Valve Type Research Articles

Feature importance explanation of prosthetic valve endocarditis through machine learning via SHAP

Abstract Introduction Diagnosing prosthetic valve endocarditis poses a significant challenge in daily clinical practice. Accurately identifying these patients is vital due to its treatment implications. Clinical and imaging assessment of suspected cases yields a substantial number of interrelated variables, which can be analyzed through machine learning techniques in order to improve diagnostic accuracy. Feature ranking facilitates identification and interpretability of relevant clinical and imaging variables in this task. Purpose To utilize machine learning feature ranking and modeling in order to improve interpretable identification of patients with prosthetic valve endocarditis. Methods 89 cases defined by the endocarditis team and 173 controls were analyzed. We implemented the SHapley Additive exPlanations (SHAP) method to evaluate feature importance. 5-fold cross-validated Xgboost models were trained and independently tested with additive clinical, echocardiographic and 18F-FDG PET/CT data. Performance was evaluated through confusion matrices, F1-scores and AUCs. These were compared against conventional logistic regression of the Duke Criteria classification. Results Mean age was 59.6 ± 15.7, with 29.7% women. 14 clinical (demographic, laboratory and cultures), 2 echocardiographic, and 5 PET/CT features were included. The XGBoost model trained with all additive features demonstrated an AUC of 0.91±0.1 and outperformed simpler models as well as the Duke classification model (AUC=0.85). The clinical variables alone achieved an AUC of 0.85±0.11, while integration with echocardiography enhanced its performance to 0.90±0.04 (Fig. 1). Feature ranking demonstrated that antibiotic treatment duration, positive blood cultures, valve type, weight and CRP were the most relevant clinical variables, while the presence of vegetation or abscess, and abnormal uptake and uptake focality on PET/CT represented the most relevant imaging variables (Fig. 2). Conclusion Machine learning-based feature ranking and modeling may significantly enhance identification of patients with prosthetic valve endocarditis beyond standard clinical criteria. Feature selection offers interpretable performance in identifying these cases, model testing in clinical decision support may be warranted.Fig. 1:Comparative AUC Analysis.Fig. 2:SHAP feature importance.

Pacing dependency after TAVI, a lasting hazard in every case?

Abstract Introduction Atrioventricular (AV) conductions abnormalities that require permanent pacemaker (PPM) occur in up to 20% of patients after TAVI. The evolution of conduction abnormalities and the long-time pacing burden have not been fully characterized. We aim to characterize ventricular pacing burden after TAVI assessing also the impact of clinical and periprocedural factors. Methods Single centre retrospective registry including all consecutive patients undergoing TAVI between 01/2014 and 08/2021 that had a PPM implanted during index admission. Patients with in-hospital death were excluded. Baseline and pacing follow-up data were collected prospectively and assessed retrospectively using local electronic health records. We examined pacing burden as the percentage of ventricular pacing (VP%) and divided our cohort in 3 groups: i VP% ≤10%, ii 10% > VP% < 90%, iii VP% ≥90%. We assessed the difference between discharge and 1y VP% and the interaction between baseline characteristics. Results 766 patients underwent TAVI and 109 (14.2%) were included. The median age was 84 years (IQR 80 ; 90) and 44% were male (n = 48). 19 patients (17.4%) had previous 1st degree AV block (AVB) and 37 patients (33.9%) had previous right bundle branch block (RBBB). A self-expandable valve was implanted in 78 patients (71.6%). The median time between TAVI and PPM was 2 days (1;5). Sustained complete AVB (cAVB) occurred in 85 patients (78.0%) and was the most common indication for PPM. Data on VP% at discharge was available for 102 patients (93.5%). The median VP% at discharge was 100% (99 ; 100) with 4 patients (3.7%) having ≤10% VP% and 87 patients (79.8%) having ≥90% VP%. 95 patients (87.2%) completed the 1y follow-up. The VP% decreased significantly between discharge and 1y follow-up - 8.0 (IQR -59 ; 0 / p <0.05 Wilcoxon test) (Figure 1), similarly across valve type. At 1y follow-up, 20 patients (18.3%) had ≤10% VP% and 43 patients (39.4%) had ≥90% VP%. In the 18 patients (19.4%) without periprocedural sustained cAVB, 9 patients (50.0%) had ≤10% VP% and 1 patient (5.6%) had ≥90% VP%. In contrast, among patients with sustained cAVB, 11 patients (14.7%) had ≤10% VP% and 40 patients (53.3%) had ≥90% VP% (p <0.05 Chi-squared) (Figure 2). Conclusions In this study cohort the pacing burden significantly decreased in the 1st year after TAVI. It was significantly lower in patients without periprocedural sustained cAVB which suggests that a more conservative management may be considered in a small subgroup of patients.

