Impact of hydration status on haemodynamics, effects of acute blood pressure-lowering treatment, and prognosis after stroke.

AIMS: Although high blood pressure (BP) is common in acute stroke and associated with poor outcome, the Efficacy of Nitric Oxide in Stroke (ENOS) trial showed no beneficial effect of antihypertensive treatment in this situation. Antihypertensive agents have accentuated effects in dehydrated patients. We assessed the impact of dehydration on haemodynamics, the effects of antihypertensive treatment, and prognosis in the ENOS trial. METHODS: ENOS randomized 4011 patients with acute stroke and raised systolic BP to a glyceryl trinitrate (GTN) patch or no GTN patch, and to continue or to stop existing antihypertensive treatment within 48 h of onset. The primary outcome was functional outcome (modified Rankin Scale, mRS) at day 90. Blood markers of dehydration at baseline were collected at two sites (n = 310) and their relationship with haemodynamics and outcome was assessed. RESULTS: There were no significant associations between dehydration markers and fall in blood pressure from baseline to day 1, and no significant interaction with allocated treatment. Overall, increasing urea was associated with an unfavourable shift in mRS [odds ratio 3.43, 95% confidence interval (CI) 1.42, 8.32; P = 0.006] and increased risk of death at day 90 (hazard ratio 4.55, 95% CI 1.51, 13.66; P = 0.007). CONCLUSIONS: Blood pressure-lowering treatment was safe in dehydrated patients, with no precipitous changes in BP, thus supporting its use in acute stroke prior to blood markers of dehydration becoming available. Increased baseline urea was associated with poor prognosis after stroke.

Inhibition of TNF-α protects in vitro brain barrier from ischaemic damage.

Cerebral ischaemia, associated with neuroinflammation and oxidative stress, is known to perturb blood-brain barrier (BBB) integrity and promote brain oedema formation. Using an in vitro model of human BBB composed of brain microvascular endothelial cells and astrocytes, this study examined whether suppression of TNF-α, a potent pro-inflammatory cytokine, might attenuate ischaemia-mediated cerebral barrier damage. Radical decreases in transendothelial electrical resistance and concomitant increases in paracellular flux across co-cultures exposed to increasing periods of oxygen-glucose deprivation alone (0.5-20 h) or followed by 20 h of reperfusion (OGD ± R) confirmed the deleterious effects of ischaemic injury on cerebral barrier integrity and function which concurred with reductions in tight junction protein (claudin-5 and occludin) expressions. OGD ± R elevated TNF-α secretion, NADPH oxidase activity, O2(-) production, actin stress fibre formation, MMP-2/9 activities and apoptosis in both endothelial cells and astrocytes. Increases in MMP-2 activity were confined to its extracellular isoform and treatments with OGD+R in astrocytes where MMP-9 could not be detected at all. Co-exposure of individual cell lines or co-cultures to an anti-TNF-α antibody dramatically diminished the extent of OGD ± R-evoked oxidative stress, morphological changes, apoptosis, MMP-2/9 activities while improving the barrier function through upregulation of tight junction protein expressions. In conclusion, vitiation of the exaggerated release of TNF-α may be an important therapeutic strategy in preserving cerebral integrity and function during and following a cerebral ischaemic attack.

Effects of blood pressure-lowering treatment in different subtypes of acute ischemic stroke.

BACKGROUND AND PURPOSE: The Scandinavian Candesartan Acute Stroke Trial (SCAST) found no benefits of blood pressure-lowering treatment with candesartan in acute stroke. We have investigated whether the effect of treatment is different in different subtypes of ischemic stroke. METHODS: SCAST was a randomized- and placebo-controlled trial of candesartan in 2029 patients presenting within 30 hours of ischemic or hemorrhagic stroke and systolic blood pressure ≥140 mm Hg. Ischemic stroke subtype was categorized by the Oxfordshire Community Stroke Project classification. There were 2 primary effect variables: the composite vascular end point of vascular death, myocardial infarction, or stroke during the first 6 months and functional outcome at 6 months. RESULTS: A total of 1733 patients with ischemic stroke were included: total anterior circulation infarcts in 129, partial anterior in 850, posterior in 236, and lacunar in 510 patients. For functional outcome there was a significant trend toward a better effect of candesartan in patients with larger infarcts (total anterior circulation or partial anterior circulation) than in patients with smaller infarcts (lacunar infarction; P=0.02). For the composite vascular end point, there were no differences in treatment effect. CONCLUSIONS: The results suggest that the effect of blood pressure-lowering treatment with candesartan may differ according to different types of acute ischemic stroke, but this needs to be confirmed in future trials. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT00120003.

Performance characteristics of methods for quantifying spontaneous intracerebral haemorrhage: data from the Efficacy of Nitric Oxide in Stroke (ENOS) trial.

