Anqing Chen

Comparison of Graft Patency Between Off-Pump and On-Pump Coronary Artery Bypass Grafting: An Updated Meta-Analysis

BACKGROUND Currently, off-pump coronary artery bypass grafting (OPCAB) and on-pump coronary artery bypass grafting (ONCAB) are 2 well-established therapeutic strategies for patients with coronary artery disease, and debate regarding which strategy provides superior graft patency is ongoing. The current study is a meta-analysis of randomized controlled trials that compared the graft patency between OPCAB and ONCAB. METHODS Data sources were PubMed, the Cochrane Library, Google Scholar, and ISI Web of Knowledge (1966-2013). We identified studies comparing graft patency after the 2 procedures as the primary intervention for patients with multivessel coronary artery disease and conducted a meta-analysis of randomized controlled trials on graft patency. RESULTS A literature search yielded 12 randomized controlled trials, for a total of 3,894 and 4,137 grafts performed during OPCAB and ONCAB procedures, respectively. Meta-analysis of these studies showed an increased risk of occlusion of all grafts (risk ratio [RR], 1.35; 95% confidence interval [CI], 1.16-1.57) and saphenous vein grafts (SVGs) (RR, 1.41; 95% CI, 1.24-1.60) in the OPCAB group, whereas there was no significant difference in graft occlusion of left internal mammary artery (LIMA) (RR, 1.15; 95% CI, 0.83-1.59) and radial artery (RR, 1.37; 95% CI, 0.76-2.47) grafts between OPCAB and ONCAB. CONCLUSIONS Meta-analysis of currently available randomized controlled trials on graft patency shows that ONCAB reduces the incidence of SVG graft occlusion significantly but does not affect LIMA and radial artery graft patency compared with OPCAB.

MicroRNA-92a Inhibition Attenuates Hypoxia/Reoxygenation-Induced Myocardiocyte Apoptosis by Targeting Smad7

Background MicroRNAs (miRNAs) regulate a lot of physiological and pathological processes, including myocardial ischemia/reperfusion. Recent studies reported that knockdown of miR-92a could attenuate ischemia/reperfusion-induced myocardial injury. In the present study, we examined the potential anti-apoptotic effects of miR-92a in a rat myocardiocyte cell line, and the possible role of Smad7 in such actions. Methodology and Results In a preliminary bioinformatic analysis, we identified SMAD family member 7 (Smad7) as a potential target for miR-92a. A luciferase reporter assay indeed demonstrated that miR-92a could inhibit Smad7 expression. Myocardial ischemia/reperfusion was simulated in rat H9c2 cells with 24-h hypoxia followed by 12-h reoxygenation. Prior to hypoxia/reoxygenation, cells were transfected by miR-92a inhibitor. In some experiments, cells were co-transfected with siRNA-Smad7. The miR-92a inhibitor dramatically reduced the release of lactate dehydrogenase and malonaldehyde, and attenuated cardiomyocyte apoptosis. The miR-92a inhibitor increased SMAD7 protein level and decreased nuclear NF-κB p65 protein. Effects of the miR-92a inhibitor were attenuated by co-transfection with siRNA-Smad7. Conclusion Inhibiting miR-92a can attenuate myocardiocyte apoptosis induced by hypoxia/reoxygenation by targeting Smad7.

Meta-Analysis of Apolipoprotein E Gene Polymorphism and Susceptibility of Myocardial Infarction

