Transcatheter aortic valve replacement (TAVR) is effective in the treatment of severe symptomatic aortic stenosis and its applicable population is also gradually expanding, but it carries risk of ischemic and bleeding events, which underscores the importance of optimizing adjuvant antithrombotic regimens. The release of the 2022 version of Chinese expert consensus on antithrombotic therapy after transcatheter aortic valve implantation has promoted the standardized and safe development of antithrombotic therapy after TAVR in China. Combined with the latest progress of antithrombotic therapy after TAVR, from emphasizing ischemia and bleeding risk assessment, single-agent antiplatelet therapy for patients without anticoagulation indications, the selection of antithrombotic strategies for patients with other antithrombotic indications, antithrombotic strategy changes in postoperative valve thrombosis and bleeding events, this article interprets this consensus.
Objective Currently, there are few researches on lordosis associated with scol iosis. To explore the effects of nickel-titanium memory alloy staple (Staple) on the growth of thoracic lordosis by observing the histological changes of cartilage cells in the osteoepiphysis of the thoracic vertebrates in goats. Methods Eighteen 2-3 months old female goats, weighing 8-12 kg, were randomly divided into long staple group (n=6), short staple group (n=6), and blank control group (n=6). Long staple (7 mm) and short staple (4 mm) were implanted into T6-11 segments of goats in long and short staplegroups by anterior approach, respectively. The blank control group was not treated. The X-ray examination was performedpre-operatively and at 3 months post-operatively to observe the changes of Cobb angle. Then the growth plates and inferior facet processes of the apex vertebral body were harvested to observe the histological grades of cartilage by HE staining, and to observe prol iferation and apoptosis of chondrocytes through immunohistochemistry double label ing staining with poly-ADPribose- polymerase-p85 and prol iferating cell nuclear antigen. Results At 3 months after operation, the T6-11 Cobb angles were significantly higher than those of pre-operation in short staple group and long staple group, which were significantly higher than those in blank control group (P lt; 0.05), but there was no significant difference between short staple group and long staple group (P gt; 0.05). The results of HE staining and immunohistochemistry double staining showed that the number of chondrocytes were reduced obviously with irregular columnar arrangement and increased volume ratio of surrounding extracellular matrix in prol iferative zone and hypertrophic zone of growth plate and inferior articular process in both long and short staple groups, and this tendency was more noticeable in long staple group. There were significant differences in the grades of prol iferation viabil ity of chondrocytes between 2 staple groups and blank control group (P lt; 0.05), but there was no significant difference tewteen long staple group and short staple group (P gt; 0.05). The prol iferation viabil ities of chondrocytes in growth plate and inferior articular process were significantly higher in blank control group than in 2 staple groups (P lt; 0.01), but there was no significant difference between long staple group and short staple group (P gt; 0.05). Conclusion The histological evidences prove that the Staple implantation by anterior approach can reduce prol iferation viabil ity of chondrocytes in growth plate and inferior articular process of the thoracic vertebrates in goats, which conduces the growth direction of thoracic vertebrates to kyphosis.
Objective To obtain highly purified and large amount of Schwann cells (SCs) by improved primary culture method, to investigate the biocompatibility of small intestinal submucosa (SIS) and SCs, and to make SIS load nerve growth factor (NGF) through co-culture with SCs. Methods Sciatic nerves were isolated from 2-3 days old Sprague Dawley rats and digested with collagenase II and trypsin. SCs were purified by differential adhesion method for 20 minutes and treated with G418 for 48 hours. Then the fibroblasts were further removed by reducing fetal bovine serum to 2.5% in H-DMEM. MTT assay was used to test the proliferation of SCs and the growth curve of SCs was drawn. The purity of SCs was calculated by immunofluorescence staining for S-100. SIS and SCs at passage 3 were co-cultured in vitro. And then the adhesion, proliferation, and differentiation of SCs were investigated by optical microscope and scanning electron microscope (SEM). The NGF content by SCs was also evaluated at 1, 2, 3, 4, 5, and 7 days by ELISA. SCs were removed from SIS by repeated freeze thawing after 3, 5, 7, 10, 13, and 15 days of co-culture. The NGF content in modified SIS was tested by ELISA. Results The purity of SCs was more than 98%. MTT assay showed that the SCs entered the logarithmic growth phase on the 3rd day, and reached the plateau phase on the 7th day. SCs well adhered to the surface of SIS by HE staining and SEM; SCs were fusiform in shape with obvious prominence and the protein granules secreted on cellular surface were also observed. Furthermore, ELISA measurement revealed that, co-culture with SIS, SCs secreted NGF prosperously without significant difference when compared with the control group (P gt; 0.05). The NGF content increased with increasing time. The concentration of NGF released from SIS which were cultured with SCs for 10 days was (414.29 ± 20.87) pg/cm2, while in simple SIS was (4.92 ± 2.06) pg/cm2, showing significant difference (P lt; 0.05). Conclusion A large number of highly purified SCs can be obtained by digestion with collagenase II and trypsin in combination with 20-minute differential adhesion and selection by G418. SIS possesses good biocompatibility with SCs, providing the basis for further study in vivo to fabricate the artificial nerve conduit.
