Relation between left ventricular function and oxidative stress in patients undergoing bypass surgery.
OBJECTIVE
To determine whether preoperative left ventricular ejection fraction (LVEF) is related to the degree of myocardial oxidative stress during bypass surgery in man.


METHODS
Observational study.


METHODS
Tertiary care centre.


METHODS
31 patients (LVEF range was 20% to 68%) undergoing elective coronary bypass surgery with blood cardioplegic reperfusion were studied. Arterial and coronary sinus blood was collected before aortic cross clamping (T0) and at 0 (T1), 15 (T2), and 30 (T3) minutes after unclamping. Transmural left ventricular biopsies were also obtained from 15 patients at T0 and at T1.


METHODS
Glutathione and adenine nucleotides were measured in myocardial biopsies, while coronary sinus-artery differences for glutathione, nucleotides, and products of lipid peroxidation were calculated from blood specimens. Creatine kinase (myocardial band; CK-MB) was measured in plasma at four and 12 hours after operation.


RESULTS
Myocardial glutathione and adenine nucleotides were correlated (p < 0.02) with preoperative LVEF both at T0 (r = 0.909 and 0.672) and T1 (r = 0.603 and 0.605). Oxidised glutathione released from the heart during reperfusion was inversely correlated with LVEF (r = -0.448, -0.466, and -0461 at T1, T2, and T3, p < 0.01), while reduced glutathione (r = 0.519 and 0.640 at T1 and T2) and glutathione redox ratio (r = 0.647, 0.714, 0.645, and 0.702 at T0, T1, T2, and T3) showed a direct correlation (p < 0.01). Lipid peroxidation at T1 was negatively related to LVEF (r = -0.492). CK-MB was also negatively related to LVEF (r = -0.440 at 4 h and -0.462 at 12 h).


CONCLUSIONS
The capacity to counterbalance oxidative burst following ischaemia and reperfusion appears to be related to the functional ability of the heart.
De Vecchi
E
E
Department of Laboratory Medicine, IRCCS H San Raffaele, Milan, Italy.
Pala
M G
MG
Di Credico
G
G
Agape
V
V
Paolini
G
G
Bonini
P A
PA
Grossi
A
A
Paroni
R
R
D000227:Adenine Nucleotides / Q000378:metabolism; D000368:Aged; D015415:Biomarkers; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000378:metabolism / Q000601:surgery*; D005260:Female; D005978:Glutathione / Q000097:blood / Q000378:metabolism; D006801:Humans; D007042:Hypoxanthines / Q000378:metabolism; D015227:Lipid Peroxidation; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D013318:Stroke Volume; D016277:Ventricular Function, Left
D000227:Adenine Nucleotides; D015415:Biomarkers; D007042:Hypoxanthines; D005978:Glutathione