Objective To analyze the preoperative risk factors of atrial fibrillation (AF) in patients with coronary artery disease after coronary artery bypass grafting (CABG). Methods From September 2007 to April 2008, the clinical information of 226 patients who underwent onpump coronary artery bypass grafting(CABG)or offpump coronary artery bypass grafting(OPCAB) was collected. The patients were divided into nonAF group and AF group according to whether AF lasted more than 5 mins in 3 days after operation. Ultrasonic cardiography (UCG) and clinical information of preoperation in two groups were analyzed. Results Twentyfour（10.6%） patients had AF after operation. There were more patients whose left atrial diameter gt;35 mm in AF group than that in nonAF group ［41.7%（10）vs. 22.3% (45),χ2=4.380, P=0.036）］, more patients had mitral regurgitation in AF group than that in nonAF group ［37.5%（9） vs. 17.3% (35),χ2=5.568, P=0.018）］, more patients had left main coronary artery involvement in AF group than that in nonAF group ［33.3% (8) vs.12.4% (25),χ2=7.560,P=0.006］, and patients in AF group were older than those in nonAF group ［65.7±9.5 years vs. 60.1±10.1 years,t=-2.724,P=0.010］. In univariate analysis, in terms of preoperative clinical indexs such as the aged, mitral regurgitation, left atrial diameter, left mainm coronary artery involvement, and postoperative clinical indexs such as ventilatory time （χ2=4.190，P=0.040）, electrocardiogram (ECG) monitoring time（χ2=5.948，P=0.015）, hospitalization expense（χ2=4.110，P=0.043）, there were significant differences between 2 groups. Conclusion Risk factors such as the aged, mitral regurgitation, left atrial diameter and left main coronary artery involvement are related to AF after CABG. Clinical index, ECG and echocardiography are helpful to predict AF, and can provide better prevention and treatment, and reduce the rate of AF.
ObjectiveTo investigate the effects of hypoxic three-dimensional culture microenvironment on the proliferation of bone marrow mesenchymal stem cells and its mechanism. MethodsP5 generation mouse bone marrow mesenchymal stem cells and P (3HB-co-4HB) were co-cultured under normoxic three-dimensional (20%) and hypoxic three-dimensional microenvironment (4%) respectively. After 24 hours, the proliferation of the two groups was determined by CCK-8 method. The expression of HIF-1α gene was detected by real-time quantitative PCR after 12 hours. Western blotting was used to detect the expression of HIF-1α protein after 24 hours. ResultsAfter 24 hours, the CCK-8 method showed that the OD value of the hypoxia group was significantly higher than that of the normoxia group (0.455±0.027 vs. 0.352±0.090, n=12, P<0.05). After 12 hours of hypoxic culture, the expression level of HIF-1α mRNA in the hypoxia group was significantly higher than that in the normoxia group (P<0.05). Compared with the normoxia group (0.47± 0.05), the relative expression level of HIF-1α protein in the hypoxia group (0.63±0.06) significantly increased in the Western blotting after 24 hours (n=3, P<0.05). ConclusionThe hypoxic three-dimensional microenvironment can promote the proliferation of bone marrow mesenchymal stem cells, which may be related to the activation of HIF-1α signaling pathway.
Objective To use direct adherent method to induce human embryonic stem cells （hESCs） to become cardiomyocytes in vitro and examine their differentiation rate. Methods Undifferentiated hESCs were seeded onto Matrigel-coated plates at a density of 1×105 cells/cm2 and cultured in MEF-conditioned medium （MEF-CM） with 8 ng/ml basic fibroblast growth factor （bFGF） for 6 days. Then MEF-CM was replaced with RPMI 1640/B27 medium supplemented with 100 ng/ml human recombinant activin A for 24 hours in hESCs culture，followed by supplementation of 10 ng/ml human recombinant bone morphogenetic protein 4 （BMP4） for 4 days in hESCs culture. The medium was then replaced with RPMI 1640/B27 medium without supplementary cytokines，and hESCs were refed every 2-3 days for 2-3 additional weeks. Self-beating cardiomyocytes and the beating frequency were observed under the microscope，and the percentage of colonies showing beating cardiomyocytes was calculated. Cardiac troponin T （cTnT），a specific marker of cardiomyocytes，was examined by immunofluorescence. Spontaneous action potentials of cardiomyocytes were measured with patch clamp technique.Apoptotic rate of cardiomyocytes was detected with apoptosis-hoechst staining kit after beating cardiomyocytes were culturedunder hypoxia for 24 hours. Results A large number of spontaneous beating cardiomyocytes were observed 13 days after induction. The average time to show beating cardiomyocytes was 13.0±1.1 days after induction，the percentage of colonies showing beating cardiomyocytes was 66.7%，and the beating frequency of cardiomyocytes was 63.0±7.0 times/minutes. Beating cardiomyocytes were cTnT-positive. Spontaneous action potentials were detected in beating cardiomyocytes.Apoptotic rate of cardiomyocytes was 8.0%±0.5% after beating cardiomyocytes were cultured under hypoxia for 24 hours. Conclusion It’s the first time to use direct adherent method to induce hESCs to become cardiomyocytes in vitro in China with the differentiation rate of 66.7% and differentiation time of 13 days.