A number of case-control studies have been conducted to clarify the association between ApoE polymorphisms and myocardial infarction (MI); however, the results are inconsistent. This meta-analysis was performed to clarify this issue using all the available evidence. Searching in PubMed retrieved all eligible articles. A total of 33 studies were included in this meta-analysis, including 18752 MI cases and 18963 controls. The pooled analysis based on all included studies showed that the MI patients had a decreased frequency of the ε2 allele (OR = 0.78, 95% CI = 0.70–0.87) and an increased frequency of the ε4 allele (OR = 1.15, 95% CI = 1.10–1.20); The results also showed a decreased susceptibility of MI in the ε2ε3 vs. ε3ε3 analysis (OR = 0.79, 95% CI = 0.68–0.90) and in the ε2 vs. ε3 analysis (OR = 0.78, 95% CI = 0.69–0.89), an increased susceptibility of MI in the ε3ε4 vs. ε3ε3 analysis (OR = 1.26, 95% CI = 1.12–1.41), in the ε4 vs. ε3 analysis (OR = 1.22, 95% CI = 1.12–1.32) and in the ε4ε4 vs. ε3ε3 analysis (OR = 1.59, 95% CI = 1.15–2.19). However, there were no significant associations among polymorphisms and MI for the following genetic models: frequency of the ε3 allele (OR = 0.99, 95% CI = 0.96–1.02); ε2ε2 vs. ε3ε3 analysis (OR = 0.73, 95% CI = 0.40–1.32); or ε2ε4 vs. ε3ε3 analysis (OR = 1.10, 95% CI = 0.99–1.21). Our results suggested that the ε4 allele of ApoE is a risk factor for the development of MI and the ε2 allele of ApoE is a protective factor in the development of MI.

Robot-assisted coronary artery bypass grafting improves short-term outcomes compared with minimally invasive direct coronary artery bypass grafting

BACKGROUND Robot-assisted coronary artery bypass grafts (RACAB) utilizing the da Vinci surgical system are increasingly used and allow the surgeon to conveniently harvest internal mammary arteries (IMAs). The aim of this study was to compare the outcomes of off-pump RACAB and minimally invasive direct coronary artery bypass grafting (MIDCAB) in the short and medium term. METHODS We performed a retrospective review of 132 patients with single- or multiple-vessel coronary artery disease who underwent minimally invasive off-pump CABG (OPCAB) between May 2009 and May 2014. The patients were divided into two groups based on the surgical approach, MIDCAB and RACAB group. The anastomosis of the left internal mammary artery (LIMA) to the left anterior descending artery (LAD) was performed as regular OPCAB through the incision on the beating heart using regular stabilization devices (Genzyme Corporation). The preoperative, intraoperative, postoperative, and follow-up data, including major adverse cardiac and cerebrovascular events (MACCE), were compared. RESULTS The preoperative data were similar. RACAB significantly shorten the intensive care unit (ICU) stay and postoperative compared with the MIDCAB group (P<0.05). There were 12 (19.7%) patients treated with a two-stage hybrid procedure in the MIDCAB group and 34 (47.9%) patients in the RACAB group (P=0.001). Thirty-day mortality was 1.6% in the MIDCAB group. There were 9 (14.7%) MIDCAB patients and 2 (2.8%) RACAB patients (P=0.013) that developed new arrhythmia. The two groups showed comparable mid-term survival (P=0.246), but the MACCEs were significantly different (P=0.038). CONCLUSIONS RACAB may be a valuable alternative for patients requiring single or simple multi-vessel coronary artery bypass grafting (CABG). Although the mid-term mortality outcomes are similar, RACAB improves short-term outcomes and mid-term MACCE-free survival compared with MIDCAB.

Role of Surgical Ventricular Restoration in the Treatment of Ischemic Cardiomyopathy

BACKGROUND Surgical ventricular restoration (SVR) has been applied as a valuable adjunct procedure for patients undergoing coronary artery bypass grafting (CABG) to correct the geometry of the left ventricle on the basis of myocardial revascularization. It is necessary to find out at least which patient cohort is more likely to benefit from this procedure. METHODS A case-control study was conducted on 221 patients with ejection fraction (EF)≤0.35 and New York Heart Association (NYHA) class III or IV, who received CABG+SVR or CABG alone from 1998 to 2008. Comparisons were made between CABG+SVR and CABG alone within two groups of patients: group 1 (preoperative left ventricular end-systolic volume index [LVESVI]<80 mL/m2, n=127) and group 2 (preoperative LVESVI≥80 mL/m2, n=94). Outcomes included improvement in EF, NYHA class, readmissions, and survival. RESULTS Patients in either group receiving SVR achieved significant LVESVI reduction postoperatively (p<0.001). In group 1, EF improvement (defined as over .05 improvement in EF) was observed in 53.7% of CABG+SVR patients compared with 48.5% for CABG patients (p 0.570). A similar percentage of patients improved to NYHA class I or II (63.0% for CABG+SVR versus 55.9% for CABG, p=0.430). Readmissions after CABG+SVR were 27.8% compared with 38.2% after CABG (p=0.225). There was no difference in survival between CABG+SVR and CABG (p=0.709). In group 2, the CABG+SVR patients showed greater EF improvement (55.6% versus 30.8%, p=0.020) and were more likely to improve to NYHA class I or II (58.3% versus 36.5%, p=0.044). Readmissions were fewer for the CABG+SVR patients than for the CABG patients (30.6% versus 57.7%, p=0.012). CABG+SVR yielded better survival than did CABG (p=0.031). CONCLUSIONS Patients with much advanced LVESVI are more likely to benefit from surgical ventricular restoration, and this surgical procedure still holds its ground in the treatment of ischemic cardiomyopathy.

