Browsing by Author "Smith, Eric E"

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    A longitudinal magnetic resonance imaging study of neurodegenerative and small vessel disease, and clinical cognitive trajectories in non demented patients with transient ischemic attack: the PREVENT study
    (2018-07-16) Tariq, Sana; d’Esterre, Christopher D; Sajobi, Tolulope T; Smith, Eric E; Longman, Richard S; Frayne, Richard; Coutts, Shelagh B; Forkert, Nils D; Barber, Philip A
    Abstract Background Late-life cognitive decline, caused by progressive neuronal loss leading to brain atrophy years before symptoms are detected, is expected to double in Canada over the next two decades. Cognitive impairment in late life is attributed to vascular and lifestyle related risk factors in mid-life in a substantial proportion of cases (50%), thereby providing an opportunity for effective prevention of cognitive decline if incipient disease is detected earlier. Patients presenting with transient ischemic attack (TIA) commonly display some degree of cognitive impairment and are at a 4-fold increased risk of dementia. In the Predementia Neuroimaging of Transient Ischemic Attack (PREVENT) study, we will address what disease processes (i.e., Alzheimer’s vs. vascular disease) lead to neurodegeneration, brain atrophy, and cognitive decline, and whether imaging measurements of brain iron accumulation using quantitative susceptibility mapping predicts subsequent brain atrophy and cognitive decline. Methods A total of 440 subjects will be recruited for this study with 220 healthy subjects and 220 TIA patients. Early Alzheimer’s pathology will be determined by cerebrospinal fluid samples (including tau, a marker of neuronal injury, and amyloid β1–42) and by MR measurements of iron accumulation, a marker for Alzheimer’s-related neurodegeneration. Small vessel disease will be identified by changes in white matter lesion volume. Predictors of advanced rates of cerebral and hippocampal atrophy at 1 and 3 years will include in vivo Alzheimer’s disease pathology markers, and MRI measurements of brain iron accumulation and small vessel disease. Clinical and cognitive function will be assessed annually post-baseline for a period of 5-years using a clinical questionnaire and a battery of neuropsychological tests, respectively. Discussion The PREVENT study expects to demonstrate that TIA patients have increased early progressive rates of cerebral brain atrophy after TIA, before cognitive decline can be clinically detected. By developing and optimizing high-level machine learning models based on clinical data, image-based (quantitative susceptibility mapping, regional brain, and white matter lesion volumes) features, and cerebrospinal fluid biomarkers, PREVENT will provide a timely opportunity to identify individuals at greatest risk of late-life cognitive decline early in the course of disease, supporting future therapeutic strategies for the promotion of healthy aging.
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    Blood pressure at age 60–65 versus age 70–75 and vascular dementia: a population based observational study
    (2017-10-27) Peng, Mingkai; Chen, Guanmin; Tang, Karen L; Quan, Hude; Smith, Eric E; Faris, Peter; Hachinski, Vladimir; Campbell, Norm R C
    Abstract Background Vascular dementia (VaD) is the second most common form of dementia. However, there were mixed evidences about the association between blood pressure (BP) and risk of VaD in midlife and late life and limited evidence on the association between pulse pressure and VaD. Methods This is a population-based observational study. 265,897 individuals with at least one BP measurement between the ages of 60 to 65 years and 211,116 individuals with at least one BP measurement between the ages of 70 to 75 years were extracted from The Health Improvement Network in United Kingdom. Blood pressures were categorized into four groups: normal, prehypertension, stage 1 hypertension, and stage 2 hypertension. Cases of VaD were identified from the recorded clinical diagnoses. Multivariable survival analysis was used to adjust other confounders and competing risk of death. All the analysis were stratified based on antihypertensive drug use status. Multiple imputation was used to fill in missing values. Results After accounting for the competing risk of death and adjustment for potential confounders, there was an association between higher BP levels in the age 60–65 cohort with the risk of developing VaD (hazard ratio [HR] 1.53 (95% confidence interval: 1.04, 2.25) for prehypertension, 1.90 (1.30, 2.78) for stage 1 hypertension, and 2.19 (1.48, 3.26) for stage 2 hypertension) in the untreated group. There was no statistically significant association between BP levels and VaD in the treated group in the age 60–65 cohort and age 70–75 cohort. Analysis on Pulse Pressure (PP) stratified by blood pressure level showed that PP was not independently associated with VaD. Conclusion High BP between the ages of 60 to 65 years is a significant risk for VaD in late midlife. Greater efforts should be placed on early diagnosis of hypertension and tight control of BP for hypertensive patients for the prevention of VaD.
