***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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    Input: AIMS Uncertainty persists regarding the impact of the off-pump technique on coronary bypass graft patency . The primary objective of this study was to assess coronary artery bypass graft patency in patients r and omized to off-pump and on-pump multivessel coronary artery bypass grafting ( CABG ) .  Secondary objectives were clinical outcomes and neuropsychological functioning . METHODS AND RESULTS One hundred and fifty patients were r and omized to off-pump ( n = 75 ) or on-pump CABG ( n = 75 ) .  Graft patency was assessed by multidetector computed tomography 5 weeks after surgery . The two groups were similar regarding patients ' characteristics and logistic Euroscore ( 3.6 vs. 3.7 % )  . Mean number of grafts performed was 3.5 ± 0.6 and 3.5 ± 0.6 in off-pump and on-pump , respectively ( P = 0.7 ) . Raw graft patency rate was 89.9 % in off-pump and 95.0 % in on-pump ( OR 2.2 , 95 % CI 1.07 - 4.44 ; P = 0.03 ) . Nineteen ( 27 % ) off-pump and 9 ( 13 % ) on-pump patients had at least one occluded graft ( P = 0.04 ) and the proportion of patent grafts per patient was 0.91 ± 0.2 in off-pump vs. 0.96 ± 0.1 in on-pump ( P = 0.06 ) . However , after adjusting by heparin dose , graft patency was not statistically different between groups ( OR 0.87 , 95 % CI 0.25 - 2.98 , P = 0.83 ) . At 30 days , there was no statistically significant difference in major adverse events and neuropsychological functioning between off-pump and on-pump groups . One-year follow-up showed similar functional class and positive treadmill exercise tests . CONCLUSIONS Under the conditions this trial was conducted , CABG performed off-pump had lower overall graft patency rate than on-pump , which was not statistically different after controlling for total heparin dose . Thirty-day complications , neuropsychological functioning , and one-year clinical and functional outcomes were not statistically different between the two techniques BACKGROUND Coronary artery bypass surgery with cardiopulmonary bypass carries a significant risk of perioperative brain injury . At least 1 % to 5 % will suffer a stroke , and at 3-months postoperatively approximately 30 % are reported to have cognitive impairment assessed by neuropsychologic testing . In off-pump surgery cardiopulmonary bypass is not used and instrumentation on the ascending aorta is reduced . The main aim of this study was to assess if off-pump surgery reduces intraoperative cerebral embolization . METHODS This was a prospect i ve and r and omized study of two comparable groups with regard to age , sex , years of education , preoperative cognitive functioning , and surgical characteristics . Fifty-two patients ( 29 off-pump ) were monitored by the use of transcranial Doppler ultrasound for cerebral microembolization during surgery . Preoperative and postoperative clinical , cerebral magnetic resonance imaging , and neuropsychologic examinations were also carried out . RESULTS There was a significant reduction in the number of cerebral microemboli during off-pump compared with on-pump surgery ( 16.3 [ range 0 to 131 ] versus 90.0 [ range 15 to 274 ] , p < 0.0001 ) . No significant difference with regard to the incidence of neuropsychologic performance ( decline in 29 % off-pump , 35 % on-pump ) or neuroradiologic findings at 3 months was found , and there was no association between the number of cerebral microemboli and cognitive outcome . CONCLUSIONS This study clearly demonstrates that off-pump surgery leads to a reduction in intraoperative cerebral microembolization . A significant reduction in the number of off-pump patients with cognitive decline or ischemic brain lesions on cerebral magnetic resonance imaging could not be demonstrated in this relatively small patient population OBJECTIVE Age is considered to be the strongest predictive factor of postoperative cognitive dysfunction ( POCD )  after cardiac surgery .  Coronary artery bypass grafting ( CABG ) without the use of cardiopulmonary bypass is considered to be less harmful to the patient , especially in terms of neurological complications . METHODS The study was a sub- study of the r and omized best bypass surgery trial that compares off-pump to on-pump treatment , with respect to peri- and postoperative morbidity in patients with a moderate to high-predicted preoperative risk . We investigated cognitive outcomes .  