BACKGROUND: Poor prognosis after intracerebral haemorrhage (ICH) is related to haemorrhage characteristics. Along with developing therapeutic interventions, we sought to understand the performance of haemorrhage descriptors in large clinical trials. METHODS: Clinical and neuroimaging data were obtained for 548 participants with ICH from the Efficacy of Nitric Oxide in Stroke (ENOS) trial. Independent observers performed visual categorisation of the largest diameter, measured volume using ABC/2, modified ABC/2, semiautomated segmentation (SAS), fully automatic measurement methods; shape, density and intraventricular haemorrhage were also assessed. Intraobserver and interobserver reliability were determined for these measures. RESULTS: ICH volume was significantly different among standard ABC/2, modified ABC/2 and SAS: (mean) 12.8 (SD 16.3), 8.9 (9.2), 12.8 (13.1) cm(3), respectively (p<0.0001). There was excellent agreement for haemorrhage volume (n=193): ABC/2 intraobserver intraclass correlation coefficient (ICC) 0.96-0.97, interobserver ICC 0.88; modified ABC/2 intraobserver ICC 0.95-0.97, interobserver ICC 0.91; SAS intraobserver ICC 0.95-0.99, interobserver ICC 0.93; largest diameter: (visual) interadjudicator ICC 0.82, (visual vs measured) adjudicator vs observer ICC 0.71; shape intraobserver ICC 0.88 interobserver ICC 0.75; density intraobserver ICC 0.86, interobserver ICC 0.73. Graeb score (mean 3.53) and modified Graeb (5.22) scores were highly correlated. Using modified ABC/2, ICH volume was underestimated in regular (by 2.2-2.5 cm(3), p<0.0001) and irregular-shaped haemorrhages (by 4.8-4.9 cm(3), p<0.0001). Fully automated measurement of haemorrhage volume was possible in only 5% of cases. CONCLUSIONS: Formal measurement of haemorrhage characteristics and visual estimates are reproducible. The standard ABC/2 method is superior to the modified ABC/2 method for quantifying ICH volume. CLINICAL TRIAL REGISTRATION: ISRCTN9941422.

Early dual versus mono antiplatelet therapy for acute non-cardioembolic ischemic stroke or transient ischemic attack: an updated systematic review and meta-analysis.

BACKGROUND: Emerging studies suggest that early administration of dual antiplatelet therapy may be better than monotherapy for prevention of early recurrent stroke and cardiovascular outcomes in acute ischemic stroke and transient ischemic attack (TIA). We performed a meta-analysis of randomized, controlled trials evaluating dual versus mono antiplatelet therapy for acute noncardioembolic ischemic stroke or TIA. METHODS AND RESULTS: We assessed randomized, controlled trials investigating dual versus mono antiplatelet therapy published up to November 2012 and the CHANCE trial (Clopidogrel in High-risk patients with Acute Non-disabling Cerebrovascular Events), for efficacy and safety outcomes in adult patients with acute noncardioembolic ischemic stroke or TIA with treatment initiated within 3 days of ictus. In total, 14 studies of 9012 patients were included in the systematic review and meta-analysis. Dual antiplatelet therapy significantly reduced risk of stroke recurrence (risk ratio, 0.69; 95% confidence interval, 0.60-0.80; P<0.001) and the composite outcome of stroke, TIA, acute coronary syndrome, and all death (risk ratio, 0.71; 95% confidence interval, 0.63-0.81; P<0.001) when compared with monotherapy, and nonsignificantly increased risk of major bleeding (risk ratio, 1.35; 95% confidence interval, 0.70-2.59, P=0.37). Analyses restricted to the CHANCE Trial or the 7 double-blind randomized, controlled trials showed similar results. CONCLUSIONS: For patients with acute noncardioembolic ischemic stroke or TIA, dual therapy was more effective than monotherapy in reducing risks of early recurrent stroke. The results of the CHANCE study are consistent with previous studies done in other parts of the world.

Blood pressure-lowering treatment with candesartan in patients with acute hemorrhagic stroke.

BACKGROUND AND PURPOSE: Early and intensive blood pressure-lowering treatment seems to be beneficial in patients with acute hemorrhagic stroke and high blood pressure. We wanted to see if similar benefits can be shown from a later and more gradual blood pressure lowering, using data from the Scandinavian Candesartan Acute Stroke Trial (SCAST). METHODS: SCAST was a randomized- and placebo-controlled, double-masked trial of candesartan given for 7 days, in 2029 patients with acute stroke and systolic blood pressure ≥140 mm Hg. We assessed the effects of candesartan in the 274 patients with hemorrhagic stroke, using the trial's 2 coprimary effect variables: the composite vascular end point of vascular death, stroke or myocardial infarction, and functional outcome at 6 months, according to the modified Rankin Scale. We used Cox proportional hazards models and ordinal regression for analysis and adjusted for key, predefined prognostic variables. RESULTS: There was no association between treatment with candesartan and risk of vascular events (17 of 144 [11.8%] versus 13 of 130 [10.0%]; hazard ratio, 1.36; 95% confidence interval, 0.65-2.83; P=0.41). For functional outcome we found evidence of a negative effect of candesartan (common odds ratio, 1.61; 95% confidence interval, 1.03-2.50; P=0.036). CONCLUSIONS: There was no evidence that blood pressure-lowering treatment with candesartan is beneficial during the first week of hemorrhagic stroke. Instead, there were signs that such treatment may be harmful, but this needs to be verified in larger studies. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT00120003.

