Skye Coote
Royal Melbourne Hospital
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Publication
Featured researches published by Skye Coote.
Stroke | 2013
Daniel Strbian; David J. Seiffge; Lorenz Breuer; Heikki Numminen; Patrik Michel; Atte Meretoja; Skye Coote; Régis Bordet; Víctor Obach; Bruno Weder; Simon Jung; Valeria Caso; Sami Curtze; Jyrki Ollikainen; Philippe Lyrer; Ashraf Eskandari; Heinrich P. Mattle; Ángel Chamorro; Didier Leys; Christopher F. Bladin; Stephen M. Davis; Martin Köhrmann; Stefan T. Engelter; Turgut Tatlisumak
Background and Purpose— The DRAGON score predicts functional outcome in the hyperacute phase of intravenous thrombolysis treatment of ischemic stroke patients. We aimed to validate the score in a large multicenter cohort in anterior and posterior circulation. Methods— Prospectively collected data of consecutive ischemic stroke patients who received intravenous thrombolysis in 12 stroke centers were merged (n=5471). We excluded patients lacking data necessary to calculate the score and patients with missing 3-month modified Rankin scale scores. The final cohort comprised 4519 eligible patients. We assessed the performance of the DRAGON score with area under the receiver operating characteristic curve in the whole cohort for both good (modified Rankin scale score, 0–2) and miserable (modified Rankin scale score, 5–6) outcomes. Results— Area under the receiver operating characteristic curve was 0.84 (0.82–0.85) for miserable outcome and 0.82 (0.80–0.83) for good outcome. Proportions of patients with good outcome were 96%, 93%, 78%, and 0% for 0 to 1, 2, 3, and 8 to 10 score points, respectively. Proportions of patients with miserable outcome were 0%, 2%, 4%, 89%, and 97% for 0 to 1, 2, 3, 8, and 9 to 10 points, respectively. When tested separately for anterior and posterior circulation, there was no difference in performance (P=0.55); areas under the receiver operating characteristic curve were 0.84 (0.83–0.86) and 0.82 (0.78–0.87), respectively. No sex-related difference in performance was observed (P=0.25). Conclusions— The DRAGON score showed very good performance in the large merged cohort in both anterior and posterior circulation strokes. The DRAGON score provides rapid estimation of patient prognosis and supports clinical decision-making in the hyperacute phase of stroke care (eg, when invasive add-on strategies are considered).
Stroke | 2017
Henry Zhao; Skye Coote; Lauren Pesavento; Leonid Churilov; Helen M. Dewey; Stephen M. Davis; Bruce C.V. Campbell
Background and Purpose— Clinical large vessel occlusion (LVO) triage scales were developed to identify and bypass LVO to endovascular centers. However, there are concerns that scale misclassification of patients may cause excessive harm. We studied the settings where misclassifications were likely to occur and the consequences of these misclassifications in a representative stroke population. Methods— Prospective data were collected from consecutive ambulance-initiated stroke alerts at 2 stroke centers, with patients stratified into typical (LVO with predefined severe syndrome and non-LVO without) or atypical presentations (opposite situations). Five scales (Rapid Arterial Occlusion Evaluation [RACE], Los Angeles Motor Scale [LAMS], Field Assessment Stroke Triage for Emergency Destination [FAST-ED], Prehospital Acute Stroke Severity scale [PASS], and Cincinnati Prehospital Stroke Severity Scale [CPSSS]) were derived from the baseline National Institutes of Health Stroke Scale scored by doctors and analyzed for diagnostic performance compared with imaging. Results— Of a total of 565 patients, atypical presentations occurred in 31 LVO (38% of LVO) and 50 non-LVO cases (10%). Most scales correctly identified >95% of typical presentations but <20% of atypical presentations. Misclassification attributable to atypical presentations would have resulted in 4 M1/internal carotid artery occlusions, with National Institutes of Health Stroke Scale score ≥6 (5% of LVO) being missed and 9 non-LVO infarcts (5%) bypassing the nearest thrombolysis center. Conclusions— Atypical presentations accounted for the bulk of scale misclassifications, but the majority of these misclassifications were not detrimental, and use of LVO scales would significantly increase timely delivery to endovascular centers, with only a small proportion of non-LVO infarcts bypassing the nearest thrombolysis center. Our findings, however, would require paramedics to score as accurately as doctors, and this translation is made difficult by weaknesses in current scales that need to be addressed before widespread adoption.
