Preoperative IABP in high-risk patients reduces postoperative lactate release and subsequent mortality

Abstract

In an article by Davies and associates, recently published in The Annals[1Davies A.R. Bellomo R. Raman J.S. Gutteridge G.A. Buxton B.F. High lactate predicts the failure of intraaortic balloon pumping after cardiac surgery.Ann Thorac Surg. 2001; 71: 1415-1420Abstract Full Text Full Text PDF PubMed Scopus (31) Google Scholar], it was reported, from a retrospective analysis of 39 patients requiring intraaortic balloon pump (IABP) support after cardiac surgery, and employing univariate analysis, that persistent high lactate predicts failure of intraaortic balloon pumping. However, cardioplegic arrest induces anaerobic myocardial metabolism which leads to a net production of lactate from glycolysis, and persistant lactate is an independent predictor of postoperative low cardiac output due to a delayed recovery of aerobic myocardial metabolism [2Rao V. Ivanov J. Weisel R.D. Cohen G. Borger A. Mickle D.A.G. Lactate release during reperfusion predicts low cardiac output syndrome after coronary bypass surgery.Ann Thorac Surg. 2001; 71: 1925-1930Abstract Full Text Full Text PDF PubMed Scopus (59) Google Scholar]. To overcome postoperative low cardiac output inotrope support, often IABP is required. Since delay in recovery of aerobic myocardial metabolism has nothing to do with IABP per se, we have some difficulties in understanding this relationship claimed by the authors. Preoperative IABP therapy in high-risk patients alleviates myocardial ischemia prior to circulatory arrest and paves the way for quick postoperative recovery to normal metabolism and less lactate formation [3Christenson J.T. Badel P. Simonet F. Schmuziger M. Preoperative intraaortic balloon pump enhances cardiac performance and improves the outcome of redo CABG.Ann Thorac Surg. 1997; 64: 1237-1244Abstract Full Text Full Text PDF PubMed Scopus (111) Google Scholar, 4Gutfinger D.E. Ott R.A. Miller M. et al.Aggressive preoperative use of intraaortic balloon pump in elderly patients undergoing coronary artery bypass grafting.Ann Thorac Surg. 1999; 67: 610-613Abstract Full Text Full Text PDF PubMed Scopus (76) Google Scholar]. It was therefore interesting to notice in Davies and coworkers’ article that 7 of 10 patients who received preoperative IABP survived compared to 37% when IABP was initiated intra- or postoperative. These results do correspond better with the more modern literature on IABP therapy [5Christenson J.T. Simonet F. Schmuziger M. Economical impact of preoperative intra-aortic balloon pump therapy in high-risk coronary patients.Ann Thorac Surg. 2000; 70: 510-515Abstract Full Text Full Text PDF PubMed Scopus (31) Google Scholar, 6Holman W.L. Li Q. Kiefe C.I. McGriffin D.C. Peterson E.D. Allman R.M. Nielsen V.G. Pacifico A.D. Prophylactic value of preincision intra-aortic balloon pump analysis of a statewide experience.J Thorac Cardiovasc Surg. 2000; 120: 1112-1119Abstract Full Text Full Text PDF PubMed Scopus (82) Google Scholar]. The authors have not separated out pre-, intra-, and postoperative balloon insertions to derive their conclusion. They refer to very old literature when they discuss their very high complication rates [1Davies A.R. Bellomo R. Raman J.S. Gutteridge G.A. Buxton B.F. High lactate predicts the failure of intraaortic balloon pumping after cardiac surgery.Ann Thorac Surg. 2001; 71: 1415-1420Abstract Full Text Full Text PDF PubMed Scopus (31) Google Scholar]. Overall IABP-related complications in 1,119 patients treated with IABP was reported to be 15%, and major complications occurred in only 4.1% [7Cohen M. Dawson M.S. Kopistansky C. McBride R. Sex and other predictors of intra-aortic balloon counterpulsation—related complications prospective study of 1119 consecutive patients.Am Heart J. 2000; 139: 282-287PubMed Scopus (72) Google Scholar]. The authors should restate their conclusion as “preoperative IABP in high-risk patients reduces postoperative lactate release and subsequent mortality.” Preoperative IABP in high-risk patients reduces postoperative lactate release and subsequent mortality: ReplyThe Annals of Thoracic SurgeryVol. 73Issue 3Preview Full-Text PDF