKSS (Greater Cincinnati/Northern Kentucky Stroke Study). We aimed to determine whether these differences continued through 2015 and whether they were driven by particular age groups. Methods- Within the GCNKSS population of 1.3 million, incident (first ever) strokes among residents ≥20 years of age were ascertained at all local hospitals during 5 periods: July 1993 to June 1994 and calendar years 1999, 2005, 2010, and 2015. Out-of-hospital cases were sampled. Sex-specific incidence rates per 100 000 were adjusted for age and race and standardized to the 2010 US Census. Trends over time by sex were compared (overall and age stratified). Sex-specific case fatality rates were also reported. Bonferroni corrections were applied for multiple comparisons. Results- Over the 5 study periods, there were 9733 incident strokes (56.3% women). For women, there were 229 (95% CI, 215-242) per 100 000 incident strokes in 1993/1994 and 174 (95% CI, 163-185) in 2015 (P<0.05), compared with 282 (95% CI, 263-301) in 1993/1994 to 211 (95% CI, 198-225) in 2015 (P<0.05) in men. Incidence rates decreased between the first and last study periods in both sexes for IS but not for intracerebral hemorrhage or subarachnoid hemorrhage. Significant decreases in stroke incidence occurred between the first and last study periods for both sexes in the 65- to 84-year age group and men only in the ≥85-year age group; stroke incidence increased for men only in the 20- to 44-year age group. Conclusions- Overall stroke incidence decreased from the early 1990s to 2015 for both sexes. Future studies should continue close surveillance of sex differences in the 20- to 44-year and ≥85-year age groups, and future stroke prevention strategies should target strokes in the young- and middle-age groups, as well as intracerebral hemorrhage.

Abstract 72: Temporal Trends in Stroke Incidence Over Time by Sex and Age in the Greater Cincinnati Northern Kentucky Stroke Study

Introduction: Data from the Greater Cincinnati/Northern Kentucky Stroke Study (GCNKSS) through 2010 showed that over time, stroke incidence rates decreased to a greater extent in men than in women. We aimed to determine whether this difference continued through 2015 and whether the differences are driven by particular age groups.

Methods: Within the GCNKSS population of 1.3 million, all incident strokes among residents ≥20 years old were ascertained at all local hospitals during 7/93–6/94 and calendar years 1999, 2005, 2010, and 2015. Out-of-hospital cases were sampled. Sex-specific incidence rates per 100,000 were adjusted for age and race, standardized to the 2010 U.S. Census. Trends over time by sex were compared (overall and age-stratified); a Bonferroni correction was applied for multiple comparisons.

Results: In total over the five study periods, there were 9721 incident strokes (ischemic, ICH, and SAH); 56.4% were women. Incidence of ischemic strokes decreased from 254 (95%CI 236,272) in 1993/4 to 177 (95%CI 164,189) in 2015 among men (p<.0001 for trend over time) and from 204 (95%CI 192,217) in 1993/4 to 151 (95%CI 141,161) in 2015 among women (p<.0001). Incidence of ICH/ SAH did not change significantly over time in either sex. In age-stratified analyses, among women, incidence of all strokes decreased among older adults (65–84 years) but not in other age categories (Figure). Among men, incidence over time decreased among older adults (65–84 and ≥ 85 years) but increased in young adults (20–44 years).

Conclusions: Stroke incidence decreased between the early 1990s and 2015 for both sexes, contrary to previous data on trends through 2010 which demonstrated a significant decrease in men but not women. Temporal changes are being driven by the 65–84 year age group in both men and women, as well as the ≥ 85 age group in men. Future prevention strategies should target young and middle age adults for both sexes as well as those over 85 for women.

Abstract WMP51: Ischemic Stroke Rates in Those With Diabetes in the Black and White Population: An Update

Background: We previously reported an increased incidence of stroke in the population with diabetes. This was particularly pronounced in those under 65 years of age. With guidelines now including glycemic monitoring during hospitalization, we examined incidence attributable to diabetes in 2010 and 2015.

