Objective To study in vitro hydrodynamics of a pneumatic pulsatile ventricular assist device developed ex?clusively by China, and establish an animal model for the detection by the device. Methods The hydromechanics experi?ment was performed on an in vitro test loop using MEDOS-System to drive the ventricular assist device, and lycerl-water so?lution was used as circulating medium. The changes of afterload pressure and the output of the pump were monitored, and the impermeability and stability were also assessed after the experiment. Six adult dogs were used as the experimental animals. The device worked in the left heart assistance mode for 1 hour then the ventricular fibrillation was induced by potassium chloride, and then defibrillated after 5 min while the device remained working. The hemodynamics data were monitored con?secutively during the trial. Results The ventricular assist device worked stably and reliably during the hemodynamic exper?iment. The pump can generate more than 4 L/min flow against the afterload pressure of 100 mmHg. There were no significant changes in heart rate at different time points in experimental dogs after left ventricular assist. Comparison between after auxil?iary immediately and former auxiliary, the diastolic blood pressure of dogs increased 30 mmHg with the ventricular assist, and the diastolic pressure increased 19 mmHg. No obvious fluctuation in blood pressure was found during the auxiliary pro?cess. The diastolic blood pressure stayed at 60 mmHg when the heart was in ventricular fibrillation, and returned to normal after electrical defibrillation. Conclusion The ventricular assist device works stably in vitro test, and the pump can meet the need of adult’s ventricular assist. It is effective and security to dogs in short term. The effects of long-term use need to be future proved.

Objective To evaluate results of surgical treatment for patients with acute type A aortic dissection using Sun’s operation and triple-branched stent graft. Methods According to the operation mode, thirty-three patients with type A aortic dissection were divided into Sun’s operation group (n=22) and triple branches aortic arch stent-graft placement op?eration (triple-branched) group (n=11). Preoperative examinations included cardiac ultrasound, aortic CT angiography (CTA), hepatic and renal functions and blood routine test in all patients. Intraoperative monitoring included the index about cardiopulmonary bypass and blood loss. The perioperative hepatic and renal functions and complications were also recorded. Survival and recovery rates were evaluated by follow-up between two groups of patients. Results There were six periopera?tive death in Sun’s group, and three patients died in triple-branched group. In triple-branched group, the intraoperative blood loss was significantly increased than that in Sun’s group [(3 586.4±2 926.8) mL vs. (2 630.5±1 821.2) mL, P<0.05]. Postoperative echocardiographic examinations revealed that the left ventricular size (LVEDd) and the aortic diameter were decreased while the left ventricular ejection fraction (LVEF) was elevated after surgery in Sun’s group [(50.9±6.9) mm vs. (55.0±7.5) mm,(28.2±1.6) mm vs. (48.8±11.0) mm, 0.620±0.031 vs. 0.469±0.104, P<0.05]. Whereas, only the aortic diame?ter was decreased after surgery in triple-branched group [(28.6±3.9) mm vs. (50.9±9.2) mm, P<0.05]. Kaplan-Meier surviv?al curve showed that five-year survival rate of Sun’s group was similar with that of triple-branched group (Log-rank χ2=0.095,P>0.05). At 5 year after operation, there were no significant differences in the recurrence of new aortic dissection, the incidence of cerebral infarction and mortality between Sun’s group and triple-branched group (P>0.05). Conclusion Sun’s operation can significantly decrease patient’s intraoperative blood loss and improve cardiac function. But its survival rate and long term results need advanced observation.

