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.
Objective To evaluate clinical outcomes of mild-to-moderate or moderate functional mitral regurgitation（FMR）after aortic valve replacement （AVR） in patients with severe aortic stenosis （AS），and analyze prognostic factors of these patients with mild-to-moderate or moderate FMR （2＋to 3＋）. Methods From September 2008 to December 2011，a total of 156 patients with severe AS （peak aortic gradient （PAG）≥50 mm Hg） as well as FMR （2＋to 3＋） underwent surgical treatment in Zhongshan Hospital. There were 95 male and 61 female patients with their average age of 59.2±10.5 years. Detailed perioperative clinical data were collected，and postoperative patients were followed up. The ratio of FMRpreoperative/FMR postoperative was calculated. Patient age，gender，body weight，history of hypertension，ventricular arrhythmia，atrial fibrillation （AF），left ventricular ejection fraction （LVEF），left ventricular end-diastolic diameter （LVEDD），left atrial diameter （LAD），pulmonary artery hypertension （PAH），PAG were assessed by logistic multivariate regression analysis. Results Six patients died postoperatively，including 4 patients with low cardiac output syndrome and 2 patients with refractory ventricular arrhythmia. Perioperative mortality was 3.8%. The average follow-up time was 20.3±8.5 months and follow-up rate was 85.3% （133/156）. Eight patients died during follow-up，including 3 patients with heart failure，2 patients with ventricular arrhythmia，and 3 patients with anticoagulation-related cerebrovascular accident. Multivariate regression analysis showed that FMR preoperative/FMR postoperative ratio was not correlated with age≥55 years，male gender，body weight≥80 kg，LVEDD≥55 mm，LVEF≤50%，history of hypertension or ventricular arrhythmia. However，LAD≥50 mm，PAH≥50 mm Hg，PAG≤75 mm Hg and preoperative AF were negatively correlated with postoperative FMR improvement. Conclusions Risk factors including LAD≥50 mm，PAH≥50 mm Hg，PAG≤75 mm Hg and preoperative AF are negatively correlated with postoperative improvement of FMR （2＋to 3＋）. Patients with severe AS and above risk factors should receive concomitant surgical treatment for their FMR during AVR，since preoperative FMR（2＋to 3＋）usually does not improve or even aggravate after AVR.
Stent migration is one of the common complications following transcatheter valve implantation. This study aims to design a “drum-shaped” balloon-expandable aortic valve stent to address this issue and conduct a mechanical analysis. The implantation process of the stent was evaluated using a method that combines numerical simulation and in vitro experiments. Furthermore, the fatigue process of the stent under pulsatile cyclic loading was simulated, and its fatigue performance was assessed using a Goodman diagram. The process of the stent migrating toward the left ventricular side was simulated, and the force-displacement curve of the stent was extracted to evaluate its anti- migration performance. The results showed that all five stent models could be crimped into a 14F sheath and enabled uniform expansion of the native valve leaflets. The stress in each stent was below the ultimate stress, so no fatigue fracture occurred. As the cell height ratio decreased, the contact area fraction between the stent and the aortic root gradually decreased. However, the mean contact force and the maximum anti-migration force first decreased and then increased. Specifically, model S5 had the smallest contact area fraction but the largest mean contact force and maximum anti-migration force, reaching approximately 0.16 MPa and 10.73 N, respectively. The designed stent achieves a “drum-shaped” change after expansion and has good anti-migration performance.
Transcatheter aortic valve replacement (TAVR) is a reasonable alternative for patients with severe aortic stenosis who are at a medium or high risk from surgery, and it’s gradually extended to low-risk groups. The safety of surgery is confirmed with the advancement of technology and the improvement of surgical instruments, but surgical complications are still common. Cardiovascular collapse is the leading cause of death during the surgery and not rare. This article reported a case of cardiovascular collapse during TAVR who were successfully rescued, while literature review on the causes and treatment of cardiovascular collapse were made.