Inhibition of Rho-kinase protects cerebral barrier from ischaemia-evoked injury through modulations of endothelial cell oxidative stress and tight junctions.

Ischaemic strokes evoke blood-brain barrier (BBB) disruption and oedema formation through a series of mechanisms involving Rho-kinase activation. Using an animal model of human focal cerebral ischaemia, this study assessed and confirmed the therapeutic potential of Rho-kinase inhibition during the acute phase of stroke by displaying significantly improved functional outcome and reduced cerebral lesion and oedema volumes in fasudil- versus vehicle-treated animals. Analyses of ipsilateral and contralateral brain samples obtained from mice treated with vehicle or fasudil at the onset of reperfusion plus 4 h post-ischaemia or 4 h post-ischaemia alone revealed these benefits to be independent of changes in the activity and expressions of oxidative stress- and tight junction-related parameters. However, closer scrutiny of the same parameters in brain microvascular endothelial cells subjected to oxygen-glucose deprivation ± reperfusion revealed marked increases in prooxidant NADPH oxidase enzyme activity, superoxide anion release and in expressions of antioxidant enzyme catalase and tight junction protein claudin-5. Cotreatment of cells with Y-27632 prevented all of these changes and protected in vitro barrier integrity and function. These findings suggest that inhibition of Rho-kinase after acute ischaemic attacks improves cerebral integrity and function through regulation of endothelial cell oxidative stress and reorganization of intercellular junctions. Inhibition of Rho-kinase (ROCK) activity in a mouse model of human ischaemic stroke significantly improved functional outcome while reducing cerebral lesion and oedema volumes compared to vehicle-treated counterparts. Studies conducted with brain microvascular endothelial cells exposed to OGD ± R in the presence of Y-27632 revealed restoration of intercellular junctions and suppression of prooxidant NADPH oxidase activity as important factors in ROCK inhibition-mediated BBB protection.

Evaluating the translational potential of progesterone treatment following transient cerebral ischaemia in male mice.

BACKGROUND: Progesterone is neuroprotective in numerous preclinical CNS injury models including cerebral ischaemia. The aim of this study was two-fold; firstly, we aimed to determine whether progesterone delivery via osmotic mini-pump would confer neuroprotective effects and whether such neuroprotection could be produced in co-morbid animals. RESULTS: Animals underwent transient middle cerebral artery occlusion. At the onset of reperfusion, mice were injected intraperitoneally with progesterone (8 mg/kg in dimethylsulfoxide). Adult and aged C57 Bl/6 mice were dosed additionally with subcutaneous infusion (1.0 µl/h of a 50 mg/ml progesterone solution) via implanted osmotic minipumps. Mice were allowed to survive for up to 7 days post-ischaemia and assessed for general well-being (mass loss and survival), neurological score, foot fault and t-maze performance. Progesterone reduced neurological deficit [F(1,2) = 5.38, P = 0.027] and number of contralateral foot-faults [F(1,2) = 7.36, P = 0.0108] in adult, but not aged animals, following ischaemia. In hypertensive animals, progesterone treatment lowered neurological deficit [F(1,6) = 18.31, P = 0.0001], reduced contralateral/ipsilateral alternation ratio % [F(1,2) = 17.05, P = 0.0006] and time taken to complete trials [F(1,2) = 15.92, P = 0.0009] for t-maze. CONCLUSION: Post-ischemic progesterone administration via mini-pump delivery is effective in conferring functional improvement in a transient MCAO model in adult mice. Preliminary data suggests such a treatment regimen was not effective in producing a protective effect in aged mice. However, in hypertensive mice, who received post-ischemic progesterone intraperitoneally at the onset of reperfusion had better functional outcomes than control hypertensive mice.

Views of paramedics on their role in an out-of-hospital ambulance-based trial in ultra-acute stroke: qualitative data from the Rapid Intervention With Glyceryl Trinitrate in Hypertensive Stroke Trial (RIGHT).

STUDY OBJECTIVE: Optimal practices for recruiting, consenting, and randomizing patients, and delivering treatment in out-of-hospital ultra-acute stroke trials, remain unclear. We aim to identify key barriers and facilitators relevant to the design and conduct of ambulance-based stroke trials and to formulate preliminary recommendations for the design of future trials. METHODS: Using semistructured interviews, we investigated the experiences and challenges faced by paramedics who took part in a randomized controlled trial in suspected ultra-acute stroke, the Rapid Intervention With Glyceryl Trinitrate in Hypertensive Stroke Trial (RIGHT), in which recruitment, consent, randomization, assessment, and treatment were delivered by paramedics before hospitalization. RESULTS: We purposively selected a diversity sample of 14 of the 78 paramedics who participated in RIGHT. We identified 13 themes (7 facilitators and 6 barriers to out-of-hospital stroke research). A simple stroke diagnostic tool, use of proxy consent on behalf of patients, and straightforward trial processes were identified as the main facilitators. Recruitment became easier with each new randomization attempt. Key barriers reported were informed consent in the emergency setting, lack of institutional support for research, learning curve and rarity (each paramedic treats only a few eligible patients), and difficulty in attending training sessions. Interviewed paramedics were motivated to participate in research. CONCLUSION: Ultra-acute stroke research in the out-of-hospital environment is feasible, but important barriers need to be addressed. Proxy consent by paramedics addresses some of the difficulties with the consent process in the out-of-hospital setting.