Stroke | 2016
Felix C. Ng; Skye Coote; Tanya Frost; Christopher F. Bladin; Philip Choi
Background and Purpose— The use of thrombolysis in acute minor ischemic stroke (MIS) remains controversial. We sought to determine the safety and efficacy of intravenous tissue-type plasminogen activator (IV-tPA) in acute MIS patients with demonstrable penumbra on computed tomographic perfusion study. Methods— Consecutive MIS patients with National Institutes of Health Stroke Scale ⩽3 were identified from a prospective single tertiary-center database over a 4.5-year period (2011–2015). Cases with demonstrable penumbra were analyzed according to treatment received: IV-tPA versus standard stroke-unit care without thrombolysis. Results— Seventy-three patients of 195 acute MIS admissions had a demonstrable penumbra (34 IV-tPA versus 39 standard stroke-unit care). Overall median National Institutes of Health Stroke Scale and premorbid modified Rankin Scale were 2 and 0, respectively. Median age was 73.2 (interquartile range, 67.3–82.8) years. There were no differences in baseline demographics, risk factors, stroke localization and cause, rates of vascular occlusion (38.2% versus 38.5%; P=1.000), or mean penumbral volume (41.3 versus 25.1 mL; P=0.150; IV-tPA versus standard stroke-unit care) between groups. There were no symptomatic intracerebral hemorrhages in either group. Patients treated with IV-tPA were more likely to have an excellent functional outcome at discharge (88.2% versus 53.9%; P=0.002) and 90 days (91.2% versus 71.8%; P=0.042). Ordinal analysis demonstrated a favorable shift in modified Rankin Scale with IV-tPA both at discharge (odds ratio, 5.23; 95% confidence interval, 1.83–12.20) and 90 days (odds ratio, 4.35; 95% confidence interval, 1.77–11.36). Conclusions— In selected MIS patients with demonstrable penumbra on computed tomographic perfusion, IV-tPA is safe and associated with significant improvement in functional outcome at discharge and 90 days.
Journal of Neurology, Neurosurgery, and Psychiatry | 2017
Henry Zhao; Lauren Pesavento; Skye Coote; Leonid Churilov; Karen Smith; Stephen Bernard; Nawaf Yassi; Stephen M. Davis; Bruce C.V. Campbell
Objectives Endovascular reperfusion is now standard treatment for large vessel occlusion (LVO) but good outcomes depend on timely therapy. Accurate identification of LVO in the pre-hospital setting has therefore become a key priority to allow ambulance bypass to endovascular centres. Several tools such as the Spanish Rapid Arterial Occlusion Evaluation Scale (RACE)1 have been developed, but paramedic studies to date have shown low specificity, despite training.1,2 We aimed to develop an identification algorithm that would provide high accuracy when used by Australian paramedics. Methods A new LVO algorithm was developed from retrospective review of discriminating clinical features and requires significant unilateral upper limb weakness (arm falls to stretcher <10 secs), plus either severe language deficit or presence of gaze deviation/severe extinction (assessed by response to shoulder tap). Initial retrospective validation was performed in consecutive code stroke patients over a 15 month period at Royal Melbourne and Box Hill hospitals in Melbourne, followed by prospective paramedic assessment at Royal Melbourne Hospital. Results Of 565 consecutive patients in the retrospective cohort (82 LVO), the overall accuracy of the LVO algorithm was 87.6%. Misclassification inaccuracies affected 4 LVO patients with clear endovascular eligibility (4.8% of all LVO), and 10 smaller infarcts incorrectly identified as LVO (5.7% of all non-LVO infarcts). Use of the algorithm by paramedics without additional training in the first 70 prospective patients (13 LVO) showed 87.9% accuracy, 83.3% sensitivity and 88.9% specificity. No LVOs with clear endovascular eligibility were missed and just 1 non-LVO infarct was misclassified. All discrimination parameters trended superior to RACE. Conclusions The new 3-item LVO algorithm has excellent sensitivity for endovascular-eligible LVO and misclassified only a small proportion of non-LVO infarcts. Despite greater simplicity, the algorithm shows better performance than the RACE and has potential to improve patient outcomes from endovascular therapy through faster treatment access.