ObjectiveTo investigate clinical outcomes of aortic valve replacement (AVR)for surgical treatment of patients with severe aortic stenosis (AS)and left ventricular dysfunction (LVD).
MethodsClinical data of 29 patients with severe AS and LVD (left ventricular ejection fraction (LVEF) < 0.50)who underwent AVR in Changhai Hospital between January 2000 and December 2011 were retrospectively analyzed. Patients with mitral stenosis were excluded from this study. There were 22 male and 7 female patients with their age of 14-76 (56.3±12.9)years. Preoperative and postoperative clinical and echocardiographic findings were compared to assess AVR effects. Possible risk factors affecting postoperative recovery of left ventricular function were analyzed according to postoperative LVEF changes.
ResultsOne patient died within 30 days after AVR. In the other 28 patients, postoperative aortic pressure gradient (APG)decreased from 97.6±25.1 mm Hg to 25.0±9.7 mm Hg, while LVEF increased from 41%±6% to 56%±11%. Postoperative left ventricular end-diastolic/systolic diameter/volume all significantly improved (all P < 0.001).
ConclusionsAVR is an effective treatment for patients with severe AS and LVD. Left ventricular function improves significantly in most patients after AVR. Patients with a less dilated left ventricle may have a better LVEF recovery.
Objective To identify the heart sounds of aortic stenosis by deep learning model based on DenseNet121 architecture, and to explore its application potential in clinical screening aortic stenosis. Methods We prospectively collected heart sounds and clinical data of patients with aortic stenosis in Tianjin Chest Hospital, from June 2021 to February 2022. The collected heart sound data were used to train, verify and test a deep learning model. We evaluated the performance of the model by drawing receiver operating characteristic curve and precision-recall curve. Results A total of 100 patients including 11 asymptomatic patients were included. There were 50 aortic stenosis patients with 30 males and 20 females at an average age of 68.18±10.63 years in an aortic stenosis group (stenosis group). And 50 patients without aortic valve disease were in a negative group, including 26 males and 24 females at an average age of 45.98±12.51 years. The model had an excellent ability to distinguish heart sound data collected from patients with aortic stenosis in clinical settings: accuracy at 91.67%, sensitivity at 90.00%, specificity at 92.50%, and area under receiver operating characteristic curve was 0.917. Conclusion The model of heart sound diagnosis of aortic stenosis based on deep learning has excellent application prospects in clinical screening, which can provide a new idea for the early identification of patients with aortic stenosis.
Aortic stenosis (AS) is the most common primary valve lesion requiring surgery or transcatheter intervention in modern era. Its prevalence is rising rapidly as a consequence of the aging population. Transcatheter aortic valve replacement (TAVR) as a therapy option for older high-risk symptomatic severe AS patients has emerged and is currently extending its indications towards surgery intermediate- and low-risk subjects. Considering the common characteristics of frailty and high comorbidity among AS patients, cardiac rehabilitation (CR) has been proven to improve not only survival but also quality of life in previous reports. CR as a classⅠ recommendation in guidelines for the prevention and treatment of cardiovascular disease has been widely used in clinical practice. The purpose of this article is to sort out the current CR programs for TAVR patients in global medical management, and explore the CR optimization program fit for China medical model in post COVID-19 pandemic era.