Interventions for deliberately altering blood pressure in acute stroke.

BACKGROUND: It is unclear whether blood pressure should be altered actively during the acute phase of stroke. This is an update of a Cochrane review first published in 1997, and previously updated in 2001 and 2008. OBJECTIVES: To assess the clinical effectiveness of altering blood pressure in people with acute stroke, and the effect of different vasoactive drugs on blood pressure in acute stroke. SEARCH METHODS: We searched the Cochrane Stroke Group Trials Register (last searched in February 2014), the Cochrane Database of Systematic reviews (CDSR) and the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 2), MEDLINE (Ovid) (1966 to May 2014), EMBASE (Ovid) (1974 to May 2014), Science Citation Index (ISI, Web of Science, 1981 to May 2014) and the Stroke Trials Registry (searched May 2014). SELECTION CRITERIA: Randomised controlled trials of interventions that aimed to alter blood pressure compared with control in participants within one week of acute ischaemic or haemorrhagic stroke. DATA COLLECTION AND ANALYSIS: Two review authors independently applied the inclusion criteria, assessed trial quality and extracted data. The review authors cross-checked data and resolved discrepancies by discussion to reach consensus. We obtained published and unpublished data where available. MAIN RESULTS: We included 26 trials involving 17,011 participants (8497 participants were assigned active therapy and 8514 participants received placebo/control). Not all trials contributed to each outcome. Most data came from trials that had a wide time window for recruitment; four trials gave treatment within six hours and one trial within eight hours. The trials tested alpha-2 adrenergic agonists (A2AA), angiotensin converting enzyme inhibitors (ACEI), angiotensin receptor antagonists (ARA), calcium channel blockers (CCBs), nitric oxide (NO) donors, thiazide-like diuretics, and target-driven blood pressure lowering. One trial tested phenylephrine.At 24 hours after randomisation oral ACEIs reduced systolic blood pressure (SBP, mean difference (MD) -8 mmHg, 95% confidence interval (CI) -17 to 1) and diastolic blood pressure (DBP, MD -3 mmHg, 95% CI -9 to 2), sublingual ACEIs reduced SBP (MD -12.00 mm Hg, 95% CI -26 to 2) and DBP (MD -2, 95%CI -10 to 6), oral ARA reduced SBP (MD -1 mm Hg, 95% CI -3 to 2) and DBP (MD -1 mm Hg, 95% CI -3 to 1), oral beta blockers reduced SBP (MD -14 mm Hg; 95% CI -27 to -1) and DBP (MD -1 mm Hg, 95% CI -9 to 7), intravenous (iv) beta blockers reduced SBP (MD -5 mm Hg, 95% CI -18 to 8) and DBP (-5 mm Hg, 95% CI -13 to 3), oral CCBs reduced SBP (MD -13 mmHg, 95% CI -43 to 17) and DBP (MD -6 mmHg, 95% CI -14 to 2), iv CCBs reduced SBP (MD -32 mmHg, 95% CI -65 to 1) and DBP (MD -13, 95% CI -31 to 6), NO donors reduced SBP (MD -12 mmHg, 95% CI -19 to -5) and DBP (MD -3, 95% CI -4 to -2) while phenylephrine, non-significantly increased SBP (MD 21 mmHg, 95% CI -13 to 55) and DBP (MD 1 mmHg, 95% CI -15 to 16).Blood pressure lowering did not reduce death or dependency either by drug class (OR 0.98, 95% CI 0.92 to 1.05), stroke type (OR 0.98, 95% CI 0.92 to 1.05) or time to treatment (OR 0.98, 95% CI 0.92 to 1.05). Treatment within six hours of stroke appeared effective in reducing death or dependency (OR 0.86, 95% CI 0.76 to 0.99) but not death (OR 0.70, 95% CI 0.38 to 1.26) at the end of the trial. Although death or dependency did not differ between people who continued pre-stroke antihypertensive treatment versus those who stopped it temporarily (worse outcome with continuing treatment, OR 1.06, 95% CI 0.91 to 1.24), disability scores at the end of the trial were worse in participants randomised to continue treatment (Barthel Index, MD -3.2, 95% CI -5.8, -0.6). AUTHORS' CONCLUSIONS: There is insufficient evidence that lowering blood pressure during the acute phase of stroke improves functional outcome. It is reasonable to withhold blood pressure-lowering drugs until patients are medically and neurologically stable, and have suitable oral or enteral access, after which drugs can than be reintroduced. In people with acute stroke, CCBs, ACEI, ARA, beta blockers and NO donors each lower blood pressure while phenylephrine probably increases blood pressure. Further trials are needed to identify which people are most likely to benefit from early treatment, in particular whether treatment started very early is beneficial.

Tranexamic acid for spontaneous intracerebral hemorrhage: a randomized controlled pilot trial (ISRCTN50867461).

