***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 — Short-term  blood pressure variability  ( BPV ) may predict outcome in acute stroke . We undertook a post hoc analysis of data from 2 r and omized controlled trials to determine the effect of short-term BPV on 2-week outcome . Methods — Controlling Hypertension and Hypotension Immediately Post Stroke ( CHHIPS ) was a trial of BP-lowering , enrolling 179 acute stroke patients ( onset < 36 hours ) . Continue or Stop Post-Stroke Antihypertensives Collaborative Study ( COSSACS ) compared a strategy of continuation versus temporarily stopping prestroke antihypertensive therapy in 763 acute stroke patients ( onset < 48 hours ) .  BPV  at baseline ( defined as SD , coefficient of variation , variation independent of the mean , and average real variability ) was derived from st and ardized casual cuff BP measures ( 6 readings < 30 minutes ) . Adjusted logistic regression models were used to assess the relation between BPV and death and disability ( modified Rankin scale>3 ) at 2 weeks . Results — Seven hundred six ( 92.5 % ) and 171 ( 95.5 % ) participants were included in the analysis for the COSSACS and CHHIPS data sets , respectively . Adjusted logistic regression analyses revealed no statistically significant associations between any of the included BPV parameters with 2-week death or disability in either study data set : COSSACS , odds ratio SD systolic BP 0.98 ( 0.78–1.23 ) ; CHHIPS , odds ratio SD systolic BP 0.97 ( 0.90–1.11 ) . Conclusions — When derived from casual cuff BP measures , short-term BPV is not a useful predictor of early ( 2 weeks ) outcome after acute stroke . Differing methodology may account for the discordance with previous studies indicating long-term ( casual BPV ) and short-term ( beat-to-beat BPV ) prognostic value . Clinical Trial Registration — COSSACS was registered on the International St and ard R and omised Controlled Trial Register ; URL : http://www.is rct n.com . Unique identifier : IS RCT N89712435 . CHHIPS was registered on the National Research Register ; URL : http://public.ukcrn.org.uk . Unique identifier : N0484128008 Background and Purpose — The associations between early blood pressure ( BP ) variability and clinical outcomes in patients with intracerebral hemorrhage after antihypertensive therapy  , recently clarified by a post hoc analysis of Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial 2 ( INTERACT2 ) , were confirmed using the Stroke Acute Management with Urgent Risk-factor Assessment and Improvement (SAMURAI)-intracerebral hemorrhage study cohort . Methods — Patients with hyperacute ( <3 hours from onset ) intracerebral hemorrhage with initial systolic BP ( SBP ) > 180 mm Hg were registered in a prospect i ve , multicenter , observational study . All patients received antihypertensive therapy based on a predefined st and ardized protocol to lower and maintain SBP between 120 and 160 mm Hg using intravenous nicardipine . BPs were measured hourly during the initial 24 hours . BP variability was determined as SD and successive variation . The associations between BP variability and hematoma expansion ( > 33 % ) , neurological deterioration within 72 hours , and unfavorable outcome ( modified Rankin Scale , 4–6 ) at 3 months were assessed . Results — Of the 205 patients , 33 ( 16 % ) showed hematoma expansion , 14 ( 7 % ) showed neurological deterioration , and 81 ( 39 % ) had unfavorable outcomes . The SD and successive variation of SBP were 13.8 ( interquartile range , 11.5–16.8 ) and 14.9 ( 11.7–17.7 ) mm Hg , respectively , and those of diastolic BP were 9.4 ( 7.5–11.2 ) and 13.1 ( 11.2–15.9 ) mm Hg , respectively . On multivariate regression analyses , neurological deterioration was associated with the SD of SBP ( odds ratio , 2.75 ; 95 % confidence interval , 1.45–6.12 per quartile ) and the successive variation of SBP ( 2.37 ; 1.32–4.83 ) , and unfavorable outcome was associated with successive variation of SBP ( 1.42 ; 1.04–1.97 ) . Hematoma expansion was not associated with any BP variability . Conclusions — SBP variability during the initial 24 hours of acute intracerebral hemorrhage was independently associated with neurological deterioration and unfavorable outcomes . Stability of antihypertensive therapy may improve clinical outcomes 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 BACKGROUND Whether rapid lowering of elevated blood pressure would improve the outcome in patients with intracerebral hemorrhage is not known . METHODS We r and omly 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 Clinical Trials.gov number , NCT00716079 . ) Background and Purpose — Certain characteristics of early blood pressure ( BP ) profiles were reported to be independent predictors of long-term outcome in the first European Cooperative Acute Stroke Study ( ECASS-I ) trial . The aim of the study was to find out the association of BP profiles with functional outcome , mortality , and hemorrhagic complications in the ECASS-II data base . Methods — We studied 793 patients with acute ischemic hemispheric stroke in the ECASS-II . After r and omization  , BP was measured every 15 minutes during the first 2 hours , then every 30 minutes during the first 8 hours , and thereafter at 1-hour intervals up to 24 hours . Individual 0- to 24-hour BP profiles were characterized by baseline , maximum , minimum , and mean BP and successive variation of the profile . The end points were favorable outcome ( modified Rankin Scale score of 0 or 1 ) at day 90 , all-cause mortality at day 90 , and hemorrhagic transformation within the first 7 days . Results — High baseline , maximum , mean level , and variability of systolic BP profiles were each inversely associated with favorable outcome ( OR=0.84 , 95 % CI : 0.74 to 0.94 ; OR=0.82 , 95 % CI : 0.73 to 0.91 ; OR=0.81 , 95 % CI : 0.71 to 0.93 ; OR=0.57 , 95 % CI : 0.35 to 0.92 , respectively ) and associated with an increased risk of parenchymal hemorrhage within the first 7 days ( OR=1.27 , 95 % CI : 1.07 to 1.51 ; OR=1.49 , 95 % CI : 1.27 to 1.75 ; OR=1.52 , 95 % CI : 1.23 to 1.87 ; OR=2.62 , 95 % CI : 1.40 to 4.87 ; respectively ) in recombinant tissue plasminogen activator-treated patients . In placebo-treated patients , high maximum , mean level , and successive variation of systolic BP profiles were inversely associated with favorable outcome ( OR=0.76 , 95 % CI : 0.66 to 0.86 ; OR=0.76 , 95 % CI : 0.65 to 0.89 ; OR=0.41 , 95 % CI : 0.22 to 0.76 ; respectively ) , although the association of baseline systolic BP and favorable outcome was not significant ( OR=0.91 , 95 % CI : 0.80 to 1.03 ) . No association with hemorrhagic transformation was found , even after the adjustment . Conclusions — The hemorrhagic transformation within the first 7 days and favorable outcome were independently associated with dynamics of BP within the first 24 hours after an acute ischemic stroke in patients treated with thrombolysis  , but in  placebo-treated patients , only with favorable outcome . Continuous BP monitoring is hence important for the prognosis and gives implication s to optimize BP management , particularly regarding a reasonable BP level and stability Objective : Impaired blood pressure regulation in the acute phase of stroke has been associated with less favorable outcome . Mechanisms and effects of blood pressure dysregulation in stroke are not well understood ; however , central autonomic impairment with sympathetic overactivity and barore 
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A descriptive review of included studies also supports these findings , and in addition , it suggests that systolic BPV may be associated with increased risk of intracranial hemorrhage in those treated with thrombolytic therapy .
CONCLUSIONS This systematic review and meta- analysis suggest that greater systolic BPV , measured early from ischemic stroke or intracerebral hemorrhage onset , is associated with poor longer-term functional outcome .