Intra, short and long-term results of mitral VIV for the degenerated surgical mitral prosthesis from italian VIV registry (MIVIV registry)

Abstract Background/Introduction Reoperation of failed bioprosthetic mitral valves is associated with significant morbidity and mortality. Transcatheter mitral valve-in-valve (MViV) replacement was explored early in the development of THVs with transseptal/transfemoral (TS/TF) and transapical (TA) approaches. Purpose This is the first Italian Registry on mitral VIV and it was designed to explore contemporary MViV outcomes with all types of balloon expandable valves. The present study out of the registry aims to asses the >10 years follow-up outcomes in terms of mortality, gender diversity, and perioperative result. Methods Participating centers used standardized definitions to collect clinical information, including patient demographic characteristics, comorbidities, functional status, quality of life indexes, procedural details, and patient outcomes from consecutive MViV cases. Cohort of 265 patients was available for the primary analysis and follow-up too.The patients were grouped by 11 hospitals in Italy performing VIV for degenerated biological mitral prostheses. Results A total of 265 pts underwent mitral VIV due to bioprosthesis degeneration between January 2010 and January 2023. They have been subdivided by transfemoral (TF) with 117 (44%) pts and transapical (TA) with 148 (55,8%) pts. Most of the patients were of female sex (59,2%) and EuroScore II for surgical re-operation was 16.1%. Mixed disease (48%) was more common than mitral regurgitation (29%) and stenosis (22%). 69,8% of the total cohort was in class NYHA III and the mean LVEF was 54%.Otherwise, there were no significant demographic differences between patients undergoing TS and TA. In TF there was more severe PVL (5%)(p-value: 0,001) and much more cases of severe grade of stenosis (54,7%) and regurgitation (57%)(p-value< 0,0001). Considering intraoperative outcomes, technical success has been established in around 97,7% of the total cohort without difference btw groups. Only 3,3% died during hospitalization without difference between groups (P-value=0,735). LVOT obstruction has been seen in 3,4% in the case of TA and 0 for TF. Only 1,5% of the total cohort underwent surgical conversion as well as embolization in only 1,1%. Overall survival from the total cohort was 91,3% at >10 years, Figure 1. Concerning the freedom from cardiac death (CV death) was 96,6% in the total cohort at 13 years. Concerning the difference between access, the general survival is established at 97,4% in TF while 86,3% in TA (p-value =0,050)(Figure 2). Freedom from CV death was 99,1% in TF and 94,5 in TA (p-value=0,209). In gender analysis differentiation, the general survival in females was 98,5% in TF and 85,6% in TA at 13 years (p-value=0,056). Conclusion(s) Transcatheter MViV using a balloon-expandable valve is associated with high technical success, a low complication rate, and a solid long-term benefit in terms of survival. Transseptal access was associated with lower mortality compared with TA access.Figure 1Figure 2

Coronary access after Transcatheter Aortic Valve Replacement (TAVR): a systematic review and meta-analysis of observational studies

Abstract Introduction Over the past two decades, transcatheter aortic valve replacement (TAVR) has transformed the management of aortic stenosis, initially for high-risk surgical candidates and subsequently for low-risk patients. However, with the expanding indications for TAVR to younger, lower-risk patients, it is crucial to assess not only the short-term clinical outcomes but also the long-term considerations for future interventions. The prevalence of coronary artery disease (CAD) in TAVR patients is relevant, and the optimal timing of percutaneous coronary intervention (PCI) remains a question, given the technical challenges associated with coronary access in TAVR patients. Methods We conducted a systematic literature review and meta-analysis according to Cochrane Collaborations and PRISMA guidelines. We included 19 eligible trials involving 1533 patients who underwent coronary angiography after TAVR. The primary endpoint was the incidence of successful selective coronary re-access. Secondary endpoints included semi-selective and non-selective access rates. The analysis was stratified by balloon-expandable (BEVs) and self-expandable valve (SEVs) types. Results Successful coronary access after TAVR was feasible in the majority of patients, with a higher success rate observed for the left main coronary artery (LM) compared to the right coronary artery (RCA). Balloon-expandable valves demonstrated the highest success rates in coronary ostia cannulation, achieving nearly 100% success for both LM and RCA. Among self-expandable valves, the Evolut R/PRO showed superior success rates in selective coronary access (76,85% (95%CI 53,34-100%) for LM and 57,27% (95%CI 32,8-81,74%) for RCA) compared to the CoreValve (45,62% (95%CI 0-92,78%) for LM and 49,19% (95%CI 0-100%) for RCA). Notably, the majority of coronary angiograms were performed due to acute coronary syndrome, primarily non-ST-segment elevation myocardial infarction (NSTEMI) and unstable angina (UA), 26,5% for NSTEMI and 23,4% for UA, respectively. Conclusions Selective coronary engagement after TAVR is generally achievable, with BEVs demonstrating superior success rates compared to SEVs. Among self-expandable valves, the Evolut R/PRO showed better outcomes than the CoreValve. These findings provide valuable insights into post-TAVR coronary access feasibility, reducing concerns about valve selection based on this criterion

Impact of protruding and ulcerated aortic atheroma on periprocedural ischemic stroke in patients undergoing transcatheter aortic valve replacement: a comprehensive analysis

