Association between time to treatment and clinical outcomes in endovascular thrombectomy beyond 6 hours without advanced imaging selection.

BACKGROUND: The effectiveness and safety of endovascular thrombectomy (EVT) in the late window (6-24 hours) for acute ischemic stroke (AIS) patients selected without advanced imaging is undetermined. We aimed to assess clinical outcomes and the relationship with time-to-EVT treatment beyond 6 hours of stroke onset without advanced neuroimaging. METHODS: Patients who underwent EVT selected with non-contrast CT/CT angiography (without CT perfusion or MR imaging), between October 2015 and March 2020, were included from a national stroke registry. Functional and safety outcomes were assessed in both early (<6 hours) and late windows with time analyzed as a continuous variable. RESULTS: Among 3278 patients, 2610 (79.6%) and 668 (20.4%) patients were included in the early and late windows, respectively. In the late window, for every hour delay, there was no significant association with shift towards poorer functional outcome (modified Rankin Scale (mRS)) at discharge (adjusted common OR 0.98, 95% CI 0.94 to 1.01, p=0.27) or change in predicted functional independence (mRS ≤2) (24.5% to 23.3% from 6 to 24 hours; aOR 0.99, 95% CI0.94 to 1.04, p=0.85). In contrast, predicted functional independence was time sensitive in the early window: 5.2% reduction per-hour delay (49.4% to 23.5% from 1 to 6 hours, p=0.0001). There were similar rates of symptomatic intracranial hemorrhage (sICH) (3.4% vs 4.6%, p=0.54) and in-hospital mortality (12.9% vs 14.6%, p=0.33) in the early and late windows, respectively, without a significant association with time. CONCLUSION: In this real-world study, there was minimal change in functional disability, sICH and in-hospital mortality within and across the late window. While confirmatory randomized trials are needed, these findings suggest that EVT remains feasible and safe when performed in AIS patients selected without advanced neuroimaging between 6-24 hours from stroke onset.

Endovascular thrombectomy beyond 24 hours from ischemic stroke onset: a propensity score matched cohort study.

BACKGROUND: The safety and functional outcome of endovascular thrombectomy (EVT) in the very late (VL; >24 hours) time window from ischemic stroke onset remains undetermined. METHODS: Using data from a national stroke registry, we used propensity score matched (PSM) individual level data of patients who underwent EVT, selected with CT perfusion or non-contrast CT/CT angiography, between October 2015 and March 2020. Functional and safety outcomes were assessed in both late (6-24 hours) and VL time windows. Subgroup analysis was performed of imaging selection modality in the VL time window. RESULTS: We included 1150 patients (late window: 1046 (208 after PSM); VL window: 104 (104 after PSM)). Compared with EVT treatment initiation between 6 and 24 hours, patients treated in the VL window had similar modified Rankin Scale (mRS) scores at discharge (ordinal shift; common OR=1.08, 95% CI 0.69 to 1.47, p=0.70). No significant differences in achieving good functional outcome (mRS ≤2 at discharge; 28.8% (VL) vs 29.3% (late), OR=0.97, 95% CI 0.58 to 1.64, p=0.93), successful reperfusion (modified Thrombolysis in Cerebral Infarction score of 2b-3) (p=0.77), or safety outcomes of symptomatic intracranial hemorrhage (p=0.43) and inhospital mortality (p=0.23) were demonstrated. In the VL window, there was no significant difference in functional outcome among patients selected with perfusion versus those selected without perfusion imaging (common OR=1.38, 95% CI 0.81 to 1.76, p=0.18). CONCLUSION: In this real world study, EVT beyond 24 hours from stroke onset or last known well appeared to be feasible, with comparable safety and functional outcomes to EVT initiation between 6 and 24 hours. Randomized trials assessing the efficacy of EVT in the VL window are warranted, but may only be feasible with a large international collaborative approach.

Association between anesthesia modality and clinical outcomes following endovascular stroke treatment in the extended time window.

