With improved dialysis techniques, the number of patients surviving after developing ESRD has increased significantly, and nearly 50% of the patients eventually die of cardiovascular diseases, rather than renal disease. After adjusting for age, race, and sex, mortality in patients with cardiovascular diseases is 10–20 times higher than that of the general population.2)
CABG or PCI: CABG is an effective treatment for severe coronary heart disease. Although to our knowledge, there are no randomized controlled studies evaluating dialysis-dependent patients with ESRD and coronary heart disease, a retrospective analysis involving 1015 dialysis-dependent patients with ESRD showed that CABG was significantly superior to PCI regarding postoperative revascularization, and long-term all-cause mortality was at least equivalent to PCI. 3) At the 5-year follow-up, CABG was associated with significantly lower rates of cardiac death, sudden death, myocardial infarction, and revascularization compared with PCI, although there was no significant difference for all-cause deaths. 4) The perioperative risk of CABG is higher than that of PCI, but patients benefit regarding long-term survival.5) Therefore, for patients with ESRD with left main or/and three-vessel coronary lesions who can undergo both PCI and CABG, we prefer CABG.
Influence factors of peri-operative death: In this study, eight patients died perioperatively, leading to a mortality rate of 15.1%. Regarding the factors associated with mortality, we found that IABP use (P=0.01), advanced age (P=0.0027), and high EuroSCORE II score (P=0.047) were associated with higher perioperative mortality. Studies have shown that ESRD with dialysis dependence is a predictor of in-hospital mortality (odds ratio: 3.1, P < 0.001), and significantly increased perioperative cardiac mortality, postoperative sepsis, and respiratory failure, 1) similar to the results in our study. Multiple factors are related to perioperative mortality, namely, surgical complexity, preoperative cardiac function grade IV (New York Heart Association classification), preoperative acute myocardial infarction, combined surgery, aortic surgery, age ≥ 70 years, history of heart failure, PAD, female sex, dialysis dependence ≥ 5 years, emergency surgery, and preoperative hypertension. 1, 6, 7, 8) Jault et al. retrospectively analyzed the results of cardiac surgery in 124 patients receiving dialysis. Of these patients, 46% constituted the coronary heart disease group (group 1), 29.8% constituted the valvular disease group (group 2), 14.5% constituted the coronary heart disease and valvular disease group (group 3), and 9.6% constituted the high-risk disease group (group 4) with conditions such as emergency, secondary, and complex diseases; aortic dissection; aortic aneurysm; and prosthetic valve endocarditis; 14.5% of patients had diabetes mellitus, resulting in an overall mortality of 16.9%. Age, sex, hypertension, diabetes mellitus, preoperative myocardial infarction, disease type, preoperative ejection fraction, and 30-day postoperative mortality were analyzed in Jault et al.’s study. The only risk factor was complex cardiac surgery. The combined overall mortality rate for group 3 and 4 was significantly higher than the combined mortality rate for group 1 and 2 (30% vs. 12.7%, respectively) . 6)
Influence factors of follow-up death: During the follow-up of our 45 discharged patients, the shortest follow-up period was 2 months (died 2 months postoperatively), and the longest was 10 years, with a median of 4.2 years. There were 19 all-cause deaths, including 10 cardiac deaths (10/19, 52.6%). The 1-, 3-, and 5-year survival rates were 93.3%, 79.5%, and 66.8%, respectively. Log rank analysis of the factors influencing patients' postoperative survival showed that PAD was the only risk factor affecting survival. Our results also indicated that even after CABG surgery, more than 50% of dialysis-dependent ESRD patients eventually died of cardiovascular diseases (acute myocardial infarction and heart failure), and that PAD was a risk factor for long-term survival. The overall survival rates were 76.9%, 60.0%, 43.9%, and 36.2% at 3, 5, 8, and 10 years, respectively. In the Kaplan–Meier model, multivariate analysis showed that age ≥ 63 years (p=0.014), diabetes mellitus (p=0.036), and PAD (p=0.044) were predictors of late death, and that diabetes mellitus (p=0.038) and LVEF ≤ 0.40 (p=0.027) were predictors of late cardiovascular events. Thus, intensive symptomatic and supportive treatment may be needed for patients older than 63 years with diabetes, PAD, and low LVEF. 9) Sezai et al. reported that the postoperative survival rates were 81.5 ± 18.5% at 1 year, 72.0 ± 28.0% at 5 years, and 68.4 ± 31.6% at 8 years. Logistic regression analysis showed that acute myocardial infarction, age ≥ 75 years, preoperative IABP implantation, and combined surgery were risk factors for early death. In particular, the prognosis of patients with preoperative left ventricular dysfunction, and IABP-assisted and combined surgery was poor. 10) In a retrospective analysis of 483 consecutive cardiac operations, patients with valvular disease, active endocarditis, and low left ventricular function had increased mid-term mortality.11) Therefore, for such patients, multiple related factors affect postoperative survival, and cardiovascular disease is still the main cause of death. To improve the surgical effect, improving CABG surgical technique and postoperative comprehensive treatment by a multidisciplinary team are needed to decrease complications in the cardiovascular system and other systems.
