VITAMIN-E FOR CORONARY-BYPASS OPERATIONS - A PROSPECTIVE, DOUBLE-BLIND, RANDOMIZED TRIAL

Background: Free radical lipid peroxidation contributes to the abnorma l metabolism and ventricular function frequently seen after cardiac op erations. Anti-oxidants may improve metabolic and functional recovery. Methods: A prospective, randomized, double-blind clinical trial was c onducted to determine the effects of vitamin E (alpha-tocopherol) (n = 14) or a corn oil placebo (n = 14) in patients undergoing elective co ronary bypass operations. The RRR-alpha-tocopheryl acetate doubled the alpha-tocopherol levels in the heart. Myocardial metabolism and ventr icular function were assessed after the operation. Results: Atrial pac ing induced myocardial lactate production in the control patients but lactate consumption in the alpha-tocophero-treated patients on bypass 25 minutes after crossclamp release. Left ventricular stroke work indi ces were higher, at similar ventricular volumes, in the alpha-tocopher ol-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 lowe r in the patients who received alpha-tocopherol. Conclusions: Pretreat ment with alpha-tocopherol sufficient to double the myocardial concent rations had a small but significant metabolic and functional effect af ter elective coronary bypass operations when compared with placebo. Th ese results do not justify pretreatment of low-risk patients, but they do justify an evaluation in high-risk patients.