BACKGROUND: There is a paucity of data on anesthesia-related outcomes for endovascular treatment (EVT) in the extended window (>6 hours from ischemic stroke onset). We compared functional and safety outcomes between local anesthesia (LA) without sedation, conscious sedation (CS) and general anesthesia (GA). METHODS: Patients who underwent EVT in the early (<6 hours) and extended time windows using LA, CS, or GA between October 2015 and March 2020 were included from a UK national stroke registry. Multivariable analyses were performed, adjusted for age, sex, baseline stroke severity, pre-stroke disability, EVT technique, center, procedural time and IV thrombolysis. RESULTS: A total of 4337 patients were included, 3193 in the early window (1135 LA, 446 CS, 1612 GA) and 1144 in the extended window (357 LA, 134 CS, 653 GA). Compared with GA, patients treated under LA alone had increased odds of an improved modified Rankin Scale (mRS) score at discharge (early: adjusted common (ac) OR=1.50, 95% CI 1.29 to 1.74, p=0.001; extended: acOR=1.29, 95% CI 1.01 to 1.66, p=0.043). Similar mRS scores at discharge were found in the LA and CS cohorts in the early and extended windows (p=0.21). Compared with CS, use of GA was associated with a worse mRS score at discharge in the early window (acOR=0.73, 95% CI 0.45 to 0.96, p=0.017) but not in the extended window (p=0.55). There were no significant differences in the rates of symptomatic intracranial hemorrhage or in-hospital mortality across the anesthesia modalities in the extended window. CONCLUSION: LA without sedation during EVT was associated with improved functional outcomes compared with GA, but not CS, within and beyond 6 hours from stroke onset. Prospective studies assessing anesthesia-related outcomes in the extended time window are warranted.

Effects of Semaglutide on Stroke Subtypes in Type 2 Diabetes: Post Hoc Analysis of the Randomized SUSTAIN 6 and PIONEER 6.

BACKGROUND: GLP-1 RA (glucagon-like peptide-1 receptor agonists), including semaglutide, may reduce stroke risk in people with type 2 diabetes. This post hoc analysis examined the subcutaneous and oral semaglutide effects, versus placebo, on stroke and its subtypes in people with type 2 diabetes at high cardiovascular risk. METHODS: SUSTAIN 6 (Trial to Evaluate Cardiovascular and Other Long-Term Outcomes With Semaglutide in Subjects With Type 2 Diabetes) and PIONEER 6 (Peptide Innovation for Early Diabetes Treatment) were randomized cardiovascular outcome trials of subcutaneous and oral semaglutide in people with type 2 diabetes at high cardiovascular risk, respectively. Time to first stroke and stroke subtypes were analyzed using a Cox proportional hazards model stratified by trial with pooled treatment as a factor. The impact of prior stroke, prior myocardial infarction or stroke, age, sex, systolic blood pressure, estimated glomerular filtration rate, and prior atrial fibrillation on treatment effects was assessed using interaction P values. Risk of major adverse cardiovascular event was analyzed according to prior stroke. RESULTS: A total of 106/6480 participants had a stroke (1.0 event/100 patient-years of observation [PYO]). Semaglutide reduced incidence of any stroke versus placebo (0.8 versus 1.1 events/100 PYO; hazard ratio, 0.68 [95% CI, 0.46-1.00]; P=0.048), driven by significant reductions in risk of small-vessel occlusion (0.3 versus 0.7 events/100 PYO; hazard ratio, 0.51 [95% CI, 0.29-0.89]; P=0.017). Hazard ratios for risk of any stroke with semaglutide versus placebo were 0.60 (95% CI, 0.37-0.99; 0.5 versus 0.9 events/100 PYO) and 0.89 (95% CI, 0.47-1.69; 2.7 versus 3.0 events/100 PYO) in those without and with prior stroke, respectively. Except for prior atrial fibrillation (Pinteraction=0.025), no significant interactions were observed between treatment effects on risk of any stroke and subgroups investigated, or between treatment effects on risk of major adverse cardiovascular event and prior stroke (Pinteraction >0.05 for all). CONCLUSIONS: Semaglutide reduced incidence of any first stroke during the trials versus placebo in people with type 2 diabetes at high cardiovascular risk, primarily driven by small-vessel occlusion prevention. Semaglutide treatment, versus placebo, lowered the risk of stroke irrespective of prior stroke at baseline. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT01720446 and NCT02692716.

Perfusion Imaging for Endovascular Thrombectomy in Acute Ischemic Stroke Is Associated With Improved Functional Outcomes in the Early and Late Time Windows.

