Hemodynamic Performance Research Articles

Decellularization Following Fixation of Explanted Aortic Valves as a Strategy for Preserving Native Mechanical Properties and Function.

Mechanical or biological aortic valves are incorporated in physical cardiac simulators for surgical training, educational purposes, and device testing. They suffer from limitations including either a lack of anatomical and biomechanical accuracy or a short lifespan, hence limiting the authentic hands-on learning experience. Medical schools utilize hearts from human cadavers for teaching and research, but these formaldehyde-fixed aortic valves contort and stiffen relative to native valves. Here, we compare a panel of different chemical treatment methods on explanted porcine aortic valves and evaluate the microscopic and macroscopic features of each treatment with a primary focus on mechanical function. A surfactant-based decellularization method after formaldehyde fixation is shown to have mechanical properties close to those of the native aortic valve. Valves treated in this method were integrated into a custom-built left heart cardiac simulator to test their hemodynamic performance. This decellularization, post-fixation technique produced aortic valves which have ultimate stress and elastic modulus in the range of the native leaflets. Decellularization of fixed valves reduced the valvular regurgitation by 60% compared to formaldehyde-fixed valves. This fixation method has implications for scenarios where the dynamic function of preserved valves is required, such as in surgical trainers or device test rigs.

Biological Valves Impervious to Calcification: Is this Holy Grail a Cup Ready to Drink?

An indefinitely lasting bioprosthesis that does not require anticoagulation treatment is the holy grail of substitutive heart surgery. However, this goal is not yet in sight with the present state of technology. Over the past few years, tremendous advances have been achieved regarding tissue anticalcification processes, hemodynamic performance and future-proofing by ensuring compatibility with transcatheter valve-in-valve procedures. The Inspiris Resilia valve (Edwards Lifesciences, Irvine, CA) was designed to incorporate all of these enhancements. It is now leaving the experimental phase and is being tested in the real world. We present here a comprehensive review of the evolution of biological prostheses, details of new anticalcification technologies, and early results of published studies as well as the experience at the European Hospital (Rome, Italy), the site of the first European implant and a leading center in various protocols. In our two years of experience with the Inspiris Resilia, there have been no cases of structural valve deterioration, endocarditis, detachment or periprocedural complication, and gradients seem to be superior to those with the previous generation of Edwards valves. While longer-term experience is clearly needed, the results thus far are encouraging.

Fluid-structure interaction simulation of calcified aortic valve stenosis.

Calcified aortic valve stenosis (CAVS) is caused by calcium buildup and tissue thickening that impede the blood flow from left ventricle (LV) to aorta. In recent years, CAVS has become one of the most common cardiovascular diseases. Therefore, it is necessary to study the mechanics of aortic valve (AV) caused by calcification. In this paper, based on a previous idealized AV model, the hybrid immersed boundary/finite element method (IB/FE) is used to study AV dynamics and hemodynamic performance under normal and calcified conditions. The computational CAVS model is realized by dividing the AV leaflets into a calcified region and a healthy region, and each is described by a specific constitutive equation. Our results show that calcification can significantly affect AV dynamics. For example, the elasticity and mobility of the leaflets decrease due to calcification, leading to a smaller opening area with a high forward jet flow across the valve. The calcified valve also experiences an increase in local stress and strain. The increased loading due to AV stenosis further leads to a significant increase in left ventricular energy loss and transvalvular pressure gradients. The model predicted hemodynamic parameters are in general consistent with the risk classification of AV stenosis in the clinic. Therefore, mathematical models of AV with calcification have the potential to deepen our understanding of AV stenosis-induced ventricular dysfunction and facilitate the development of computational engineering-assisted medical diagnosis in AV related diseases.