Objective To further investigate the possible mechanism of the correction of scol iosis with Staple by quantifying the effect of Staple on growth rate of vertebral growth plates in goat scol iosis. Methods Experimental scol iosis was created in 10 juvenile female goats by using unilateral pedicle screws asymmetric tethering. After 8-10 weeks, goats were divided randomly into Staple treated group (n=5) and control group (n=5). All tethers were removed in both groups and Staplegroup underwent anterior vertebral stapl ing with 4-5 shape memory alloy Staples along the convexity of the maximal curvature after posterior tether being removed. All goats were observed for an additional 8-13 weeks, the Cobb angle were measured to observe the correction of scol iosis. The fluorochromes Oxytetracycl ine and Calcein were administered respectively 18 and 3 days before death to label the ossifying front under the growth plates. Superior intervertebral disc of apical vertebra and two adjacent growth plates were completely harvested in all goats. All specimens were embedded with polymethyl methacrylate and sl iced undecalcified. The growth rates of the vertebral growth plates were calculated by measuring the distance between the two fluorescent l ines with fluorescence microscope. Results Nine (5 in Staple treated group and 4 in control group) of 10 tethered goats had progressive scol iotic curves of significant magnitude after 8-10 weeks of tethering. In Staple treated group, the Cobb angles were (34.8 ± 12.4)° at the instant after treatment , and (15.6 ± 11.7)° 8-13 weeks after treatment; showing statistically significant difference (P lt; 0.05). In the control group, the Cobb angles were (49.3 ± 18.0)° at the instant after treatment, and(49.0 ± 17.6)° 8-13 weeks after treatment; showing no statistically significant difference (P gt; 0.05). In Staple treated group, the growth rate of growth plate in the concavity (3.27 ± 0.96) μm/d was higher than that in convexity (1.84 ± 0.52) μm/d (P lt; 0.05), while the growth rate of the concavity did not differ significantly from that of the convexity in control group (P gt; 0.05). Conclusion Staple can significantly alter the growth rates of two sides of vertebrae in scol iosis with the growth rate of concavity exceeding the one of convexity, which results in correction of deformity.
Mitral regurgitation is the most common heart valvular disease at present. In the past, mitral regurgitation was mainly treated by surgical mitral valve repair or replacement. However, with the progress of transcatheter interventional techniques and instruments in recent years, transcatheter mitral valve interventional therapy has gradually shown its advantages and benefited patients. The purpose of this article is to review the progress of transcatheter mitral valve intervention in this year, and to provide prospects for the future of transcatheter mitral valve treatment.
Objective To explore the risk factors for long-term death of patients with acute myocardial infarction (AMI) and reduced left ventricular ejection fraction (LVEF), and develop and validate a prediction model for long-term death. Methods This retrospective cohort study included 1013 patients diagnosed with AMI and reduced LVEF in West China Hospital of Sichuan University between January 2010 and June 2019. Using the RAND function of Excel software, patients were randomly divided into three groups, two of which were combined for the purpose of establishing the model, and the third group was used for validation of the model. The endpoint of the study was all-cause mortality, and the follow-up was until January 20th, 2021. Cox proportional hazard model was used to evaluate the risk factors affecting the long-term death, and then a prediction model based on those risk factors was established and validated. Results During a median follow-up of 1377 days, 296 patients died. Multivariate Cox regression analysis showed that age≥65 years [hazard ratio (HR)=1.842, 95% confidence interval (CI) (1.067, 3.179), P=0.028], Killip class≥Ⅲ[HR=1.941, 95%CI (1.188, 3.170), P=0.008], N-terminal pro-brain natriuretic peptide≥5598 pg/mL [HR=2.122, 95%CI (1.228, 3.665), P=0.007], no percutaneous coronary intervention [HR=2.181, 95%CI (1.351, 3.524), P=0.001], no use of statins [HR=2.441, 95%CI (1.338, 4.454), P=0.004], and no use of β-blockers [HR=1.671, 95%CI (1.026, 2.720), P=0.039] were independent risk factors for long-term death. The prediction model was established and patients were divided into three risk groups according to the total score, namely low-risk group (0-2), medium-risk group (4-6), and high-risk group (8-12). The results of receiver operating characteristic curve [area under curve (AUC)=0.724, 95%CI (0.680, 0.767), P<0.001], Hosmer-Lemeshow test (P=0.108), and Kaplan-Meier survival curve (P<0.001) showed that the prediction model had an efficient prediction ability, and a strong ability in discriminating different groups. The model was also shown to be valid in the validation group [AUC=0.758, 95%CI (0.703, 0.813), P<0.001]. Conclusions In patients with AMI and reduced LVEF, age≥65 years, Killip class≥Ⅲ, N-terminal pro-brain natriuretic peptide≥5598 pg/mL, no percutaneous coronary intervention, no use of statins, and no use of β-blockers are independent risk factors for long-term death. The developed risk prediction model based on these risk factors has a strong prediction ability.