Valve Size Research Articles

TCT-859 Impact of Aortic Valve Annular Dimensions Assessment in Various MDCT Systolic Phases on Optimization of Balloon Expandable TAVR Valve Size Selection and Valve Oversizing Percentage

TCT-859 Impact of Aortic Valve Annular Dimensions Assessment in Various MDCT Systolic Phases on Optimization of Balloon Expandable TAVR Valve Size Selection and Valve Oversizing Percentage

CharActeristics, sizing anD outcomes of stenotic, tapered, rapHe-type bicuspid aOrtic valves treated with trans-catheter device implantation: Insights the AD HOC registry

BackgroundRaphe-type bicuspid aortic valve (BAV) is a potential hostile scenario in trans-catheter aortic valve replacement (TAVR) due to pronounced calcium burden, possibly associated with tapered valve configuration. Trans-Catheter heart valve (THV) sizing strategy (annular vs. supra-annular) is controversial in this valve subtype. ObjectivesTo describe the phenotypical characteristics of severe, tapered, raphe-type, BAV stenosis undergoing TAVR and to explore safety and efficacy of modern-generation THVs, analysing the impact of annular and supra-annular sizing strategies on short- and mid-terms outcomes. MethodsThis is a retrospective, multicenter registry enrolling consecutive stenotic Sievers type 1 BAV treated with TAVR. Study population was divided into tapered and non-tapered configuration according to MSCT analysis. Matched comparison between annular and supra-annular sizing groups was performed in tapered population. ResultsFrom January 2016 to June 2023, 897 patients were enrolled. Of them, 696 patients displayed a tapered configuration. Of those, 510 received a THV according to annular sizing. After propensity score matching 186 matched pairs were selected. Technical success (96.2 % vs 94.1 %, OR 1.61 [0.61–4.24], p = 0.34), 30-day device success (83.6 % in both groups, OR 1.42 [0.78–2.57], p = 0.25) and 30-day early safety (71.8 % vs 70.5 %, OR 1.07 [0.68–1.68], p = 0.78) were similar between the annular and supra-annular sizing groups; a higher post-TAVR gradient was observed in supra-annular group, although it was only 2 mmHg mean. At mid-term follow-up, the rate of clinical efficacy was 84.7 %. ConclusionsTAVR with modern-generation devices is safe and effective for tapered raphe-type BAV, showing comparable results for annular and supra-annular sizing strategies.

Flow Performance Analysis of Non-Return Multi-Door Reflux Valve: Experimental Case Study

Non-return multi-door reflux valves are essential in fluid control systems to prevent reverse flow and maintain system integrity. This study experimentally analyzes the flow performance of multi-door check valves under different operating conditions, focusing on pressure testing and evaluating their effectiveness in preventing backflow. A wide-ranging experimental setup was designed and implemented to simulate real-world scenarios, facilitating accurate measurement of flow rates, pressure differences, and valve response times. The collected experimental data were analyzed to evaluate the valve’s performance in terms of flow capacity, pressure drop, and hydraulic efficiency. Additionally, the effects of factors such as valve size, valve configuration, and fluid properties (water) on performance were considered. It was found that the non-return multi-door reflux valve has been proven effective and reliable in preserving system integrity and maintaining unidirectional flow at the same time during pressure testing. It exhibits no backflow, remains stable and constant across varied flow conditions, and demonstrates a low pressure drop and high flow capacity, making it suitable for critical pressure testing applications. The response curve revealed that valve opening takes longer to reach higher flow rates than closing, indicating pressure instability during transition periods. This non-linear relationship indicates possible irregularities in pressure drop response to flow rate changes, highlighting potential areas for further investigation.

