***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 
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    ***EXAMPLES*** 
    Input: Recent studies suggest that delirium is associated with risk of dementia and also acceleration of decline in existing dementia . However , previous studies may have been confounded by incomplete ascertainment of cognitive status at baseline . Herein , we used a true population sample to determine if delirium is a risk factor for incident dementia and cognitive decline . We also examined the effect of delirium at the pathological level by determining associations between dementia and neuropathological markers of dementia in patients with and without a history of delirium . The Vantaa 85 + study examined 553 individuals ( 92 % of those eligible ) aged ≥85 years at baseline , 3 , 5 , 8 and 10 years .  Brain autopsy was performed in 52 % . Fixed and r and om-effects regression models were used to assess associations between ( i ) delirium and incident dementia and ( ii ) decline in Mini-Mental State Examination scores in the whole group . The relationship between dementia and common neuropathological markers ( Alzheimer-type , infa rcts and Lewy-body ) was modelled , stratified by history of delirium . Delirium increased the risk of incident dementia ( odds ratio 8.7 , 95 % confidence interval 2.1–35 ) . Delirium was also associated with worsening dementia severity ( odds ratio 3.1 , 95 % confidence interval 1.5–6.3 ) as well as deterioration in global function score ( odds ratio 2.8 , 95 % confidence interval 1.4–5.5 ) . In the whole study population , delirium was associated with loss of 1.0 more Mini-Mental State Examination points per year ( 95 % confidence interval 0.11–1.89 ) than those with no history of delirium . In individuals with dementia and no history of delirium ( n = 232 ) , all pathologies were significantly associated with dementia . However , in individuals with delirium and dementia ( n = 58 ) , no relationship between dementia and these markers was found . For example , higher Braak stage was associated with dementia when no history of delirium ( odds ratio 2.0 , 95 % confidence interval 1.1–3.5 , P = 0.02 ) , but in those with a history of delirium , there was no significant relationship ( odds ratio 1.2 , 95 % confidence interval 0.2–6.7 , P = 0.85 ) . This trend for odds ratios to be closer to unity in the delirium and dementia group was observed for neuritic amyloid , apolipoprotein ε status , presence of infa rcts , α-synucleinopathy and neuronal loss in substantia nigra . These findings are the first to demonstrate in a true population study that delirium is a strong risk factor for incident dementia and cognitive decline in the oldest-old . However , in this study , the relationship did not appear to be mediated by classical neuropathologies associated with dementia CONTEXT Coronary artery bypass graft ( CABG ) surgery is associated with a decline in cognitive function , which has largely been attributed to the use of cardiopulmonary bypass ( on-pump procedures ) . Cardiac stabilizers facilitate CABG surgery without use of cardiopulmonary bypass ( off-pump procedures ) and should reduce the cognitive decline associated with on-pump procedures . OBJECTIVE To compare the effect of CABG surgery with ( on-pump ) and without ( off-pump ) cardiopulmonary bypass on cognitive outcome . DESIGN AND SETTING R and omized controlled trial conducted in the Netherl and s of CABG surgery patients enrolled from March 1998 through August 2000 , with 3- and 12-month follow-up . PARTICIPANTS AND INTERVENTION Patients scheduled for their first CABG surgery ( mean age , 61 years ; n = 281 ) were r and omly assigned to off-pump surgery ( n = 142 ) or on-pump surgery ( n = 139 ) . MAIN OUTCOME MEASURES Cognitive outcome at 3 and 12 months , which was determined by psychologists ( blinded for r and omization ) who administered 10 neuropsychological tests before and after surgery . Quality of life , stroke rate , and all-cause mortality at 3 and 12 months were secondary outcome measures . RESULTS Cognitive outcome could be determined at 3 months in 248 patients .  Cognitive decline occurred in 21 % in the off-pump group and 29 % in the on-pump group ( relative risk [ RR ] , 0.65 ; 95 % confidence interval [ CI ] , 0.36 - 1.16 ; P = .15 ) . The overall st and ardized change score ( ie , improvement of cognitive performance ) was 0.19 in the off-pump vs 0.13 in the on-pump group ( P = .03 ) . At 12 months , cognitive decline occurred in 30.8 % in the off-pump group and 33.6 % in the on-pump group ( RR , 0.88 ; 95 % CI , 0.52 - 1.49 ; P = .69 ) . The overall st and ardized change score was 0.19 in the off-pump vs 0.12 in the on-pump group ( P = .09 ) . No statistically significant differences were observed between the on-pump and off-pump groups in quality of life , stroke rate , or all-cause mortality at 3 and 12 months . CONCLUSION Patients who received their first CABG surgery  without cardiopulmonary bypass had improved cognitive outcomes 3 months after the procedure , but the effects were limited and became negligible at 12 months OBJECTIVE To investigate cognitive outcome after on and off pump coronary artery bypass grafting . METHODS Seventy patients between 50 and 80 years with stable angina pectoris , ejection fraction > 30 % , serum creatinine < 150 micromol/l , and lack of tight main stem stenosis were r and omized to on or off pump coronary artery bypass grafting . St and ardized neuropsychological tests evaluated attention , verbal and visuo-spatial short-term and working memory , verbal learning , delayed recall , visuo-motor speed , and aspects of executive functions . Levels of anxiety and depression were also investigated . Testing was performed before and at 1 week , 1 and 6 months after surgery . RESULTS There was no difference in cognitive impairment ( defined as a 20 % reduction in at least 20 % of the tests ) between groups . The incidence at 1 week post-operatively was 57 % in the on pump group and 58 % in the off pump group , after 1 month 30 % and 12 % and after 6 months 19 % and 15 % , respectively ( p for interaction=0.19 ) . There was no difference between groups in anxiety ( p=0.18 ) or depression ( p=0.48 ) . CONCLUSIONS This prospect i ve , r and omized study showed no differences in post-operative cognitive function after on pump compared to off pump coronary artery bypass grafting in low risk patients Importance Delirium is associated with  accelerated cognitive decline .  