BACKGROUND: The impact on clinical outcomes of patient selection using perfusion imaging for endovascular thrombectomy (EVT) in patients with acute ischemic stroke presenting beyond 6 hours from onset remains undetermined in routine clinical practice. METHODS: Patients from a national stroke registry that underwent EVT selected with or without perfusion imaging (noncontrast computed tomography/computed tomography angiography) in the early (<6 hours) and late (6-24 hours) time windows, between October 2015 and March 2020, were compared. The primary outcome was the ordinal shift in the modified Rankin Scale score at hospital discharge. Other outcomes included functional independence (modified Rankin Scale score ≤2) and in-hospital mortality, symptomatic intracerebral hemorrhage, successful reperfusion (Thrombolysis in Cerebral Infarction score 2b-3), early neurological deterioration, futile recanalization (modified Rankin Scale score 4-6 despite successful reperfusion) and procedural time metrics. Multivariable analyses were performed, adjusted for age, sex, baseline stroke severity, prestroke disability, intravenous thrombolysis, mode of anesthesia (Model 1) and including EVT technique, balloon guide catheter, and center (Model 2). RESULTS: We included 4249 patients, 3203 in the early window (593 with perfusion versus 2610 without perfusion) and 1046 in the late window (378 with perfusion versus 668 without perfusion). Within the late window, patients with perfusion imaging had a shift towards better functional outcome at discharge compared with those without perfusion imaging (adjusted common odds ratio [OR], 1.45 [95% CI, 1.16-1.83]; P=0.001). There was no significant difference in functional independence (29.3% with perfusion versus 24.8% without; P=0.210) or in the safety outcome measures of symptomatic intracerebral hemorrhage (P=0.53) and in-hospital mortality (10.6% with perfusion versus 14.3% without; P=0.053). In the early time window, patients with perfusion imaging had significantly improved odds of functional outcome (adjusted common OR, 1.51 [95% CI, 1.28-1.78]; P=0.0001) and functional independence (41.6% versus 33.6%, adjusted OR, 1.31 [95% CI, 1.08-1.59]; P=0.006). Perfusion imaging was associated with lower odds of futile recanalization in both time windows (late: adjusted OR, 0.70 [95% CI, 0.50-0.97]; P=0.034; early: adjusted OR, 0.80 [95% CI, 0.65-0.99]; P=0.047). CONCLUSIONS: In this real-world study, acquisition of perfusion imaging for EVT was associated with improvement in functional disability in the early and late time windows compared with nonperfusion neuroimaging. These indirect comparisons should be interpreted with caution while awaiting confirmatory data from prospective randomized trials.

The cost of providing mechanical thrombectomy in the UK NHS: a micro-costing study.

INTRODUCTION: The clinical efficacy and cost-effectiveness of mechanical thrombectomy (MT) for the treatment of large vessel occlusion stroke is well established, but uncertainty remains around the true cost of delivering this treatment within the NHS. The aim of this study was to establish the cost of providing MT within the hyperacute phase of care and to explore differences in resources used and costs across different neuroscience centres in the UK. METHOD: This was a multicentre retrospective study using micro-costing methods to enable a precise assessment of the costs of MT from an NHS perspective. Data on resources used and their costs were collected from five UK neuroscience centres between 2015 and 2018. RESULTS: Data were collected on 310 patients with acute ischaemic stroke treated with MT. The mean total cost of providing MT and inpatient care within 24 hours was £10,846 (95% confidence interval (CI) 10,527-11,165) per patient. The main driver of cost was MT procedure costs, accounting for 73% (£7,943; 95% CI 7,649-8,237) of the total 24-hour cost. Costs were higher for patients treated under general anaesthesia (£11,048; standard deviation (SD) 2,654) than for local anaesthesia (£9,978; SD 2,654), mean difference £1,070 (95% CI 381-1,759; p=0.003); admission to an intensive care unit (ICU; £12,212; SD 3,028) against for admission elsewhere (£10,179; SD 2,415), mean difference £2,032 (95% CI 1,345-2,719; p<0001).The mean cost within 72 hours was £12,440 (95% CI 10,628-14,252). The total costs for the duration of inpatient care before discharge from a thrombectomy centre was £14,362 (95% CI 13,603-15,122). CONCLUSIONS: Major factors contributing to costs of MT for stroke include consumables and staff for intervention, use of general anaesthesia and ICU admissions. These findings can inform the reimbursement, provision and strategic planning of stroke services and aid future economic evaluations.

Estimating the effectiveness and cost-effectiveness of establishing additional endovascular Thrombectomy stroke Centres in England: a discrete event simulation.