A total of 120 elderly patients ( mean age 76 years , SD 4.5 years ) underwent  cognitive testing  before surgery , of which 90 patients ( 47 vs 43 ) were available for retesting at 1 year ( mean 370 days ) postoperatively , using a neuropsychological test battery that included seven parameters from four tests . POCD was defined as the occurrence of at least two deficits out of the seven possible scores . Secondary analysis was performed based on definition of 20 % decline in cognitive scores compared to baseline , and using z-score analysis . RESULTS The incidence of POCD was 19 % ( 95 % CI 9 - 33 ) in the off-pump group and 9 % ( 95 % CI 3 - 22 ) in the on-pump group ( p=0.18 ) . There were no significant differences in the incidence of cognitive decline between the off-pump and on-pump group regardless of the definition applied . CONCLUSIONS We were unable to detect that CABG surgery without cardiopulmonary bypass was associated with significantly better cognitive outcome in elderly high-risk patients 1 year after the operation 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 It is unknown whether avoidance of cardiopulmonary bypass during  coronary artery bypass grafting  affects cerebral injury or long-term neuropsychological function . METHODS Two hundred unselected patients were r and omized to off-pump coronary artery bypass or on-pump coronary artery bypass grafting between March 2000 and August 2001 . One hundred sixty-eight patients had early postoperative brain magnetic resonance imaging . Eighty-seven returned after a mean of 7.5 years of follow-up ; 67 had repeat magnetic resonance imaging , and 76 had neuropsychological testing . RESULTS There were 26 deaths among patients undergoing off-pump coronary artery bypass and 31 among patients undergoing cardiopulmonary bypass as of March 2009 . Seventy-six patients ( 41 undergoing cardiopulmonary bypass  and 35 undergoing off-pump coronary artery bypass ) had neuropsychological testing at late follow-up . Groups were similar in age , sex , depression , and IQ . Patients undergoing off-pump coronary artery bypass showed better attention , performing better at tracking and mentally manipulating information ( P = .011 ) . Patients undergoing off-pump coronary artery bypass demonstrated better cognitive reasoning and made fewer errors in reasoning ( P = .05 ) ; they also showed a trend toward better verbal learning ( P = .064 ) . There were no domains in which patients undergoing cardiopulmonary bypass outperformed those undergoing off-pump coronary artery bypass . Early magnetic resonance imaging in 168 patients showed no significant differences between groups in temporal or frontal lobe atrophy , subcortical white matter lesions , or acute infa rct ions . There were no significant differences between groups in atrophy over time or new subcortical white matter lesions or infa rct ions . Acute perioperative cerebral infa rct ions were more common and atrophy more progressive during follow-up among diabetic than nondiabetic patients . CONCLUSIONS After a mean of 7.5 years of follow-up , patients undergoing off-pump coronary artery bypass performed better than those undergoing cardiopulmonary bypass in several neuropsychological domains ; these differences were small and of uncertain clinical importance . Early brain magnetic resonance imaging showed no significant differences in acute cerebral infa rct ions between the off-pump coronary artery bypass and cardiopulmonary bypass groups 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 BACKGROUND Neurologic and clinical morbidity after  coronary artery bypass grafting ( CABG )  can be significant . By avoiding cardiopulmonary bypass , off-pump CABG ( OPCAB ) may reduce morbidity . METHODS Sixty patients ( 30 CABG and 30 OPCAB ) were prospect ively r and omized . Neurocognitive testing was performed before the operation and 2 weeks and 1 year after the operation . Neurologic testing to detect stroke and (99m)Tc-HMPAO whole-brain single photon emission computed tomography scanning to assess cerebral perfusion were performed before the operation and 3 days afterward . Bilateral middle cerebral artery transcranial Doppler scanning was performed intraoperatively to detect cerebral microemboli . All examiners were blinded to treatment group . Clinical morbidity 
    Output:
    
The results suggested that CPB may not be associated with cognitive decline that is associated with CABG surgery