Mid-term results of coronary bypass graft surgery in patients with ischaemic left ventricular systolic dysfunction and no detected myocardial viability

OBJECTIVES There are concerns about effects of surgical revascularization on patients with ischaemic systolic dysfunction when no signs of myocardial viability have been detected by nuclear imaging preoperatively. We reviewed our data to determine the efficacy of coronary bypass graft in this special patient cohort. METHODS A retrospective review with prospectively collected clinical data was conducted on 87 consecutive patients between 2000 and 2012 whose left ventricular ejection fraction was less than 40%. All patients received positron emission tomography examination before undergoing coronary artery bypass graft and showed no signs of myocardial viability. Improvements in ejection fraction, postoperative re-examination of myocardial viability by nuclear imaging and freedom from major cardiac events were observed. Survival was calculated using Kaplan-Meier analysis. RESULTS The 30-day mortality rate was 7%. Ejection fraction improvement (defined as over 5%) was observed in 13 (16%) patients within 6 months postoperatively. Ejection fraction improvement was observed in 46 (58%) patients by the end of the first year and 50 (63%) patients by the second year. It was noted that 25 (32%) and 43 (54%) patients progressed to heart functional class I or II at 1 and 5 years, respectively. Positron emission tomography examination showed enhanced myocardial viability in the non-viable ventricular wall segment in 53 (67%) patients at 1 year. Freedom from major adverse cardiac events was observed in 56 (71%) patients at 1 year and 47 (60%) patients at 5 years. Survival rates were 82 and 66% at 1 and 5 years, respectively. CONCLUSIONS Coronary artery bypass graft proved to be a positive choice of treatment for patients with severe ischaemic systolic dysfunction when there was no viable myocardium detected through nuclear imaging.

Off-pump coronary artery bypass surgery outcomes in patients with ischaemic left ventricular systolic dysfunction with or without detected viable myocardium

OBJECTIVES The prognostic value of myocardial viability before coronary bypass grafting remains controversial. The present study evaluated the effects of off-pump coronary artery bypass (OPCAB) grafting on patients with coronary artery disease (CAD) with or without viable myocardium (VM) preoperatively detected via nuclear imaging. METHODS A total of 115 consecutive patients with 3-vessel disease and impaired left ventricular ejection fraction (LVEF ≤ 45%) who underwent OPCAB grafting were recruited in this prospective study. The patients were divided into 2 groups based on myocardial viability, the non-viable myocardium (NVM, 55 patients) and VM (60 patients) groups. Positron emission tomography and radionuclide imaging examination were applied to evaluate the myocardium viability. A Kaplan-Meier analysis was conducted to evaluate the 1-year survival rate. RESULTS The preoperative data were similar between groups. An improvement in the LVEF was observed in both groups 12 months after OPCAB grafting (P < 0.05). A binary logistic regression revealed that NVM was an independent predictor of a 5% improvement in LVEF at 6 months (P = 0.012). The rate of main adverse cardiovascular and cerebrovascular events (MACCEs) rate at 1 year was similar between the 2 groups (P = 0.06). At 1 year, the death rates were 14.5% in the NVM group and 5% in the VM group (P = 0.17). A Cox regression analysis revealed that NVM and age were independent predictors of mortality [the hazard ratio for death associated with NVM and age were 1.62, 95% confidence interval (CI) = 1.16-2.89, P = 0.036 and 1.05, 95% CI = 0.98-1.12, P =0.025, respectively]. CONCLUSIONS The MACCEs and mortality rates of the NVM group were higher than those of the VM group. However, OPCAB surgery improved LVEF, regardless of myocardium status. Therefore, the assessment of myocardial viability might not be the sole deciding factor in decision-making process regarding OPCAB surgery.

