Browsing by Author "Demchuk, Andrew M"

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    Association of fibrinogen level with early neurological deterioration among acute ischemic stroke patients with diabetes
    (2017-05-19) Lee, Seong-Joon; Hong, Ji M; Lee, Sung E; Kang, Dae R; Ovbiagele, Bruce; Demchuk, Andrew M; Lee, Jin S
    Abstract Background Diabetes mellitus (DM) is a risk factor for early neurological deterioration (END) in acute ischemic stroke. The prothrombotic protein fibrinogen is frequently elevated in patients with diabetes, and may be associated with poorer prognoses. We evaluated whether fibrinogen is associated with END in patients with diabetes after acute ischemic stroke. Methods We included 3814 patients from a single hospital database admitted within 72 h of onset of ischemic stroke. END was defined as an increase in the National Institutes of Health Stroke Scale (NIHSS) ≥2 within 7 days post-admission. In the total population (END, n = 661; non-END, n = 3153), univariate and multivariate analyses were performed to assess fibrinogen as an independent predictor for END. We then performed propensity score matching and univariate analyses for DM (END, n = 261; non-END, n = 522) and non-DM populations (END, n = 399; non-END, n = 798). Multiple logistic analyses were performed after matching for fibrinogen as a risk factor in each subgroup. Results Fibrinogen levels were higher in the END group than in the non-END group (367 ± 156 mg/dL vs. 347 ± 122 mg/dL, p = 0.002), though they were not associated with END in logistic regression analyses. Fibrinogen levels were found to be an independent predictor for END, but only in the DM population (fibrinogen levels 300–599 mg/dL, odds ratio: 1.618, 95% confidence interval: 1.037–2.525, p = 0.034, fibrinogen levels ≥600 mg/dL, 2.575, 1.018–6.514, p = 0.046; non-DM population, p = 0.393). The diabetes-fibrinogen interaction for the entire cohort was p = 0.101. Conclusions Elevated fibrinogen is dose-dependently associated with END in patients with diabetes following acute ischemic stroke.
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    Expanding the evidence of endovascular treatment for acute ischemic stroke: patient–centered outcomes, population–level impact, and patients presenting with mild stroke symptoms
    (2020-10-06) Zerna, Anna Charlotte; Hill, Michael D; Demchuk, Andrew M; Rabi, Doreen M
    Endovascular treatment (EVT) for anterior circulation acute ischemic stroke due to large?vessel occlusion is the new standard of care resulting in reduced disability compared to medical treatment. Practice guidelines recommend the use of EVT but can only speak to the evidence provided by clinical trials and might not be appropriate when complex medical decisions need to consider the heterogeneity of patients in routine clinical care. Brought about by the limitations of the clinical trials, the work described in this doctoral thesis aimed to assess the long–term sustainability of efficacy of EVT, the utilization of post–stroke outcomes that are patient–centered and more meaningful to affected individuals, and the effectiveness of EVT in patient populations that have not been part of clinical trial cohorts. These are commonly older patients with comorbidities and patients presenting with mild stroke symptoms. The miFUNCTION scale was shown to display greater granularity in the mild to moderately–severe disability range post–stroke compared to the modified Rankin Scale and thus provide more insight into the patient's ability and capacity to engage in meaningful life roles after EVT. In a population–based analysis, adult patients undergoing EVT spent on average more than one week longer at home within the first 90 days compared with patients receiving medical treatment. Home?time was used as a novel, health?economic, and patient?centered outcome. For patients presenting with mild symptoms, EVT resulted in similar 90–day outcomes compared to medical management despite an increased risk of neurological deterioration at 24 hours. Due to uncertainty regarding the risk–benefit–ratio, a well–designed clinical trial will need to establish how best to treat these patients. Overall, the work described here provides greater understanding of how the benefits and risks of EVT might vary across the population and differ from the rather homogenous patient cohort that has been assessed in the clinical trials. The results of this research will be meaningful to patients who experience acute ischemic strokes caused by large vessel occlusion and also aid with economic and regulatory decisions to more broadly offer and organize EVT across Alberta and beyond.
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    Minimal sufficient balance randomization for sequential randomized controlled trial designs: results from the ESCAPE trial
    (2017-11-02) Sajobi, Tolulope T; Singh, Gurbakhshash; Lowerison, Mark W; Engbers, Jordan; Menon, Bijoy K; Demchuk, Andrew M; Goyal, Mayank; Hill, Michael D
    Abstract Background We describe the implementation of minimal sufficient balance randomization, a covariate-adaptive randomization technique, used for the “Endovascular treatment for Small Core and Anterior circulation Proximal occlusion with Emphasis on minimizing CT to recanalization times” (ESCAPE) trial. Methods The ESCAPE trial is a prospective, multicenter, randomized clinical trial that enrolled subjects with the following main inclusion criteria: less than 12 h from symptom onset, age 18 years or older, baseline NIHSS score > 5, ASPECTS score > 5 and computed tomography angiography (CTA) evidence of carotid T/L or M1-segment middle cerebral artery (MCA) occlusion, and at least moderate collaterals by CTA. Patients were randomized using a real-time, dynamic, Internet-based, minimal sufficient balance randomization method that balanced the study arms with respect to baseline covariates including age, sex, baseline NIHSS score, site of arterial occlusion, baseline ASPECTS score and treatment with intravenously administered alteplase. Results Permutation-based tests of group differences confirmed group balance across several baseline covariates including sex (p = 1.00), baseline NIHSS score (p = 0.95), site of arterial occlusion (p = 1.00), baseline ASPECTS score (p = 0.28), treatment with intravenously administered alteplase (p = 0.31), and age (p = 0.67). Conclusion Results from the ESCAPE trial demonstrate the feasibility and the benefit of this covariate adaptive randomization scheme in small-sample trials and for data monitoring endeavors. Trial registration ESCAPE trial – NCT01778335 – at www.clinicaltrials.gov . Registered on 29 January 2013.