Objective To investigate the role and mechanism of peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α) in the activation of aortic valve interstitial cells (AVICs) in aortic stenosis. Methods Isolating primary AVICs and stimulating their activation with transforming growth factor β1 (TGF-β1, 30 ng/mL), the expression of PGC-1α was detected. The activation of AVICs induced by TGF-β1 was observed after overexpression of PGC-1α by adenovirus or inhibition of PGC-1α function by GW9662. The possible downstream molecular mechanism of PGC-1α in AVICs activation was screened. Finally, the phenotype was further verified in primary human AVICs. Results The expression of PGC-1α decreased after the activation of AVICs induced by TGF-β1 (control group: 1.00±0.18; 24 h: 0.31±0.10; 48 h: 0.32±0.06; 72 h: 0.20±0.07; P<0.05). Specific overexpression of PGC-1α by adenovirus inhibited the activation of AVICs induced by TGF-β1 stimulation (periostin: 3.17±0.64 vs. 1.45±0.54, P<0.05; α-smooth muscle actin: 0.77±0.11 vs. 0.28±0.06, P<0.05). On the contrary, inhibition of PGC-1α function by GW9662 promoted the activation of AVICs (periostin: 2.20±0.68 vs. 7.99±2.50, P<0.05). Subsequently, it was found that PGC-1α might inhibit the activation of AVICs through downregulating the expression of calcium/calmodulin-dependent protein kinase (CAMK1δ) (0.97±0.04 vs. 0.74±0.11, P<0.05), and downregulating the expression of CAMK1δ alleviated the activation of AVICs (periostin: 1.76±0.11 vs. 0.99±0.20, P<0.05). The possible mechanism was that the activation of mammalian target of rapamycin (mTOR) signaling pathway was inhibited by reducing the accumulation of reactive oxygen species (ROS) (778.3±139.4 vs. 159.3±43.2, P<0.05). Finally, the protective effect of PGC-1α overexpression was verified in the activated phenotype of human AVICs (periostin: 2.73±0.53 vs. 1.63±0.14, P<0.05; connective tissue growth factor: 1.27±0.04 vs. 0.48±0.09, P<0.05). Conclusions The expression of PGC-1α significantly decreases during the activation of AVICs induced by TGF-β1. The overexpression of PGC-1α significantly inhibites the activation of AVICs, suggesting that PGC-1α plays a protective role in the activation of AVICs. The possible mechanism is that PGC-1α can inhibit the activation of CAMK1δ-ROS-mTOR pathway. In conclusion, interventions based on PGC-1α expression levels are new potential therapeutic targets for aortic stenosis.
Objective To systematically evaluate the impact of pulmonary hypertension (PH) on the prognosis of patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR). Methods A computerized search was conducted in CNKI, Wanfang Data, VIP, CBM, PubMed, The Cochrane Library, EMbase, and Web of Science databases from inception to June 2023 for cohort studies on the prognostic impact of PH in severe AS patients undergoing TAVR. Two researchers independently screened the literature, extracted data, and assessed the quality of included studies. Stata 17.0 software was used for meta-analysis. Results A total of 16 cohort studies were included, all with Newcastle-Ottawa Scale scores≥7. Meta-analysis results showed that, compared with AS patients without PH, those with PH had significantly higher 1-year all-cause mortality after TAVR [OR=2.10, 95%CI (1.60, 2.75), P<0.01], 30-day all-cause mortality [OR=2.09, 95%CI (1.54, 2.83), P<0.01], and cardiovascular mortality [OR=1.49, 95%CI (1.18, 1.90), P<0.01]. The differences between the two groups in major bleeding events, stroke, myocardial infarction, pacemaker implantation, and postoperative renal failure were not statistically significant. For outcome indicators with significant heterogeneity, subgroup analyses were performed based on PH measurement methods, diagnostic criteria, and different types of PH. The results showed that most subgroup combined results were consistent with the overall findings and that heterogeneity was significantly reduced. Conclusion PH significantly increases the 30-day all-cause mortality, 1-year all-cause mortality, and cardiovascular mortality in patients with severe AS undergoing TAVR.
Due to the lack of calcification of the aortic valve, it is difficult to provide effective support for the fixation of artificial valve in aortic stenosis characterized by leaflet thickening. There is a risk of postoperative perivalvular leakage and secondary valve implantation, which is widely regarded as a relative contraindication for transcatheter aortic valve replacement (TAVR). But aortic valvuloplasty and self-expanding transcatheter aortic valve has showed its safety and efficacy. This paper reports a patient with bicuspid aortic valve characterized by leaflet thickening treated with TAVR. After the operation, the patient’s symptom of exertional dyspnea was significantly improved, New York Heart Association class increased to Ⅱ, no perivalvular leakage was found, and the mean transaortic pressure gradient and the maximum aortic valve velocity decreased significantly.