Abstract Backgrounds Aortic atherosclerosis has the potential to impact both the strategy and outcomes of transcatheter aortic valve replacement (TAVR). Past research has established a correlation between the thickness and volume of aortic atheroma with periprocedural ischemic stroke and long-term mortality. However, there is limited investigation into the relationship between the morphology of aortic atheroma and outcomes following TAVR. Purpose The study aimed to assess the influence of protruding and ulcerated aortic atheroma on the occurrence of periprocedural ischemic stroke following TAVR. Methods A total of 979 patients who underwent TAVR between February 2012 and May 2019, and had retrospectively available data from contrast-enhanced computed tomography, were included in this analysis. The presence of protruding or ulcerated atheroma was evaluated across four aortic segments: ascending aorta, aortic arch, descending aorta, and abdominal aorta. Protruding aortic atheroma was defined as atheroma with a thickness exceeding 3 mm and protruding components. Ulcerated aortic atheroma was defined as atheroma presenting with ulcer-like disruption of the intima. The primary endpoint assessed was periprocedural ischemic stroke occurring within 48 hours following TAVR. Results The frequencies of protruding and ulcerated aortic atheroma were as follows: 0.2% in the ascending aorta, 6.5% in the aortic arch, 11.1% in the descending aorta, 15.7% in the abdominal aorta, and 24.2% in the entire aorta (Figure 1). Among the 979 patients analyzed, 25 (2.6%) experienced periprocedural ischemic stroke. Patients with protruding or ulcerated aortic atheroma exhibited a significantly higher incidence of periprocedural ischemic stroke compared to those without (5.5% vs. 1.6%, p=0.0010). Multivariate logistic analysis revealed that protruding or ulcerated aortic atheroma, particularly in the aortic arch, independently increased the risk of periprocedural ischemic stroke. (Table 1). Among the subset of patients (309, 34%) undergoing transfemoral TAVR (TF-TAVR) with a self-expandable valve, those with protruding or ulcerated aortic atheroma had a notably higher incidence of periprocedural ischemic stroke compared to those without (9.6% vs. 1.6%, p=0.0083). Conversely, among patients (587, 66%) undergoing TF-TAVR with a balloon-expandable valve, there was no statistically significant difference in the incidence of periprocedural ischemic stroke between those with and without protruding or ulcerated aortic atheroma (4.2% vs. 1.8%, p=0.102). Conclusions Protruding and ulcerated aortic atheroma, particularly in the aortic arch, were linked to a higher risk of periprocedural ischemic stroke post-TAVR. Consequently, careful selection of TAVR strategy, including valve type and procedural approach, is essential for patients with such aortic lesions.Figure 1Table 1

HV interval measure immediately before TAVI with SEV for predicting pacemaker implantation

Abstract Introduction Although improvements, new onset persistent disturbances in electrocardiogram (ECG) after transcatheter aortic valve implantation (TAVI) remains up to 34% at hospital discharge (1), needing permanent pacemaker implantation (PPM) in self-expanding valves (SEV) as high as 15-27% (2,3). In post TAVI scenario, European Society of Cardiology guidelines recommend an electrophyisiologic study centered in His-ventricular electrogram (HV) interval measure for assessing risk of progression to high auriculoventricular block (AVB), if abnormal a PPM is indicated (4,5). We aim to predict PPM through basal HV interval measurement prior TAVI with SEV. Furthermore, we aim to compare different current SEV with basal HV interval and the distinct rate of PPM before discharge. Methods and Results Single-center prospective cohort study, patients with severe aortic stenosis scheduled for TAVI, sinus rhythm at intervention day, without PPM or history of PPM indication were included. At time of TAVI, contralateral venous puncture to femoral arterial access was made, a tetrapolar catheter was advanced and placed at the septal aspect of tricuspid valve searching for His electrogram. A mobile polygraph was used to measure ECG parameters and HV interval before TAVI. Then, a tetrapolar catheter was advanced to ventricle to perform rapid stimulation as part of habitual valve implantation protocol. After procedure, we performed rhythm surveillance for at least >48-72 hours and based in electrical evolution one of three decisions was made: 1)PPM implant, 2)late post TAVI HV interval re-measure or 3)clinical daily ECG vigilance, if this last was normal, unchanged from basal or with new but stable conduction disturbances, discharge were indicated following ESC guidelines. A total of 41 patients were enrolled, median age 84±4 years, 24 females (54.5%), PR mean 198±42ms, QRS mean 112±30ms. 18 had a 1st degree AVB (40.9%) of whom 13 (72.5%) had a PR ˂240ms. EPS data showed prior HV interval mean of 55±9ms. A Mild abnormal HV interval (56-69ms) were seen in 21 patients (51.2%), of whom 12 had a narrow QRS. SEV implanted were 11 (25%) Medtronic CoreValve Evolut+, 5 (11.4%) Biosensors Allegra, 25 (56.8%) Abbott Navitor. Post TAVI procedure, 5 (12.2%) women and 8 (19.5%) men met criteria for PPM implantation before discharge. One woman was implanted 6 days after discharge due to high AVB (66ms HV interval prior TAVR). In a multivariate analysis including sex, age, PR, QRS and HV interval >55ms, valve type the RR (IC 95% 1.37-30.99) risk of PPM was 6.52 folds higher (p=0.019). Conclusions An HV interval >55ms before TAVI with SEV increases risk of PPM after TAVI and before hospital discharge. There was no difference in PPM implantation after TAVI between different SEV types in our center.