BACKGROUND: We have previously modelled that the optimal number of comprehensive stroke centres (CSC) providing endovascular thrombectomy (EVT) in England would be 30 (net 6 new centres). We now estimate the relative effectiveness and cost-effectiveness of increasing the number of centres from 24 to 30. METHODS: We constructed a discrete event simulation (DES) to estimate the effectiveness and lifetime cost-effectiveness (from a payer perspective) using 1 year's incidence of stroke in England. 2000 iterations of the simulation were performed comparing baseline 24 centres to 30. RESULTS: Of 80,800 patients admitted to hospital with acute stroke/year, 21,740 would be affected by the service reconfiguration. The median time to treatment for eligible early presenters (< 270 min since onset) would reduce from 195 (IQR 155-249) to 165 (IQR 105-224) minutes. Our model predicts reconfiguration would mean an additional 33 independent patients (modified Rankin scale [mRS] 0-1) and 30 fewer dependent/dead patients (mRS 3-6) per year. The net addition of 6 centres generates 190 QALYs (95%CI - 6 to 399) and results in net savings to the healthcare system of £1,864,000/year (95% CI -1,204,000 to £5,017,000). The estimated budget impact was a saving of £980,000 in year 1 and £7.07 million in years 2 to 5. CONCLUSION: Changes in acute stroke service configuration will produce clinical and cost benefits when the time taken for patients to receive treatment is reduced. Benefits are highly likely to be cost saving over 5 years before any capital investment above £8 million is required.

Associations Between 30-Day Mortality, Specialist Nursing, and Daily Physician Ward Rounds in a National Stroke Registry.

Background and Purpose- Well-organized stroke care is associated with better patient outcomes, but the most important organizational factors are unknown. Methods- Data were extracted from the Sentinel Stroke National Audit Programme of adults with acute stroke treated in stroke hospitals in England and Wales between April 2013 and March 2015. Multilevel models with random intercepts for hospitals were used to estimate the association of each variable with 30-day mortality to estimate the impact of admission to differently organized hospitals. Results- Of the 143 578 patients with acute stroke admitted to 154 hospitals, 14.4% died within 30 days of admission. In adjusted analyses, admission to hospitals with higher ratios of nurses trained in swallow screening was associated with reduced odds of death ( P=0.004), and admission to hospitals with daily physician ward rounds was associated with 10% lower odds of mortality compared with less-frequent ward rounds (95% CI, 0.82-0.98; P=0.013). Number of stroke admissions and overall ratio of registered nurses on duty at weekends were not found to be independently associated with mortality after adjustment for other factors. Conclusions- If these associations are causal, an extra 1332 deaths annually in England and Wales could be saved by hospitals providing care associated with a ratio of nurses trained in swallow screening of at least 3 per 10 beds and daily stroke physician ward rounds.

Estimating the number of UK stroke patients eligible for endovascular thrombectomy.

INTRODUCTION: Endovascular thrombectomy is a highly effective treatment for acute ischemic stroke due to large arterial occlusion. Routine provision will require major changes in service configuration and workforce. An important first step is to quantify the population of stroke patients that could benefit. We estimated the annual UK population suitable for endovascular thrombectomy using standard or advanced imaging for patient selection. PATIENTS AND METHODS: Evidence from randomised control trials and national registries was combined to estimate UK stroke incidence and define a decision-tree describing the endovascular thrombectomy eligible population. RESULTS: Between 9620 and 10,920 UK stroke patients (approximately 10% of stroke admissions) would be eligible for endovascular thrombectomy annually. The majority (9140-9620) would present within 4 h of onset and be suitable for intravenous thrombolysis. Advanced imaging would exclude 500 patients presenting within 4 h, but identify an additional 1310 patients as eligible who present later. DISCUSSION: Information from randomised control trials and large registry data provided the evidence criterion for 9 of the 12 decision points. The best available evidence was used for two decision points with sensitivity analyses to determine how key branches of the tree affected estimates. Using the mid-point estimate for eligibility (9.6% of admissions) and assuming national endovascular thrombectomy coverage, 4280 patients would have reduced disability. CONCLUSION: A model combining published trials and register data suggests approximately 10% of all stroke admissions in the UK are eligible for endovascular thrombectomy. The use of advanced imaging based on current published evidence did not have a major impact on overall numbers but could alter eligibility status for 16% of cases.

