Chengxiong Gu

Impact of Obstructive Sleep Apnea Syndrome on Endothelial Function, Arterial Stiffening, and Serum Inflammatory Markers: An Updated Meta‐analysis and Metaregression of 18 Studies

Background Obstructive sleep apnea syndrome (OSAS) has been indicated to contribute to the development of cardiovascular disease; however, the underlying mechanism remains unclear. This study aimed to test the hypothesis that OSAS may be associated with cardiovascular disease by elevating serum levels of inflammatory markers and causing arterial stiffening and endothelial dysfunction. Methods and Results Related scientific reports published from January 1, 2006, to June 30, 2015, were searched in the following electronic literature databases: PubMed, Excerpta Medica Database, ISI Web of Science, Directory of Open Access Journals, and the Cochrane Library. The association of OSAS with serum levels of inflammatory markers, endothelial dysfunction, and arterial stiffening were investigated. Overall, 18 eligible articles containing 736 patients with OSAS and 424 healthy persons were included in this meta‐analysis. Flow‐mediated dilation in patients with moderate–severe OSAS was significantly lower than that in controls (standardized mean difference −1.02, 95% CI −1.31 to −0.73, P<0.0001). Carotid‐femoral pulse wave velocity (standardized mean difference 0.45, 95% CI 0.21–0.69, P<0.0001), augmentation index (standardized mean difference 0.57, 95% CI 0.25–0.90, P<0.0001), and serum levels of high‐sensitivity C‐reactive protein and C‐reactive protein (standardized mean difference 0.58, 95% CI 0.42–0.73, P<0.0001) were significantly higher in patients with OSAS than in controls. Conclusion OSAS, particularly moderate–severe OSAS, appeared to reduce endothelial function, increase arterial stiffness, and cause chronic inflammation, leading to the development of cardiovascular disease.

Preoperative Statin Therapy and Renal Outcomes After Cardiac Surgery: A Meta-analysis and Meta-regression of 59,771 Patients

BACKGROUND The purpose of this study was to investigate the effects of preoperative statin therapy (PST) on short- and long-term renal dysfunction after cardiac surgery. METHODS We searched for reports that investigated the effects of PST on renal outcomes after cardiac surgery in the electronic literature databases PubMed, Ovid, and Elsevier. RESULTS Twenty-six reports including 59,771 patients were selected for meta-analysis. The meta-analysis revealed that PST significantly reduced the incidence of postoperative renal dysfunction (odds ratio [OR], 0.89; 95% confidence interval [CI], 0.84-0.95; P < 0.0001) without significant heterogeneity (I(2) = 28.1%; P = 0.093). PST also significantly reduced the need for postoperative renal replacement therapy (OR = 0.76; 95% CI, 0.62-0.92; z = 2.77; P = 0.006); particularly in the subgroup of patients who underwent isolated coronary artery bypass grafting, the rate of renal replacement therapy was reduced by 56% (OR, 0.44; 95% CI, 0.30-0.66; z = 4.08; P < 0.0001) with low heterogeneity (I(2) = 18.7%; P = 0.297). Meta-analysis for the outcome of acute kidney injury (AKI) revealed that PST reduced the incidence of postoperative AKI by 13% (OR, 0.87; 95% CI, 0.80-0.94; P = 0.001) and 7% (OR, 0.93; 95% CI, 0.86-0.99; P = 0.031), respectively, for subgroups of patients whose AKI was evaluated using the Acute Kidney Injury Network (AKIN) or the Risk, Injury, Failure, Loss, and End Stage (RIFLE) criteria, without significant heterogeneity for either. CONCLUSIONS PST might be a promising therapy to reduce renal complications after cardiac surgery although large-scaled randomized controlled trials are needed to further verify the conclusion.

Short- and Long-Term Patient Outcomes From Combined Coronary Endarterectomy and Coronary Artery Bypass Grafting: A Meta-Analysis of 63,730 Patients (PRISMA).

