Invited Commentary

Abstract

The population prevalence of patients receiving hemodialysis (HD) due to end stage renal disease is progressively increasing, and cardiovascular complications have been identified as the most common cause of death in these patients [1U.S. Renal Data System2011 Atlas of CKD and ESRD.http://www.usrds.org/atlas.aspxGoogle Scholar]. As a consequence, cardiac operations on HD patients are becoming more common. Traditionally, the results of myocardial revascularization in these patients have been poor because of advanced coronary disease and complications from the underlying condition. Indeed, guidelines from the European Society of Cardiology on myocardial revascularization suggest accounting for the general condition of the HD patient and life expectancy when considering a revascularization strategy [2Kolh P. Wijns W. Danchin N. et al.Guidelines on myocardial revascularization.Eur J Cardiothorac Surg. 2010; 38: S1-S52Crossref PubMed Scopus (316) Google Scholar]. The article by Takami and colleagues provides important new data on predictors of early and late outcomes after coronary artery bypass grafting (CABG) in HD patients [3Takami Y. Tajima K. Kato W. et al.Predictors for early and late outcomes after coronary artery bypass grafting in hemodialysis patients.Ann Thorac Surg. 2012; 94: 1940-1946Abstract Full Text Full Text PDF PubMed Scopus (26) Google Scholar]. In their retrospective analysis of 152 HD patients, the authors found a significant reduction in hospital mortality with the introduction of an off-pump coronary artery bypass (OPCAB) in 2003. Early mortality decreased from 15.3% in the pre-OPCAB era to 6.3% afterward. Crude mortality in these patients is still significantly higher that in the general CABG population, but the improvement associated with the introduction of OPCAB in their experience was noteworthy. The effect of off-pump CABG on renal function in non-HD patients remains controversial [4Lamy A. Devereaux P.J. Prabhakaran D. et al.Off-pup or on-pump coronary artery bypass grafting at 30 days.N Eng J Med. 2012; 366: 1489-1497Crossref PubMed Scopus (530) Google Scholar, 5Elmistekawy E. Chan V. Bourke M.E. et al.Off-pump coronary artery bypass grafting does not preserve renal function better than on-pump coronary artery bypass grafting: results of a case-matched study.J Thorac Cardiovasc Surg. 2012; 143: 85-92Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar], but OPCAB may confer a clear benefit in the specific subgroup of HD patients. One may speculate as to the possible mechanisms leading to this association, with OPCAB potentially resulting in less manipulations of the aorta, a lower need for transfusion, volume replacement and hemodilution, and therefore fewer strokes, a shorter duration of mechanical ventilation, and a lower incidence of infections. Another important finding of this study was that the long-term survival of HD patients who underwent CABG appeared equivalent to that of HD patients who did not undergo myocardial revascularization. Thus, despite the high early mortality, CABG effectively returns HD patients to their life expectancy curve. Although indication bias in selecting patients was likely in Takami's study, this finding carries important implications for the patient and clinician when considering HD patients for coronary surgery. External validation by further studies will be needed to confirm whether OPCAB is indeed the optimal strategy for myocardial revascularization in HD patients. Moreover, future studies may consider the role of minimally invasive procedures such as minimally invasive cardiac surgery-CABG in further reducing surgical trauma [6McGinn Jr, J.T. Usman S. Lapierre H. Pothula V.R. Mesana T.G. Ruel M. Minimally invasive coronary artery bypass grafting: dual-center experience in 450 consecutive patients.Circulation. 2009; 120: S78-S84Crossref PubMed Scopus (139) Google Scholar], considering that mediastinitis is the most common fatal complication in HD patients after conventional surgery [7Liu J.Y. Birkmeyer J.O. Sanders J.H. et al.Risk of morbidity and mortality in dyalisis patients undergoing coronary artery bypass surgery.Circulation. 2000; 102: 2973-2977Crossref PubMed Scopus (192) Google Scholar]. Predictors for Early and Late Outcomes After Coronary Artery Bypass Grafting in Hemodialysis PatientsThe Annals of Thoracic SurgeryVol. 94Issue 6PreviewMarkedly higher hospital and long-term mortality after coronary artery bypass grafting (CABG) have been reported in hemodialysis (HD)-dependent patients. We tried to identify the predictors for short-term and long-term outcomes after CABG, which have not been well studied. Full-Text PDF