BACKGROUND: Spontaneous intracerebral hemorrhage (ICH) can be devastating, particularly if hematoma expansion (HE) occurs. Tranexamic acid (TA), an antifibrinolytic drug, significantly reduced mortality in bleeding patients after trauma in the large CRASH-2 trial. The CRASH-2 ICH substudy found that TA nonsignificantly reduced mortality and dependency in traumatic ICH. The aim of this study was to assess the feasibility of performing a randomized controlled trial of tranexamic acid in spontaneous ICH, ahead of a definitive study. METHODS: We performed a single-center, prospective, randomized (2:1), double-blind, placebo-controlled blinded endpoint trial of TA (intravenous 1 g bolus, 1 g infusion/8 h) in acute (<24 hours) spontaneous ICH. The primary objective was to test the feasibility of recruiting to the trial. Other objectives included tolerability (adverse events) and the effect of TA on HE and death and dependency. RESULTS: The trial was feasible, with 24 patients enrolled (TA, n=16; placebo, n=8) between March 2011 and March 2012, and acceptable-only 3 patients declined to participate. All patients received the correct randomized treatment; 1 patient in the TA group did not complete the infusion because of neurologic deterioration. There were no significant differences in secondary outcomes including adverse events, HE, death, and dependency. One patient in the TA group had a deep vein thrombosis . CONCLUSIONS: This, the first randomized controlled trial of TA in ICH, found that the protocol could be delivered on schedule (2 patients/mo) and was feasible. Larger studies are needed to assess safety and efficacy of TA in ICH.

Relationship between poststroke cognition, baseline factors, and functional outcome: data from "efficacy of nitric oxide in stroke" trial.

BACKGROUND: Poststroke cognitive impairment is common and identification of prognostic factors associated with it and its relationship with other functional outcomes may help in developing preventative strategies. METHODS: Previously independent patients with acute stroke, enrolled into the ongoing "Efficacy of Nitric Oxide in Stroke" trial, were assessed by telephone on day 90 for cognitive impairment using modified versions of "Mini Mental State Examination" (MMSE-M) and "Telephone Instrument for Cognitive Status" (TICS-M) scales and category fluency. The relationship of cognitive impairment with baseline prognostic factors and other functional outcomes at day 90 were studied. RESULTS: The analysis included 1572 patients, mean age 69 years (standard deviation, 12), and female 40%. By 90 days, 246 patients had died, and cognitive impairment was present in 38%. Increasing age, stroke severity, heart rate, and presence of cerebral atrophy on baseline neuroimaging were associated with cognitive impairment (all P < .001). Hypertension and atrial fibrillation were also associated with category fluency and MMSE-M, respectively. Cognition was significantly related to other functional outcomes, TICS-M with dependency (modified Rankin Scale, rs = -.562, P < .001); disability (Barthel Index, rs = .577, P < .001); mood (Zung Depression Score, rs = -.542, P < .001); and quality of life (Euro Quality of life-5 Descriptor, rs = .519, P < .001). CONCLUSIONS: In previously independent individuals, cognitive impairment was common 3 months after stroke and related to increasing age, stroke severity, hypertension, atrial fibrillation, and cerebral atrophy on brain scanning. Cognition was related to dependency, disability, low mood, and quality of life. Hence, treatment directed toward reducing dependency might also reduce cognitive impairment.

Very low quality of life after acute stroke: data from the Efficacy of Nitric Oxide in Stroke trial.

BACKGROUND AND PURPOSE: Health-related quality of life, a key outcome after stroke, plays a role in the analysis of treatment cost-effectiveness. Some measures of health-related quality of life allow for a quality of life worse than death; the characteristics of such patients have not been well described. METHODS: Data from the Efficacy of Nitric Oxide in Stroke (ENOS) trial were used to explore health-related quality of life after stroke. The EuroQol questionnaire (EQ-5D) was performed at day 90, and a health utility score (HUS) was calculated. HUS was defined as follows: poor-good HUS>0, death HUS=0, and very poor HUS<0. The characteristics and outcomes of patients with HUS<0 were then explored. RESULTS: Of the 2569 patients, 303 (11.8%) died, and of the 2238 with quality of life data available, of whom 724 (32.3%) were completed by a proxy, 1959 (87.5%) had an HUS>0 and 279 (12.5%) had an HUS<0. Patients with HUS<0 were more likely to be older, women, have severe stroke, have proxy responders, and be institutionalized. Dominant hemisphere strokes were more likely to have proxy responders but not HUS<0. HUS was strongly correlated with dependency (modified Rankin Scale, r=-0.78) and disability (Barthel index, r=0.84) and moderately correlated with mood (Zung depression score, r=-0.59) and baseline severity (r=0.51). All but 1 patient with modified Rankin Scale of 5 had an HUS<0. CONCLUSIONS: Very low health-related quality of life is relatively common after stroke, particularly in patients with mobility problems or who are dependent on help for usual activities, and is related to poor functional outcome measures. CLINICAL TRIAL REGISTRATION URL: http://www.controlled-trials.com/. Unique identifier: ISRCTN99414122.