Outcomes of percutaneous coronary interventions after transcatheter aortic valve replacement

Abstract Background The number of percutaneous coronary interventions (PCI) after transcatheter aortic valve replacement (TAVR) is expected to increase with the extension of this treatment toward younger and lower-risk patients. However, little is known about the prognosis of this evolving subset of patients. Purpose This study aims to assess the clinical outcomes of patients undergoing PCI after TAVR. Methods Patients undergoing PCI after TAVR were retrospectively included from 20 centers across 7 European Countries from July 2008 to November 2023. The patients and procedural characteristics at the time of PCI, post-discharge antithrombotic regimen, and clinical outcomes were collected by each center. The primary endpoint was major adverse cardiovascular events (MACE), a composite of cardiovascular death, myocardial infarction, or stroke. Results A total of 464 patients underwent PCI at a median interval of 106 days (interquartile range: 40-502) after TAVR (45.4% balloon-expandable, 49.6% self-expandable, and 5.0% mechanically-expandable valve). The cohort had a mean age of 80.9±6.2 years, a mean Euroscore II of 5.5±6.2, and 48% had undergone prior PCI or coronary artery bypass graft. Indications for PCI included chronic coronary syndrome (64.6%), non-ST elevation myocardial infarction (20.5%), unstable angina (7.9%), ST elevation myocardial infarction (5.7%), and other acute reasons (1.2%). PCI was complex in approximately 20% of the cases and radial access was utilized only in about 47.4% of them. Still, PCI success rate was 96.7%, achieving complete revascularization in 70.5% of cases. There were 19 periprocedural myocardial infarctions (4.3%). The predominant antithrombotic regimen was 12-month dual antiplatelet therapy (49.1% of patients). MACE incidence over one year of follow-up was 11.8% (95% CI: 9.0%-15.4%), with no differences among TAVR valve types (p-value=0.260). The incidences of the individual component of MACE were 8.7% for cardiovascular deaths, 5.3% for myocardial infarctions, and 2.3% for strokes. Conclusion At present, patients undergoing PCI after TAVR represents a high-risk subgroup. Nonetheless, elucidating actionable factors could potentially improve their outcomes. This preliminary analysis did not reveal any association with the type of implanted valve.

Native Sinus Hemodynamics and Thrombosis in Transcatheter Heart Valve: Effect of Implant Depth and Coronary Flow.

This study aimed to investigate the hemodynamic and anatomic factors associated with sinus thrombosis following transcatheter aortic valve replacement (TAVR), integrating invivo patient data analysis and invitro experiments. Postprocedural, 4-dimensional, multiphase computed tomography data from 211 patients enrolled in the ADAPT-TAVR (Anticoagulation Versus Dual Antiplatelet Therapy for Prevention of Leaflet Thrombosis and Cerebral Embolization After Transcatheter Aortic Valve Replacement) study were analyzed. The prevalence of native sinus thrombosis was examined in relation to valve type, implant depth, and anatomic features. Invitro experiments used particle image velocimetry to observe changes in sinus flow based on the transcatheter heart valves (23-mm SAPIEN3, Edwards Lifesciences; and 29-mm CoreValve, Medtronic) height and coronary artery flow. Native sinus thrombosis was more common in self-expanding valves (39.1% versus 14.9%, P=0.004). In per-cusp analysis of invivo patient data, adjusted transcatheter heart valve implant depth (odds ratio, 1.2 [95% CI, 1.1-1.3]; P<0.001), noncoronary sinus of Valsalva (odds ratio, 4.0 [95% CI, 2.0-7.8]; P<0.001), sinus inflow diameter (odds ratio, 0.8 [95% CI, 0.6-0.9]; P=0.008), and implanted valve size (odds ratio, 0.8 [95% CI, 0.7-1.0]; P=0.025) were significant factors associated with native sinus thrombosis. In the invitro experiments, CoreValve showed noticeable flow stasis compared with SAPIEN3. High-positioned SAPIEN3 was linked to reduced velocity within the native sinus of Valsalva. Coronary artery flow led to higher sinus velocity and improved particle washout, reducing sinus thrombosis risk. This study provides insights into the relationship between transcatheter heart valve deployment and native sinus thrombosis, emphasizing the role of anatomic factors in relation to the risk of sinus thrombosis.

Cost-effectiveness analysis of valvular surgery in high- and low- to middle-income countries: A scoping review.

Global disparities in valvular surgery services exist. Cost-effectiveness analysis (CEA) and cost-utility analysis can be used to guide national investment decisions. This scoping review aims to synthesize economic evaluations for valvular surgery by income settings and provide recommendations. A systematic literature review identified primary CEAs or CUAs in English comparing surgical management strategies for valvular heart disease. MEDLINE, Embase, CINAHL, Web of Science, and Business Source Complete were searched using keywords "valvular surgery," "valve disease," "cost-effectiveness," and "cost-benefit analysis". Articles comparing outcomes or costs only were excluded. Search results were uploaded and screened on COVIDENCE. Variables from eligible articles were charted in a spreadsheet. Twenty articles were eligible, six from low- and middle-income countries (LMICs) and 14 from high-income countries (HICs). In HICs, the top conditions were degenerative aortic valve disease (7/14) and mitral valve disease (4/14) compared to congenital (2/6) and rheumatic heart diseases (2/6) in LMICs. HICs evaluated new technologies and techniques, whereas LMICs compared different valve types or surgery versus no intervention. Most articles used published studies (12/20) or databases (7/20) to conduct their CEA and quality-adjusted life years was the most common effectiveness measure (12/20). Comparator interventions were cost-effective in all LMIC articles and in 8/14 for HICs. Economic evaluations are mostly conducted in HICs and for adult conditions. More analyses in LMICs are needed. This can be facilitated by maintaining databases, documenting costs, and implementing quality of life assessments.