A modelling tool for capacity planning in acute and community stroke services.

BACKGROUND: Mathematical capacity planning methods that can take account of variations in patient complexity, admission rates and delayed discharges have long been available, but their implementation in complex pathways such as stroke care remains limited. Instead simple average based estimates are commonplace. These methods often substantially underestimate capacity requirements. We analyse the capacity requirements for acute and community stroke services in a pathway with over 630 admissions per year. We sought to identify current capacity bottlenecks affecting patient flow, future capacity requirements in the presence of increased admissions, the impact of co-location and pooling of the acute and rehabilitation units and the impact of patient subgroups on capacity requirements. We contrast these results to the often used method of planning by average occupancy, often with arbitrary uplifts to cater for variability. METHODS: We developed a discrete-event simulation model using aggregate parameter values derived from routine administrative data on over 2000 anonymised admission and discharge timestamps. The model mimicked the flow of stroke, high risk TIA and complex neurological patients from admission to an acute ward through to community rehab and early supported discharge, and predicted the probability of admission delays. RESULTS: An increase from 10 to 14 acute beds reduces the number of patients experiencing a delay to the acute stroke unit from 1 in every 7 to 1 in 50. Co-location of the acute and rehabilitation units and pooling eight beds out of a total bed stock of 26 reduce the number of delayed acute admissions to 1 in every 29 and the number of delayed rehabilitation admissions to 1 in every 20. Planning by average occupancy would resulted in delays for one in every five patients in the acute stroke unit. CONCLUSIONS: Planning by average occupancy fails to provide appropriate reserve capacity to manage the variations seen in stroke pathways to desired service levels. An appropriate uplift from the average cannot be based simply on occupancy figures. Our method draws on long available, intuitive, but underused mathematical techniques for capacity planning. Implementation via simulation at our study hospital provided valuable decision support for planners to assess future bed numbers and organisation of the acute and rehabilitation services.

Microalbuminuria could improve risk stratification in patients with TIA and minor stroke.

OBJECTIVE: Transient ischemic attacks (TIA) and minor strokes are important risk factors for recurrent strokes. Current stroke risk prediction scores such as ABCD2, although widely used, lack optimal sensitivity and specificity. Elevated urinary albumin excretion predicts cardiovascular disease, stroke, and mortality. We explored the role of microalbuminuria (using albumin creatinine ratio (ACR)) in predicting recurrence risk in patients with TIA and minor stroke. METHODS: Urinary ACR was measured on a spot sample in 150 patients attending a daily stroke clinic with TIA or minor stroke. Patients were followed up at day 7, 30, and 90 to determine recurrent stroke, cardiovascular events, or death. Eligible patients had a carotid ultrasound Doppler investigation. High-risk patients were defined as those who had an event within 90 days or had >50% internal carotid artery (ICA) stenosis. RESULTS: Fourteen (9.8%) recurrent events were reported by day 90 including two deaths. Fifteen patients had severe ICA stenosis. In total, 26 patients were identified as high risk. These patients had a higher frequency of previous stroke or hypercholesterolemia compared to low-risk patients (P = 0.04). ACR was higher in high-risk patients (3.4 [95% CI 2.2-5.2] vs. 1.7 [1.5-2.1] mg/mmol, P = 0.004), independent of age, sex, blood pressure, diabetes, and previous stroke. An ACR greater than 1.5 mg/mmol predicted high-risk patients (Cox proportional hazard ratio 3.5 (95% CI 1.3-9.5, P = 0.01). INTERPRETATION: After TIA or minor stroke, a higher ACR predicted recurrent events and significant ICA stenosis. Incorporation of urinary ACR from a spot sample in the acute setting could improve risk stratification in patients with TIA and minor stroke.

Weekly variation in health-care quality by day and time of admission: a nationwide, registry-based, prospective cohort study of acute stroke care.

