Transcatheter aortic valve replacement (TAVR) as a mature technology has been widely applied in Western countries. In China, with the first two domestic prostheses being approved for commercial use, the technology now is expecting a fast development. In this article, we reviewed the features of Chinese aortic stenosis patients, the early Chinese experience of TAVR, the application of domestic prostheses and remaining problems.
In 2020, due to the impact of the novel coronavirus epidemic, the development of transcatheter heart valve therapy has been shown to slow down, but there are still many aspects worth noting. The indication of monoclonal antibody after transcatheter aortic valve replacement (TAVR) should be further clarified. Low surgical risk patients were included in TAVR relative indications. Mitraclip G4 was approved by CE. The indication of atrial septal occlusion after mitraclip should be further clarified. The technique of coaptation augmentation is expected to become a new method of mitral valve interventional repair. Tendyne transcatheter mitral valve was approved by European Union. Transcatheter tricuspid valve treatment equipments, TriClip and PASCAL obtained CE mark. TAVR technology is being popularized rapidly in China, and what’s more, balloon dilated valve Sapien 3 and new recyclable repositioning valve system-Venus plus have entered the domestic market. A number of mitral valve therapeutic instruments have appeared one after another, and China's first tricuspid valve lux has completed its FIM research. Finally, with the improvement of devices and technology in the future, interventional therapy of heart valve is expected to benefit more patients.
Mitral regurgitation (MR) is the most common heart valve disease. In recent years, the rise of interventional therapy has expanded the indications of interventional treatment for patients with MR, but the epidemiological characteristics of MR (especially the number of patients with MR requiring treatment) in China are still unclear. In this paper, we analyzed and estimated the number of MR patients in China based on three epidemiological studies in Europe and America, and referring to the patients population surveys from Zhongshan Hospital Affiliated to Fudan University, the Second Affiliated Hospital Zhejiang University School of Medicine and Beijing Fuwai Hospital. Our analysis estimated that about 7.5 million patients with MR need intervention in China, including about 5.5 million patients with severe MR.
Atrial functional mitral regurgitation has been referred to patients with atrial fibrillation related functional mitral regurgitation without left ventricular dysfunction and it has nowadays received remarked attention in structural heart disease field. Significant dilation of mitral annulus and left atrium, insufficient leaflet remodeling, iatrogenic leaflet tethering, reduced annular contractility and increased valve stress by flattened saddle shape of the annulus might be important triggers of atrial functional mitral regurgitation. Recently, several studies indicated that transcatheter edge-to-edge mitral valve repair could be an effective strategy for atrial functional mitral regurgitation. In this review, the definition, mechanism together with efficacy and safety of transcatheter edge-to-edge mitral valve repair in atrial functional mitral regurgitation are discussed.
Transcatheter edge-to-edge repair (TEER) originated from surgical edge-to-edge repair. MitraClip is the first mature TEER device, and the TEER based on MitraClip is far ahead of many transcatheter mitral valve repair (TMVr) technologies in terms of safety, effectiveness and popularity, so it is named separately in the latest guidelines. The TEER has the following advantages: consistent with basic medical principles, few implants, precise target, less invasive and repeatable. However, there are also some shortcomings, such as the relatively complex design of transfemoral device, target single and relatively narrow indications. At present, the main clinical data of TEER are mainly from the clinical practice of MitraClip. Based on the three-year outcomes of COAPT study, both 2020 ACC/AHA guideline and 2020 ACC expert consensus decision pathway on the management of mitral regurgitation recommend in patients with chronic heart failure with left ventricular dysfunction and severe mitral regurgitation in nonresponders to medicine treatment. Edward's PASCAL, another TEER device, has two models. Among the domestic TEER devices, the ValveClamp of Hanyu medical technology has many distinct advantages, such as simple operation, large clamping area, high clamping efficiency and no need of X-ray. DragonFly, another domestic TEER device, has also completed its feasibility study. There are five trends of TEER in the future: further expansion of indications, combination with other interventional techniques, repeatable operations, transcatheter mitral valve replacement after TEER, and continuous improvement and innovation of equipment.
Mitral regurgitation is one of the most common heart valve diseases. Transcatheter edge-to-edge repair (TEER) is currently the most developed and commonly used interventional technique for mitral regurgitation and is recommended by the latest European and American guidelines for patients who are at high surgical risk. TEER device usually consists of a clamping device and a delivery system. The trajectory of the clamping device is called the trajectory, and the trajectory can be well established with the five dimensions movement of the delivery system: left-right oscillation, anterior-posterior oscillation, overall parallel movement, the clamping device's own clockwise rotation, and vertical up-and-down movement. The delivery system's anteroposterior and lateral oscillations are concentrated on the virtual puncture site. Furthermore, the location of the septal puncture site has a significant impact on the establishemnt of the trajectory. The evulation of three variables and adherence to the "4M principles" are necessary for the successful TEER. The three variables are: the position of the clip in the center of the regurgitation,the arm orientation of the clip perpendicular to the boundary of anterior and posterior leaflets, as well as the appropriate length of clamping. The "4M principles" include favorable valve morphology, residual mitral regurgitation below grade 2+, mean transvalvular pressure≤5 mm Hg, and an appropriate amount of leaflets clamping. Patients' baseline situation, the degree of mitral regurgitation and ventricular remodeling, as well as the valve morphology and the outcome of the procedure, are the factors determining the prognosis of patients after TEER.