Journal of Neurology | 2017
Felix C. Ng; Skye Coote; Tanya Frost; Christopher F. Bladin; Philip Choi
Diffusion-weighted imaging (DWI) changes in transient ischaemic attack and minor ischaemic stroke (TIA/MIS) patients predict a poorer prognosis with increased risk of recurrent strokes and persistent disability [1, 2]. Identifying these patients in the hyperacute setting may allow early risk stratification to aid clinical decision making. Recent reports evaluating the prognostic value of CT perfusion studies (CTP) have predominantly focused on moderate to severe stroke patients [3, 4]. In this study, we sought to determine the utility of CTP as a prognostic modality in TIA/MIS patients by investigating the association between acute ischaemic changes on CTP and the presence of abnormal restricted diffusion on follow-up DWI magnetic resonance imaging (DWI-positive). We compared the prevalence of a DWI-positive result between patients with and without a CTP ischaemic lesion among 138 consecutive TIA/MIS patients identified from a prospective tertiary stroke centre database over 4.5 years (2011–2015). The main inclusion criteria were (1) presentation within 4.5 h of symptoms onset, (2) NIH Stroke Scale B3, (3) underwent CTP while symptomatic and (4) had follow-up DWI. CTP ischaemic lesion was defined as an area of prolonged time-to-peak corresponding to the presenting symptoms as assessed by two experienced raters blinded to all other clinical information. TIA was defined using time-based criteria as a focal cerebral ischaemic event with symptoms lasting less than 24 h. T test, Fisher exact test and logistic regression were used for statistical analysis. Overall, the mean age was 71.8 years (standard deviation 13.3), and the median presenting NIH Stroke Scale was 2 [interquartile range (IQR) 1–3] (Table 1). Median symptoms duration was 110 min (IQR 78–145) among twenty-nine TIA patients (21.0%). Sixty-two patients had a CTP ischaemic lesion in the study cohort. Twenty-eight patients (20.3%) received intravenous alteplase thrombolysis at the discretion of the treating neurologist. Among non-thrombolysed patients (n = 110), those with CTP ischaemic lesions were significantly more likely to have a DWI-positive result (100% vs, 49.3%, p\ 0.01), have atrial fibrillation (AF) (34.3% vs. 16.0%, p = 0.046) and be disabled on discharge (modified Rankin Scale C2) (40.6% vs. 25.6%, p = 0.04) compared to patients with a normal CTP. In addition, CTP ischaemic lesion was associated with a significant shift in the distribution of modified Rankin Scale towards higher disability at discharge (odds ratio 3.33; 95% confidence interval, 1.56–7.09). There were no differences between groups among baseline demographics, presenting NIH Stroke Scale domains involved, stroke location, cardiovascular risk factors and CTP ischaemic lesion volume. CTP had high specificity (100%, 95% confidence interval 89.3–100%), high positive predictive value (100%, 95% confidence interval 87.7–100%) but moderate sensitivity (48.6%, 95% confidence interval 36.7–60.7%) in detecting a DWI-positive result in non-thrombolysed patients. All patients with CTP ischaemic lesions developed abnormal restricted diffusion unless alteplase thrombolysis was administered (100 vs. 77.8%; p\ 0.01). & Felix C. Ng [email protected]
Stroke | 2018
Henry Zhao; Lauren Pesavento; Skye Coote; Edrich Rodrigues; Patrick Salvaris; Karen Smith; Stephen Bernard; Michael Stephenson; Leonid Churilov; Nawaf Yassi; Stephen M. Davis; Bruce C.V. Campbell
Background and Purpose— Clinical triage scales for prehospital recognition of large vessel occlusion (LVO) are limited by low specificity when applied by paramedics. We created the 3-step ambulance clinical triage for acute stroke treatment (ACT-FAST) as the first algorithmic LVO identification tool, designed to improve specificity by recognizing only severe clinical syndromes and optimizing paramedic usability and reliability. Methods— The ACT-FAST algorithm consists of (1) unilateral arm drift to stretcher <10 seconds, (2) severe language deficit (if right arm is weak) or gaze deviation/hemineglect assessed by simple shoulder tap test (if left arm is weak), and (3) eligibility and stroke mimic screen. ACT-FAST examination steps were retrospectively validated, and then prospectively validated by paramedics transporting culturally and linguistically diverse patients with suspected stroke in the emergency department, for the identification of internal carotid or proximal middle cerebral artery occlusion. The diagnostic performance of the full ACT-FAST algorithm was then validated for patients accepted for thrombectomy. Results— In retrospective (n=565) and prospective paramedic (n=104) validation, ACT-FAST displayed higher overall accuracy and specificity, when compared with existing LVO triage scales. Agreement of ACT-FAST between paramedics and doctors was excellent (&kgr;=0.91; 95% confidence interval, 0.79–1.0). The full ACT-FAST algorithm (n=60) assessed by paramedics showed high overall accuracy (91.7%), sensitivity (85.7%), specificity (93.5%), and positive predictive value (80%) for recognition of endovascular-eligible LVO. Conclusions— The 3-step ACT-FAST algorithm shows higher specificity and reliability than existing scales for clinical LVO recognition, despite requiring just 2 examination steps. The inclusion of an eligibility step allowed recognition of endovascular-eligible patients with high accuracy. Using a sequential algorithmic approach eliminates scoring confusion and reduces assessment time. Future studies will test whether field application of ACT-FAST by paramedics to bypass suspected patients with LVO directly to endovascular-capable centers can reduce delays to endovascular thrombectomy.