AbstractThis meta-analysis aimed to compare the short- and long-term outcomes in patients undergoing combined coronary endarterectomy and coronary artery bypass grafting (CE + CABG) versus isolated CABG, and particularly to examine subgroup patients with high-risk profile and patients with diffuse disease in the left anterior descending artery (LAD).Studies published between January 1, 1970 and May 31, 2015 were searched in the literature databases, including Ovid Medline, Embase, PubMed, and ISI Web of Science.A total of 30 eligible studies including 63,730 patients were analyzed.Five authors extracted data from the included studies independently.Meta-analysis on the total patients revealed that CE + CABG was associated with significantly increased 30-day postoperative all-cause mortality compared with isolated CABG (OR = 1.86, 95% CI: 1.66–2.08, z = 10.99, P < 0.0001). Subgroup analysis on patients with high-risk profile and patients with diffuse disease in the LAD showed that 30-day mortality after CE + CABG was 2.6 folds (OR = 2.60, 95% CI: 1.39–4.86, z = 2.99, P = 0.003) and 3.93 folds (OR = 3.93, 95% CI: 1.40–11.0, z = 2.60, P = 0.009) of that after isolated CABG in the respective subgroup. In contrast, the mortality was comparable in CE + off-pump CABG and CE + on-pump CABG groups (OR = 0.53, 95% CI: 0.18–1.55, z = 1.16, P = 0.248). In addition, the incidences of perioperative myocardial infarction (MI) and 30-day postoperative complications, including low output syndrome (LOS), MI, ventricular tachycardia (VT), and renal dysfunction after CE + CABG were significantly higher than those after isolated CABG (all P < 0.05). In high-risk patient subgroup, CE + CABG significantly increased the incidences of postoperative LOS, MI, and renal function compared with isolated CABG (all P < 0.05). The incidence of perioperative myocardial after CE + CABG was 2.86 and 2.92 times of that after isolated CABG in high-risk patients and patients with diffuse disease in LAD, respectively. Analysis on the recent reports (published later than 2000) showed consistent results as the analysis including all the eligible reports. Long-term survival was comparable in CE + CABG and isolated CABG groups (hazardous ratio = 1.16, 95% CI: 0.32–4.22, z = 0.23, P = 0.819).CE + CABG appears to be associated with poor short-term outcomes, particularly in high-risk patients and patients with diffuse disease in the LAD.

Repair of functional tricuspid regurgitation: comparison between suture annuloplasty and rings annuloplasty.

BACKGROUND The purpose of this study was to review our experience with modified De Vega tricuspid annuloplasty versus ring annuloplasty for treating functional tricuspid regurgitation (TR). METHODS In all, 448 consecutive patients undergoing tricuspid annuloplasty with concomitant procedures between 2000 and 2012 were included. Modified De Vega annuloplasty was performed in 216 patients (group 1) and ring annuloplasty in 232 patients (group 2). Clinical and echocardiographic follow-up results were used to assess TR grade. Recurrent TR was defined as grade 2 or greater at echocardiography. RESULTS Preoperative clinical and echocardiographic characteristics were comparable in the two groups. Early mortality was similar (group 1, 0.9%, versus group 2, 1.3%; p<0.67). Follow-up was available for 97%; New York Heart Association class and symptoms of right-side heart failure were significantly improved. Survival rates at 1 and 5 years were comparable (97% and 84% for group 1, and 96% and 82% for group 2, respectively). Postoperative echocardiography showed significant improvement in tricuspid valve function, with reduction in TR grade from 3.4 to 0.6, and no differences between groups. However, recurrence-free survival was better for group 2 than for group 1 (78.8% versus 74.5%; p<0.62). Risk factors for recurrent TR included severity of preoperative TR, atrial fibrillation, and pulmonary hypertension. CONCLUSIONS The modified De Vega tricuspid annuloplasty is acceptable for repair of functional TR and improvements in clinical and echocardiographic status on a long-term basis, although the long-term recurrence-free survival appeared to be lower than that for ring annuloplasty.

Targeting the proinflammatory cytokine tumor necrosis factor-α to alleviate cardiopulmonary bypass-induced lung injury (Review)

Pulmonary dysfunction is one of the most frequent complications associated with cardiopulmonary bypass (CPB). Multiple factors, including the contact of blood with the artificial surface of the CPB circuit, ischemia‑reperfusion and lung ventilator arrest elicit inflammatory reactions, consequently resulting in CPB‑induced lung injury. The proinflammatory cytokine tumor necrosis factor‑α (TNF‑α) has been demonstrated to have a critical role in mediating CPB‑induced pulmonary inflammation. The present review evaluated previous studies and summarized the effects of CPB on TNF‑α level in the serum and lung tissue of patients and animal models of CPB, the underlying mechanism of TNF‑α‑mediated lung injury and the therapeutic strategies for the inhibition of TNF‑α activity and production to attenuate CPB‑induced lung injury. TNF‑α level in the serum and lung tissue is significantly increased during and following CPB. TNF‑α mediates CPB‑induced lung damage by directly inducing apoptosis in alveolar epithelial cells and lung endothelial cells and by indirectly modulating the function of immune cells, including monocytes and macrophages. A functional neutralizing antibody to TNF‑α can reduce pulmonary TNF‑α production and attenuate CPB‑induced lung injury in a rabbit model of CPB. Inhibition of TNF‑α function and production using a neutralizing antibody to TNF‑α appears to be a promising therapeutic strategy to alleviate CPB‑induced lung injury.