Predicting clinical outcomes after thrombolysis using the iScore: results from the Virtual International Stroke Trials Archive.

BACKGROUND AND PURPOSE: The ischemic stroke risk score (iScore) is a validated tool developed to estimate the risk of death and functional outcomes early after an acute ischemic stroke. Our goal was to determine the ability of the iScore to estimate clinical outcomes after intravenous thrombolysis tissue-type plasminogen activator (tPA) in the Virtual International Stroke Trials Archive (VISTA). METHODS: We applied the iScore (www.sorcan.ca/iscore) to patients with an acute ischemic stroke within the VISTA collaboration to examine the effect of tPA. We explored the association between the iScore (<200 and ≥200) and the primary outcome of favorable outcome at 3 months defined as a modified Rankin scale score of 0 to 2. Secondary outcomes included death at 3 months, catastrophic outcomes (modified Rankin scale, 4-6), and Barthel index >90 at 3 months. RESULTS: Among 7140 patients with an acute ischemic stroke, 2732 (38.5%) received tPA and 711 (10%) had an iScore ≥200. Overall, tPA treatment was associated with a significant improvement in the primary outcome among patients with an iScore <200 (38.9% non-tPA versus 47.5% tPA; P<0.001) but was not associated with a favorable outcome among patients with an iScore ≥200 (5.5% non-tPA versus 7.6% tPA; P=0.45). In the multivariable analysis after adjusting for age, baseline National Institutes of Health Stroke Scale, and onset-to-treatment time, there was a significant interaction between tPA administration and iScore; tPA administration was associated with 47% higher odds of a favorable outcome at 3 months among patients with an iScore <200 (odds ratio, 1.47; 95% confidence interval, 1.30-1.67), whereas the association between tPA and favorable outcome among those with an iScore ≥200 remained nonsignificant (odds ratio, 0.80; 95% confidence interval, 0.45-1.42). A similar pattern of benefit with tPA among patients with an iScore <200, but not ≥200, was observed for secondary outcomes including death. CONCLUSIONS: The iScore is a useful and validated tool that helps clinicians estimate stroke outcomes. In stroke patients participating in VISTA, an iScore <200 was associated with better outcomes at 3 months after tPA.

Hematopoietic stem cell (CD34+) uptake of superparamagnetic iron oxide is enhanced by but not dependent on a transfection agent.

BACKGROUND AIMS: Tracking the fate of cells after infusion would be a valuable asset for many stem cell therapies, but very few (cell) labels are approved for human therapeutic use. Superparamagnetic iron oxide particles (SPIO) can be internalized into stem cells in vitro to allow real-time tracking with gradient echo magnetic resonance imaging, but SPIO are approved for (diagnostic) imaging and not for (therapeutic) cell labeling in vivo. In this study, we investigated the possibility of labeling stem cells with an SPIO approved for patient use, albeit in a novel manner by enhancing uptake with the use of a transfection agent, also approved for patient use. Although there are many reports of hematopoietic stem cells being labeled with SPIO, there is some controversy regarding the efficiency of this and whether undifferentiated CD34+ progenitor (stem) cells are able to take up iron in the absence of a transfection agent to enhance the process. METHODS: Human CD34+ cells were treated in vitro as follows: incubation with (i) medium only (control), (ii) ferumoxide (Endorem) and (iii) ferumoxide (Endorem) plus exposure to a transfection agent (protamine sulfate). Cells were incubated for 2, 4 and 24 hours and assessed for viability, differentiation capacity and visualized in vitro with 3-T magnetic resonance imaging. The cells were also analyzed by means of flow cytometry and morphology examined by electron microscopy. RESULTS: CD34+ hematopoietic progenitor cells can internalize ferumoxide (Endorem) independently of a transfection agent. However, uptake of ferumoxide is enhanced after exposure to protamine sulfate. Iron labeling of CD34+ cells in this manner does not affect cell viability and does not appear to affect the potential of the cells to grow in culture. Iron-labeled CD34+ cells can be visualized in vitro on 3-T magnetic resonance image scanning. CONCLUSIONS: Endorem and protamine sulfate can be combined to promote iron oxide nanoparticle uptake by CD34+ cells, and this methodology can potentially be used to track the fate of cells in a clinical trial setting because both compounds are (separately) approved for clinical use.

Effect of the neutral CLOTS 1 trial on the use of graduated compression stockings in the Efficacy of Nitric Oxide Stroke (ENOS) trial.