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    Health-related Quality of Life After Stroke
    (2021-06-21) Joundi, Raed A; Smith, Eric E; Hill, Michael D; Patten, Scott B
    Background: Health-related quality of life (HRQoL) is increasingly being used to measure outcomes in patients with stroke. Differences in HRQoL with age, impairments in specific domains, and effects of treatments on HRQoL are not very well understood.Objectives: To determine the overall HRQoL in patients post stroke, how HRQoL differs by age, sex, other baseline characteristics, and effects of acute stroke treatment on HRQoL.Methods: A systematic review and meta-analysis was done to pool HRQoL values over the past 25 years of overall stroke survivors and stratify by age, sex, and time since stroke. A population- based study of Canadian respondents with and without stroke was completed to assess the impact of stroke on HRQoL and specific domains, and differences with age. Lastly, data from the ESCAPE randomized trial was used to determine the impact of endovascular thrombectomy on HRQoL and specific domains at 90 days post-stroke with exploration of differences by age.Results: In the meta-analysis of 107 studies, stroke survivors had substantially lower HRQoL compared to population norms as measured by health utility scores, and utility was lower in older individuals, females, and closer to stroke onset. In the population-based study, HRQoL in respondents with prior stroke was significantly lower than controls, overall and in domains of mobility, cognition, pain, and emotion. Those aged 60-74 had the greatest reduction in HRQoL compared to controls. In the ESCAPE trial, endovascular thrombectomy substantially improved HRQoL in patients with acute ischemic stroke, particularly in domains of self-care, usual activities, and mobility, and partially driven by a mortality benefit in the elderly. Among survivors, those aged 60-79 had the greatest benefit to HRQoL.Conclusions: HRQoL is highly impaired in stroke survivors, with particular impact on mobility, self-care, usual activities, cognition, pain, and emotional health. Those at older age and women have lower HRQoL. Endovascular thrombectomy is an effective treatment for improving HRQoL post stroke, with a large effect size when accounting for mortality. HRQoL is an important metric to evaluate stroke outcomes and is complementary to conventional disability scales. These findings may be useful for future analyses of stroke interventions, and clinical or economic studies of HRQoL after stroke.
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    National surveillance of stroke quality of care and outcomes by applying post-stratification survey weights on the Get With The Guidelines-Stroke patient registry
    (2021-02-04) Ziaeian, Boback; Xu, Haolin; Matsouaka, Roland A; Xian, Ying; Khan, Yosef; Schwamm, Lee S; Smith, Eric E; Fonarow, Gregg C
    Abstract Background The U.S. lacks a stroke surveillance system. This study develops a method to transform an existing registry into a nationally representative database to evaluate acute ischemic stroke care quality. Methods Two statistical approaches are used to develop post-stratification weights for the Get With The Guidelines-Stroke registry by anchoring population estimates to the National Inpatient Sample. Post-stratification survey weights are estimated using a raking procedure and Bayesian interpolation methods. Weighting methods are adjusted to limit the dispersion of weights and make reasonable epidemiologic estimates of patient characteristics, quality of hospital care, and clinical outcomes. Standardized differences in national estimates are reported between the two post-stratification methods for anchored and non-anchored patient characteristics to evaluate estimation quality. Primary measures evaluated are patient and hospital characteristics, stroke severity, vital and laboratory measures, disposition, and clinical outcomes at discharge. Results A total of 1,388,296 acute ischemic strokes occurred between 2012 and 2014. Raking and Bayesian estimates of clinical data not available in administrative data are estimated within 5 to 10% of margin for expected values. Median weight for the raking method is 1.386 and the weights at the 99th percentile is 6.881 with a maximum weight of 30.775. Median Bayesian weight is 1.329 and the 99th percentile weights is 11.201 with a maximum weight of 515.689. Conclusions Leveraging existing databases with patient registries to develop post-stratification weights is a reliable approach to estimate acute ischemic stroke epidemiology and monitoring for stroke quality of care nationally. These methods may be applied to other diseases or settings to better monitor population health.