The pathologic substrates of this association are not yet known , that is , whether they are the same as those associated with dementia , are independent , or are interrelated . Objective To examine whether the accelerated cognitive decline observed after delirium is independent of the pathologic processes of classic dementia . Design , Setting , and Participants Harmonized data from 987 individual brain donors from 3 observational cohort studies with population -based sampling ( Vantaa 85 + , Cambridge City Over-75s Cohort , Cognitive Function and Ageing Study ) performed from January 1 , 1985 , through December 31 , 2011 , with a median follow-up of 5.2 years until death , were used in this study . Neuropathologic assessment s were performed with investigators masked to clinical data . Data analysis was performed from January 1 , 2012 , through December 31 , 2013 . Clinical characteristics of brain donors were not different from the rest of the cohort . Outcome ascertainment was complete given that the participants were brain donors . Exposures Delirium ( never vs ever ) and pathologic burden of neurofibrillary tangles , amyloid plaques , vascular lesions , and Lewy bodies . Effects modeled using r and om-effects linear regression and interactions between delirium and pathologic burden were assessed . Outcomes Change in Mini-Mental State Examination ( MMSE ) scores during the 6 years before death . Results There were 987 participants ( 290 from Vantaa 85 + , 241 from the Cambridge City Over-75s Cohort , and 456 from the Cognitive Function and Ageing Study ) with neuropathologic data ; mean ( SD ) age at death was 90 ( 6.4 ) years , including 682 women ( 69 % ) .  The mean MMSE score 6 years before death was 24.7 points . The 279 individuals with delirium ( 75 % women ) had worse initial scores ( −2.8 points ; 95 % CI , −4.5 to −1.0 ; P < .001 ) . Cognitive decline attributable to delirium was −0.37 MMSE points per year ( 95 % CI , −0.60 to −0.13 ; P < .001 ) . Decline attributable to the pathologic processes of dementia was −0.39 MMSE points per year ( 95 % CI , −0.57 to −0.22 ; P < .001 ) . However , the combination of delirium and the pathologic processes of dementia result ed in the greatest decline , in which the interaction contributed an additional −0.16 MMSE points per year ( 95 % CI , −0.29 to −0.03 ; P = .01 ) . The multiplicative nature of these variables result ed in individuals with delirium and the pathologic processes of dementia declining 0.72 MMSE points per year faster than age- , sex- , and educational level – matched controls . Conclusions and Relevance Delirium in the presence of the pathologic processes of dementia is associated with accelerated cognitive decline beyond that expected for delirium or the pathologic process itself . These findings suggest that additional unmeasured pathologic processes specifically relate to delirium . Age-related cognitive decline has many contributors , and these findings at the population level support a role for delirium acting independently and multiplicatively to the pathologic processes of classic dementia The choice of coronary artery bypass grafting ( CABG ) as an intervention for coronary artery disease has been clouded by concerns about postoperative cognitive decline . Long‐term cognitive decline after CABG has been reported , but without appropriate control subjects , it is not known whether this decline is specific to CABG or related to other factors such as cerebrovascular disease BACKGROUND Advanced age is associated with increased systemic atherosclerosis and is a consistent neurologic risk factor after coronary artery bypass grafting ( CABG ) . METHODS We studied prospect ively whether varying degrees of a total atherosclerotic score derived from the brain , carotid arteries , and ascending aorta predicted postoperative neuropsychologic ( NP ) dysfunction and stroke in 177 elderly patients ( > or = 60 years ) undergoing CABG .  RESULTS Group L ( low total atherosclerotic score ) had rates of NP dysfunction of 25 % and 4 % , group I ( intermediate ) had rates of 33 % and 22 % , and group H ( high ) had rates of 79 % and 43 % on postoperative days 1 and 7 , respectively ( p < 0.001 ) . The incidence of stroke was higher in group H ( 14.3 % ) than in groups I and L ( 7.8 % and 0.9 % ; p = 0.013 ) . Stepwise logistic regression analysis demonstrated the significant predictors of NP dysfunction on postoperative day 7 to be total atherosclerotic score , peripheral vascular disease , and diabetes mellitus , and those of stroke to be total atherosclerotic score , peripheral vascular disease , and hyperlipidemia . CONCLUSIONS Perioperative evaluation of craniocervical and aortic atherosclerosis is useful to identify a high-risk patient at postoperative NP dysfunction and stroke after CABG BACKGROUND Cerebral injury remains a significant complication of cardiac operations . We determined the incidence of cerebral dysfunction in a population of elderly patients undergoing open chamber cardiac operations ( group 1 ) as compared with a younger population ( group 2 ) and an age-matched group of elderly patients undergoing major noncardiac operations ( group 3 ) . METHODS Sixty-eight patients ( 55 for open chamber cardiac operations and 13 for noncardiac operations ) were prospect ively studied . Patients were evaluated preoperatively and postoperatively before hospital discharge using a  complete neurologic examination and a battery of st and ard neuropsychometric tests , and at surgical follow-up with neuropsychometric tests only . RESULTS Postoperative changes detected by neurologic examination consisted of the appearance of new primitive reflexes in all groups . No statistically significant differences in incidence were found . The neuropsychometric performance of group 1 patients was statistically different from that of patients in groups 2 and 3 only in the early follow-up period . CONCLUSIONS Elderly patients having open chamber cardiac operations exhibit significantly more cerebral dysfunction in the early postoperative period than those 
    Output:
    
Conclusion The results of this meta- analysis demonstrate that cognitive impairment and delirium are major issues in CABG patients which require specific attention .