Pulmonary Artery Perfusion with Anti-Tumor Necrosis Factor Alpha Antibody Reduces Cardiopulmonary Bypass-Induced Inflammatory Lung Injury in a Rabbit Model

Inflammatory lung injury is one of the main complications associated with cardiopulmonary bypass (CPB). Tumor necrosis factor-α (TNF-α) is one of the key factors mediating the CPB-induced inflammatory reactions. Our previous studies have shown that endotracheal administration of anti-tumor necrosis factor-α antibody (TNF-α Ab) produces some beneficial effects on lung in a rabbit CPB model. In this study, we further examined the effects of pulmonary artery perfusion with TNF-α Ab (27 ng/kg) on lung tissue integrity and pulmonary inflammation during CPB and investigated the mechanism underlying the TNF-α Ab-mediated effects in a rabbit model of CPB. Our results from transmission electron microscopy showed that the perfusion with TNF-α Ab alleviated CPB-induced histopathological changes in lung tissue. The perfusion with TNF-α Ab also prevented CPB-induced pulmonary edema and improved oxygenation index. Parameters indicating pulmonary inflammation, including neutrophil count and plasma TNF-α and malondialdehyde (MDA) levels, were significantly reduced during CPB by pulmonary artery perfusion with TNF-α Ab, suggesting that the perfusion with TNF-α Ab reduces CPB-induced pulmonary inflammation. We further investigated the molecular mechanism underlying the protective effects of TNF-α Ab on lung. Our quantitative RT-PCR analysis revealed that pulmonary artery perfusion with TNF-α Ab significantly decreased TNF-α expression in lung tissue during CPB. The apoptotic index in lung tissue and the expression of proteins that play stimulatory roles in apoptosis pathways including the fas ligand (FasL) and Bax were markedly reduced during CPB by the perfusion with TNF-α Ab. In contrast, the expression of Bcl-2, which plays an inhibitory role in apoptosis pathways, was significantly increased during CPB by the perfusion with TNF-α Ab, indicating that the perfusion with TNF-α Ab significantly reduces CPB-induced apoptosis in lung. Thus, our study suggests that pulmonary artery perfusion with TNF-α Ab might be a promising approach for attenuating CPB-induced inflammatory lung injury.

Distal end side-to-side anastomoses of sequential vein graft to small target coronary arteries improve intraoperative graft flow

BackgroundEnd-to-side anastomoses to connect the distal end of the great saphenous vein (GSV) to small target coronary arteries are commonly performed in sequential coronary artery bypass grafting (CABG). However, the oversize diameter ratio between the GSV and small target vessels at end-to-side anastomoses might induce adverse hemodynamic condition. The purpose of this study was to describe a distal end side-to-side anastomosis technique and retrospectively compare the effect of distal end side-to-side versus end-to-side anastomosis on graft flow characteristics.MethodsWe performed side-to-side anastomoses to connect the distal end of the GSV to small target vessels on 30 patients undergoing off-pump sequential CABG in our hospital between October 2012 and July 2013. Among the 30 patients, end-to-side anastomoses at the distal end of the GSV were initially performed on 14 patients; however, due to poor graft flow, those anastomoses were revised into side-to-side anastomoses. We retrospectively compared the intraoperative graft flow characteristics of the end-to-side versus side-to-side anastomoses in the 14 patients. The patient outcomes were also evaluated.ResultsWe found that the side-to-side anastomosis reconstruction improved intraoperative flow and reduced pulsatility index in all the 14 patients significantly. The 16 patients who had the distal end side-to-side anastomoses performed directly also exhibited satisfactory intraoperative graft flow. Three-month postoperative outcomes for all the patients were satisfactory.ConclusionsSide-to-side anastomosis at the distal end of sequential vein grafts might be a promising strategy to connect small target coronary arteries to the GSV.

The application of intraoperative transit time flow measurement to accurately assess anastomotic quality in sequential vein grafting.