Objective To evaluate the short term outcome after mitral valve replacement with the Perimount bovine pericardial valve. Methods Eighty-eight patients underwent mitral valve replacement with the bovine pericardial valve in hospital were included in this study. Postoperative general condition including mortality and cerebral hemorrhage was observed. The hemodynamic and New York heart disease association (NYHA) heart function classification were recorded by Doppler echocardiograms before operation, postoperative 1 week, 3 months and 1 year after mitral valve replacement. Values of the different time points of NYHA, left atrial diameter (LA), left ventricular end diastolic diameter (LVDD), left ventricular end systolic diameter (LVSD), left ventricular ejection fraction (LVEF) and pulmonary artery pressure (PAP) were compared. The hemodynamic parameters were also compared including the peak cross valve pressure (PG), mean cross valve pressure (MG), peak cross valve velocity (PV) and effective orifice area (EOA) 1 week, 3 months and 1 year after surgery. Results There were two cases (2.3%) dead in one year (one died of cerebral hemorrhage and another one died of thromboembolism). There was 1 perivalvular leakage (1.2%). There was no endocarditis or structural valve deterioration. NYHA cardiac function was improved at postoperative 3 months and 1 year (P < 0.05). The values of LA, LVDD and PAP were significantly decreased at postoperative 1 week, 3 months and 1 year compared with those before operation (P<0.05). Values of LVSD and LVEF were significantly decreased at postoperative 1 week compared with those before operation (P<0.05). The value of LVEF was significantly increased at postoperative 3 months and 1 year (P<0.05). Compared with postoperative 1 week, the values of LA and LVEF were significantly increased at postoperative 3 months and 1 year (P < 0.05). There were no significant differences in PG, MG, PV and EOA between postoperative 1 week, 3 months and 1 year. Conclusion With the excellent performance of cardiac function recovery, left ventricular restoration and hemodynamic, the Perimount bovine pericardial valve remains a reliable choice as a mitral tissue valve.

Objective To investigate the effect of rhBNP in treating pulmonary hypertension after mitral value replacement (MVR) compared with PGE1.Methods 60 patients with pulmonary hypertension after MVR were randomly divided into 3 groups(control group, PGE1 group and rhBNP group).Hemodynamic factors(MAP, CVP, mPAP, etc.) were monitored before and after taking medicine at 1 h, 6 h, 24 h, respectively including drug withdrawal 2 h.TXA2 and cGMP were analyzed by ELISA.To observe the levels of TXA2 and cGMP in plasma before and after treatment with rhBNP and PGE1 for three times (24 h, 1 week and 3 months).Information about patients'mechanical ventilation time was also recorded.Results Patients' mechanical ventilation time in PGE1 group was the shortest.MAP, mPAP, PRVI, PAWP were reduced after treatment by medicine 1 h for in PGE1 group.However, these indexes were rebound after drug withdrawal.mPAP, PRVI, PAWP in rhBNP group decreased after treatment by medicine at 6 h.The decreased level of mPAP was less than that in PGEI group.In control group, TXA2 went down and cGMP went up after operation.After taking medicine at 24 h, TXA2 decreased and cGMP increased in both PGE1 and rhBNP group.The increased level in rhBNP group was higher than that of control group.With medicine, the decreased level of TXA2 in PGE1 was also higher than that in rhBNP group.The going-up of cGMP in rhBNP was higher than that in PGE1.Conclusion Both rhBNP and PGE1 can reduce pulmonary artery pressure, PGE1 is more effective than that of rhBNP.

Objective To study the effects of semaphorin 5A (SEMA5A) gene silencing by lentivirus?mediated short hairpin RNA(shRNA)on biological activity of malignant melanoma cell line A375. Methods Two pairs of interference sequences for SEMA5A gene(shRNA1 and A375?shRNA2)and a pair of control interference sequences were designed to build lentiviral vectors, which were then transfected into HEK293T cells to gain lentivirus. A375 cells were divided into three groups:experimental group(A375?shRNA1 and A375?shRNA2 cells)transfected with the lentivirus containing shRNA1 or shRNA2, negative control group (A375?con cells) transfected with that containing the control shRNA, and blank control group(A375 cells)receiving no transfection. The A375 cells with stable knockdown of SEMA5A gene expression were screened by puromycin. Subsequently, reverse transcription?PCR and Western?blot analysis were performed to detect mRNA and protein expressions of Semaphorin 5A in these cells, and methyl thiazolyl tetrazolium(MTT)assay was applied to evaluate the growth of cells. The scratch assay and invasion assay were conducted to estimate migration and invasion ability of cells. Results The lentivirus containing the SEMA5A?targeting shRNAs or control shRNA was successfully transfected into A375 cells, and stably transfected cells were gained after puromycin selection. The expressions of semaphorin 5A mRNA and protein in the A375?shRNA2 cells were significantly reduced compared with those in the A375?con and A375 cells(all P < 0.05). MTT assay showed that the growth of A375?shRNA2 cells was significantly slower than that of A375?con and A375 cells(both P<0.05), while there was no significant difference in the growth rate between A375?con and A375 cells(P>0.05). The scratch assay showed that there was no obvious cell migration into the scratch in the experiment group, whereas the scratch was almost covered by cells in the negative control group and blank control group. The invasion assay showed that the number of A375?shRNA2 cells passing through the Transwell chamber was significantly smaller than that of A375 and A375?con cells(both P<0.05), while there was no significant difference between that of A375 and A375?con cells(P > 0.05). Conclusion The silencing of SEMA5A gene by lentivirus?mediated shRNA could effectively down?regulate the expression of semaphorin 5A, and inhibit the growth, invasion and migration of A375 cells.