BACKGROUND: Studies in many health systems have shown evidence of poorer quality health care for patients admitted on weekends or overnight than for those admitted during the week (the so-called weekend effect). We postulated that variation in quality was dependent on not only day, but also time, of admission, and aimed to describe the pattern and magnitude of variation in the quality of acute stroke care across the entire week. METHODS: We did this nationwide, registry-based, prospective cohort study using data from the Sentinel Stroke National Audit Programme. We included all adult patients (aged >16 years) admitted to hospital with acute stroke (ischaemic or primary intracerebral haemorrhage) in England and Wales between April 1, 2013, and March 31, 2014. Our outcome measure was 30 day post-admission survival. We estimated adjusted odds ratios for 13 indicators of acute stroke-care quality by fitting multilevel multivariable regression models across 42 4-h time periods per week. FINDINGS: The study cohort comprised 74,307 patients with acute stroke admitted to 199 hospitals. Care quality varied across the entire week, not only between weekends and weekdays, with different quality measures showing different patterns and magnitudes of temporal variation. We identified four patterns of variation: a diurnal pattern (thrombolysis, brain scan within 12 h, brain scan within 1 h, dysphagia screening), a day of the week pattern (stroke physician assessment, nurse assessment, physiotherapy, occupational therapy, and assessment of communication and swallowing by a speech and language therapist), an off-hours pattern (door-to-needle time for thrombolysis), and a flow pattern whereby quality changed sequentially across days (stroke-unit admission within 4 h). The largest magnitude of variation was for door-to-needle time within 60 min (range in quality 35-66% [16/46-232/350]; coefficient of variation 18·2). There was no difference in 30 day survival between weekends and weekdays (adjusted odds ratio 1·03, 95% CI 0·95-1·13), but patients admitted overnight on weekdays had lower odds of survival (0·90, 0·82-0·99). INTERPRETATION: The weekend effect is a simplification, and just one of several patterns of weekly variation occurring in the quality of stroke care. Weekly variation should be further investigated in other health-care settings, and quality improvement should focus on reducing temporal variation in quality and not only the weekend effect. FUNDING: None.

Gender, socioeconomic, and ethnic differences in sleep patterns in school-aged children.

OBJECTIVES: Age-related changes in sleep behavior are well described in children, yet the effect of gender, socioeconomic status (SES), and ethnicity is less clear. These factors are important when developing culturally and socially appropriate guidelines for healthy sleep. The objective of our study was to examine the effects of age, gender, SES, and ethnicity on sleep patterns in school-aged children. METHODS: A cross-sectional survey was conducted through primary schools in Adelaide, South Australia. Parents reported demographic information and sleep patterns for school and non-school days for 1845 children aged 5 to 10years. RESULTS: 48% of the cohort were boys (mean age, 7.7±1.7y), 85% were Caucasian, and there was an equal distribution across defined SES bands. Sleep duration reduced with age and was shorter on non-school than school nights as a result of later bedtimes. Boys, children from low SES areas, and non-Caucasian children reported shorter sleep times than girls, children from high SES areas, and Caucasian children, respectively. Non-Caucasian children from low SES areas reported the shortest sleep opportunity. CONCLUSIONS: The results from our study suggest that in addition to biological mechanisms, sleep behaviors are culturally and socially driven and should be considered when developing recommendations for healthy sleep in children.

Will delays in treatment jeopardize the population benefit from extending the time window for stroke thrombolysis?

BACKGROUND AND PURPOSE: Pooled analyses show benefits of intravenous alteplase (recombinant tissue-type plasminogen activator) treatment for acute ischemic stroke up to 4.5 hours after onset despite marketing approval for up to 3 hours. However, the benefit from thrombolysis is critically time-dependent and if extending the time window reduces treatment urgency, this could reduce the population benefit from any extension. METHODS: Based on 3830 UK patients registered between 2005 to 2010 in the Safe Implementation of Treatments in Stroke-International Stroke Thrombolysis Registry (SITS-ISTR), a Monte Carlo simulation was used to model recombinant tissue-type plasminogen activator treatment up to 4·5 hours from onset and assess the impact (numbers surviving with little or no disability) from changes in hospital treatment times associated with this extended time window. RESULTS: We observed a significant relation between time remaining to treat and time taken to treat in the UK SITS-ISTR data set after adjustment for censoring. Simulation showed that as this "deadline effect" increases, an extended treatment time window entails that an increasing number of patients are treated at a progressively lower absolute benefit to a point where the population benefit from extending the time window is entirely negated. CONCLUSIONS: Despite the benefit for individual patients treated up to 4.5 hours after onset, the population benefit may be reduced or lost altogether if extending the time window results in more patients being treated but at a lower absolute benefit. A universally applied reduction in hospital arrival to treatment times of 8 minutes would confer a population benefit as large as the time window extension.

Anticoagulation for atrial fibrillation: should warfarin be temporarily stopped or continued after acute cardioembolic stroke?