Plasma levels of growth differentiation factor-15 are associated with myocardial injury in patients undergoing off-pump coronary artery bypass grafting.

Growth differentiation factor-15 (GDF-15) has recently emerged as a risk predictor in patients with cardiovascular diseases. We therefore aimed to investigate the role of GDF-15 in the occurrence of cardiac injury during off-pump coronary artery bypass grafting (OPCAB). 55 consecutive patients with coronary artery diseases were recruited in this prospective, observational study. All patients were operated for OPCAB surgery. Serial blood samples were collected preoperatively, 12 hours and 36 hours after surgery. GDF-15, together with C-reactive protein, cardiac troponin I, creatine kinase MB and N-terminal pro B-type natriuretic peptide levels in plasma were measured at each time-point. GDF-15 levels increased significantly at 12 hours after surgery, attaining nearly 2.5 times the baseline levels (p < 0.001). Postoperative GDF-15 levels correlated positively with cTnI (p = 0.003) and EuroSCORE II (p = 0.013). According to the ROC curves, postoperative plasma GDF-15 was found to be the best biomarker to predict perioperative cardiac injury, compared with cTnI, CK-MB and EuroSCORE II. Circulating GDF-15 is a promising novel biomarker for identifying perioperative myocardial injury in patients undergoing OPCAB.

Second ectopic recurrence of mitral valve myxomas after resection

Cardiac myxomas are the commonest primary cardiac tumors, accounting for 50% of cases (1). Arising from the endocardial tissue, most of myxomas are located in the left atrium, with the percentage from 75% to 83% of the total; while the percentage in the right atrium is less, up to 10–18%, and they often appear more frequently in the area near to fossa ovalis (1,2).

Plasma levels of matrix metalloproteinase 9 in patients undergoing off-pump coronary artery bypass grafting

BACKGROUND Matrix metalloproteinase 9 (MMP9) has recently emerged as a risk predictor in patients with cardiovascular diseases. However, little is known about the significance of increased plasma MMP9 in patients with perioperative myocardial injury. We aimed to investigate the role of MMP9 in the occurrence of myocardial injury during off-pump coronary artery bypass grafting (OPCAB). METHODS A total of 34 consecutive patients with coronary artery diseases (CAD) were recruited in this prospective, observational study. All patients were operated for OPCAB surgery. Serial blood samples were collected preoperatively and 12 hours after surgery. MMP9, together with cardiac troponin I (cTnI), creatinine kinase myocardial b fraction (CK-MB), C-reactive protein (CRP), and N-terminal pro B-type natriuretic peptide (NT-proBNP) levels in plasma were measured at each time-point. RESULTS MMP9 levels increased significantly at 12 hours after surgery, attaining nearly 2 times the baseline levels (P=0.0001). There was a significant correlation between preoperative (pre-OP) circulating levels of MMP9 and the left ventricular ejection fraction (LVEF) (r=0.48; P=0.004) as well as European System for Cardiac Operative Risk Evaluation (EuroSCORE) II (r=0.43; P=0.012). Patients were in New York Heart Association (NYHA) functional class III or IV heart failure showed a significantly higher MMP9 levels (1,348.0±337.2 vs. 630.4±93.0 ng/L, P=0.012) as compared to the patients in NYHA functional class I and II. No significant correlation was observed between MMP9 and age (P=0.612), serum creatinine (P=0.185), CRP (P=0.207), NT-proBNP (P=0.058). A significant correlation was observed in these data between the post-OP MMP9 and cTnI (r=0.35; P=0.003). CONCLUSIONS Our study first established a connection between MMP9 and OPCAB procedure, suggesting that MMP9 could be a novel biomarker for identifying perioperative myocardial injury in patients undergoing OPCAB.