Methods: Ischemic strokes in the 5-county Greater Cincinnati/Northern Kentucky region were ascertained, then physician verified, at all 15 area hospitals using ICD-9 codes 430 to 436 or ICD10 codes I60 to I68. First ever ischemic strokes in patients aged 20 years and older were included in this analysis. Population age-specific rates of diabetes were estimated using the 2009-2010 and 2015-2016 NHANES databases, then applied to local population numbers, extracted from the US Census Bureau website, to estimate the denominator for calculation of incidence rates. Incidence rates were adjusted by age race and sex, as appropriate, to the 2010 US population. Diabetes was defined as reported in the electronic medical record or glycohemoglobin A1c &gt 6.4% during hospitalization.

Results: There were a total of 4141 ischemic strokes; 55% female and 22% black. Stroke rates continue to be substantially higher in those with diagnosed diabetes, than those without diabetes overall and for those less than 65 years in both time periods, as well as those 65 years and older except for the black population in 2010. Racial disparities continue in both the less than 65 and 65 years and older age groups. Stroke rates were higher for Blacks in the less than 65 year age group for those both with and without diabetes; with risk ratios ranging from 1.3 to 2.7. Of note the stroke rate has decreased between 2010 and 2015 for those with diabetes <65 years of age. (Table)

Conclusions: The population with diabetes continues to be at increased risk of stroke, especially in those less than 65 years of age and those of black race.

Abstract TP221: Cerebellar Infarction Presentations: A Population-Based Study From the Greater Cincinnati/Northern Kentucky Stroke Study

Background: Cerebellar lesions reportedly account for 2-7% of acute infarct visits, but this may be an underestimate since prior studies were not population-based or from the modern imaging era. Cerebellar symptoms are also often nonspecific such that increased MRI use might lead to a higher proportion of stroke due to cerebellar lesions. Details about presenting features of cerebellar infarcts and baseline medication use are also not well known.

Methods: We used the 2010 Greater Cincinnati/Northern Kentucky Stroke Study. Strokes were identified by screening ICD9 codes 430-436 and physician verification. Infarct location was categorized as isolated cerebellar, mixed cerebellar (cerebellar plus ≥1 other location), or non-cerebellar. Isolated dizziness was defined as dizziness/vertigo without other focal symptoms. Atherosclerotic cardiovascular disease (ASCVD) 10-year risk scores were calculated. Descriptive statistics and multivariable logistic regression were used to compare infarct categories.

Results: Isolated cerebellar lesions occurred in 4.6% (90/1940; 95% CI, 3.7%-5.7%) of infarct events. An additional 4% (77/1940; 95%CI, 3.1%-4.9%) were mixed cerebellar infarcts. Mixed cerebellar infarcts had clinical characteristics more similar to non-cerebellar events than to cerebellar events. The multivariable model found an association of isolated cerebellar infarct with low NIHSS (odds ratio [OR] 2.3, 95% CI 1.1-4.8) and any dizziness/vertigo (OR 5.1, 95% CI, 2.4-10.6), but not with isolated dizziness/vertigo, age, or sex. Median ASCVD scores were high in all infarct categories (21, interquartile range [IQR] 9-35 for isolated cerebellar; 32, IQR 15-42 for mixed cerebellar; 31, IQR 16-52 for all others). Both cerebellar and non-cerebellar strokes had a high frequency of baseline antiplatelet or anticoagulant use (52.1% vs 56.2%), whereas baseline statin therapy was less common in isolated cerebellar infarcts (34.1% vs 43.8%).

Conclusions: This population-based study during the modern imaging era found that about 5% of stroke cases have isolated cerebellar infarcts and nearly 9% have any cerebellar infarct. Both cerebellar and non-cerebellar presentations have high baseline vascular risk and antiplatelet/anticoagulant use.

Stroke Center Certification Is Associated With Improved Guideline Concordance

Measurement of quality of stroke care has become increasingly important, but data come mostly from programs in hospitals that choose to participate in certification programs, which may not be representative of the care provided in nonparticipating hospitals. The authors sought to determine differences in quality of care metric concordance for acute ischemic stroke among hospitals designated as a primary stroke center, comprehensive stroke center, and non-stroke center in a population-based epidemiologic study. Significant differences were found in both patient demographics and in concordance with guideline-based quality metrics. These differences may help inform quality improvement efforts across hospitals involved in certification as well as those that are not.