POSC111 Cost-Minimization Analysis of Bovine and Porcine Bioprosthetic Aortic Valves for the Treatment of Severe Aortic Stenosis in Colombia

Surgical Aortic Valve Replacement (SAVR) is the recommended treatment for severe aortic stenosis according to current guidelines in Latin America. The most commonly bioprosthetic valves used today are from porcine or bovine tissue. Regarding the valve selection rational , previous studies have reported superior hemodynamic performance using bovine compared with porcine valves and long-term outcomes have been recently reported. Additionally, considering the current restricted budget scenario, a rational resource utilization is vital. Therefore, the aim of this study was to conduct a long-term costs study of both bovine and porcine valves in Colombia from a public payers perspective. A cost-minimization analysis was carried out based in a Markov model with annual cycle length to estimate costs associated to each alternative over a 15-year time horizon. The model and the transition probabilities were based in the long-term clinical results previously reported in a previous study and were validated with local clinical experts. Considered costs included the initial procedure, the valves, standard monitoring, and reoperation. A 3.5% annual discount rate was considered according to local guidelines. All costs were estimated using the Social Security (Instituto del Seguro Social) Rates Manual and are presented in 2021 COP. Bovine valves presented a cost difference of -$1,149,865 COP versus porcine valves over the 15-year time horizon, which makes them a cost-saving alternative. Bovine valves were associated to $32,031,426 COP whereas porcine valves to $33,181,291 and the main cost driver between both alternatives was the reoperation rate. Savings associated to bovine valves were presented after the 10th year. From a public healthcare payer perspective, using bovine valves in SAVR patients could represent savings after the 10th year for the Colombian healthcare system. Considering the inevitable epidemiological transition, a rational use of resources is relevant, today more than ever.

Semi-Automatic Planning and Three-Dimensional Electrospinning of Patient-Specific Grafts for Fontan Surgery.

This paper proposes a semi-automatic Fontan surgery planning method for designing and manufacturing hemodynamically optimized patient-specific grafts. Fontan surgery is a palliative procedure for patients with a single ventricle heart defect by creating a new path using a vascular graft for the deoxygenated blood to be directed to the lungs, bypassing the heart. However, designing patient-specific grafts with optimized hemodynamic performance is a complex task due to the variety of patient-specific anatomies, confined surgical planning space, and the requirement of simultaneously considering multiple design criteria for vascular graft optimization. To address these challenges, we used parameterized Fontan pathways to explore patient-specific vascular graft design spaces and search for optimal solutions by formulating a nonlinear constrained optimization problem, which minimizes indexed power loss (iPL) of the Fontan model by constraining hepatic flow distribution (HFD), percentage of abnormal wall shear stress (%WSS) and geometric interference between Fontan pathways and the heart models (InDep) within clinically acceptable thresholds. Gaussian process regression was employed to build surrogate models of the hemodynamic parameters as well as InDep and [Formula: see text] (conduit model smoothness indicator) for optimization by pattern search. We tested the proposed method on two patient-specific models (n=2). The results showed the automatically optimized (AutoOpt) Fontan models hemodynamically outperformed or at least are comparable to manually optimized Fontan models with significantly reduced surgical planning time (15 hours versus over 2 weeks). We also demonstrated feasibility of manufacturing the AutoOpt Fontan conduits by using electrospun nanofibers.

Transapical-transcatheter aortic valve implantation using the Edwards SAPIEN 3 valve.

Scarcely any data has been published on the mid-term effect of transapical-transcatheter aortic valve implantation (TA-TAVI) using the Edwards SAPIEN 3 valve (S3; Edwards Lifesciences Corp., Irvine, CA, USA). We present mid-term clinical and echocardiographic outcomes after TA-TAVI utilizing S3. Between 02/2014-06/2017, 122 elderly patients with severe aortic stenosis underwent TA-TAVI utilizing S3 at our institution. We conducted clinical and echocardiographic follow-up. The mean follow-up was 15 months. All end-point-related outcomes were adjudicated according to Valve Academic Research Consortium-2 definitions. The STS-score of the entire cohort was 6.26±4.6. More than one-third of the patients exhibited severe peripheral artery disease. The 30-d all-cause mortality, all-stroke rate, and myocardial infarction of the entire cohort were 4.1%, 1.6%, and 0.8% respectively. Median survival time of the entire cohort was 35 months. The cumulative mid-term myocardial infarction and stroke rate was 2.6% and 3.5%, respectively. The postoperative moderate/severe paravalvular leakage occurred in 1.6% of cases. At discharge, one-year and two-year postprocedure peak/mean gradients were 16.6±8.3/ 9±5.1 mmHg, 18±6.9/ 10±4.5 mmHg, and 22.2±5.4/ 12.8±4.6 mmHg, respectively. The rate of new pacemaker cases was 14.1%. Acute kidney injury network 2/3 appears, as an independent predictor of mortality. We observed very promising early and mid-term clinical outcomes with a high degree of device success and good hemodynamic performance after TA-TAVI using the S3 in the intermediate risk patient profile.

