Vitamin E for coronary bypass operations. A prospective, double-blind, randomized trial.
BACKGROUND
Free radical lipid peroxidation contributes to the abnormal metabolism and ventricular function frequently seen after cardiac operations. Antioxidants may improve metabolic and functional recovery.


METHODS
A prospective, randomized, double-blind clinical trial was conducted to determine the effects of vitamin E (alpha-tocopherol) (n = 14) or a corn oil placebo (n = 14) in patients undergoing elective coronary bypass operations. The RRR-alpha-tocopheryl acetate doubled the alpha-tocopherol levels in the heart. Myocardial metabolism and ventricular function were assessed after the operation.


RESULTS
Atrial pacing induced myocardial lactate production in the control patients but lactate consumption in the alpha-tocopherol-treated patients on bypass 25 minutes after crossclamp release. Left ventricular stroke work indices were higher, at similar ventricular volumes, in the alpha-tocopherol-treated group, which indicates improved preload recruitable stroke work, and diastolic compliance was greater 4 hours after the operation. The postoperative creatine kinase cardiac isoenzyme levels were lower in the patients who received alpha-tocopherol.


CONCLUSIONS
Pretreatment with alpha-tocopherol sufficient to double the myocardial concentrations had a small but significant metabolic and functional effect after elective coronary bypass operations when compared with placebo. These results do not justify pretreatment of low-risk patients, but they do justify an evaluation in high-risk patients.
Yau
T M
TM
Department of Clinical Biochemistry, Toronto Hospital, Ontario, Canada.
Weisel
R D
RD
Mickle
D A
DA
Burton
G W
GW
Ingold
K U
KU
Ivanov
J
J
Mohabeer
M K
MK
Tumiati
L
L
Carson
S
S
D000328:Adult; D000368:Aged; D001026:Coronary Artery Bypass; D003402:Creatine Kinase / Q000097:blood; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D006321:Heart / Q000187:drug effects; D006801:Humans; D007527:Isoenzymes; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000737:chemistry / Q000378:metabolism*; D010101:Oxygen Consumption; D011292:Premedication; D011446:Prospective Studies; D016276:Ventricular Function / Q000187:drug effects*; D014810:Vitamin E / Q000032:analysis / Q000494:pharmacology / Q000627:therapeutic use*
D007527:Isoenzymes; D007773:Lactates; D014810:Vitamin E; D019344:Lactic Acid; D003402:Creatine Kinase