Transcatheter edge-to-edge repair (TEER) for mitral regurgitation (MR) is known as M-TEER. Its strengths include: precise targets and fewer implants; simple and clear principles for catheterization; originating from dependable medical concepts and broad applicability. Furthermore, TEER offers advantages in real-time hemodynamic and effectiveness measurement throughout the procedure over surgical edge-to-edge repair (SEER). When it comes to patients with degenerative mitral regurgitation , M-TEER should aim to deliver more optimum procedural outcomes. In functional mitral regurgitation, a modest transvalvular gradients or moderate residual shunt can be tolerated with M-TEER, which reduces the risk of problems and has no bearing on the patient's prognosis.
Mitral regurgitation (MR) is a kind of valvular heart disease with a complicated pathogenesis. However, the current clinical understanding of MR mostly stays in a purely spatial perspective. We suggest that the evaluation of MR should break through the limited thinking of the area of a two-dimensional single frame, and transfer to a comprehensive evaluation of three-dimensional space-time integration (i.e. four-dimensional space-time). Secondly, it is of significance to pay attention to the time mechanism and time thinking of the occurrence of MR. The amount of MR may be different in different cardiac cycles or within the same cardiac cycle. Finally, changes in the time dimension of cardiac contraction can lead to the occurrence of MR and sometimes it is necessary to understand MR from time thinking rather than spatial thinking.
ObjectiveTo study the biocompatibility of bioprosthetic heart valve material with a non-glutaraldehyde-based treatment, and to provide the safety data for the clinical application. MethodsAll the tests were conducted according to GB/T16886 standards. The in vitro cytotoxicity was determined by methyl thiazolyl tetrazolium assay. Fifteen guinea pigs were divided into a test group (n=10) and a control group (n=5) in the skin sensitization test. Three New Zealand white rabbits were used in the intradermal reactivity test. Five sites on both sides of the rabbit back were set as test sites and control sites, respectively. In the acute systemic toxicity test, a total of 20 ICR mice were randomly assigned to 4 groups: a test group (polar medium), a control group (polar medium), a test group (non-polar medium) and a control group (non-polar medium), 5 in each group. Forty SD rats were divided into a test group (n=20) and a control group (n=20) in the subchronic systemic toxicity test. ResultsThe viability of the 100% extracts of the bioprosthetic heart valve material with a non-glutaraldehyde-based treatment was 75.2%. The rate of positive reaction was 0.0%. The total intradermal reactivity test score was 0. There was no statistical difference in the body weight between the test group and control group in the acute systemic toxicity test. There was no statistical difference in the body weight, organ weight, organ weight/body weight ratio, blood routine test or blood biochemistry between the test group and control group in the subchronic systemic toxicity test. ConclusionThe bioprosthetic heart valve material with a non-glutaraldehyde-based treatment has satisfying biocompatibility, which conforms to relevant national standards. The material might be a promising material for application in valve replacement.
ObjectiveTo investigate the operation of transcatheter aortic valve replacement (TAVR), the use of TAVR instruments and the current situation of TAVR-related nursing in our country, to reveal the characteristics of TAVR in various hospitals in our country, and to provide reference data for improving perioperative nursing and industry development of TAVR. MethodsA questionnaire survey was conducted among the head nurses of the cardiac catheterization laboratories of 51 hospitals in China that carried out TAVR operations, with a total of 5 items and 23 questions. The current situation of TAVR operation methods, intraoperative instruments and nursing care in China were analyzed. ResultsThe number of hospitals in China which started conducting TAVR and the beginning year were: 2 in 2010, 1 in 2012, 1 in 2013, 1 in 2015, 11 in 2016, 13 in 2017, 15 in 2018 and 7 in 2019; the number of transfemoral TAVR in 2019: 32 (62.75%) hospitals conducted on less than 20 patients, 7 (13.73%) hospitals 20-<50 patients, 6 (11.76%) hospitals 50-100 patients and 6 (11.76%) hospitals more than 100 patients; TAVR strategies adopted by most hospitals were: general anesthesia (90.20%), the use of vascular sealers (80.39%), backing by cardiac surgeon (74.51%) and using homemade prosthetic valves. Conclusion At present, the number of TAVR carried out in Chinese hospitals is still far behind that of developed countries in Europe and the United States. Our country has adopted the form of multidisciplinary cardiac team cooperation and formed a TAVR nursing model with Chinese characteristics.