Mid-term outcomes of valve replacement surgery with or without coronary artery bypass grafting in patients with overweight and obesity: A cohort study.

Current data evaluating outcomes of valve replacement surgery in patients with overweight/obesity is contradictory. There is a scarce study comparing outcomes of valve surgery considering the type of valve involved in the procedure. We followed outcomes in patients with overweight and obesity after valve replacement surgery with or without coronary artery bypass graft (CABG) and also patients with aortic valve replacement (AVR) and mitral valve replacement (MVR), separately to compare their mid-term prognosis in each group. Consecutive patients who had undergone cardiac valve surgery with or without CABG in Tehran Heart Center were enrolled. We enrolled 3158 patients. Median survival was 125.71 ± 82.20 weeks in patients with overweight/obesity. We found a significantly higher LVDd, LVDs and RVDd in patients with CABG (51.85 ± 7.31, 36.80 ± 8.81 and 30.04 ± 3.58, respectively) compared to the valve group (50.10 ± 6.35 mm, 35.08 ± 7.29 mm and 29.76 ± 4.07 mm, respectively). All-cause mortality is significantly higher in patients with AVR (5.7%) than those with MVR (3.3%). Patients with CABG are at higher risk of myocardial infarction (MI) compared to the ones without CABG (0.8% vs. 0.1%). No significant interaction was observed between the type of valve surgery (AVR/MVR) or valve surgery combinations (valve/valve + CABG) (p-values = .81 vs. .97, respectively). Post-operative outcomes in patients with overweight/obesity depend on several factors such as type of valve involved and presence of CABG. Risk management can lower the rate of mortality and morbidity in these patients.

Transcatheter Aortic Valve Implantation by Valve Type in Women With Small Annuli

Historically, women with aortic stenosis have experienced worse outcomes and inadequate recognition compared to men, being both underdiagnosed and undertreated, while also facing underrepresentation in clinical trials. To determine whether women with small aortic annuli undergoing transcatheter aortic valve replacement have better clinical and hemodynamic outcomes with a self-expanding valve (SEV) or balloon-expandable valve (BEV). The Small Annuli Randomized to Evolut or SAPIEN Trial (SMART) was a large-scale randomized clinical trial focusing on patients with small aortic annuli undergoing transcatheter aortic valve replacement, randomized to receive SEVs or BEVs and included 716 patients treated at 83 centers in Canada, Europe, Israel, and the US from April 2021 to October 2022. This prespecified secondary analysis reports clinical and hemodynamic findings for all 621 women enrolled in SMART. Data for this report were analyzed from February to April 2024. Transcatheter aortic valve replacement with an SEV or a BEV. The composite coprimary clinical end point comprised death, disabling stroke, or heart failure-related rehospitalization. The coprimary valve function end point was the incidence of bioprosthetic valve dysfunction, both assessed through 12 months. Secondary end points included the incidence of moderate or severe prosthesis-patient mismatch. A total of 621 women (mean [SD] age, 80.2 [6.2] years; 312 randomized to the SEV group and 309 to the BEV group) were included in the present analysis. At 12 months, there were no significant differences in the coprimary clinical end point between the SEV and BEV groups (9.4% vs 11.8%, absolute risk difference -2.3%; 95% CI -7.2 to 2.5, P = .35). However, SEV implantation was associated with less bioprosthetic valve dysfunction (8.4% vs 41.8%; absolute risk difference, -33.4%; 95% CI, -40.4 to -26.4; P < .001). SEV implantation resulted in lower aortic valve gradients and larger effective orifice areas at 30 days and 12 months and less mild or greater aortic regurgitation at 12 months compared to BEV implantation. Prosthesis-patient mismatch was significantly lower with SEVs, regardless of the definition used and adjustment for body mass index. Use of SEVs was associated with better quality of life outcomes as assessed by the Valve Academic Research Consortium-3 ordinal quality of life measure. Among women with severe symptomatic aortic stenosis and small aortic annuli undergoing transcatheter aortic valve replacement, the use of SEVs, compared to BEVs, resulted in similar clinical outcomes and a markedly reduced incidence of bioprosthetic valve dysfunction through 12 months, including a lower risk of prosthesis-patient mismatch and better 12-month quality of life. ClinicalTrials.gov Identifier: NCT04722250.

