Browsing by Author "Heritier, Stephane"
Now showing 1 - 5 of 5
Results Per Page
Sort Options
Item Head position and cerebral blood flow velocity in acute ischemic stroke: a systematic review and meta-analysis.(Karger, 2014) Lavados, Pablo; Heritier, Stephane; Muñoz Venturelli, Paula; Brunser, Alejandro; Anderson, Craig; Arima, Hisatomi; Olavarría, VerónicaBACKGROUND: Patients with acute ischemic stroke (AIS) have impaired vasomotor reactivity, especially in the affected cerebral hemisphere, such that they may depend directly on systemic blood pressure to maintain perfusion to vulnerable 'at risk' penumbral tissue. As the sitting up position may affect cerebral perfusion by decreasing cerebral blood flow (CBF) in salvageable tissue, positioning AIS patients with their head in a lying flat position could increase CBF through collateral circulation or gravitational force. We wished to quantify the effect of different head positions on mean flow velocity (MFV) by transcranial Doppler ultrasonography (TCD) in AIS patients to assess the potential for benefit (or harm) of head positioning in a clinical trial. METHODS: We performed a systematic review and meta-analysis of observational studies with TCD to evaluate differences in cerebral MFV between the lying flat and sitting up head positions in AIS. For each study and each comparison, we obtained the mean value of changes in MFV and its variance. RESULTS: A total of 303 studies were identified, but 298 were excluded for varying reasons; 4 papers met the inclusion criteria and 57 patients were included in the meta-analysis for calculation of the overall mean difference in MFV. We found a significant increase in MFV from a bed angle of 30 to 15° (4.6 cm/s, 95% confidence interval, CI, 2.9-6.2, p < 0.001) and from 30 to 0° (8.3 cm/s, 95% CI 5.3-11.3, p < 0.001) in the affected hemisphere but not on the normal side in AIS patients. CONCLUSIONS: In AIS patients, MFV increased significantly in the side affected by the stroke but not in the unaffected side when they were positioned in a lying flat head position at 0 or 15° compared to an upright head position at 30°. The clinical significance of these findings is now undergoing further randomized evaluation in the international multicenter Head Position in Acute Stroke Trial (HeadPoST).Item Head Position in Stroke Trial (HeadPoST) - sitting-up vs lying-flat positioning of patients with acute stroke: study protocol for a cluster randomised controlled trial(Biomed Central Ltd., 2015) Muñoz, Paula; Arima, Hisatomi; Lavados, Pablo; Brunser, Alejandro; Peng, Bin; Cui, Liying; Song, Lily; Billot, Laurent; Boaden, Elizabeth; Hackett, Maree; Heritier, Stephane; Stephen, Jan; Middleton, Sandy; Olavarría, Verónica; Lim, Joyce; Lyndle, Richard; Heeley, Emma; Thompson, Robinson; Pontes, Octavio; Natsagdorj, Lkhamtsoo; Ruey-Tay, Lin; Watkins, Caroline; Anderson, CraigBACKGROUND: Positioning a patient lying-flat in the acute phase of ischaemic stroke may improve recovery and reduce disability, but such a possibility has not been formally tested in a randomised trial. We therefore initiated the Head Position in Stroke Trial (HeadPoST) to determine the effects of lying-flat (0°) compared with sitting-up (≥ 30°) head positioning in the first 24 hours of hospital admission for patients with acute stroke. METHODS/DESIGN: We plan to conduct an international, cluster randomised, crossover, open, blinded outcome-assessed clinical trial involving 140 study hospitals (clusters) with established acute stroke care programs. Each hospital will be randomly assigned to sequential policies of lying-flat (0°) or sitting-up (≥ 30°) head position as a 'business as usual' stroke care policy during the first 24 hours of admittance. Each hospital is required to recruit 60 consecutive patients with acute ischaemic stroke (AIS), and all patients with acute intracerebral haemorrhage (ICH) (an estimated average of 10), in the first randomised head position policy before crossing over to the second head position policy with a similar recruitment target. After collection of in-hospital clinical and management data and 7-day outcomes, central trained blinded assessors will conduct a telephone disability assessment with the modified Rankin Scale at 90 days. The primary outcome for analysis is a shift (defined as improvement) in death or disability on this scale. For a cluster size of 60 patients with AIS per intervention and with various