Supra-Annular Self-Expanding Versus Balloon-Expandable Valves for Valve-in-Valve Transcatheter Aortic Valve Replacement

Self-expanding (SE) and balloon-expandable (BE) transcatheter heart valves (THVs) have not been extensively studied in valve-in-valve transcatheter aortic valve replacement (ViV-TAVR). We compared outcomes of supra-annular SE and BE THVs used for ViV-TAVR via a retrospective analysis of institutional data (2013-2023) including all patients undergoing ViV-TAVR (TAVR in previous surgical AVR). Unmatched and propensity-matched (1:1) comparisons of clinical and echocardiographic outcomes were undertaken between SE and BE THV along with Kaplan-Meier survival analysis. A total of 315 patients undergoing ViV-TAVR were included of which 73% received a SE THV. Median age was 77 years and women comprised 42.5% of the population. Propensity-score matching (1:1) yielded 81 matched pairs. Implanted aortic valve size was comparable between the groups (23 mm [23-26] vs. 23mm [23-26], p=0.457). At 30 days following ViV-TAVR, the SE group had a lower mean aortic valve gradient (14 mmHg [11-18] vs. 17.5 mmHg [13-25], p=0.007). A higher number of BE patients had severe prosthesis-patient mismatch (PPM) (16% vs. 6.2%, p=0.04). At one-year follow-up, the SE group had a lower aortic valve gradient (14.0 mmHg [9.6-19] vs. 17 mmHg [13-25], p=0.04) compared to the BE group. 30-day mortality was 2.7% while one-year mortality was 7.5% and comparable between the groups. Survival and stroke incidence were similar in both groups up to 5 years. In conclusion, both SE and BE THVs had comparable survival following ViV-TAVR. The higher residual aortic valve gradients in BE THVs are likely due to valve design and warrant long-term evaluation for potential structural valve degeneration.

Balloon-Expandable vs Self-Expanding Valves for Transcatheter Treatment of Sievers Type 1 Bicuspid Aortic Stenosis.

Balloon-expandable valves (BEVs) and self-expanding valves (SEVs) have different features that may impact the outcomes of patients with Sievers type 1 bicuspid aortic valve (BAV) stenosis undergoing transcatheter aortic valve replacement. This study sought to compare procedural and clinical outcomes of BEVs and SEVs in Sievers type 1 BAV stenosis. AD-HOC (Characteristics, Sizing, and Outcomes of Stenotic Raphe-Type Bicuspid Aortic Valves Treated With Transcatheter Device Implantation) is an observational registry enrolling patients with Sievers type 1 BAV stenosis undergoing transcatheter aortic valve replacement with current-generation BEVs and SEVs at 24 international centers. A 1:1 propensity score matching analysis was performed to adjust for baseline imbalances. The primary endpoint was midterm major adverse events, defined as a composite of all-cause death, neurologic events, or hospitalization for heart failure. Among 955 eligible patients, propensity score matching resulted in 301 pairs. At a median follow-up of 1.3years, BEVs and SEVs had a similar risk of major adverse events (BEV vs SEV: HR: 0.75; 95%CI: 0.49-1.16; P = 0.200). Technical success was similar (OR: 1.38; 95%CI: 0.63-3.04; P = 0.421). At 30days, BEVs were associated with a lower risk of new permanent pacemaker implantation (OR: 0.42; 95%CI: 0.24-0.72; P = 0.002) and moderate or greater paravalvular regurgitation (OR: 0.16; 95%CI: 0.05-0.48; P = 0.001) but a higher risk of severe patient-prosthesis mismatch (OR: 3.03; 95%CI 1.02-8.95; P = 0.045). Current-generation BEVs and SEVs proved similar technical success and midterm clinical efficacy in Sievers type 1 BAV stenosis. Compared to SEVs, BEVs were associated with less permanent pacemaker implantation and moderate or greater paravalvular regurgitation but with more severe patient-prosthesis mismatch.

Trends and Outcomes of Aortic Root Enlargement During Bioprosthetic Aortic Valve Replacement

