***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background and Purpose — Among patients with acute stroke , high blood pressure is often associated with poor outcome , although the reason is unclear . We analyzed data from the International Stroke Trial ( IST ) to explore the relationship between  systolic blood pressure ( SBP ) , subsequent clinical events over the next 2 weeks , and functional outcome at 6 months in patients with acute stroke . Methods — We included in the analysis 17 398 patients from IST with confirmed ischemic stroke . A single measurement of SBP was made immediately before r and omization . Clinical events within 14 days of r and omization were recorded : recurrent ischemic stroke , symptomatic intracranial hemorrhage , death result ing from presumed cerebral edema , fatal coronary heart disease , and death . Survival and dependency were assessed at 6 months . Outcomes were adjusted for age , sex , clinical stroke syndrome , time to r and omization , consciousness level , atrial fibrillation , and treatment allocation ( aspirin , unfractionated heparin , both , or neither ) . Results — A U-shaped relationship was found between baseline SBP and both early death and late death or dependency : early death increased by 17.9 % for every 10 mm Hg below 150 mm Hg ( P < 0.0001 ) and by 3.8 % for every 10 mm Hg above 150 mm Hg ( P = 0.016 ) . The rate of recurrent ischemic stroke within 14 days increased by 4.2 % for every 10–mm Hg increase in SBP ( P = 0.023 ) ; this association was present in both fatal and nonfatal recurrence . Death result ing from presumed cerebral edema was independently associated with high SBP ( P = 0.004 ) . No relationship between symptomatic intracranial hemorrhage and SBP was seen . Low SBP was associated with a severe clinical stroke ( total anterior circulation syndrome ) and an excess of deaths from coronary heart disease ( P = 0.002 ) . Conclusions — Both high blood pressure and low blood pressure were independent prognostic factors for poor outcome , relationships that appear to be mediated in part by increased rates of early recurrence and death result ing from presumed cerebral edema in patients with high blood pressure and increased coronary heart disease events in those with low blood pressure . The occurrence of symptomatic intracranial hemorrhage within 14 days was independent of SBP Background and Purpose — The practicalities of doing ambulance-based trials where paramedics perform all aspects of a clinical trial involving patients with ultra-acute stroke have not been assessed . Methods — We performed a r and omized controlled trial with screening , consent , r and omization , and treatment performed by paramedics prior to hospitalization . Patients with probable ultra-acute stroke ( < 4 hours ) and systolic blood pressure ( SBP ) > 140 mm Hg were r and omized to transdermal glyceryl trinitrate ( GTN ; 5 mg/24 hours ) or none ( blinding under gauze dressing ) for 7 days with the first dose given by paramedics . The primary outcome was SBP at 2 hours . Results — Of a planned 80 patients , 41 ( 25 GTN , 16 no GTN ) were enrolled > 22 months with median age [ interquartile range ] 79 [ 16 ] years ; men 22 ( 54 % ) ; SBP 168 [ 46 ] ; final diagnosis : stroke 33 ( 80 % ) and transient ischemic attack 3 ( 7 % ) .  Time to r and omization was 55 [ 75 ] minutes . After treatment with GTN versus no GTN , SBP at 2 hours was 153 [ 31 ] versus 174 [ 27 ] mm Hg , respectively , with difference −18 [ 30 ] mm Hg ( P=0.030 ) . GTN improved functional outcome with a shift in the modified Rankin Scale by 1 [ 3 ] point ( P=0.040 ) . The rates of death , 4 ( 16 % ) versus 6 ( 38 % ; P=0.15 ) , and serious adverse events , 14 ( 56 % ) versus 10 ( 63 % ; P=0.75 ) , did not differ between GTN and no GTN . Conclusions — Paramedics can successfully enroll patients with ultra-acute stroke into an ambulance-based trial . GTN  reduces SBP at 2 hours and seems to be safe in ultra-acute stroke . A larger trial is needed to assess whether GTN improves functional outcome . Clinical Trial Registration — URL : http://www.controlled-trials.com/IS RCT N66434824/66434824 . Unique identifier : 66434824 Background and Purpose — Female sex is predictive of poor functional outcome in stroke , even after correction for prognostic factors . Poor quality of life ( QoL ) is observed in stroke survivors with lower scores seen in the most disabled patients . We used data from the Tinzaparin in Acute Ischaemic Stroke Trial ( TAIST ) to assess the relationship between sex and QoL after ischemic stroke . Methods — TAIST was a r and omized , controlled trial assessing the safety and efficacy of tinzaparin versus aspirin in 1484 patients with acute ischemic stroke .  