BACKGROUND AND PURPOSE: Current evidence suggests that the time lag from the publication of randomised clinical trial results to changes in prescribing behaviour for drugs is gradually reducing. However, the effect of results of clinical trials of devices and non-pharmacological interventions on clinical practice is less clear. METHODS: Prospective data from the ongoing international 'Efficacy of Nitric Oxide Stroke' (ENOS) trial were analysed to assess the use of graduated compression stockings (GCS) for deep vein thrombus (DVT) prophylaxis in acute stroke patients before and after publication of the large 'Clots in Legs Or sTockings after Stroke' (CLOTS-1) trial. RESULTS: Data on GCS use were available for 1971 patients with acute stroke enrolled into ENOS from February 2003 to April 2011; of these, 498 (25.3%) wore GCS. Prior to publication of CLOTS-1, GCS use was common (>50%) in the UK, Australasia and Canada but infrequent in Asia and the rest of Europe. After publication of CLOTS-1, use of GCS in the UK declined from 398/656 (61%) to 20/567 (4%) (p<0.001) but not elsewhere (eg, in Australasia (57% before publication vs 70% after publication, p=0.24, but based on small numbers). Practice change was apparent within 3 months of the study publication and was sustained thereafter. There was no change in DVT rates before and after CLOTS-1 (0.8% vs 1.0%). CONCLUSIONS: GCS use declined dramatically following the reporting of the CLOTS-1 trial. The results support the notion that a neutral trial of a device can influence clinical practice rapidly, which is important with a widely used and moderately expensive (time and finance) intervention.

Publication bias in reports of animal stroke studies leads to major overstatement of efficacy.

The consolidation of scientific knowledge proceeds through the interpretation and then distillation of data presented in research reports, first in review articles and then in textbooks and undergraduate courses, until truths become accepted as such both amongst "experts" and in the public understanding. Where data are collected but remain unpublished, they cannot contribute to this distillation of knowledge. If these unpublished data differ substantially from published work, conclusions may not reflect adequately the underlying biological effects being described. The existence and any impact of such "publication bias" in the laboratory sciences have not been described. Using the CAMARADES (Collaborative Approach to Meta-analysis and Review of Animal Data in Experimental Studies) database we identified 16 systematic reviews of interventions tested in animal studies of acute ischaemic stroke involving 525 unique publications. Only ten publications (2%) reported no significant effects on infarct volume and only six (1.2%) did not report at least one significant finding. Egger regression and trim-and-fill analysis suggested that publication bias was highly prevalent (present in the literature for 16 and ten interventions, respectively) in animal studies modelling stroke. Trim-and-fill analysis suggested that publication bias might account for around one-third of the efficacy reported in systematic reviews, with reported efficacy falling from 31.3% to 23.8% after adjustment for publication bias. We estimate that a further 214 experiments (in addition to the 1,359 identified through rigorous systematic review; non publication rate 14%) have been conducted but not reported. It is probable that publication bias has an important impact in other animal disease models, and more broadly in the life sciences.

Discontinuation of antiplatelet study medication and risk of recurrent stroke and cardiovascular events: results from the PRoFESS study.

BACKGROUND: Several case control studies have reported an increased risk of cardiovascular events following discontinuation of antiplatelet agents in high-risk patients. We therefore sought to investigate the risk of recurrent stroke and cardiovascular events following discontinuation of antiplatelet study medication in the Prevention Regimen for Effectively Avoiding Second Strokes (PRoFESS) trial, a large randomized secondary stroke prevention study. METHODS: The recurrent stroke and cardiovascular event rates following discontinuation of aspirin plus extended-release dipyridamole (ASA + ERDP) or clopidogrel were compared to the event rates in the on-treatment populations (patients who had discontinued their antiplatelet medication due to an outcome event were kept in the on-treatment population in order not to underestimate the on-treatment stroke rate). RESULTS: In 7,212 treated ASA + ERDP patients, the stroke incidence rate for the on-treatment group was 729 strokes with an average exposure of 17,048 person-years (0.12 per 1,000 person-days). For 7,864 treated clopidogrel patients, the stroke incidence rate for the on-treatment group was 737 strokes with an average exposure of 18,715 person-years (0.11 per 1,000 person-days). ASA + ERDP was discontinued in 2,843 patients (in 57.7% due to an adverse event, 28.2% noncompliance, 1.4% loss to follow-up, 4.5% withdrawal of consent and 8.1% other/nonspecified reasons) and clopidogrel was permanently discontinued in 2,176 patients (49.0% due to an adverse event, 34.2% noncompliance, 1.8% loss to follow-up, 5.3% withdrawal of consent and 9.7% other/nonspecified reasons). Within 30 days, a recurrent stroke occurred in 31 patients (0.37 per 1,000 person-days) after discontinuation of ASA + ERDP and in 15 patients (0.24 per 1,000 person-days) after discontinuation of clopidogrel. This corresponds to an absolute excess risk of 0.77% within 30 days after discontinuation of ASA + ERDP and 0.40% within 30 days after discontinuation of clopidogrel compared with the on-treatment study populations. A combined vascular endpoint (stroke, myocardial infarction, vascular death) occurred in 68 patients (0.82 per 1,000 person-days) within 30 days after discontinuation of ASA + ERDP and in 47 patients (0.75 per 1,000 person-days) within 30 days after discontinuation of clopidogrel. This corresponds to an absolute excess risk of 2.02% within 30 days after discontinuation of ASA + ERDP and 1.83% within 30 days after discontinuation of clopidogrel compared with the on-treatment study populations. CONCLUSION: Discontinuation of antiplatelet medication after ischemic stroke should be advocated only when the risk and severity of bleeding clearly outweigh the risk of cardiovascular events.