BackgroundAortic root enlargement (ARE) during aortic valve replacement (AVR) mitigates prosthesis-patient mismatch, but its use has been low. Transcatheter aortic valve-in-valve (VIV) as a treatment for failing bioprosthetic valves is limited by small surgical valves, renewing interest in ARE during the index AVR. This study demonstrates trends and outcomes of ARE after commercial approval of VIV in 2015. MethodsThis retrospective cohort study analyzed 2182 patients undergoing nonemergent AVR between August 2007 and December 2022. Endocarditis, aortic dissection, and concomitant root replacement or ventricular assist device placement were excluded. Trends in ARE use, valve size, and types were compared. Outcome measures included 30-day mortality and gradients and were compared between patients with and without ARE. ResultsOverall, 74 patients (3.4%) underwent ARE, 14 (1.0%) before 2015 and 60 (7.6%, P < .0001) after 2015. Use of smaller valves (19-21 mm) decreased from 372 (26.8%) before 2015 to 85 (10.7%, P < .0001) after 2015. ARE group was younger than the AVR-alone group (64 vs 68 years, P = .001) but had similar predicted risk of mortality (median, 1.7%). Both groups had comparable postoperative mean gradients (ARE: 11 vs AVR-alone: 10 mm Hg, P = .42). ARE had higher 30-day mortality (5 [7%] vs 48 [2%], P = .014); however, no difference was found in elective patients (2 of 65 [3%] vs 39 of 1898 [2%], P = .57). ConclusionsARE use has increased since commercial approval of VIV. The addition of ARE to AVR did not affect early safety in elective cases, and postoperative gradients were similar to those in patients not requiring ARE. Further studies are required to determine long-term outcomes after ARE, including VIV candidacy.

Construction of virtual airway model to assist surgical correction of velopharyngeal insufficiency with posterior pharyngeal flap

ObjectivePosterior pharyngeal flap (PPF) is one of the most common surgical technique to correct velopharyngeal insufficiency(VPI), during which controlling the sizes of the lateral pharyngeal ports(LPP) is the key to outcomes. One innovative procedure was developed to well control the size of LPP. Materials and methods40 patients with repaired cleft palate were collected from June 2022 to August 2023. All patients were diagnosed with VPI, and treated with modified PPF surgery. For each patient, upper airway model was reconstructed, and the virtual airway model of PPF was designed. The nasal valve area was measured as it was considered to be the narrowest part of the upper airway. The upper airway resistances under different sizes of LPP was predicted through computational fluid dynamics analysis. The minimum size of each lateral pharyngeal port without obviously increase of upper airway resistance was calculated through effect of lateral pharyngeal ports’ size on upper airway resistance. Postoperative follow-up was 6–18 months, including speech outcome and respiration outcome. Resting soft palate length (RVL), effective working length of soft palate (EWL) and angle of soft palate elevation (AVL) were measured and compared according to the lateral cephalometric radiograph. ResultsThere was a linear relationship between the threshold value and nasal valve (R = 0.62). Among the forty patients, the average size of nasal valve was 47.81 mm2, the average size of the threshold value of LPP was 31.63mm2. The proportion of velopharyngeal closure competence after surgery was 95 %. Compared with the preoperative measurements, there were significantly increase of RVL, EWL and AVL (P < 0.05). There were significantly difference in the nasal obstruction symptom evaluation score in long-term follow-up compared to short-term follow-up (P < 0.05), and no one needed flap revision. There was no significant difference in nasal respiration and nasal resistance before and after surgery (P > 0.05). ConclusionWith the help of computer fluid dynamics analysis, it is possible to predict the threshold size of lateral pharyngeal port without obviously increasing upper airway resistance and reduce the risk of suffering from airway obstruction for patients undergoing PPF surgery.

Comparison of four aortic bioprostheses: Hancock II vs. St Jude Trifecta vs. Carpentier-Edwards Perimount Magna vs. Magna Ease-mid-term results (COMPARE SAVR study).