OBJECTIVES Intraoperative transit time flow measurement (TTFM) is widely used to assess anastomotic quality in coronary artery bypass grafting (CABG). However, in sequential vein grafting, the flow characteristics collected by the conventional TTFM method are usually associated with total graft flow and might not accurately indicate the quality of every distal anastomosis in a sequential graft. The purpose of our study was to examine a new TTFM method that could assess the quality of each distal anastomosis in a sequential graft more reliably than the conventional TTFM approach. METHODS Two TTFM methods were tested in 84 patients who underwent sequential saphenous off-pump CABG in Beijing An Zhen Hospital between April and August 2012. In the conventional TTFM method, normal blood flow in the sequential graft was maintained during the measurement, and the flow probe was placed a few centimetres above the anastomosis to be evaluated. In the new method, blood flow in the sequential graft was temporarily reduced during the measurement by placing an atraumatic bulldog clamp at the graft a few centimetres distal to the anastomosis to be evaluated, while the position of the flow probe remained the same as in the conventional method. This new TTFM method was named the flow reduction TTFM. Graft flow parameters measured by both methods were compared. RESULTS Compared with the conventional TTFM, the flow reduction TTFM resulted in significantly lower mean graft blood flow (P < 0.05); in contrast, yielded significantly higher pulsatility index (P < 0.05). Diastolic filling was not significantly different between the two methods and was >50% in both cases. Interestingly, the flow reduction TTFM identified two defective middle distal anastomoses that the conventional TTFM failed to detect. Graft flows near the defective distal anastomoses were improved substantially after revision. CONCLUSIONS In this study, we found that temporary reduction of graft flow during TTFM seemed to enhance the sensitivity of TTFM to less-than-critical anastomotic defects in a sequential graft and to improve the overall accuracy of the intraoperative assessment of anastomotic quality in sequential vein grafting.

Prognosis of Percutaneous Coronary Intervention and Coronary Artery Bypass Grafts for Ostial Right Coronary Lesions in Propensity‐Matched Individuals

OBJECTIVE Our aim was to evaluate the relative safety and efficacy of percutaneous coronary intervention (PCI) with drug-eluting stents (DES) versus coronary artery bypass grafts (CABG) for the treatment of ostial right coronary stenosis (ORCS) lesions. METHODS Three hundred fifty-nine cases of ORCS lesion were treated via CABG (n = 232) or PCI (n = 127) procedures. Propensity scores for undergoing the CABG procedure were estimated and used to match 105 pairs of patients between the two groups. Kaplan-Meier major adverse cardiac and cerebrovascular events (MACCE)-free curves were constructed to compare long-term MACCE-free survival between the two groups. RESULTS For the 105 propensity-matched pairs, patients were more likely to undergo repeat revascularization with CABG in the PCI group than in the CABG group during the first 30 days (4 cases vs. 0 case, P= 0.043, χ(2) = 4.08) and the 1-year follow-up (5 cases vs. 0 case, P= 0.02, χ(2) = 5.17). With a mean follow-up of 12.04 ± 6.47 months and a total of 210.67 patient-years, the freedom from MACCE in the CABG group was significantly higher than that in the PCI group (Log rank test, χ(2) = 4.48, P= 0.03). There were no significant differences in the rates of death, myocardial infarction, nonfatal stroke, death/myocardium infarction/stroke, or repeated PCI between the two groups during the first 30 days and during the 1-year follow-up period. CONCLUSION For OCRS lesions, CABG provided greater protection than PCI procedure in terms of freedom from MACCE, mainly due to the reduced number of repeated revascularization procedures. CABG should be considered as first-choice revascularization strategy for ORCS lesions.

A pilot study of systolic dyssynchrony index by real-time three-dimensional echocardiography predicting clinical outcomes to surgical ventricular reconstruction in patients with left ventricular aneurysm

OBJECTIVES The aim of the study was to detect whether the systolic dyssynchrony index (SDI) assessed by real-time 3D echocardiography (RT3DE) could predict clinical outcomes of patients with ventricular aneurysm in response to surgical ventricular reconstruction (SVR). METHODS In total, 120 individuals underwent RT3DE, including 30 healthy volunteers and 90 patients with ventricular aneurysm. All patients underwent clinical and echocardiographic assessments at baseline and at 12 months after SVR. The SDI was defined as the SD of time to minimum systolic volume of the 16 left ventricular (LV) segments, expressed in percent RR duration. SVR responder was defined as a >15% decrease in LV end-systolic volume, reduction in NYHA functional class or 20% relative increase in the LV ejection fraction (LVEF). RESULTS The SDI was significantly higher in patients with aneurysm, at 14.3% compared with 2.0% in healthy volunteers (P <0.047). The SDI was negatively correlated with the LVEF. After SVR, 86 patients were responders. In this patient subgroup, the SDI exhibited an immediate significant decrease (to 7.7%; P <0.034) and a progressive decrease during 12 months of follow-up (to 4.9%; P <0.044). The SDI can discriminate SVR responders. Receiver-operating characteristic curve analysis yielded cut-off values of SDI 14.3% best associated with SVR response; area under the curve was 0.79 with reduction in NYHA class, 0.86 with increase in EF and 0.66 with decrease in the end-systolic volume. CONCLUSIONS RT3DE can be used to assess LV mechanical dyssynchrony in patients with aneurysm. SVR produces a mechanical intraventricular resynchronization and SDI can predict improvement following SVR.