Sustained increases of plasma homocysteine, copper, and serum ceruloplasmin after coronary artery bypass grafting.
BACKGROUND
Homocysteine (Hcy) is an independent risk factor for coronary artery disease, but there are no reports on Hcy levels in patients undergoing coronary artery bypass graft (CABG) surgery. Interactions between Hcy and copper may mediate the vasculopathic impact of Hcy, and this may play a role in vein graft failure. The aim of this study was to assess the perioperative levels of Hcy, copper, ceruloplasmin (CP), folate, and vitamin B12 in patients undergoing myocardial revascularization surgery.


METHODS
Blood samples were taken from 55 consecutive patients undergoing elective conventional CABG (43 male; mean age, 63.2 +/- 5.2 years) 1 day preoperatively and postoperatively at 1 day, 6 days, and 6 weeks. Hcy, copper, CP, red cell folate, vitamin B12, creatinine, and C-reactive protein (CRP) were then measured using standard clinical chemistry methods. The same protocol was applied to 10 patients (7 male; mean age, 63.3 +/- 5.2 years) undergoing off-pump coronary artery bypass (OPCAB) surgery.


RESULTS
In the conventional CABG group, there were significant increases in the plasma concentrations at 6 days and 6 weeks postoperatively of Hcy (from 10.1 to 11.6 and 13.5 micromol/L, respectively), plasma copper (from 13.5 to 20.3 and 18.5 micromol/L), and serum ceruloplasmin (from 0.3 to 0.41 and 0.44 g/L). CRP and vitamin B12 were elevated at 6 days but not 6 weeks after the operation. In contrast, red cell folate and creatinine were not significantly changed. The subgroup analysis for the OPCAB patients showed the same trend as for the conventional group.


CONCLUSIONS
Coronary surgery precipitates a significant and sustained increase in the blood concentrations of Hcy and copper, which is not due to a decrease in folate and vitamin B12, altered renal function, or inflammation. Further studies are required to establish whether the concomitant increase in Hcy and copper plays an etiological role in vein graft disease.
Jeremy
Jamie Y
JY
Bristol Heart Institute, Bristol Royal Infirmary, United Kingdom. j.y.jeremy@bris.ac.uk
Shukla
Nilima
N
Angelini
Gianni D
GD
Day
Andrew
A
Wan
Innes Y P
IY
Talpahewa
Sudath P
SP
Ascione
Raimondo
R
D000368:Aged; D002315:Cardiopulmonary Bypass; D002570:Ceruloplasmin / Q000378:metabolism*; D003300:Copper / Q000097:blood*; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000097:blood / Q000601:surgery*; D005260:Female; D005492:Folic Acid / Q000097:blood; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D011183:Postoperative Complications / Q000097:blood*; D012307:Risk Factors; D014805:Vitamin B 12 / Q000097:blood
D006710:Homocysteine; D003300:Copper; D005492:Folic Acid; D002570:Ceruloplasmin; D014805:Vitamin B 12