A Comparative Study Of Long-term Clinical Outcomes And Graft Patency Rates Between Extracorporeal And Off-pump Coronary Artery Bypass Grafting

Coronary artery bypass grafting(CABG)is the most important treatment for ischemic heart disease.As my country enters an aging society,the incidence and challenges of ischemic heart disease are becoming more and more obvious.The volume of CABG surgeries has continued to surge over the years.Coronary artery bypass grafting is divided into CABG under cardiopulmonary bypass(On-pump CABG)and CABG under off-pump(Off-pump CABG)according to whether cardiopulmonary bypass is used or not.Compared with On-pump CABG,previous studies believe that Off-pump CABG has better safety for patients with severe aortic calcification and renal insufficiency before surgery,and is beneficial to the prognosis of patients after surgery.At the same time,Off-pump CABG has the disadvantage that the surgical process is not conducive to complete revascularization.With the advancement of myocardial protection technology,cardiopulmonary bypass technology,anesthesia technology and surgical technology in recent years,the advantages of the two surgical methods are gradually approaching.At present,these prognosis-related researches are very controversial for patients need CABG to choose operation method to get more beneficial.The two largest clinical controlled studies on this issue in the academic community to date include the ROOBY study(NCT00032630)and the CORONARY study(NCT00463294).In 2009,Professor AL Shroyer led the organization of the ROOBY study.The randomized controlled single-blind study enrolled 2203 CABG patients in 18 heart centers in the United States.The results of a 1-year follow-up showed that the clinical results of Off-pump CABG and the patency rate of grafts less than On-pump patients,the 5-year follow-up results showed that the 5-year survival rate of Off-pump CABG patients was lower than On-CABG patients.The data did not compare the 5-year graft patency rate.In 2012,the CORONARY study organized by Professor Lamy included 79 research centers from 19 countries,and Fuwai Hospital participated in the study as one of them.Unlike the ROOBY study,the CORONARY study has stricter selection criteria for surgeons in order to avoid the interference of the surgeon's surgical technique on the research results.The CORONARY study analyzed the clinical results of 30 days after surgery and 5 years after surgery.It showed that On-pump CABG and Off-pump CABG had no difference in the incidence of adverse events such as death and recurrent myocardial infarction.The patency rate of grafts was not reported.The results of the ROOBY study and the CORONARY study were published in the NEJM journal,while the results of the two studies were significantly different.The follow-up time of the above two studies is 5 years after surgery,which only reflects the different clinical results of the two surgical procedures in the middle postoperative period.At the same time,the patency of the graft after CABG is an important factor related to the poor prognosis of patients,however the above two studies all not discussed the patency of the graft in their studies.Based on the above research background,we carry out a series of follow-up analysis work on the long-term clinical results and graft patency rate of CABG patients,aimed to reveal the difference between the long-term clinical results of On-pump CABG and Off-pump CABG and find the influencing factors to improve the prognosis of CABG patients.Part ?.Comparison of Long-term Clinical Results between On-pump and Off-pump Coronary Artery BypassObjective:Previous studies on the clinical outcomes between on-pump coronary artery bypass(CABG)and off-pump CABG is debatable and these studies mainly reported the postoperative early medium-term follow-up results and the long-term follow-up data are lacking.This study aims to compare the major clinical events between the On-pump CABG through the long-term follow-up.Methods:Betweeen May 2007 and October 2011,349 patients were randomized to off-pump or on-pump CABG as part of the CORONARY trial at Fuwai Hospital.The information of major adverse cardiovascular and cerebrovascular events(MACCE)including all-cause death,non-fatal myocardial infarction,stroke,and re-coronary revascularization was collected by telephone follow-up.Results:Of the 349 patients enrolled in the study,174 were in the On-pump CABG group and 175 were in the Off-pump CABG group and the mean follow-up time is 6.5±1.7 years.The long-term clinical results of patients in the On-pump CABG group and the Off-pump CABG group showed that the long-term incidence of adverse events in the On-pump CABG group lower than in the Off-pump CABG group:All-cause mortality(13.8%vs 15.4%,95%confidence interval[CI]:0.48-1.60,P=0.659),non-fatal myocardial infarction(1.7%vs 2.3%,95%CI:0.17-3.40,P=0.708),secondary coronary revascularization(2.9%vs 4.6%,95%CI:0.20-1.93,P=0.402),stroke(7.5%vs 8.6%,95%CI:0.40-1.87,P=0.705),there was no statistically significant difference.Kaplan-Meier survival curve analysis showed that there was no significant difference in long-term survival(log-rank test P=0.643)and the major cardiovascular and cerebrovascular events(log-rank test P=0.306)between the two groups.Conclusions:This study suggests that On-pump CABG group appeared to offer a better long-term prognosis compared with Off-pump CABG even there was no statistical differences for the limited study population.Part ?.Long-term Graft Patency after Off-Pump and On-Pump Coronary Artery BypassObjective:Graft patency after coronary artery bypass grafting is the main factor affecting the prognosis of CABG.The data of bridging vessel patency rate are relatively few in the previous studies on the comparative clinical results by the two surgical methods,which may be related to the difficulty of imaging examination during follow-up work to evaluate the postoperative bridging vessel lesions.In this study,based on the follow-up analysis of bridging vessel conditions after bypass surgery,the long-term graft patency rates between On-pump CABG and Off-pump CABG was compared and the risk factors for occlusion of bridging vessel were analyzed.Methods:By telephone invitation,computed tomography(CT)imaging technique was used to follow up 349 cases of CORONARY artery bypass grafting in Fuwai Hospital.The imaging data collected during the follow-up were randomly assigned to two experienced imaging experts for analysis and interpretation to determine the patency of graft vessels.Logistic multivariate regression was used to analyze the independent risk factors for graft vessels occlusion.Results:Complete clinical data were collected from 206 patients undergoing coronary artery bypass grafting with a mean follow-up time of 6.7±1.7 years.Among them,99 cases were in the On-pump CABG group and 107 cases in the Off-pump CABG group.These patients underwent a total of 723 grafts,and the overall rate of graft patency did not differ significantly between the off-pump and on-pump groups(87.4%vs 88.9%,P=0.527).The patency rate of the posterior descending branch was lower than average.Logistic multiple factors regression analysis suggest preoperative hyperlipidemia is independent associated with the occlusion of graft vessels(Odds Ratio[OR]2.26,95 CI 1.15 to 4.43,P=0.018).Conclusion:This study suggests that there is no significant difference in the long-term graft patency rate between On-pump CABG and Off-pump CABG patients.The posterior descending branch is more likely to occlude.Preoperative hyperlipidemia is an independent risk factor for graft vessels occlusion.