QoL was measured at 180 days postr and omization using the Short Form-36 health survey , which assesses QoL across 8 domains . The relationship between sex and each domain was assessed using ordinal regression , both unadjusted and adjusted for key prognostic factors . Results — Of the 1484 patients r and omized into TAIST , 216 had died at 180 days postr and omization . A total of 1268 survivors were included in this analysis , 694 males ( 55 % ) and 574 females ( 45 % ) . Females tended to score lower than males across all QoL domains ( apart from general health ) ; statistically significant lower scores were seen for physical functioning ( OR : 0.58 , 95 % CI : 0.47 to 0.72 ) , vitality ( OR : 0.79 , 95 % CI : 0.64 to 0.98 ) , and mental health ( OR : 0.75 , 95 % CI : 0.61 to 0.93 ) . The results for physical functioning and mental health remained significant after adjustment for prognostic variables ( OR : 0.73 , 95 % CI : 0.58 to 0.92 ; OR : 0.76 , 95 % CI : 0.60 to 0.95 , respectively ) . Conclusions — QoL , in particular physical function and mental health domains , is lower in female patients after stroke . This difference persists even after correction for known prognostic factors such as age and stroke severity Summary Background High blood pressure is associated with poor outcome after stroke . Whether blood pressure should be lowered early after stroke , and whether to continue or temporarily withdraw existing antihypertensive drugs , is not known . We assessed outcomes after stroke in patients given drugs to lower their blood pressure . Methods In our multicentre , partial-factorial trial , we r and omly assigned patients admitted to hospital with an acute ischaemic or haemorrhagic stroke and raised systolic blood pressure ( systolic 140–220 mm Hg ) to 7 days of transdermal glyceryl trinitrate ( 5 mg per day ) , started within 48 h of stroke onset , or to  no glyceryl trinitrate ( control group ) . A subset of patients who were taking antihypertensive drugs before their stroke were also r and omly assigned to continue or stop taking these drugs . The primary outcome was function , assessed with the modified Rankin Scale at 90 days by observers masked to treatment assignment . This study is registered , number IS RCT N99414122 . Findings Between July 20 , 2001 , and Oct 14 , 2013 , we enrolled 4011 patients .  Mean blood pressure was 167 ( SD 19 ) mm Hg/90 ( 13 ) mm Hg at baseline ( median 26 h [ 16–37 ] after stroke onset ) , and was significantly reduced on day 1 in 2000 patients allocated to glyceryl trinitrate compared with 2011 controls ( difference −7·0 [ 95 % CI −8·5 to −5·6 ] mm Hg/–3·5 [ –4·4 to −2·6 ] mm Hg ; both p<0·0001 ) , and on day 7 in 1053 patients allocated to continue antihypertensive drugs compared with 1044 patients r and omised to stop them ( difference −9·5 [ 95 % CI −11·8 to −7·2 ] mm Hg/–5·0 [ –6·4 to −3·7 ] mm Hg ; both p<0·0001 ) . Functional outcome at day 90 did not differ in either treatment comparison — the adjusted common odds ratio ( OR ) for worse outcome with glyceryl trinitrate versus no glyceryl trinitrate was 1·01 ( 95 % CI 0·91–1·13 ; p=0·83 ) , and with continue versus stop antihypertensive drugs OR was 1·05 ( 0·90–1·22 ; p=0·55 ) . Interpretation In patients with acute stroke and high blood pressure , transdermal glyceryl trinitrate lowered blood pressure and had acceptable safety but did not improve functional outcome . We show no evidence to support continuing prestroke antihypertensive drugs in patients in the first