Journal of Neurology, Neurosurgery, and Psychiatry | 2018
Henry Zhao; Skye Coote; Lauren Pesavento; Francesca Langenberg; Patricia Desmond; Damien Easton; Lindsay Bent; Shane Foster; Michael Stephenson; Karen Smith; Stephen Bernard; Christopher F. Bladin; Dominique A. Cadilhac; Bernard Yan; Bruce C.V. Campbell; Mark W. Parsons; Geoffrey A. Donnan; Stephen M. Davis
Introduction The Melbourne mobile stroke unit (MSU) project is the first Australian pre-hospital stroke service that delivers on-scene imaging, treatment and triage. The MSU vehicle consists of a Mercedes Sprinter-5 chassis with on-board CereTom 8-slice portable CT scanner and telemedicine capabilities. On-board crew consists of a neurologist/telemedicine, nurse, radiographer and two paramedics (advanced-life-support and mobile-intensive-care). The MSU service is co-dispatched within 20 km of Royal Melbourne Hospital. We describe the service activity since project launch. Methods Data are sourced from the Melbourne MSU registry, an ongoing prospectively collected database of all MSU dispatched cases since November 2017. Results In the first 50 operational days, there were a total of n=255 dispatches (5.1/day), of which 47% of patients received on-scene attendance. On-scene CT was performed on 52% of all attendances. Of n=29 suspected ischaemic stroke cases<6 hours of symptom onset (24% of attended), n=10 (34%) received pre-hospital thrombolysis and n=6 (21%) were directed for endovascular thrombectomy. 30% of patients were thrombolysed within 90 min of symptom onset. A total of n=7 (14% of all stroke) patients were recommended to bypass the closest hospital to a specialist centre for endovascular, neurosurgical or other services. The median scene-to-thrombolysis time of 36.5 min was substantially better than Australian in-hospital averages and represented an estimated 30–45 min time saving compared to in-hospital treatment. Discussion The Melbourne MSU project shows that pre-hospital diagnosis and treatment of stroke patients is feasible and associated with substantial time saving in providing acute stroke treatment and triage. Future research will focus on optimising MSU dispatch and cost-effectiveness analysis.
International Journal of Stroke | 2018
Henry Zhao; Skye Coote; Lauren Pesavento; Brett Jones; Edrich Rodrigues; Jo Lyn Ng; Felix C. Ng; Bernard Yan; Mark W. Parsons; Bruce C.V. Campbell; Damien Easton; Geoffrey A. Donnan; Stephen M. Davis
Background Administration of intravenous idarucizumab to reverse dabigatran anticoagulation prior to thrombolysis for patients with acute ischemic stroke has been previously described, but not in the prehospital setting. The speed and predictability of idarucizumab reversal is well suited to prehospital treatment in a mobile stroke unit and allows patients with recent dabigatran intake to access reperfusion therapy. Aims To describe feasibility of prehospital idarucizumab administration prior to thrombolysis on the Melbourne mobile stroke unit. Methods The Melbourne mobile stroke unit is a specialized stroke ambulance servicing central metropolitan Melbourne, Australia and provides prehospital assessment, scanning and treatment with an integrated CT scanner and multidisciplinary stroke team. All cases were identified through the mobile stroke unit treatment registry since launch in November 2017. Results Of a total of n = 20 thrombolysis cases in the first 4 months of operation, three patients (15%) received intravenous idarucizumab 5 g for dabigatran reversal prior to thrombolysis. Mean time between idarucizumab administration and thrombolysis was approximately 10 minutes. Two of the three patients were shown to have large vessel occlusion on CTA in the mobile stroke unit and proceeded to endovascular thrombectomy. At 24 hours, only one patient had a small amount of asymptomatic petechial hemorrhage on follow-up imaging. All patients demonstrated substantial neurological recovery and were discharged to inpatient rehabilitation. Conclusions Rapid treatment with prehospital administration of idarucizumab prior to thrombolysis using a mobile stroke unit is feasible and facilitates hyperacute treatment.
Journal of Stroke & Cerebrovascular Diseases | 2018
WenWen Zhang; Skye Coote; Tanya Frost; Helen M. Dewey; Philip M.C. Choi
Stroke | 2017
Henry Zhao; Skye Coote; Helen M. Dewey; Stephen M. Davis; Bruce C.V. Campbell