Objective: To investigate the changes of peripheral cardiotrophin-1 (CT-1) and brain natriuretic peptide (BNP) concentrations in patients undergoing off-pump coronary artery bypass grafting (OPCABC), and the clinical significance of peripheral CT-1 and BNP in cardiac surgery thereof. Methods:Fifty elective OPCABG patients were included in the study. The concentrations of CT-l and BNP were measured before surgery, and at 6 hours, 72 hours, 1 week and 10 months after the operation respectively. The clinical data of the heart function were also collected in patients . Results:(1 )The peripheral CT-1 levels were significantly higher at 10 months after OPCABC than those before operation. (2 )The concentration of peripheral BNP increased at 6 hours after operation. The peak level was found at 72 hours, and remained higher level until the 1 week after operation. The BNP concentration was returned to the normal level at 10 months after OPCABG. (3 )The baseline levels of CT-1 and BNP were both positively correlated with NYHA rank and the diameter of the left ventricular end-diastolic dimension (LVEED), but negatively correlated with left ventricular ejection fraction (LVEF). However, no correlations were found between CT-1 and BNP and NYHA rank, LVEF or LVEED at 10 months after OPCAB. Conclusion:The perioperative blood BNP levels were increased significantly by OPCABG, while perioperative level of CT-1 increased slowly compared with that of BNP. In cardiac surgery,perioperative concentrations of CT-1 and BNP may reflect the cardiac function in patients before OPCABG. The further studies are warranted to assess the prognosis.

Objective:To investigate the clinical efficacy of Sun's procedure and debranching hybrid procedure in the treatment of elderly acute Stanford type A aortic dissection.Methods:53 elderly patients(aged over 60 years old) with acute Stanford type A aortic dissection admitted to Tianjin Chest hospital from January 2017 to June 2018 were selected and divided into Sun's procedure group of 35 patients and debranching hybrid procedure group of 18 patients. The history of cerebral infarction before operation was more in the hybridization operation group than in the Sun's operation group, and the difference of other preoperative data was not statistically significant. The brain protection strategy was adopted in both groups. During Sun's procedure, bilateral anterograde cerebral perfusion and descending aorta balloon occlusion were performed to maintain the blood supply of lower limbs.And the total aortic arch and branch blood vessels were closed by stent-graft in debranching hybrid procedure.The basic data and perioperative conditions of the patients were statistically analyzed, and the postoperative results and short-term prognosis were compared between the two groups after 1 year of follow-up.Results:The hybrid group avoided circulatory arrest, and the lowest intraoperative nasopharyngeal temperature was slightly higher than that of the Sun' s group[(25.1±0.4)℃ ratio(27.7±0.6)℃)]. However, there were no significant difference in the operation time[(178.9±43.5)min ratio(166.9±95.4)min] and intraoperative blood loss[(1 724.9±1 394.2)ml ratio(1 590.7±920.5)ml] between the two groups, and no significant difference in postoperative renal failure(20% ratio 11.1%), cerebrovascular accident(cerebral infarction/cerebral hemorrhage)(11.4% ratio 5.6%), cognitive dysfunction(17.1% ratio 11.1%), ventilator assistance time[84.0(25.0, 160.0) hours ratio 61.7(17.3, 90.5) hours], ICU stay time[6.5(2.9, 14.3) days ratio 4.4(2.0, 6.1) days] and so on. There were 3 perioperative deaths in Sun's group and 2 perioperative deaths in hybrid group.The mean follow-up time of the two groups was 14.8 months. During the follow-up period of Sun's group, no new cerebrovascular event and 1 case of distal false lumen of the descending thoracic aorta active blood flow occurred and 1 case died 2 months after the operation.There was 1 case of new cerebrovascular events in hybrid group and no death. The 1-year survival rate was similar between the two groups.Conclusion:For patients over 60 years old with acute Stanford type A aortic dissection, Sun's procedure and hybrid procedure are safe and effective.

