OLAVARRIA IANISZEWSKY, VERONICA VIVIANA
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OLAVARRIA IANISZEWSKY, VERONICA VIVIANA
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OLAVARRIA IANISZEWSKY, VERONICA VIVIANA
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v.olavarria@udd.cl
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57204794060

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Statistical analysis plan of the head position in acute ischemic stroke trial pilot (HEADPOST pilot)

2017 , OLAVARRIA IANISZEWSKY, VERONICA VIVIANA , Hisatomi Arima , Craig S Anderson , BRUNSER, ALEJANDRO , MUÑOZ VENTURELLI, PAULA ANDREA , Laurent Billot , LAVADOS GERMAIN, PABLO MANUEL

Background The HEADPOST Pilot is a proof-of-concept, open, prospective, multicenter, international, cluster randomized, phase IIb controlled trial, with masked outcome assessment. The trial will test if lying flat head position initiated in patients within 12 h of onset of acute ischemic stroke involving the anterior circulation increases cerebral blood flow in the middle cerebral arteries, as measured by transcranial Doppler. The study will also assess the safety and feasibility of patients lying flat for ≥24 h. The trial was conducted in centers in three countries, with ability to perform early transcranial Doppler. A feature of this trial was that patients were randomized to a certain position according to the month of admission to hospital. Objective To outline in detail the predetermined statistical analysis plan for HEADPOST Pilot study. Methods All data collected by participating researchers will be reviewed and formally assessed. Information pertaining to the baseline characteristics of patients, their process of care, and the delivery of treatments will be classified, and for each item, appropriate descriptive statistical analyses are planned with comparisons made between randomized groups. For the outcomes, statistical comparisons to be made between groups are planned and described. Results This statistical analysis plan was developed for the analysis of the results of the HEADPOST Pilot study to be transparent, available, verifiable, and predetermined before data lock. Conclusions We have developed a statistical analysis plan for the HEADPOST Pilot study which is to be followed to avoid analysis bias arising from prior knowledge of the study findings. Trial registration The study is registered under HEADPOST-Pilot, ClinicalTrials.gov Identifier NCT01706094.

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Cluster-Randomized, Crossover Trial of Head Positioning in Acute Stroke

2017 , Craig S. Anderson , Hisatomi Arima , LAVADOS GERMAIN, PABLO MANUEL , Laurent Billot , Maree L. Hackett , OLAVARRIA IANISZEWSKY, VERONICA VIVIANA , MUÑOZ VENTURELLI, PAULA ANDREA , BRUNSER RABOVICH, ALEJANDRO MICHEL , Bin Peng , Liying Cui , Lily Song , Kris Rogers , Sandy Middleton , Joyce Y. Lim , Denise Forshaw , C. Elizabeth Lightbody , Mark Woodward , Octavio Pontes-Neto , H. Asita De Silva , Ruey-Tay Lin , Tsong-Hai Lee , Jeyaraj D. Pandian , Gillian E. Mead , Thompson Robinson , Caroline Watkins

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No benefit of flat head positioning in early moderate–severe acute ischaemic stroke: a HeadPoST study subgroup analysis

2020 , BRUNSER, ALEJANDRO , Menglu Ouyang , Hisatomi Arima , Pablo M Lavados , Thompson Robinson , MUÑOZ VENTURELLI, PAULA ANDREA , Verónica V Olavarría , Laurent Billot , Marre L Hackett , Lili Song , Sandy Middleton , Octavio Pontes-Neto , Tsong-Hai Lee , Caroline Watkins , Craig S Anderson

BackgroundAlthough the Head Positioning in acute Stroke Trial (HeadPoST) showed no effect of the flat head position (FP; vs sitting up head position (SUP)) on functional outcome, we hypothesised that it could still offer benefits if commenced early in those with acute ischaemic stroke (AIS) of at least moderate severity.MethodsSubgroup analysis of HeadPoST in participants with National Institutes of Health Stroke Scale (NIHSS) scores ≥7, ≥10 and ≥14, randomised to FP or SUP <4.5 hours of AIS onset on functional outcomes defined by a shift in scores on the modified Rankin scale (mRS) and death/disability (mRS scores 3–6), and any cardiovascular serious adverse event. Logistic regression analyses were undertaken adjusted for study design and baseline risk factors.ResultsThere was no significant differential treatment effect in patient subgroups defined by increasing baseline NIHSS scores: adjusted OR and 95% CI for ordinal shift and binary (3–6) mRS scores: for NIHSS ≥7 (n=867) 0.92 (0.67 to 1.25) and 0.74 (0.52 to 1.04); NIHSS ≥ 10 (n=606) 0.80 (0.58 to 1.10) and 0.77 (0.49 to 1.19); NIHSS ≥14 (n=378) 0.82 (0.54 to 1.24) and 1.22 (0.69 to 2.14).ConclusionsEarly FP had no significant effect in patients with moderate–severe AIS.Trial registration numberNCT02162017.