assumptions including an intracluster correlation coefficient of 0.03, a sample size of 16,800 patients at 140 centres will provide 90 % power (α 0.05) to detect at least a 16 % relative improvement (shift) in an ordinal logistic regression analysis of the primary outcome. The treatment effect will also be assessed in all patients with ICH who are recruited during each treatment study period. DISCUSSION: HeadPoST is a large international clinical trial in which we will rigorously evaluate the effects of different head positioning in patients with acute stroke.Item Rapid blood-pressure lowering in patients with acute intracerebral hemorrhage(Massachusetts Medical Society, 2013) Anderson, Craig; Heeley, Emma; Huang, Yining; Wang, Jiguang; Stapf, Christian; Delcourt, Candice; Lindley, Richard; Robinson, Thompson; Lavados, Pablo; Neal, Bruce; Hata, Jun; Arima, Hisatomi; Parsons, Mark; Li, Yuechun; Wang, Jinchao; Heritier, Stephane; Li, Qiang; Woodward, Mark; Simes, John; Davis, Stephen; Chalmers, JohnBACKGROUND: Whether rapid lowering of elevated blood pressure would improve the outcome in patients with intracerebral hemorrhage is not known. METHODS: We randomly assigned 2839 patients who had had a spontaneous intracerebral hemorrhage within the previous 6 hours and who had elevated systolic blood pressure to receive intensive treatment to lower their blood pressure (with a target systolic level of <140 mm Hg within 1 hour) or guideline-recommended treatment (with a target systolic level of <180 mm Hg) with the use of agents of the physician's choosing. The primary outcome was death or major disability, which was defined as a score of 3 to 6 on the modified Rankin scale (in which a score of 0 indicates no symptoms, a score of 5 indicates severe disability, and a score of 6 indicates death) at 90 days. A prespecified ordinal analysis of the modified Rankin score was also performed. The rate of serious adverse events was compared between the two groups. RESULTS: Among the 2794 participants for whom the primary outcome could be determined, 719 of 1382 participants (52.0%) receiving intensive treatment, as compared with 785 of 1412 (55.6%) receiving guideline-recommended treatment, had a primary outcome event (odds ratio with intensive treatment, 0.87; 95% confidence interval [CI], 0.75 to 1.01; P=0.06). The ordinal analysis showed significantly lower modified Rankin scores with intensive treatment (odds ratio for greater disability, 0.87; 95% CI, 0.77 to 1.00; P=0.04). Mortality was 11.9% in the group receiving intensive treatment and 12.0% in the group receiving guideline-recommended treatment. Nonfatal serious adverse events occurred in 23.3% and 23.6% of the patients in the two groups, respectively. CONCLUSIONS: In patients with intracerebral hemorrhage, intensive lowering of blood pressure did not result in a significant reduction in the rate of the primary outcome of death or severe disability. An ordinal analysis of modified Rankin scores indicated improved functional outcomes with intensive lowering of blood pressure. (Funded by the National Health and Medical Research Council of Australia; INTERACT2 ClinicalTrials.gov number, NCT00716079.).Item Statistical analysis plan for the Head Position in Stroke Trial (HeadPoST): An international cluster cross-over randomized trial(2017) Billot, Laurent; Woodward, Mark; Arima, Hisatomi; Hackett, Maree L; Muñoz Venturelli, Paula; Lavados, Pablo; Brunser, Alejandro; Peng, Bin; Cui, Liying; Song, Lily; Heritier, Stephane; Jan, Stephen; Middleton, Sandy; Olavarría, Verónica V; Lim, Joyce; Robinson, Thompson; Pontes-Neto, Octavio; Watkins, Caroline; Anderson, Craig SBackground 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.Item Statistical analysis plan for the second INTEnsive blood pressure Reduction in Acute Cerebral hemorrhage Trial (INTERACT2): a large-scale investigation to solve longstanding controversy over the most appropriate management of elevated blood pressure in the hyperacute phase of intracerebral hemorrhage(Sage Publications, 2013) Anderson, Craig; Heeley, Emma; Heritier, Stephane; Arima, Hisatomi; Woodward, Mark; Lindley, Richard; Neal, Bruce; Huang, Yining; Wang, Ji-Guang; Parsons, Mark; Stapf, Christian; Robinson, Tom; Lavados, Pablo; Delcourt, Candice; Davis, Stephen; Chalmers, JohnThe Statistical analysis plan (SAP) for the second INTEnsive blood pressure Reduction in Acute Cerebral hemorrhage Trial (INTERACT2).