Comparative analysis of performance of different types of Tesla valves

Abstract The Tesla valve is a valve with no moving parts. Its special configuration also allows the pressure drop of fluid passing through the Tesla valve from the reverse inlet to be much greater than the pressure drop of fluid passing through the Tesla valve from the forward inlet. Therefore, the Tesla valve has a certain degree of single pilot connectivity and pressure reduction capability. This article selected 8 common types of Tesla valves, By using numerical calculation method through Fluent simulation, the differences of resistance coefficient, pressure drop and Di value of 8 types of single-stage Tesla valves under three different working conditions were compared. In order to explore the performance of 8 kinds of Tesla valves under the three working conditions. At the same time, the relationship between the flow state and the structure of each part of the fluid before and after passing through the distributary pipe is analyzed. The simulation results show that due to the different structure of various Tesla valves, the flow rate, pressure and turbulent kinetic energy of the fluid inside the valve also have different changes. At the same time, there are many similarities in the flow state of some Tesla valves with similar structural types. Finally, according to the calculation results, the advantages and disadvantages of various types of Tesla valves and their applications are analyzed.

RATE OF ASCENDING AORTIC ENLARGEMENT IN A LARGE ECHOCARDIOGRAPHIC COHORT: ASSOCIATED RISK FACTORS AND ADVERSE AORTIC EVENTS

BackgroundUnderstanding ascending aortic aneurysm growth and associated risk factors is critical to advising appropriate echocardiographic follow-up intervals for patients. This study aimed to identify aortic aneurysm growth rate on serial echocardiograms as well as the clinical and demographic variables that contribute to baseline aortic size and subsequent aortic growth. MethodsPatients identified with ascending aortic aneurysm and undergoing serial echocardiograms within five years were evaluated. Ascending aortic size was measured as part of routine echocardiogram exams. Clinical and demographic variables including aortic valve type (trileaflet, bicuspid or prosthetic) were evaluated for association with baseline aortic size as well as with aortic progression rate. Clinical events including aortic dissection, elective or emergent surgical repair were recorded. Results3639 patients were identified, (78% males, median age of 69 years, 175 (4.8%) with bicuspid valve, and 206 (5.6%) with prior aortic valve replacement (AVR). Patients with larger aorta at baseline were older with higher tobacco use and prior prosthetic valves. Over a mean of 2.4 years, aortic growth was observed and differed by valve type (trileaflet valve: 0.08 mm/year , bicuspid valve: 0.4 mm/year , p<0.001). In six patients who developed aortic dissection the estimated average annual growth rate was 0.98 mm/year. ConclusionsIn a large echo cohort, aortic aneurysm growth rate was 0.08 mm/year though higher in those with bicuspid valves ( 0.4 mm/ year), but initial aortic size did not correlate with change in the aortic progression rate. This data may help inform recommended echocardiographic surveillance intervals.

Natural biomaterials in the management of the aortic valve pathology. Biomedical and clinical aspects: A review.

Heart valve diseases are a prevalent cardiovascular pathology worldwide, affecting nearly 2.5% of the population. Degenerative aortic stenosis is the most common form of heart valve disease. The treatment options include surgical or transcatheter procedures. There are two main categories of valve prostheses available: mechanical heart valves constructed from synthetic materials and bioprosthetic heart valves made from natural biomaterials. The choice of valve type depends on various factors, including the underlying medical condition, suitability for anticoagulation, valve durability, and the patient's age and preferences. Mechanical heart valves have the advantage of long-term durability. However, patients receiving mechanical implants are subjected to lifelong anticoagulation therapy with an increased risk of thromboembolism and bleeding. Natural biomaterials do not require long-term anticoagulation. However, they experience degenerative changes leading to structural valve deterioration that may require reoperation. The purpose of this article is to review the role of natural biological materials used for aortic valve replacement or repair, assess their biomedical and clinical advantages and limitations, and analyze the direction and perspectives of future development.

Enhancing commercial check valves in downhole pump applications through laboratory testing system development

In this study, we aim to enhance the performance and longevity of downhole pumps employed in crude oil extraction in the oil industry. Downhole pumps play a pivotal role in the rod-pump system, comprising traveling and standing valves that function similarly to ball check valves. However, these valves often experience premature wear and tear. To address this concern, we embarked on experiments involving various check valve alternatives to conventional ball valves within downhole pumps. The testing conditions were controlled precisely. Furthermore, we evaluated four distinct check valve types, the original (representing the incumbent ball valves), spring-poppet (C), spring-ball (CB), and spring-poppet with soft-seated (S6C) check valves, within a controlled laboratory environment. We employed a TEXAPON N70 solution to replicate the properties and temperature conditions of crude oil. A portable ultrasonic flow meter was used to quantify the pump flow rate and assess its volumetric efficiency. In addition, we recorded data on the polished-rod load and plunger displacement to generate dynamometer cards, thereby enabling a comprehensive evaluation of the operational performance of the pump. Furthermore, we conducted a vacuum test to scrutinize valve leakage, which is a crucial indicator of the operational lifespan of a downhole pump. Our findings show that incorporating the CB check valve with the RHB pump in oil wells operated by the PTT Exploration and Production Public Company Limited (PTTEP) could result in a 15 % increase in volumetric efficiency and a remarkable 160 % improvement in durability compared to the original ball check valve.