Abstract WP265: Racial Differences in Left Atrial Size Among Patients With Ischemic Stroke

Introduction: Blacks in the U.S. face twice the risk of ischemic stroke as whites, and this disparity is not fully explained by established stroke risk factors. Although atrial fibrillation (AF) is a major risk factor for stroke, blacks are less often diagnosed with AF than whites. It is unclear whether this paradox exists because AF is less thoroughly ascertained in blacks compared to whites or because blacks have less predisposing substrate and thus a truly lower risk of AF.

Hypothesis: Based on our prior work, we hypothesized that black patients with ischemic stroke less often have left atrial enlargement, a major predisposing factor for AF.

Methods: We compared left atrial size in black versus white patients in the Greater Cincinnati/Northern Kentucky Stroke Study, a study of racial disparities in stroke incidence in a nationally representative population of 1.3 million. We obtained reports of echocardiograms performed for stroke evaluation among patients in the 2010 and 2015 study periods. Patients with known AF or atrial flutter were excluded. Investigators blinded to patients’ characteristics abstracted left atrial diameter from echocardiogram reports. Linear regression was used to examine the association between race and left atrial diameter after adjustment for demographics, body mass index, and comorbidities.

Results: Among 2,980 cases of ischemic stroke without AF, the median age was 66 years, 52% were female, and 30% were black. The overall mean left atrial diameter was 3.65 (±0.69) cm. Despite a higher burden of vascular risk factors and comorbidities, blacks had significantly smaller left atrial diameters (mean difference, -0.10 cm; 95% CI, -0.04 to -0.17 cm). This difference persisted after adjustment for demographics, comorbidities, and body mass index (adjusted mean difference, -0.15 cm; 95% CI, -0.09 to -0.21 cm).

Conclusions: In a population-based sample, we found that black patients with ischemic stroke had smaller left atrial size than white patients. Our results suggest that the paradox of greater stroke risk but lower AF risk in blacks compared with whites at least partly stems from a lesser degree of AF substrate in blacks.

Abstract WMP54: Updated Population Trends in Substance Abuse Preceding Stroke in Young Adults: 1993/1994 to 2015

Objective: To update trends on documented substance abuse among young adults (18-54 years old) with stroke within the Greater Cincinnati/Northern Kentucky Stroke Study population, to include preliminary results from 2015.

Background: Substance abuse is associated with stroke. In our population, we previously reported increases in overall substance abuse, smoking history, and use of alcohol or drugs <24 hours prior to stroke onset. We also found increased illicit drug use in the 35 to 54 age group from 1993/94 through 2010. We now report trends after adding 2015 preliminary results.

>Design/Methods: Using ICD-9 discharge codes 430-436, potential acute stroke events are identified among 18- to 55-year-old residents of the 5 county study region. Five one-year study periods are included (7/93-6/94, 1999, 2005, 2010, 2015). Study nurses abstract all events which then undergo physician review. We searched for trends in smoking history, illicit drug use, heavy alcohol consumption, overall substance abuse (current smoking, alcohol, and illicit drug), and urine/blood test positive for alcohol or illicit drugs at presentation.

Results: There were 2220 stroke events (75 % ischemic). Sex and age distribution remained stable; however, percent black increased from 35% to 46% between 1993/94 and 2015, as did the proportion of ischemic strokes (74% to 77%). Current smoking and alcohol use remained stable while illicit drug use increased significantly overall and within the age subgroups of 18-34 years and 35-54 years (see table).

Conclusions: Illicit drug use continues to increase among young adults with stroke. Even though the possibility of testing bias needs to be explored further, our reported results are likely an under estimation of true rates as there are no readily available tests for new designer drugs which have become more available since the early 2000’s. Future analysis will also focus on the relationship between our findings and the U.S. opioid epidemic.

