title: Cardiopulmonary bypass affects cognitive brain function after coronary artery bypass grafting.
abstract: BACKGROUND
  The causes for cognitive impairment after coronary artery bypass grafting (CABG) have long been a topic for debate.
  
  
  METHODS
  We prospectively followed 308 consecutive, unselected survivors of CABG at our institution. In addition to determination of clinical measurements, cognitive brain function was measured objectively by P300 auditory-evoked potentials before CABG, at 7-day and at 4-month follow-up. Standard psychometric tests (Trail Making Test A, Mini Mental State Examination) were also performed.
  
  
  RESULTS
  At 7-day follow-up cognitive P300 auditory-evoked potentials were significantly impaired compared with preoperative levels (peak latencies: 376 +/- 40 ms versus 366 +/- 37 ms, p = 0.0001). P300 measurements were almost normalized at 4-month follow-up (peak latencies: 369 +/- 33 ms, p = NS versus preoperative). Standard psychometric tests failed to detect this subclinical cognitive impairment. Multiple regression analysis revealed that use of cardiopulmonary bypass was the only independent predictor of impaired cognitive brain function at 7-day (p < 0.0001) and 4-month follow-up (p = 0.0008). The presence of diabetes mellitus (p = 0.0135) or concomitant repair of significant carotid artery stenosis (p = 0.0049) was predictive of late improvement of cognitive brain function at 4-month follow-up.
  
  
  CONCLUSIONS
  Objective cognitive P300 auditory-evoked potential measurements demonstrate that the use of cardiopulmonary bypass is the only predictor of short- and long-term cognitive brain dysfunction after CABG. Interestingly, the presence of diabetes mellitus and concomitant repair of a significant carotid artery stenosis were predictive for long-term cognitive benefit.
authors.affiliation: Department of Cardiothoracic Surgery, Vienna General Hospital, Austria.
authors.forename: J
authors.initials: J
authors.lastname: Kilo
authors.forename: M
authors.initials: M
authors.lastname: Czerny
authors.forename: M
authors.initials: M
authors.lastname: Gorlitzer
authors.forename: D
authors.initials: D
authors.lastname: Zimpfer
authors.forename: H
authors.initials: H
authors.lastname: Baumer
authors.forename: E
authors.initials: E
authors.lastname: Wolner
authors.forename: M
authors.initials: M
authors.lastname: Grimm
mesh_terms: D000368:Aged; D002315:Cardiopulmonary Bypass; D016893:Carotid Stenosis / Q000175:diagnosis / Q000503:physiopathology; D003072:Cognition Disorders / Q000175:diagnosis* / Q000503:physiopathology; D001026:Coronary Artery Bypass; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011183:Postoperative Complications / Q000175:diagnosis* / Q000503:physiopathology; D011446:Prospective Studies; D011930:Reaction Time / Q000502:physiology; D012307:Risk Factors