Choice of surgical technique: Because ESRD patients experience many complications after cardiopulmonary bypass, we prefer to use an off-pump technique and graft using the internal mammary artery, as much as possible. The rates of perioperative complications following off-pump CABG, such as bleeding, allogeneic blood transfusion, duration of mechanical ventilation, positive inotropic drug support, perioperative myocardial infarction, and new atrial fibrillation, are lower than those for CABG under traditional cardiopulmonary bypass.12) Shroff et al. reported Of the 13 085 dialysis patients (2001–2006) in the US Renal Data System database, 2335 (17.8%) patients underwent off-pump CABG. Off-pump CABG significantly reduced all-cause mortality (hazard ratio 0.92, 95% CI: 0.86–0.99; P =.02), with the most obvious benefit occurring in the first year postoperatively. There was no difference in all-cause mortality between the two groups in the second year follow-up. Additionally, no difference was found between the groups for cardiovascular mortality, and the use of the internal mammary artery significantly improved postoperative survival (hazard ratio 0.92; 95% CI: 0.87–0.98; P =.0057). 13) Compared with CABG under conventional extracorporeal circulation, CABG without cardiopulmonary bypass can achieve better long-term survival. 14) Some studies suggested that off-pump CABG has no significant advantage for dialysis-dependent patients. Ten retrospective studies (2762 patients undergoing off-pump CABG, and 11 310 patients undergoing CABG under traditional cardiopulmonary bypass) reported no significant difference in early mortality, hemostasis by thoracotomy, allogeneic blood transfusion rates, stroke, or atrial fibrillation between the two surgical methods. Patients undergoing off-pump CABG were extubated earlier (p < 0.01). There was also no difference in 3-year survival postoperatively,15) and no difference in mortality, myocardial infarction, stroke, or revascularization rates, even at 30 days, 1 year, and throughout the follow-up period. 16) Most studies confirmed the use of the internal mammary artery (17, 18). For patients with multivessel disease and an average follow-up of 2.5 years, bilateral internal mammary arteries skeletonized in situ decreased all-cause mortality (p=0.02) and cardiovascular mortality (p=0.04) .17) At 3-, 5-, 7-, and 10 years of follow-up (mean, 5.2 years) in 130 ESRD patients undergoing CABG, the use of bilateral internal mammary arteries significantly reduced the rate of cardiovascular events in ESRD patients without diabetes (p=0.0143) . 18)
Peritoneal dialysis or hemodialysis: The results of our study showed that peritoneal dialysis and hemodialysis had no effect on perioperative and short- or medium-term prognosis, which was consistent with the survival results of Kumar et al.19) There was no difference in preoperative general data between the 36 patients receiving peritoneal dialysis and the 72 patients receiving hemodialysis, or in 2-year survival rate postoperatively, but the number of patients experiencing perioperative complications such as postoperative infection and delayed extubation, and the number who died were higher in the hemodialysis group.19) It has also been reported that both in-hospital and 1-year postoperative mortality rates in peritoneal dialysis patients are higher than for hemodialysis patients. In one study, among the patients who died in-hospital, more hemodialysis patients died from cardiac events vs patients receiving peritoneal dialysis who died from septic toxic shock.20)