Transfermoral transcatheter aortic valve implantation using self-expanding Allegra bioprosthesis: One-year single-center outcomes.

BackgroundThe NAUTILUS study aimed to evaluate the safety and performance of the Allegra bioprosthesis in high-risk recipients undergoing transcatheter aortic valve implantation and previously reported 30-day outcomes. In the current investigation 1-year results of the trial are presented.MethodsTwenty-seven recipients with severe, symptomatic aortic valve stenosis at high surgical risk, who underwent treatment using the next-generation self-expanding Allegra via transfemoral approach were prospectively enrolled. Clinical endpoints assessed were: mortality, stroke, permanent pacemaker implantation, New York Heart Association class and re-hospitalizations. Prosthetic valve performance evaluation comprised of: mean gradient, effective orifice area and paravalvular leak.ResultsPatients were elderly (82.8 ± 4.2 years) and predominantly female (n = 19, 70.4%). All of them were deemed to be at high surgical risk with a mean logistic EuroSCORE of 12.5 ± 6.7. The bioprosthesis was successfully implanted in 92.6% of the cases (n = 25). At 1-year, all-cause mortality was 12.0% (n = 3) and stroke was 4.0% (n = 1). Three (12%) of patients developed complete atrioventricular block and received permanent pacemakers. 84% of patients were in New York Heart Association class II or lower. Need for subsequent hospitalization arose in 48% patients. The echocardiographic assessment confirmed an acceptable hemodynamic profile of the Allegra with low mean transprosthetic gradient (9.5 ± 3.4 mmHg), absence of severe paravalvular leak and a 20%-presence of moderate paravalvular leak.ConclusionsThe current follow-up observation study shows that the Allegra was associated with a satisfactory safety profile and hemodynamic performance at 1-year after implantation.

Comparative Early and Long Term Results of Mitral Valve Surgery between Right Mini Thoracotomy and Full Sternotomy Approach

Background: Conventional mitral valve surgery (MVS) requires median sternotomy. Right mini thoracotomy (RMT) MVS is an alternative non sternotomy approach aiming for less bleeding, pain reduction, rapid recovery, cosmetic satisfaction, safety and effectiveness of the procedure. Objectives: To report early and late clinical results comparing RMT versus full sternotomy (FS) MVS. Materials and Methods: 574 consecutive patients underwent MVS were prospectively non randomized reviewed during January 2002 to October 2018. There were 241 in FS group and 241 in RMT group by age and Euro II score matching. Baseline characteristics were compared. Early and late clinical outcomes of 30 days mortality, reoperation for bleeding, stroke, prolonged ventilation, renal failure, permanent pacemaker, and echocardiographic hemodynamic performance were assessed and compared between two groups. All patient follow-up to December 2020. Results: Similar results were found between RMT and FS MVS groups including age 58.8+13.6, 57.2+14.2, p=0.2, new AF 5 (2%), 4 (1.7%), p=1.0), except for more degenerative valve pathology (79%, 50%, p<0.001). There were more re operation for bleeding 2 (0.8%), 1 (0.3%), p=0.9, less aortic cross clamp time (107+37.3, 115.4+36.4, p=0.017), less cardiopulmonary bypass time (157.6+51.2, 171.3+53.4, p=0.005), less bleeding and blood transfusion requirement in the RMT group. Early clinical results of 30 days mortality, stroke, renal failure, new pacemaker, and hemodynamic performance at one month, three to six month, and one year were comparable in both groups. Mean follow-up (year) was 5.2+2.5 (RMT) and 10.2+4.0 (FS). Survival probability and freedom from MACCE at ten years in RMT and FS group were 94.05%, 95.44% and 99.5%, 90.46%, p<0.001, respectively. Conclusion: RMT approach for MVS is associated with cosmetic satisfaction, less bleeding, similar effective hemodynamic performance and non-inferiority early and late clinical results to FS approach. Keywords: Mitral valve surgery; Right mini thoracotomy

