Serum S-100 protein release and neuropsychologic outcome during coronary revascularization on the beating heart: a prospective randomized study.
OBJECTIVE
Our purpose was to establish whether coronary revascularization on the beating heart without cardiopulmonary bypass is less harmful to the brain than conventional surgery with cardiopulmonary bypass as indicated by measures of cognitive function or by changes in serum concentrations of S-100 protein, a recognized biochemical marker of cerebral injury.


METHODS
We conducted a prospective randomized trial in which the assessors of the outcome measures were blind to the treatment received. Sixty patients without known neurologic abnormality, undergoing coronary revascularization, were prospectively randomized to 1 of 2 groups: (1) cardiopulmonary bypass (32 degrees C-34 degrees C) and cardioplegic arrest (on pump) with intermittent antegrade warm blood cardioplegia or (2) surgery on the beating heart (off pump). Neuropsychologic performance was assessed before and 12 weeks after the operation. Serum S-100 protein concentration was measured at intervals up to 24 hours after the operation.


RESULTS
The groups had similar preoperative characteristics. There were no deaths or major neurologic complications in either group, nor was there any difference between groups in the chosen index of neurologic deterioration. Serum S-100 protein concentrations were higher in the on-pump group at 30 minutes, but any such difference between groups had disappeared 4 hours later. The extent of the changes in S-100 protein was unrelated to the index of neuropsychologic deterioration.


CONCLUSIONS
The changes in S-100 protein concentration suggest that the brain and/or blood-brain barrier may be more adversely affected during coronary artery surgery with cardiopulmonary bypass than during surgery on the beating heart, but that this may not be reflected in detectable neuropsychologic deterioration at 12 weeks.
Lloyd
C T
CT
Bristol Heart Institute, Department of Anaesthesia, University of Bristol, Bristol Royal Infirmary, Bristol, United Kingdom.
Ascione
R
R
Underwood
M J
MJ
Gardner
F
F
Black
A
A
Angelini
G D
GD
D000368:Aged; D015415:Biomarkers / Q000097:blood; D002315:Cardiopulmonary Bypass / Q000009:adverse effects; D003072:Cognition Disorders / Q000097:blood / Q000175:diagnosis* / Q000209:etiology*; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019964:Mood Disorders / Q000097:blood / Q000175:diagnosis / Q000209:etiology; D009204:Myocardial Revascularization / Q000009:adverse effects*; D009483:Neuropsychological Tests; D011446:Prospective Studies; D009418:S100 Proteins / Q000097:blood*; D016896:Treatment Outcome
D015415:Biomarkers; D009418:S100 Proteins