J Thorac Cardiovasc Surg 1997;114:1128
© 1997 Mosby, Inc.
Effect of preoperative antioxidant supplements on perioperative myocardial injury
J. Westhuyzen , PhDa,
A. D. Cochrane , FRACS, FRCS (Cth)b
Division of Chemical Pathology
Royal Brisbane Hospital
Brisbane 4029, Australiaa
Reply to the Editor:
We thank Drs. Wait and Grayburn for their interest and for raising the important question of sublethal myocardial injury in patients undergoing cardioplegic ischemic arrest. We used clinically important markers of irreversible myocardial injury to determine the antioxidant protective effect of
-tocopherol and ascorbic acid, and we did not specifically examine the possibility of a beneficial but lesser effect on functional impairment ("stunning"). However, there are very few "perfect" measures of postoperative function and many are open to one criticism or another. The inotropic requirement is a "soft" measure and can vary markedly depending on the concomitant degree of volume administered, the depth of anesthesia or postoperative sedation, and the particular guidelines for blood pressure and filling pressures regarded as acceptable in that hospital. In fact, very few patients in this study required any inotropic support in the postoperative period.
We agree that further studies should look for more subtle effects; however, if the antioxidant effects are small and transient, the clinical benefit of treatment may be only marginal.