TARGETED SEQUENCING REVEAL TWO PATHOGENIC MUTATIONS IN LDLR AND APOE GENES IN PATIENT WITH FAMILY HYPERCHOLESTEROLEMIA: CASE REPORT

Familial hypercholesterolemia (FH) is a serious inherited disorder that can lead to early development of cardiovascular disease (CVD) due to the high blood cholesterol levels. In our study, we identified in FH patient likely pathogenic variant of LDLR and APOE genes. Interest in the homozygous state of FH is understandable given its rarity and severe health consequences. The homozygous state, when both LDL receptor alleles mutated, demonstrates even higher cholesterol levels and an earlier and more severe clinical course compared with the heterozygous state. In our study, we report an interesting case of homozygous FH due to its rare prevalence. Patient U., 16 years old, woman, admitted to the National Research Cardiac Surgery Center (NRCC), was diagnosed with FH, congenital heart disease (CHD), bicuspidal aortic valve (AV) type 1. Both parents (mother and father) were included for reliable analysis. DNA was isolated from the venous blood sample by using the column method of QIAamp DNA Mini Kit. Targeted NGS using TruSight Cardio panel for 174 genes was performed on MiSeq, Illumina. Identified genetic variants were classified according to the ACMG guidelines. Pathogenic variants were validated by Sanger sequencing. Additionally, databases of the VarSome and ClinVar were used for analysis. Sequencing of 96 genes and bioinformatics analysis identified 2 likely pathogenic variants - C526T:p.R176C in APOE and G295A:p.E99K in LDLR gene, 4 uncertain significance variants in APOB, TTN, COL3A1, NOTCH1 and 90 benign variants in APOB, TTN, LAMA4, MYPN, DMD. LDLR (G295A:p.E99K) and APOE (C526T:p.R176C) were validated and confirmed by Sanger sequencing in patients and her father and mother. The main function of the APOE gene is to make the protein apolipoprotein E, which is involved in fat metabolism. In our study, the patient had a heterozygous variant of СT polymorphism rs7412 in the APOE gene, which indicates the presence of a possible disorder of fat metabolism. LDLR gene encodes a protein called low-density lipoprotein receptor, which is responsible for the uptake of cholesterol-carrying lipoprotein particles in cells. In our study, a patient with a homozygous AA variant of the LDLR gene was found to be pathogenic. Disruption of the uptake of cholesterol-carrying lipoprotein particles in cells can have serious consequences for the body. This can lead to cholesterol accumulation in the blood and tissues, which in turn can contribute to the development of atherosclerosis and other CVD. We found that both parents had a heterozygous genotype of G295A:p.E99K in LDLR gene; and mother had a heterozygous genotype and father had a homozygous genotype of C526T:p.R176C in APOE gene. In our study, we found the genetic mutations - two likely pathogenic genetic variants LDLR (G295A:p.E99K) and APOE (C526T:p.R176C) associated with FH in patient with clinical phenotype of FH using TruSight Cardio targeted panel of 96 genes. Genetic testing using targeted NGS or whole exome sequencing would be useful for right diagnosis and might improve personalize treatment for these patients. To identify other genes associated with FH whole exome sequencing can be recommend. Supported by Committee of Science of the Ministry of Science and Higher Education of Republic of Kazakhstan (AP14869903), (BR21881970) and Nazarbayev University CRP (211123CRP1608).

Thrombocytopenia after transcatheter aortic valve implantation

Introduction and objectivesThrombocytopenia frequently occurs after transcatheter aortic valve implantation (TAVI) but its impact is poorly understood. We aimed to analyze the incidence, clinical impact, and predictors of acquired thrombocytopenia after TAVI. MethodsThis retrospective multicenter registry included 3913 patients undergoing TAVI with a baseline platelet count of ≥ 100 *109/L. Acquired thrombocytopenia was defined as a decrease in baseline platelet count of ≥ 50% (early nadir ≤ 3 days and late nadir ≥ 4 days) post-TAVI. The primary endpoint was 30-day all-cause mortality and secondary endpoints were procedural safety and 2-year all-cause mortality. ResultsThe incidence of acquired thrombocytopenia was 14.8% (early nadir: 61.5%, late nadir: 38.5%). Thirty-day mortality occurred in 112 (3.0%) patients and was significantly higher in those with thrombocytopenia (8.5% vs 2.0%, adjusted OR, 2.3; 95%CI, 1.3-4.2). Procedural safety was lower and 2-year mortality was higher in patients with thrombocytopenia vs those without (52.1 vs 77.0%; P <.001, and 30.2% vs 16.8%; HR, 2.2, 95%IC, 1.3-2.7) and especially in those with late nadir thrombocytopenia (45.8% vs 54.5%; P=.056, and 38.6% vs 23.8%, HR, 2.1; 95%CI, 1.5-2.9). Independent predictors of thrombocytopenia comprised baseline and procedural factors such as body surface area, absence of diabetes, poorer renal function, peripheral vascular disease, nontransfemoral access, vascular complications, type of transcatheter heart valve, and earlier TAVI procedures. ConclusionsAcquired thrombocytopenia was common (15%) after TAVI and was associated with increased short- and mid-term mortality and decreased procedural safety. Moreover, late thrombocytopenia compared with early thrombocytopenia was associated with significantly worse clinical outcomes. Further investigations are needed to elucidate the etiologic mechanisms behind these findings.