In the era of percutaneous aortic valve implantation, biological valves are the preferred prostheses implanted in patients undergoing surgical aortic valve replacement (sAVR). The aim was to present a real-life analysis of mid-term sAVR outcomes for the four aortic bioprostheses: the Hancock II, the Carpentier-Edwards Perimount Magna, the Carpentier-Edwards Perimount Magna Ease and the Trifecta valve. This is a retrospective study based on data from the Polish National Cardiac Surgery Database. The study population comprised of 1,589 consecutive patients, of whom 432 were in the Hancock II group, 356 in the Carpentier-Edwards Perimount Magna group, 427 in the Carpentier-Edwards Magna Ease group, and 374 in the Trifecta group. A comparison of the four groups was performed using analysis of variance (ANOVA) or Kruskal-Wallis test with appropriate post hoc tests (Tukey HSD or Steel-Dwass, respectively). Patients in the Hancock II group were older, had higher New York Heart Association (NYHA) and Canadian Cardiovascular Society (CCS) classes, had lower prevalence of hypertension and hyperlipidemia but higher prevalence of diabetes. The lowest mean valve size was observed in Trifecta group and the highest was in the Magna group (P<0.001). Survival analysis showed no significant differences in in-hospital mortality: 3.9% in Hancock II, 3.1% in Perimount, 3.3% in Magna and 2.1% in Trifecta group. Five-year mortality was significantly higher in Hancock II group (25.7%) compared to the other bioprostheses: 12.1% in Perimount, 9.1% in Magna and 10.70% in Trifecta group respectively. The 5-year mortality rate was significantly higher in the Hancock II group compared to the other bioprostheses. In contrast, Trifecta, Perimount Magna, and Magna Ease had similar 5-year mortality rates.

Mechanical Characteristics and Miniaturization Design of the Electromagnetic Valve Used in Drilling Robots

The maximum radial size of the conventional three-bit four-way electromagnetic cartridge valve is greater than the largest containable size of the fluid control valve used for downhole robots. This paper proposes two kinds of solutions to reduce the radial dimension of the three-bit four-way electromagnetic insertion valve: one is to reduce the radial arrangement of the coil and increase the axial arrangement of the coil, and the other is to reduce the diameter of the moving iron core to reduce the winding radius of the coil. Using the theoretical model established in the following text, a simulation experiment was conducted. The results show that the movement of the valve spool is basically completed within 30 ms. Then, a matching experiment on the electromagnetic insertion valve was designed and conducted. The experimental results show that the opening time of the solenoid valve on the left coil is about 52 ms, and the opening time of the solenoid valve on the right coil is about 44 ms. The reaction time of the valve spool is suitable for the practical application of the solenoid valve. The significance of this paper is the reduced radial size of the three-bit four-way electromagnetic insertion valve. These improvements have reduced the size of downhole drilling robots, which facilitates the application of downhole drilling robots in narrower environments.

A Novel Protocol for Contrast-Free Transcatheter Aortic Valve Replacement Evaluation and Implantation

BackgroundWe aimed to develop a transcatheter aortic valve replacement (TAVR) sizing algorithm and implantation method to facilitate safe and effective TAVR without contrast use in patients with severe chronic kidney disease (CKD) who do not yet require renal replacement therapy. Patients with CKD are a challenging patient subset to treat using standard TAVR care pathways which most usually require the use of iodinated contrast media both during gated computed tomography (CT) angiography sizing, and valve deployment. Iodinated contrast exposure may worsen kidney function in a dose-dependent fashion, and may result in a need for renal replacement therapy. Therefore, a method to eliminate, or greatly lessen, contrast exposure during TAVR is highly desirable. MethodsOne hundred sixty patients who underwent standard CT angiography and TAVR implantation were used to develop (100 patients) and validate (60 patients) an algorithm to predict balloon-expandable valve size using measurements available from noncontrast CT. Model accuracy was measured using Pearson correlation between algorithm-predicted valve size and actual size used based on annular area. As proof of concept, we then report a case series of 35 consecutive patients who underwent TAVR evaluation and implantation with moderate sedation and no contrast between May 2021 and April 2024. ResultsThe valve sizing algorithm incorporates sinus and sinotubular junction diameters, both available from a reformatted noncontrast, cardiac-gated CT. The algorithm demonstrated a strong correlation with the actual valve size used (development cohort R = 0.81, validation cohort R = 0.76). Thirty-five patients underwent “no-contrast TAVR” with noncontrast CT for valve sizing. Forty-eight percent were urgent inpatient TAVR. Technical procedural success, as defined by the VARC3 criteria, was 100%, with no patient deaths during the index procedure. Three patients had a mild paravalvular leak. No valve embolization or need for a second valve occurred. Four patients required a pacemaker. ConclusionsWe present a novel algorithm for TAVR evaluation and implantation without the use of iodinated contrast media in a high-risk patient subset with CKD.