Colony stimulating factors (including erythropoietin, granulocyte colony stimulating factor and analogues) for stroke.

BACKGROUND: Colony stimulating factors (CSFs), also called haematopoietic growth factors, regulate bone marrow production of circulating red and white cells, and platelets. Some CSFs also mobilise the release of bone marrow stem cells into the circulation. CSFs have been shown to be neuroprotective in experimental stroke. OBJECTIVES: To assess (1) the safety and efficacy of CSFs in people with acute or subacute ischaemic or haemorrhagic stroke, and (2) the effect of CSFs on circulating stem and blood cell counts. SEARCH METHODS: We searched the Cochrane Stroke Group Trials Register (last searched September 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 4), MEDLINE (1985 to September 2012), EMBASE (1985 to September 2012) and Science Citation Index (1985 to September 2012). In an attempt to identify further published, unpublished and ongoing trials we contacted manufacturers and principal investigators of trials (last contacted April 2012). We also searched reference lists of relevant articles and reviews. SELECTION CRITERIA: We included randomised controlled trials recruiting people with acute or subacute ischaemic or haemorrhagic stroke. CSFs included stem cell factor (SCF), erythropoietin (EPO), granulocyte colony stimulating factor (G-CSF), granulocyte-macrophage colony stimulating factor (GM-CSF), macrophage-colony stimulating factor (M-CSF, CSF-1), thrombopoietin (TPO), or analogues of these. The primary outcome was functional outcome at the end of the trial. Secondary outcomes included safety at the end of treatment, death at the end of follow-up, infarct volume and haematology measures. DATA COLLECTION AND ANALYSIS: Two review authors (TE and NS) independently extracted data and assessed trial quality. We contacted study authors for additional information. MAIN RESULTS: We included a total of 11 studies involving 1275 participants. In three trials (n = 782), EPO therapy was associated with a significant increase in death by the end of the trial (odds ratio (OR) 1.98, 95% confidence interval (CI) 1.19 to 3.3, P = 0.009) and a non-significant increase in serious adverse events. EPO significantly increased the red cell count with no effect on platelet or white cell count, or infarct volume. Two small trials of carbamylated EPO have been completed but have yet to be reported. We included eight small trials (n = 548) of G-CSF. G-CSF was associated with a non-significant reduction in early impairment (mean difference (MD) -0.4, 95% CI -1.82 to 1.01, P = 0.58) but had no effect on functional outcome at the end of the trial. G-CSF significantly elevated the white cell count and the CD34+ cell count, but had no effect on infarct volume. Further trials of G-CSF are ongoing. AUTHORS' CONCLUSIONS: There are significant safety concerns regarding EPO therapy for stroke. It is too early to know whether other CSFs improve functional outcome.

Impact of resting heart rate on mortality, disability and cognitive decline in patients after ischaemic stroke.

AIMS: Recurrent stroke is a frequent and disabling event. A high heart rate is associated with cardiovascular outcomes. We investigated the effects of the resting heart rate on cardiovascular and neurological outcomes after recurrent stroke in the high-risk population of the PRoFESS study. METHODS AND RESULTS: A total of 20,165 patients after ischaemic stroke (mean age 66.1, SD 8.6 years) assigned to the treatment arms of the PRoFESS trial were pooled divided by quintiles of the baseline heart rate and analysed according to cardiovascular and functional outcomes after stroke: recurrent stroke and major cardiovascular outcomes such as stroke, myocardial infarction, and worsening or new-onset heart failure as well as death from cardiovascular and non-cardiovascular causes. Pre-defined endpoints were disability after a recurrent stroke, assessed with the modified Rankin scale (mRS) and the Barthel index at 3 months, and cognitive function, assessed with the Mini-Mental State Examination (MMSE) score at 4 weeks after randomization and at the penultimate visit. Patients in the two highest quintiles of heart rate (77-82 and >82 b.p.m.) were at a higher risk for total death [hazard ratio (HR) 1.42, 95% CI 1.19-1.69 and HR 1.74, 95% CI 1.48-2.06, P < 0.0001] compared with the lowest quintile. Similar results were observed for vascular death [71-≤76 b.p.m., HR 1.39 (1.11-1.74), P < 0.0001] and non-vascular death [from >82 b.p.m., HR 1.66 (1.29-2.13), P = 0.0016]. Myocardial infarction (P = 0.7084) and recurrent stroke (P = 0.1379) were not significantly associated with the baseline heart rate. Hazard ratios were adjusted to multiple confounders including the baseline blood pressure. In the group of patients with a recurrent stroke, an association of a lower heart rate to better outcomes was measured with the Barthel index across all heart rate groups. In addition, there was a significant association of the baseline heart rate to the occurrence of significant cognitive decline according to an MMSE score ≤24 points at 1 month and at the penultimate visit or a decline of ≥2 points between these two time periods. Better independence score at a low heart rate were observed. CONCLUSION: The heart rate is a risk indicator for mortality in patients with stroke and, importantly, a low heart rate is associated with a better functional outcome and less cognitive decline after an ischaemic stroke. TRIAL REGISTRATION: ClinicalTrials.gov, number NTC00153062.