Abstract WP360: Sex Differences in Patient Centered Outcomes Obtained from Electronic Medical Records in the Greater Cincinnati Northern Kentucky Stroke Study

Introduction: Previous data have shown worse post-stroke outcomes in women than men based on non-patient centered outcomes (modified rankin score (mRS)) obtained via patient contact. Our aim was to compare sex differences in post-stroke outcomes in a population-based cohort using patient-centered outcome measures obtained from the electronic medical record (EMR).

Methods: Patients with ischemic stroke (IS) who presented to a single healthcare system (4 hospitals and outpatient facilities) in Northern Kentucky during 1/2015-12/2015, a subsample of the Greater Cincinnati Northern Kentucky Stroke Study, were included. Those who died prior to study time points were excluded. Cases of IS were ascertained by trained study nurses using ICD codes and EMR review. Outcomes (mRS and quality of life (EQ5D)) were estimated from EMR, a method previously shown to have good interrater agreement with telephone follow-up. EQ5D measures health-related quality of life across 5 dimensions. Utility weighted mRS (UW-mRS) were calculated by applying validated weights to mRS. Outcomes at 3- and 6-months were compared by sex using ordinal logistic regression for mRS and linear regression for UW-mRS and EQ5D, adjusted by demographics, pre-stroke mRS, stroke severity, and co-morbidities.

Results: We included 382 cases; 51% were women, 94% were white. Women were older (median (IQR) 71 (61-81) vs. 66 (57-77)) than men, but pre-stroke mRS was similar (median (IQR) 1 (0-3) vs. 1 (0-2)). NIHSS was similar by sex (median 3 IQR (1-6) vs. 2 (1-5)). After adjustment, 3- and 6-month outcomes were similar by sex.

Conclusions: In our cohort, sex differences in unadjusted outcomes may be related to age, pre-stroke functional status, co-morbidities, and depression, as differences were not present in adjusted models. Relatively minor strokes in our cohort may also explain similar outcomes by sex. Future studies should strive to identify intervenable targets to improve patient-centered outcomes post-stroke.

Abstract TMP57: Racial Disparities in Recurrent Stroke Rates: Preliminary Results From the Greater Cincinnati/Northern Kentucky Population in 2015

Introduction: The REGARDS study previously reported a lack of racial disparity in recurrent ischemic stroke (IS) events, despite large racial differences in incident IS. We sought to evaluate recurrent stroke rates at 1 year after an index ischemic (IS) or hemorrhagic (ICH and SAH) stroke or TIA within a large, biracial population representative of the US in terms of % blacks and sociodemographics with a large number of index events

Methods: The Greater Cincinnati/Northern Kentucky Stroke Study ascertained all hospitalized strokes and TIAs among residents of a 5-county population of 1.3 million in 7/1/14-12/31/14 (blacks only) and 2015 (all residents), as well as recurrent strokes (but not TIAs) in 2016. One year risk of recurrent stroke was estimated by Kaplan-Meier analysis. Association between recurrent stroke and demographics/risk factors was assessed by proportional hazards analysis.

Results: Among the 2014-15 cases, there were 3883 index events (2512 IS, 374 ICH, 92 SAH, 900 TIA, 5 unknown type). Median age was 70 (IQR 59, 81); 27% were black and 54% female. Recurrent events within 12 months of the index event occurred in 319 patients (276 IS, 38 ICH, 5 SAH). Those with recurrence were more likely black than those without (34% vs 27%, p<0.01). No differences between those with recurrence and those without was seen for age at index event (median 70 vs 70, p=0.33) or sex (female 56% vs 54%, p=0.44). One-year risk of recurrent stroke was 9.3% overall (11.3% black, 8.6% white); 10.0% after index IS, 11.2% for ICH/SAH, 7.2% after TIA. Hazard ratio for risk of recurrent stroke for blacks compared with whites, adjusted for age and sex, was 1.38 (95% CI 1.09, 1.75).

Discussion: The risk of recurrent stroke was significantly associated with index event type and stroke risk factors (hypertension, diabetes, smoking, and prior stroke). Black race was not a significant independent predictor of recurrent stroke after adjusting for other known stroke risk factors.