Objective:Using different machine learning methods to construct and screen the best prediction model for predicting the risk of death within 30 days after surgery in patients with acute type A aortic dissection.Methods:Five hundred and twenty-one patients with acute type A aortic dissection who underwent surgery between 2015 and 2022 were included, after collecting their perioperative date and screening them, 329 patients were retained. two different groups of predictor variables were generated by using Lasso regression and principal component analysis, after that, logistic regression, support vector machine algorithm, random forest algorithm, gradient boosting algorithm, and super learning algorithm were used to develop prediction models for the risk of death within 30 days after surgery. Finally, we compare the models and select the best one. Results:The AUC values for all models rangrd from 0.791-0.959. The model using Lasso regression to determine the predictor variables and built by the super learning algorithm had the best prediction with an AUC value of 0.959. Conclusion:The super learning algorithm better than other algorithms in predicting death within 30 days after acute type A aortic dissection.

Objective:This study was conducted to investigate the independent risk factors for predicting the occurrence of acute Stanford type A aortic dissection(TAAD), and to construct a nomogram model for predicting the occurrence of TAAD.Methods:The clinical data of patients meeting the diagnostic criteria for TAAD admitted to Tianjin Chest Hospital from June 2016 to December 2021 and healthy people examined by the physical examination center of Tianjin Chest Hospital during the same period were retrospectively collected, and the independent risk factors for TAAD were predicted by propensity matching analysis. Univariate and multivariate Logistic regression were used to analyze the variables with statistical differences, and a nomogram model was constructed to predict the occurrence of TAAD disease according to the screened risk factors. Results:A total of 148 patients in the TAAD group and 5 690 patients in the control group were collected. After bias matching analysis, 148 pairs were successfully matched. Multivariate Logistic regression analysis was performed on the matching results. The results showed that hypertension(HBP), diabetes mellitus(T2DM), Lp(a), very low density lipoprotein(VLDL) and apolipoprotein A1/B(ApoA1/B) were independent risk factors for the development of TAAD. HBP, Lp(a) and ApoA1/B were pathogenic factors( OR 7.267, 1.010 and 2.199, P<0.05, respectively), while T2DM and VLDL were protective factors( OR 0.173 and 0.139, P<0.05). Based on the independent risk factors obtained by multi-factor Logistic regression analysis, a nomogram model of TAAD incidence was constructed. The area under ROC curve( AUC) for predicting the onset of TAAD was 81.6%(95% CI: 0.766-0.863), and the internal calibration curve was close to the standard curve. Conclusion:This model has a good degree of differentiation and calibration, which is helpful for clinicians to guide healthy people to prevent the occurrence of TAAD and provide a theoretical basis for the prevention of TAAD.

Objective:To investigate the efficacy and safety of prolonged dual antiplatelet therapy (DAPT) (aspirin + clopidogrel) after coronary artery bypass grafting (CABG) for more than 12 months.Methods:1 900 patients who received CABG treatment in Tianjin Chest Hospital from January 2019 to October 2020 were continuously included, and 1 528 patients were finally identified according to the inclusion and exclusion criteria. According to whether the patients continued to take DAPT treatment 12 months after discharge, they were divided into the extended DAPT group and the standard DAPT group. Cox multivariate regression and propensity score matching (PSM) analysis were performed on major cardiovascular and cerebrovascular adverse events (MACCE) and clinically related bleeding events in the two groups during 12-24 months after discharge to evaluate the efficacy and safety of extended DAPT treatment for more than 12 months. Results:Of the 1 528 patients, 624 (40.8%) continued to take DAPT 12 months after discharge. Compared with patients receiving standard DAPT, patients receiving extended DAPT had a lower incidence of MACCE within 12 to 24 months ( HR=0.597, 95% CI: 0.399-0.892, P=0.012); ( HR=0.519, 95% CI: 0.338-0.798, P=0.003), and there was no significant increase in clinically relevant bleeding risk ( HR=1.209, 95% CI: 0.522-2.798, P=0.658), ( HR=1.112, 95% CI: 0.452-2.737, P=0.817). At the same time, prolonged DAPT treatment also brought a good net benefit. Conclusion:Prolonged DAPT treatment after CABG for more than 12 months significantly reduced the risk of ischemia at 12-24 months after surgery, and did not significantly increase the risk of bleeding at 12-24 months after surgery. It may be beneficial for patients treated with CABG to continue DAPT (aspirin+ clopidogrel) on the basis of intensive DAPT therapy for 1 year.