Transcatheter Valve-in-Valve Replacement With Balloon- Versus Self-Expanding Valves in Patients With Degenerated Stentless Aortic Bioprosthesis

Valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR) has been associated with favorable outcomes in patients with degenerated stentless bioprosthesis. However, whether the outcomes after ViV TAVR for failed stentless bioprosthesis differ between balloon-expandable valves (BEVs) and self-expanding valves (SEVs) remains unknown. Therefore, we retrospectively analyzed 59 consecutive patients who underwent ViV TAVR for failed stentless bioprsothesis with BEVs (n = 42) versus SEVs (n = 17) in a single-health care system between 2013 and 2022. Overall, the mean age was 70.8 years and 74.6% were men. The mean transcatheter valve size was 26.3 ± 2.2 mm for BEVs and 26.4 ± 4 mm for SEVs (p = 0.93). The mean Society of Thoracic Surgeons score was 6.0 ± 3.6 for BEVs and 7.5 ± 5.5 for SEVs (p = 0.22). Compared with patients who received BEVs, those who received SEVs had higher rates of device malposition (2.4% vs 23.5%, p <0.01), postdeployment balloon dilation (11.9% vs 35.5%, p = 0.04) and need for a second transcatheter device (2.4% vs 35.5%, p <0.01). However, both groups showed similar improvement in aortic valve function at 30-day and 1-year follow-up (incidence of 1-year severe patient-prosthesis mismatch in BEVs: 17.6% vs 14.3% in SEVs, p = 0.78). The 1- and 3-year mortality did not differ between BEVs and SEVs (11.9% vs 11.8% and 25% vs 30%, respectively, Log rank p = 0.9). In conclusion, performing ViV TAVR for failed stentless bioprsothesis is technically challenging, especially when using SEVs; however, satisfactory positioning is possible in most cases, with excellent hemodynamic and clinical outcomes with BEVs and SEVs.

Transjugular Transcatheter Tricuspid Valve Replacement: Early Compassionate Use Outcomes

BackgroundData on procedural and early outcomes after transjugular transcatheter tricuspid valve replacement (TTVR) are limited. ObjectivesThis study sought to evaluate first-in-man procedural and clinical outcomes after transjugular TTVR with a special focus on patients who received large device sizes in whom TTVR outcomes have been questioned. MethodsThe retrospective registry included patients who underwent TTVR using the LuX-Valve Plus system (Jenscare Biotechnology Co Ltd) for symptomatic tricuspid regurgitation (TR) from January 2022 until February 2024 at 15 international centers in a compassionate use setting. The endpoints were procedural TR reduction, in-hospital death, adverse events, and 1-month survival. We further stratified results according to the size of the implanted device (<55 vs ≥55 mm). ResultsThe registry included a total of 76 patients at a median age of 78 years (Q1-Q3: 72-83 years, 47.4% women). TR was reduced to ≤2+ and ≤1+ in 94.7% and 90.8% of patients (75.0% of patients received TTVR devices ≥55 mm) with well-sustained results at 1-month follow-up (TR ≤2+ in 95.0% and ≤1+ 86.8%). Residual TR was paravalvular in all cases. In-hospital death occurred in 4 patients (5.3%). Four patients (5.3%) underwent cardiac surgery during index hospitalization. Major in-hospital bleeding events occurred in 5 patients (6.6%). New in-hospital pacemaker implantation was required in 3.9% of patients in the overall cohort (5.7% in “pacemaker-naive” individuals). No cases of valve thrombosis, stroke, myocardial infarction, or pulmonary embolism were observed. At 1-month follow-up, survival was 94.4%, and NYHA functional class significantly improved. One further patient received a pacemaker, 1 further bleeding event occurred, and 2 patients underwent reintervention or surgery within the first 30 days after TTVR. No differences in procedural outcomes or adverse events were observed after stratification for valve size. ConclusionsTransjugular TTVR appears to be a safe and effective treatment option for patients with severe TR with comparable outcomes in very large tricuspid anatomies.