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Head position and cerebral blood flow in acute ischemic stroke patients: Protocol for the pilot phase, cluster randomized, Head Position in Acute Ischemic Stroke Trial (HeadPoST pilot)

2016 , BRUNSER, ALEJANDRO , MUÑOZ VENTURELLI, PAULA ANDREA , LAVADOS GERMAIN, PABLO MANUEL , Javier Gaete , Sheila Martins , Hisatomi Arima , Craig S Anderson , OLAVARRIA IANISZEWSKY, VERONICA VIVIANA

Rationale Few proven interventions exist for acute ischemic stroke (AIS), and most are expensive and restricted in applicability. Lying flat ‘head down’ positioning of AIS patients has been shown to increase by as much as 20%, mean cerebral blood flow velocities (CBFV) measured by transcranial Doppler (TCD) but whether this translates into clinical improvement is uncertain. Aim To determine if the lying flat position increases mean CBFV in the affected territory as compared to the sitting up position in AIS patients. Methods and design Head Position in Acute Ischemic Stroke Trial (HeadPoST pilot) is a cluster randomized (clusters being months), assessor-blinded end-point, phase IIb trial, where consecutive adults with anterior circulation AIS within 12 h of symptom onset are positioned to a randomized position for 48 h with TCD performed serially. Study outcomes Primary outcome is mean CBFV on TCD at 1 and 24 h after positioning. Secondary outcomes include: serious adverse events, neurological impairment at seven days, and death and disability at 90 days. Sample size estimates Assuming an increase of 8.3 (SD 11.4) cm/s in average of mean CBFV when tilted from 30° to 0°, 46 clusters are required (92 patients in total) to detect a 20% increase of mean CBFV with 90% power and 5% level of significance. Conclusion HeadPoST pilot is a cluster randomized multicenter clinical trial investigating the effect of head positioning on mean CBFV in anterior circulation AIS.

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Quantifying regional variations in components of acute stroke unit (ASU) care in the international HeadPoST study

2020 , Menglu Ouyang , Yao Zhang , Xia Wang , Lili Song , Laurent Billot , Thompson Robinson , LAVADOS GERMAIN, PABLO MANUEL , Hisatomi Arima , Maree L. Hackett , OLAVARRIA IANISZEWSKY, VERONICA VIVIANA , MUÑOZ VENTURELLI, PAULA ANDREA , Sandy Middleton , Caroline L. Watkins , Octavio M. Pontes-Neto , Tsong-Hai Lee , BRUNSER, ALEJANDRO , Craig S. Anderson

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Low-Dose versus Standard-Dose Intravenous Alteplase in Acute Ischemic Stroke

2016 , Craig S. Anderson , Thompson Robinson , Richard I. Lindley , Hisatomi Arima , LAVADOS GERMAIN, PABLO MANUEL , Tsong-Hai Lee , Joseph P. Broderick , Xiaoying Chen , Guofang Chen , Vijay K. Sharma , Jong S. Kim , Nguyen H. Thang , Yongjun Cao , Mark W. Parsons , Christopher Levi , Yining Huang , Verónica V. Olavarría , Andrew M. Demchuk , Philip M. Bath , Geoffrey A. Donnan , Sheila Martins , Octavio M. Pontes-Neto , Federico Silva , Stefano Ricci , Christine Roffe , Jeyaraj Pandian , Laurent Billot , Mark Woodward , Qiang Li , Xia Wang , Jiguang Wang , John Chalmers

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Statistical analysis plan for the Head Position in Stroke Trial (HeadPoST): An international cluster cross-over randomized trial

2017 , Laurent Billot , Mark Woodward , Hisatomi Arima , Maree L Hackett , MUÑOZ VENTURELLI, PAULA ANDREA , LAVADOS GERMAIN, PABLO MANUEL , BRUNSER, ALEJANDRO , Bin Peng , Liying Cui , Lily Song , Stephane Heritier , Stephen Jan , Sandy Middleton , OLAVARRIA IANISZEWSKY, VERONICA VIVIANA , Joyce Lim , Thompson Robinson , Octavio Pontes-Neto , Caroline Watkins , Craig S Anderson