Objective To analyze the efficacy of off-pump coronary artery bypass grafting (OPCABG) in elderly patients with coronary artery disease complicated with moderate ischemic mitral regurgitation. Methods The clinical data of patients aged≥70 years with coronary artery disease complicated with moderate mitral regurgitation, and undergoing OPCABG from January 2009 to January 2020 in Beijing Anzhen Hospital were retrospectively analyzed. The echocardiographic indicators of the patients were compared preoperatively, postoperatively before discharge and during the follow-up. Results Finally 239 patients were enrolled. There were 136 males and 103 females, aged 74.1±3.2 years. Before postoperative discharge, 49 (20.5%) patients had no mitral regurgitation, 144 (60.3%) mild regurgitation, 46 (19.2%) moderate regurgitation, and 0 severe regurgitation. The area of mitral regurgitation was significantlyimproved (2.5±1.8 cm2 vs. 5.6±1.0 cm2, P<0.001). There were 10 (4.2%) patients of hospital death, 23 (9.6%) of low cardiac output, 3 (1.3%) of myocardial infarction, and 8 (3.3%) of nervous system injury after operation. As a result, 208 (90.8%) patients were followed up and the mean follow-up time was 3.4 years (range 1-9 years). The cumulative survival rates at postoperative 2, 4, 6, and 8 years were 95.8%, 88.0%, 78.4%, and 73.1%, respectively. Postoperative follow-up showed significant improvements compared with those before surgery in the area of mitral regurgitation, left ventricular ejection fraction, left ventricular end-diastolic and left ventricular end-systolic diameters (all P＜0.05). Duirng the follow-up, the major adverse cardiac and cerebrovascular events were all cause death in 22 (10.6%) patients, including cardiac death in 17 (8.2%) patients, myocardial infarction in 7 (3.4%) patients, heart failure in 24 (11.5%) patients, cerebrovascular events in 11 (5.3%) patients, re-hospitalization due to heart disease in 23 (11.1%) patients, and none of the patients with myocardial infarction were revascularized. Conclusion The mid- and long-term outcomes of OPCABG in the treatment for elderly patients with coronary artery disease complicated with moderate ischemic mitral regurgitation is good.
ObjectiveTo provide experimental data and theoretical support for further studying the maturity of cardiac patches in other in vitro experiments and the safety in other in vivo animal experiments, through standard chemically defined and small molecule-based induction protocol (CDM3) for promoting the differentiation of human induced pluripotent stem cells (hiPSCs) into myocardium, and preliminarily preparing cardiac patches. MethodsAfter resuscitation, culture and identification of hiPSCs, they were inoculated on the matrigel-coated polycaprolactone (PCL). After 24 hours, the cell growth was observed by DAPI fluorescence under a fluorescence microscope, and the stemness of hiPSCs was identified by OCT4 fluorescence. After fixation, electron microscope scanning was performed to observe the cell morphology on the surface of the patch. On the 1st, 3rd, 5th, and 7th days of culture, the cell viability was determined by CCK-8 method, and the growth curve was drawn to observe the cell growth and proliferation. After co-cultured with matrigel-coated PCL for 24 hours, hiPSCs were divided into a control group and a CDM3 group, and continued to culture for 6 days. On the 8th day, the cell growth was observed by DAPI fluorescence under a fluorescence microscope, and hiPSCs stemness was identified by OCT4 fluorescence, and cTnT and α-actin for cardiomyocyte marker identification. ResultsImmunofluorescence of hiPSCs co-cultured with matrigel-coated PCL for 24 hours showed that OCT4 emitted green fluorescence, and hiPSCs remained stemness on matrigel-coated PCL scaffolds. DAPI emitted blue fluorescence: cells grew clonally with uniform cell morphology. Scanning electron microscope showed that hiPSCs adhered and grew on matrigel-coated PCL, the cell outline was clearly visible, and the morphology was normal. The cell viability assay by CCK-8 method showed that hiPSCs proliferated and grew on PCL scaffolds coated with matrigel. After 6 days of culture in the control group and the CDM3 group, immunofluorescence showed that the hiPSCs in the control group highly expressed the stem cell stemness marker OCT4, but did not express the cardiac markers cTnT and α-actin. The CDM3 group obviously expressed the cardiac markers cTnT and α-actin, but did not express the stem cell stemness marker OCT4. ConclusionhiPSCs can proliferate and grow on matrigel-coated PCL. Under the influence of CDM3, hiPSCs can be differentiated into cardiomyocyte-like cells, and the preliminary preparation of cardiac patch can provide a better treatment method for further clinical treatment of cardiac infarction.