Two-Year Clinical Follow-Up Assessment of the Novel Cingular Surgical Bovine Pericardial Valve.

Objectives: To evaluate the 2-year clinical safety and hemodynamic outcomes of the Cingular bovine pericardial bioprosthesis.Methods: A prospective, multicenter, single-arm trial was conducted in patients who required aortic or mitral valve replacement. From March 2016 to October 2017, 197 patients were implanted with the Cingular bovine pericardial valve at five sites in China. The clinical outcomes and hemodynamic performance were assessed through a 2-year follow-up. Clinical safety events were reviewed by an independent clinical events committee, and echocardiographic data were assessed by an independent core laboratory.Results: The mean age was 66.9 ± 4.9 years. The 2-year survival rate was 96.4%. A complete 2-year clinical follow-up was achieved in 189 of 190 survivors. No case of structural valve deterioration, major perivalvular leak, prosthetic valve endocarditis, or valve-related reoperation was seen. For the aortic valve, the mean pressure gradient observed was 12.5 ± 4.0 mm Hg, and the effective orifice area (EOA) was 2.0 ± 0.3 cm2. For the smaller size aortic valves, 19 mm and 21 mm, respective mean EOA values of 1.7 ± 0.2 cm2 and 1.8 ± 0.2 cm2 were found. The values for mean pressure gradient and mean EOA for mitral bioprostheses were 4.0 ± 1.4 mm Hg and 2.2 ± 0.3 cm2, respectively. There was no significant change between 1-year and 2-year hemodynamic performance.Conclusions: The Cingular bovine pericardial valve showed favorable clinical safety and hemodynamic outcomes over a 2-year follow-up. Further follow-up is required to validate the long-term durability.

Experiencia inicial con prótesis aórtica transcatéter Portico™ Abbott. Una alternativa eficaz y versátil

ObjectiveTranscatheter aortic valve implantation is a good alternative for treatment of severe aortic valvulopathy. We present our initial experience with the Portico™ Abbott prosthesis at Centro Médico Teknon in Barcelona. Patients and methodsBetween February 2020 and June 2021, 30 patients underwent Portico™ Abbott transcatheter aortic prostheses implant (mean age: 75.7±3.1 years, 56.5% males). Twenty-nine underwent isolated valve replacement. One patient required associated coronary surgery. The approach was open surgical; transfemoral in 22 patients (73.3%), transaxillary in 4 (13.3%) and transcarotid in 4 (13.3%). The patients were studied at discharge and at 30 days. ResultsThe implant was successful in 100% of the patients. One patient (3.3%) died during the procedure due to cardiogenic shock. There were no vascular or neurological complications. In 3 patients (10.3%) it was necessary to implant a permanent pacemaker. Minimal residual leak in 10 (33.3%), mild in 7 patients (23.3%). Mean gradient: 5±0.8mmHg in native valves and 10.25±2.2mmHg in valve-in-valve cases. ICU stay 22.56±4h and post-procedure stay 4.1 days±0.8. Follow-up at 30 days without other complications. ConclusionsIn our initial experience, the Abbott™ Portico prosthesis has proven to be feasible, very effective and very versatile to adapt to scenarios of high technical complexity. The complications were low, the results satisfactory and the early haemodynamic performance excellent.