Utilizing a sutureless valve for prosthetic valve endocarditis after aortic root replacement

BackgroundReoperation following aortic root replacement is associated with significantly high operative mortality. Etiologies related to infection are known to increase the operative mortality rate more than other etiologies. In such a clinical setting, a sutureless valve could lower the operative mortality by shortening the cardiac arrest and the operative time.Case presentationA 61-year-old male underwent emergent aortic root and total arch replacement with an open stent graft for acute type-A aortic dissection. A bioprosthetic valve was employed for aortic root replacement using the double-sewing ring technique. A fungal infection by Candida parapsilosis was postoperatively detected and improved with intravenous antifungal drug administration. However, he developed congestive heart failure one year later, and the blood cultures turned positive repeatedly for Candida parapsilosis. The prosthetic valve infection was suspected upon identifying vegetation on the bioprosthetic valve through transthoracic echocardiography. The computed tomography scan and operative findings confirmed that the infection was localized on the prosthetic valve. Consequently, the infected valve was removed without a vascular conduit, and a sutureless valve was implanted. The postoperative course was uneventful, without any evidence of recurrent fungal infection, and the patient was discharged on postoperative day 28.ConclusionsDeploying a sutureless valve can facilitate a more straightforward and minimally invasive redo procedure. Preoperative computed tomography can predict the valve size, which is the key to implanting a sutureless valve successfully after the modified Bentall procedure.

Von Willebrand Factor Dynamics in Patients with Aortic Stenosis Undergoing Surgical and Transcatheter Valve Replacement.

Aortic stenosis (AS) is a prevalent valvular disorder that poses a significant burden on healthcare systems due to its debilitating symptoms and high mortality rates if left untreated. Surgical aortic valve replacement (SAVR) and transcatheter aortic valve replacement (TAVR) are the primary interventions for severe AS, but perioperative complications such as bleeding remain a concern. Von Willebrand factor (VWF), a crucial player in hemostasis, is known to be altered in AS and may contribute to the hemostatic imbalance observed in these patients. This prospective study aimed to investigate the association between prosthetic valve type, size, and postprocedural VWF levels in patients undergoing aortic valve replacement (AVR) for severe AS. This study involved 39 consecutive patients diagnosed with severe AS who underwent SAVR or TAVR. By elucidating the VWF dynamics associated with different prosthetic valves, this study sought to provide valuable insights into personalized valve selection and perioperative management strategies.

Feasibility, Accuracy, and Reproducibility of Aortic Valve Sizing for Transcatheter Aortic Valve Implantation Using Virtual Reality.

Detailed visualization and precise measurements of aortic valve dimensions are critical for the success of transcatheter aortic valve implantation and for the prevention of complications. Currently, multislice computed tomography is the gold standard for assessment of the aortic annulus and surrounding structures to determine the prosthesis size. New technologies such as virtual reality (VR) not only enable 3-dimensional (3D) visualization with the potential to improve understanding of anatomy and pathology but also allow measurements in 3D. This study aims to investigate the feasibility, accuracy, and reproducibility of VR for the visualization of the aortic valve, the surrounding structures, and its role in preprocedural sizing for transcatheter aortic valve implantation. Based on the preprocedural multislice computed tomography data, 3mensio measurements and 3D visualizations and measurements using VR software were performed retrospectively on 60 consecutive patients who underwent transcatheter aortic valve implantation at our heart center. There were no significant differences but strong correlations between the VR measurements compared with those performed with the 3mensio software. Furthermore, excellent or good intra- and interobserver reliability could be demonstrated for all values. In a structured questionnaire, users reported that VR simplified anatomical understanding, improved 3D comprehension of adjacent structures, and was associated with very good self-perceived depth perception. The use of VR for preprocedural transcatheter aortic valve implantation sizing is feasible and has precise and reproducible measurements. In addition, 3D visualization improves anatomical understanding and orientation. To evaluate the potential benefits of 3D visualization for planning further cardiovascular interventions, research in this field is needed.