Background There is evidence to indicate that the lying flat head position increases cerebral blood flow and oxygenation in patients with acute ischemic stroke, but how these physiological effects translate into clinical outcomes is uncertain. The Head Position in Stroke Trial aims to determine the comparative effectiveness of lying flat (0°) compared to sitting up (≥30°) head positioning, initiated within 24 h of hospital admission for patients with acute stroke. Design An international, pragmatic, cluster-randomized, crossover, open, blinded outcome assessed clinical trial. Each hospital with an established acute stroke unit (cluster) site was required to recruit up to 140 consecutive cases of acute stroke (one phase of head positioning before immediately crossing over to the other phase of head positioning), including both acute ischemic stroke and intracerebral hemorrhage, in each randomized head position as a ‘business as usual’ policy. Objective To outline in detail the predetermined statistical analysis plan for the study. Methods All accumulated data will be reviewed and formally assessed. Information regarding baseline characteristics of patients, their process of care and management will be outlined, and for each item, statistically relevant descriptive elements will be described. For the trial outcomes, the most appropriate statistical comparisons are described. Results A statistical analysis plan was developed that is transparent, verifiable, and predetermined before completion of data collection. Conclusions We developed a predetermined statistical analysis plan for Head Position in Stroke Trial to avoid analysis bias arising from prior knowledge of the findings, in order to reliably quantify the benefits and harms of lying flat versus sitting up early after the onset of acute stroke. Trial registration ClinicalTrials.gov identifier NCT02162017; ANZCTR identifier ACTRN12614000483651

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Low blood pressure and adverse outcomes in acute stroke: HeadPoST study explanations

2020 , Menglu Ouyang , MUÑOZ VENTURELLI, PAULA ANDREA , Laurent Billot , Xia Wang , Lili Song , Hisatomi Arima , LAVADOS GERMAIN, PABLO MANUEL , Maree L. Hackett , OLAVARRIA IANISZEWSKY, VERONICA VIVIANA , BRUNSER, ALEJANDRO , Sandy Middleton , Octavio M. Pontes-Neto , Tsong-Hai Lee , Caroline L. Watkins , Thompson Robinson , Craig S. Anderson

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Influence of Including Patients with Premorbid Disability in Acute Stroke Trials: The HeadPoST Experience

2021 , Xia Wang , Tom J. Moullaali , Menglu Ouyang , Laurent Billot , Else Charlotte Sandset , Lili Song , Candice Delcourt , Maree L. Hackett , Caroline L. Watkins , Thompson G. Robinson , Jie Yang , LAVADOS GERMAIN, PABLO MANUEL , BRUNSER, ALEJANDRO , OLAVARRIA IANISZEWSKY, VERONICA VIVIANA , MUÑOZ VENTURELLI, PAULA ANDREA , Hisatomi Arima , Sandy Middleton , Octávio M. Pontes-Neto , Jeyaraj Durai Pandian , Kris Rogers , Craig S. Anderson

<b><i>Background:</i></b> Patients with premorbid functional impairment are generally excluded from acute stroke trials. We aimed to determine the impact of including such patients in the Head Positioning in acute Stroke Trial (HeadPoST) and early additional impairment on outcomes. <b><i>Methods:</i></b> Post hoc analyses of HeadPoST, an international, cluster-randomized crossover trial of lying-flat versus sitting-up head positioning in acute stroke. Associations of early additional impairment, defined as change in modified Rankin scale (mRS) scores from premorbid levels (estimated at baseline) to Day 7 (“early ΔmRS”), and poor outcome (mRS score 3–6) at Day 90 were determined with generalized linear mixed model. Heterogeneity of the trial treatment effect was tested according to premorbid mRS scores 0–1 versus 2–5. <b><i>Results:</i></b> Of 8,285 patients (38.9% female, mean age 68 ± 13 years) with complete data, there were 1,984 (23.9%) with premorbid functional impairment (mRS 2–5). A significant linear association was evident for early ∆mRS and poor outcome (per 1-point increase in ΔmRS, adjusted odds ratio 1.20, 95% confidence interval 1.14–1.27; <i>p</i> &#x3c; 0.0001). Patients with greater premorbid functional impairment were less likely to develop additional impairment, but their risk of poor 90-day outcome significantly increased with increasing (worse) premorbid mRS scores (linear trend <i>p</i> &#x3c; 0.0001). There was no heterogeneity of the trial treatment effect by level of premorbid function. <b><i>Conclusions:</i></b> Early poststroke functional impairment that exceeded premorbid levels was associated with worse 90-day outcome, and this association increased with greater premorbid functional impairment. Yet, including premorbid impaired patients in the HeadPoST did not materially affect the subsequent treatment effect. <b><i>Clinical Trial Registration:</i></b> HeadPoST is registered at http://www.ClinicalTrials.gov (NCT02162017).

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Regional variation in acute stroke care organisation

2016 , MUÑOZ VENTURELLI, PAULA ANDREA , Thompson Robinson , LAVADOS GERMAIN, PABLO MANUEL , OLAVARRIA IANISZEWSKY, VERONICA VIVIANA , Hisatomi Arima , Laurent Billot , Maree L. Hackett , Joyce Y. Lim , Sandy Middleton , Octavio Pontes-Neto , Bin Peng , Liying Cui , Lily Song , Gillian Mead , Caroline Watkins , Ruey-Tay Lin , Tsong-Hai Lee , Jeyaraj Pandian , H. Asita de Silva , Craig S. Anderson

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