Despite anticoagulation for atrial fibrillation, some patients still suffer an ischaemic stroke. The issue of whether to stop or continue warfarin, or possibly to reverse the anticoagulation is an area of uncertainty. Continued anticoagulation may, however, increase haemorrhagic transformation of the infarct. In this article we review the published evidence in an attempt to quantify the risks and benefits of each treatment strategy and identify areas for further research.

Does telephone follow-up improve blood pressure after minor stroke or TIA?

BACKGROUND: hypertension is a common risk factor for stroke/transient ischaemic attack (TIA) and there is good evidence that blood pressure (BP) control prevents recurrent stroke. We investigated whether telephone follow-up (TFU) improved risk factor management in hypertensive patients after stroke/TIA. METHODS: we conducted a randomised controlled trial and assigned hypertensive patients within 1 month of stroke or TIA to receive usual care (n = 27) or usual care plus regular TFU (n = 29). Primary outcome was the difference in 12 h ambulatory systolic BP change from baseline to 6 months (DeltaSBP) in both groups. TFU at 7 days, 1, 2 and 4 months included patient-focussed education and goal setting. RESULTS: mean baseline BP was 145/83 mm Hg (standard deviation (SD) 21/14). There was no significant difference in DeltaSBP over 6 months with TFU. Median DeltaSBP was 0 mm Hg (interquartile range 19.5) in the TFU group and 3.0 mm Hg (20) fall in the usual care group (P = 0.29). Post hoc analysis showed that statin use increased from baseline to 6 months (P = 0.02) and cholesterol was significantly lower at 6 months in all patients (mean reduction 0.95 mmol/l; P < 0.001). CONCLUSION: our study found TFU that promoted patient-led management of risk factors did not improve BP control over 6-month follow-up in primary care after stroke/TIA.

Effects of antihypertensive treatment after acute stroke in the Continue or Stop Post-Stroke Antihypertensives Collaborative Study (COSSACS): a prospective, randomised, open, blinded-endpoint trial.

BACKGROUND: Up to 50% of patients with acute stroke are taking antihypertensive drugs on hospital admission. However, whether such treatment should be continued during the immediate post-stroke period is unclear. We therefore aimed to assess the efficacy and safety of continuing or stopping pre-existing antihypertensive drugs in patients who had recently had a stroke. METHODS: The Continue or Stop Post-Stroke Antihypertensives Collaborative Study (COSSACS) was a UK multicentre, prospective, randomised, open, blinded-endpoint trial. Patients were recruited at 49 UK National Institute for Health Research Stroke Research Network centres from January 1, 2003, to March 31, 2009. Patients aged over 18 years who were taking antihypertensive drugs were enrolled within 48 h of stroke and the last dose of antihypertensive drug. Patients were randomly assigned (1:1) by secure internet central randomisation to either continue or stop pre-existing antihypertensive drugs for 2 weeks. Patients and clinicians who randomly assigned patients were unmasked to group allocation. Clinicians who assessed 2-week outcomes and 6-month outcomes were masked to group allocation. The primary endpoint was death or dependency at 2 weeks, with dependency defined as a modified Rankin scale score greater than 3 points. Analysis was by intention to treat. This trial is registered with the International Standard Randomised Controlled Trial Register, number ISRCTN89712435. FINDINGS: 763 patients were assigned to continue (n=379) or stop (n=384) pre-existing antihypertensive drugs. 72 of 379 patients in the continue group and 82 of 384 patients in the stop group reached the primary endpoint (relative risk 0.86, 95% CI 0.65-1.14; p=0.3). The difference in systolic blood pressure at 2 weeks between the continue group and the stop group was 13 mm Hg (95% CI 10-17) and the difference in diastolic blood pressure was 8 mm Hg (6-10; difference between groups p<0.0001). No substantial differences were observed between groups in rates of serious adverse events, 6-month mortality, or major cardiovascular events. INTERPRETATION: Continuation of antihypertensive drugs did not reduce 2-week death or dependency, cardiovascular event rate, or mortality at 6 months. Lower blood pressure levels in those who continued antihypertensive treatment after acute mild stroke were not associated with an increase in adverse events. These neutral results might be because COSSACS was underpowered owing to early termination of the trial, and support the continuation of ongoing research trials. FUNDING: The Health Foundation and The Stroke Association.