few days after acute stroke . Funding UK Medical Research Council High blood pressure in acute stroke is common and appears to be associated with a poor outcome . Lowering blood pressure might therefore improve outcome , provided that cerebral perfusion is not compromised . We assessed the effects of glyceryl trinitrate ( GTN ) on cerebral and systemic hemodynamic measures in acute stroke . Ninety patients with acute ischemic or hemorrhagic stroke were r and omized within 72 hours of ictus to transdermal GTN given daily for 10 days ( either 5 mg , 5 mg for 4 days then 10 mg , or 10 mg ) or control . Twenty-four hour blood pressure monitoring , middle cerebral artery blood velocity , cardiac output , augmentation index , and plasma nitric oxide levels were each measured at baseline and then on days 1 , 4 , 5 , and 10 . The primary outcome was blood pressure on day 1 . We found that GTN lowered mean peripheral arterial blood pressure on day 1 by 5.3 % to 6.7 % in a dose dependent manner as compared with control ( mean , SD ) : control , 108.8 ( 15.1 ) mmHg ; 5 mg , 102.5 ( 13.9 ) mmHg ; 5/10 mg , 103.4 ( 14.9 ) mmHg ; 10 mg , 101.5 ( 12.6 ) mmHg ; ( P = .005 ) . Increasing the dose from 5 to 10 mg on day 5 result ed in an overall reduction in blood pressure of 11.4 % as compared with leaving the dose at 5 mg ( P = .006 ) . GTN reduced peripheral pulse pressure , central aortic blood pressure , pulse pressure , and augmentation index on day 1 . Middle cerebral artery blood velocity and pulsatility index in the affected hemisphere , cardiac output , systemic peripheral resistance , and plasma nitric oxide levels were not altered by GTN . Treatment with GTN was associated with headache : control 0 ( 0 % ) , GTN 9 ( 15 % ) ( P = .027 ) ; no negative effect on end-of-treatment death or deterioration , or 3 month death or dependency was discernable . GTN reduced peripheral blood pressure in a dose-dependent fashion in patients with acute stroke at day 1 and also reduced central blood pressure and augmentation index . In contrast , GTN did not alter middle cerebral artery blood velocity or pulsatility index in the affected hemispheres , suggesting that cerebral blood flow did not change . A trial assessing the effect of lowering blood pressure with GTN on safety and functional outcome in patients with acute stroke is now warranted Background We aim ed to make individual patient data from the International Stroke Trial  ( IST ) , one of the largest r and omised trials ever conducted in acute stroke , available for public use , to facilitate the planning of future trials and to permit additional secondary analyses . Methods For each r and omised patient , we have extracted data on the variables assessed at r and omisation , at the early outcome point ( 14-days after r and omisation or prior discharge ) and at 6-months and provide them as an analysable data base . Results The IST data set includes data on 19 435 patients with acute stroke , with 99 % complete follow-up . Over 26.4 % patients were aged over 80 years at study entry . Background stroke care was limited and none of the patients received thrombolytic therapy . Conclusions The IST data set provides a source of primary data which could be used for planning further trials , for sample size calculations and for novel secondary analyses . Given the age distribution and nature of the background treatment given , the data may be of value in planning trials in older patients and in re source -poor setting High blood pressure ( BP ) is common in acute stroke and is independently associated with a poor outcome . Lowering BP might improve outcome if it did not adversely affect cerebral blood flow ( CBF ) or cerebral perfusion pressure . We investigated the effect of glyceryl trinitrate ( [ GTN ] an NO donor ) on quantitative CBF , BP , and cerebral 
    Output:
    
Conclusion It was feasible to perform a multicenter ambulance-based ultra-acute stroke trial in the UK and to treat with glyceryl trinitrate versus sham .
The relatively unselected cohort of stroke patients is broadly representative of those admitted to hospital in the UK .