Outcomes of transcatheter aortic valve implantation for native aortic valve regurgitation.

Large datasets of transcatheter aortic valve implantation (TAVI) for pure aortic valve regurgitation (PAVR) are scarce. We aimed to report procedural safety and long-term clinical events (CE) in a contemporary cohort of PAVR patients treated with new-generation devices (NGD). Patients with grade III/IV PAVR enrolled in the FRANCE-TAVI Registry were selected. The primary safety endpoint was technical success (TS) according to Valve Academic Research Consortium 3 criteria. The co-primary endpoint was defined as a composite of mortality, heart failure hospitalisation and valve reintervention at last follow-up. From 2015 to 2021, 227 individuals (64.3% males, median age 81.0 [interquartile range {IQR} 73.5-85.0] years, with EuroSCORE II 6.0% [IQR 4.0-10.9]) from 41 centres underwent TAVI with NGD, using either self-expanding (55.1%) or balloon-expandable valves (44.9%; p=0.50). TS was 85.5%, with a non-significant trend towards increased TS in high-volume activity centres. A second valve implantation (SVI) was needed in 8.8% of patients, independent of valve type (p=0.82). Device size was ≥29 mm in 73.0% of patients, post-procedure grade ≥III residual aortic regurgitation was rare (1.2%), and the permanent pacemaker implantation (PPI) rate was 36.0%. At 30 days, the incidences of mortality and reintervention were 8.4% and 3.5%, respectively. The co-primary endpoint reached 41.6% (IQR 34.4-49.6) at 1 year, increased up to 61.8% (IQR 52.4-71.2) at 4 years, and was independently predicted by TS, with a hazard ratio of 0.45 (95% confidence interval: 0.27-0.76); p=0.003. TAVI with NGD in PAVR patients is efficient and reasonably safe. Preventing the need for an SVI embodies the major technical challenge. Larger implanted valves may have limited this complication, outweighing the increased risk of PPI. Despite successful TAVI, PAVR patients experience frequent CE at long-term follow-up.

Coagulation, fibrinolysis and platelet drop in patients undergoing transfemoral transcatheter aortic valve implantation.

Transcatheter aortic valve implantation (TAVI) leads to transient platelet activation and hypercoagulation status, resulting in thrombocytopenia. This study investigated the associations of coagulation/fibrinolysis status after transfemoral TAVI with valve type, post-TAVI thrombocytopenia, and complication of TAVI. Thrombin-antithrombin complex (TAT) and fibrin/fibrinogen degradation product (FDP) levels were measured before and 1 h, 1 day, and 2 days after TAVI. A percentage drop in platelet count (DPC) was determined from the pre- and lowest post-procedural values. SAPIEN 3 (S3) was implanted in 158 patients and Evolut PRO/PRO+ (Evolut) in 117. Both TAT and FDP increased after TAVI. Pre-TAVI balloon dilatation was generally performed on patients undergoing implantation with Evolut. Peak TAT was then stratified into 4 quartiles (Q1 to Q4). Of all 275 study patients, 69 patients reached ultra-hypercoagulation status (Q4). S3, TAVI without pre-balloon dilatation, DPC and bleeding complications were significantly associated with the ultra-hypercoagulation status after TAVI. TAT was significantly greater 1 h after S3 implantation than Evolut (median [IQR], 43.1 [34.1-59.6] vs. 31.0 [25.0-40.4] ng/mL; p < 0.001). In contrast, FDP levels did not differ between the two at any measurement point. The difference in DPC among the peak TAT quartiles was statistically significant (p < 0.001). The occurrence of bleeding complications was significantly higher in the group with ultra-hypercoagulation status (5.8% vs. 1.0%, p = 0.036). The increase in coagulation status and post-TAVI thrombocytopenia were significantly greater after S3 implantation. Ultra-hypercoagulation after TAVI was related to bleeding complications.

Left Ventricular Reverse Remodeling after Surgical Aortic Valve Replacement for Aortic Regurgitation-An Explorative Study.

The timing of treatment for chronic aortic valve regurgitation (AR), especially in asymptomatic patients, is gaining attention since less invasive strategies have become available. The aim of the present study was to evaluate left ventricular reverse remodeling after aortic valve replacement (AVR) for severe AR. Patients (n = 25) who underwent surgical AVR for severe AR with left ventricular ejection fraction (LVEF) less than 55% were included in this study. Preprocedural and follow-up clinical and echocardiographic measurements of LVEF and left ventricular (LV) diameters were retrospectively analyzed. Mean LVEF increased significantly following surgical AVR (p < 0.0001). LV diameters showed a clear regression (p = 0.0088). Younger patients and those receiving a mechanical valve tended to have less improved LVEF on follow-up than patients over 60 years or the ones who were implanted with a biological prosthesis (p = 0.0239 and p = 0.069, respectively). Gender had no effect on the degree of LVEF improvement (p = 0.4908). We demonstrated significant LV reverse remodeling following AVR for AR. However, more data are needed on LV functional and geometrical improvement comparing the different types of valve prostheses to provide an optimal treatment strategy.