Identifying the influence of airbag structure on driver injury during a crash using a dummy model

This study undertakes the analysis of collision scenario using a car model with a dummy and airbags, in the event of a direct collision with a hard wall, one of the necessary studies of passive safety. To describe in detail, the input conditions, a simulation problem of the driver's seat displacements was performed and this displacements data was exported as boundary conditions for the collision simulation. The results simulation crash show that the calculated energy values and simulation results are approximately the same (7.381E+07 and 7.367E+07), energy is converted from kinetic energy into internal energy of the elements. The airbag deployment simulation results are similar to NHTSA's previous research, both in terms of graph shape and maximum value. The impact of the collision incident on the driver is not excessively large, as evidenced by surveys on head (HIC 300), thigh (F 2.8 kN), and neck (F3,098 kN; T 190 Nm) injuries. However, the study proceeds to further analyze and assess the airbag's structure, examining its influence on these metrics, concluding that changes in the exhaust valve size (increase from 1000 mm2 to 2000 mm2) lead to a reduction in the evaluated parameters. These results suggest changes to the airbag structure to enhance driver safety, as well as a simpler simulation model to save analysis time

Predicted prosthesis–patient mismatch and long-term clinical outcomes after transcatheter aortic valve replacement: A SWEDEHEART study

BackgroundThe impact of prosthesis–patient mismatch (PPM) after transcatheter aortic valve replacement (TAVR) is uncertain. This study was performed to investigate the risk of all-cause mortality, heart failure hospitalization, and aortic valve reintervention in patients with and without predicted PPM after TAVR. MethodsThis nationwide, population-based cohort study included all patients who underwent transfemoral primary TAVR in Sweden from 2008 to 2022 in the SWEDEHEART register. PPM was defined according to published effective orifice areas for each valve model and size. The patients were divided into those with and without PPM. Additional baseline characteristics and outcome data were obtained from other national health data registers. Regression standardization was used to adjust for intergroup differences. ResultsOf 8485 patients, 7879 (93%) had no PPM and 606 (7%) had PPM. The crude cumulative incidence of all-cause mortality at 1, 5, and 10 years in patients with versus without PPM was 7% versus 9%, 40% versus 44%, and 80% versus 85%, respectively. After regression standardization, there was no between-group difference in long-term mortality, and the absolute difference at 10 years was 1.5% (95% confidence interval, −2.9%–6.0%). The mean follow-up was 3.0 years (maximum, 14 years). There was no difference in the risk of heart failure hospitalization or aortic valve reintervention. ConclusionsThe risk of all-cause mortality, heart failure hospitalization, or aortic valve reintervention was not higher in patients with than without predicted PPM following TAVR. Furthermore, PPM was present in only 7% of patients, and severe PPM was almost nonexistent.

Radiation exposure of patients undergoing transcatheter aortic valve implantation and factors contributing to it

Abstract Background/ Introduction Aortic stenosis (AS) is a calcific disease which affects the aortic valve leaflets and is commonly prevalent in people who are 65 years and older. The global burden of AS is expected to keep on increasing due to the longer life expectancy as well as the morbidity and mortality associated with the disease. Transcatheter aortic valve implantation is utilised for the management of AS. Currently, TAVI is recommended as a first-line treatment for patients who are 75 years and older and those who are at an intermediate to high surgical risk, with the aim of becoming the first treatment option for patients who are 65 years and older. However, one of the concerns of TAVI is the need of ionising radiation during valve placement. The study of exposure to ionising radiation in the TAVI population is becoming progressively more important to consider due to the broader population being considered and the long-term effects related to radiation. Purpose Locally there was no data available covering this topic, thus the aim of the study was to quantify the radiation dose that patients receive during TAVI procedures and to determine any procedural and patient factors that contribute to this radiation dose. Methods Retrospective data analysis was performed for procedures effected between January 2019 and December 2022. All the patients that underwent a transfemoral (TF) TAVI and fit within the inclusion criteria were included in the study. The data was collected from medical databases and underwent a process of data cleaning before information relating to patient and procedural characteristics was extracted. Data about percutaneous coronary interventions (PCI) that were performed during the same time period by the same operators was collected for comparison purposes. Results In total the data of 241 TAVI patients was analysed. Dose Area Product (DAP) was the main radiation metric utilised to quantify the radiation dose. Non-parametric statistical tests were performed due to right-skewedness. The median (IQR) DAP for these procedures was 9000 cGym2 (5975-13150) and the median (IQR) fluoroscopy time was 18.25 minutes (15, 23.5). The years 2019 and 2020 had the lowest median DAP. The DAP obtained in this study is lower than the European DRLs of 13000 cGym2. The median (IQR) DAP (5320cGym2 (2385-9860)), and fluoroscopy time (13.75 mins (8.25-21.62)) for PCIs were lower than for TAVI and this difference is statistically significant (P = &amp;lt;0.001). DAP was not significantly related only to age category and the operator’s combination. Generalised linear models (GLM) showed that prosthetic valve size, body surface area (BSA) and aortic valve gradient are statistically significant predictors of DAP. Conclusion This study shows that the local TAVI patients receive a radiation dose which is within acceptable European limits and that valve size and patient’s BSA are the variables that impacted the radiation dose.

