title: Neurocognitive function and cerebral emboli: randomized study of on-pump versus off-pump coronary artery bypass surgery.
abstract: BACKGROUND
  Neurocognitive impairment can be a debilitating complication after coronary artery bypass graft surgery (CABG). Cardiopulmonary bypass, in particular, cerebral emboli, has been implicated. We compared neurocognitive function and cerebral emboli in patients undergoing on-pump and off-pump CABG.
  
  
  METHODS
  212 patients admitted for CABG were randomly assigned to on-pump (n = 104) or off-pump (n = 108) surgery. Embolic signals were detected with bilateral transcranial Doppler ultrasonography of the middle cerebral artery. Neurocognitive tests were administered preoperatively, on discharge from hospital, at 6 weeks, and at 6 months after surgery. Composite neurocognitive scores were derived using principal component analysis and were compared between the two groups, using analysis of covariance to adjust for baseline values.
  
  
  RESULTS
  At discharge from hospital, the adjusted composite neurocognitive score was 0.25 standard deviations greater in the off-pump group compared with the on-pump group (95% confidence interval: 0.05 to 0.45; p = 0.01). There was no significant difference at 6 weeks (0.09 standard deviations, 95% confidence interval: -0.11 to +0.30; p = 0.4) and 6 months (-0.002 standard deviations, 95% confidence interval: -0.23 to +0.23; p = 1.0). Median number of embolic signals was 1,605 (751 to 2,473) during on-pump and 9 (4 to 27) in off-pump CABG (p < 0.001). Age, length of education, and on-pump status were independent predictors of the predischarge neurocognitive score (p = 0.02, 0.03, and 0.006, respectively).
  
  
  CONCLUSIONS
  Cerebral emboli are more prevalent during on-pump CABG. At discharge from hospital, neurocognitive function is better after off-pump surgery, possibly as a result of the lower embolic load. However, the difference in neurocognitive function does not persist at 6 weeks and 6 months.
authors.affiliation: Department of Cardiac Surgery, St. George's Hospital Medical School, London, United Kingdom.
authors.forename: Reza
authors.initials: R
authors.lastname: Motallebzadeh
authors.forename: J Martin
authors.initials: JM
authors.lastname: Bland
authors.forename: Hugh S
authors.initials: HS
authors.lastname: Markus
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Kaski
authors.forename: Marjan
authors.initials: M
authors.lastname: Jahangiri
mesh_terms: D000368:Aged; D003071:Cognition; D001026:Coronary Artery Bypass / Q000009:adverse effects* / Q000401:mortality; D047549:Coronary Artery Bypass, Off-Pump / Q000009:adverse effects* / Q000401:mortality; D005260:Female; D006801:Humans; D020766:Intracranial Embolism / Q000000981:diagnostic imaging / Q000209:etiology*; D007431:Intraoperative Complications; D008297:Male; D008875:Middle Aged; D009420:Nervous System / Q000503:physiopathology*; D009483:Neuropsychological Tests; D011159:Population Surveillance / Q000379:methods; D011184:Postoperative Period; D020521:Stroke / Q000209:etiology; D016896:Treatment Outcome; D017585:Ultrasonography, Doppler, Transcranial