A single-coil-driven tristable electromagnetic mini valve with multiple working states

Electromagnetic mini valves have attracted great interest in medical devices for their excellent performance and high integration. In state-of-the-art research, most mini valves have only two working states, while certain ones featuring three to four working states necessitate multiple driving sources. To solve these problems, a novel tristable electromagnetic mini valve with three stable working states achieved by a single coil was proposed. The actuation mechanism of this mini valve mainly comprises a cylindrical magnet (CM) and a ring magnet (RM) coaxially arranged. In the absence of current through the coil, the stability of the magnets is upheld by their mutual repulsion and the attraction of the iron core. Upon modifying both the magnitude and orientation of the current, one of the magnets traverses from one terminus to another each time. The two magnets are either stationary at the start point or the endpoint. Thereby, four position relationships are formed, three of which are stable. The minimum response time and energy consumption are 3.75 ms and 0.013 J, respectively. The working pressure of the valve ranges from 0 to 200 kPa. The maximum flow rate and back pressure reach 10.5 L/min and 180 kPa, respectively. A tristable design contributes to lower energy consumption, and the three-working-state function actuated by a single coil facilitates a diminution in the size of the mini valve. Consequently, a diminished quantity of valves is realized for multiple degree-of-freedom pneumatic actuator control, which promotes the miniaturization of the whole system. The dimensions and performance of the proposed mini valve substantiate its potential in pneumatic medical devices.

Effect Of Transcatheter Heart Valve Size And Deployment Height On Coronary Flow Obstruction

Coronary artery disease (CAD) is commonly found in patients with aortic stenosis; therefore, its prevalence is high in patients that are candidate for transcatheter aortic valve replacement (TAVR). As the TAVR procedure is expanding into younger and lower-risk population, the importance of early CAD monitoring and detection, as well as determination of potential impact of implant design or deployment strategy on CAD progression is of great importance. In this study, we investigate the effect of transcatheter heart valve (THV) size and deployment height on coronary flow obstruction during normotensive hemodynamic flow conditions. We employ unsteady, pulsatile flow, generated by a left heart model, and utilize clinically relevant geometry, pressure, and flow waveforms. Of particular interest is to understand the interaction between THV and anatomy regarding coronary flow obstruction. For a wide range of parameters, we examine two distinct THV deployment scenarios: nominal deployment – high coronary blockage (ND-HCB), and high deployment – low coronary blockage (HD-LCB). Additionally, we investigated the impact of the locations of coronary ostia and THV commissure alignment onto the risk of coronary flow obstruction. With the aid of 2D-2C particle image velocimetry (PIV), the distinctive flow patterns within the aortic sinus space are identified from the response of the flow to the presence of THV. Comparison between two THV deployment scenarios revealed that ND-HCB configurations lead to formation of stagnant flow zones, while the HD-LCB configuration provided an adequate washout of the entire coronary sinus. The optimal washout of the aortic root sinus is achieved when the distance between native leaflets and coronary ostia is maximized. Furthermore, results showed that up to 4% improvement in the coronary flow rate can be achieved if commissure alignment procedure is performed. As the coronary artery obstruction phenomenon is additive in its nature, a pre-existing stenotic condition in association with suboptimal THV deployment may lead to increased risk of full coronary blockage and immediate need for coronary intervention. In conclusion, this study using an experimental coronary assessment tool may provide potential insights to inform pre-procedural TAVR strategies in challenging patients’ anatomies, thereby maximizing the associated benefit.