443 Arterial hypertension in aortic valve stenosis: a critical update

Abstract Aims Aortic stenosis (AS) is a very common valve disease and is associated with high mortality once it becomes symptomatic. Arterial hypertension (HT) has a high prevalence among patients with AS leading to worst left ventricle remodelling and faster degeneration of the valve. HT also seems to interfere with the assessment of the severity of AS leading to an underestimation of the real degree of stenosis. Treatment of HT in AS has historically been associated with reluctance due to both the lack of clear guidelines and the fear of adverse effects, but the most recent evidence shows as several drugs that can be used. Methods The pathophysiology of the combination of AS and HT is the association of a first fixed mechanical obstruction of the aortic root and a second obstruction due to systemic vascular resistance. Consequently, a decrease in systemic vascular resistance through, for example, the administration of vasodilators could theoretically cause a drop in systemic pressure due to the fixed mechanical obstruction given by the stenosis which prevents an increase in cardiac output. This theory was the basis for avoiding vasodilators in patients with AS. Results There is a unanimous opinion on maintaining blood pressure values of 130–139 mmHg of systolic and 70–90 mmHg of diastolic, but there is not the same agreement on which drugs to adopt to achieve the aforementioned values. Renin-Angiotensin-Aldosterone system inhibitors are certainly the first-line treatment thanks to their cardioprotective, plaque stabilizing, and antiarrhythmic effect since they are also associated with increased survival rates and greater left ventricular mass reduction in patients after surgical or transcatheter aortic valve replacement for severe AS. If blood pressure is not yet controlled, the addition of a beta-blocker should be considered: metoprolol has the greatest literature, showing not only an improvement in haemodynamic and metabolic performance but also a reduction in mortality in patients who already presented with coronary artery disease. Mineralocorticoid receptor antagonist can be used, among them eplerenone has been studied and can be useful to relieve symptoms of patients with a flare-up of heart failure by reducing the preload, provided that a close fluid and echocardiographic monitoring is implemented. Conclusions The use of phosphodiesterase 5 inhibitors can improve the haemodynamic status of patients with aortic stenosis and reduce the level of left ventricular hypertrophy, as well as improve pulmonary circulation and exercise tolerability of patients with AS, however it should be considered that in other studies sildenafil was associated with a worse clinical outcome. Calcium channel blocker are one the most used medications in patients with HT, but their use was associated with a 7-fold relative risk of all-cause mortality independent of known confounders and was also associated with an adverse effect on treadmill exercise and higher risk of all-cause mortality in patients with AS.

549 The role of conventional and speckle tracking echocardiography in the evaluation of leadless endocardial pacing with Micra-AV

Abstract Aims Micra-AV pacing system is a leadless pacemaker (LP) implanted in the right ventricle which can provide atrio-ventricular (AV) synchronous pacing. Echocardiographic data assessing left ventricle contractility 24–48 h after Micra AV implantation are lacking. To evaluate via conventional echocardiography and speckle-tracking echocardiography (STE), which was the best pacing modality (VVI vs. VDD) able to ensure the most efficient hemodynamic performance assessed by left ventricle ejection fraction (LF-EF) and global longitudinal strain (GLS). Methods and results We studied nine patients with high degree AV-block, enrolled in our Institution in a range of time of 5 months. All patients had first degree AV block (PQ interval between 160 and 340 ms). They were considered suitable candidates for MICRA-AV implantation according to current guidelines. Both LF-EF and GLS were performed 24–48 h after device implantation by two experienced echocardiographic physicians. The mean age of the population was 79 ± 8 years (8 were male, 89%). Risk factors more represented were hypertension and dyslipidaemia. The maximum PQ interval was 256 ± 51 ms. VDD pacing modality allows better LV-EF values than those obtained with a VVI stimulation (with a difference that was statistically significant difference, P-value = 0.008). Similarly, we obtained better GLS values during VDD pacing as respect to VVI (P-value = 0.008). Conclusions Left ventricle ejection fraction and LV-GLS improve early after leadless MICRA-AV implantation during VDD as compared to VVI pacing modality.

Dynamic Echocardiographic Assessments Reveal Septal E/e' Ratio as Independent Predictor of Intradialytic Hypotension in Maintenance for Hemodialysis Patients with Preserved Ejection Fraction.

Background: Intradialytic hypotension (IDH) is a frequent and grave complication of hemodialysis (HD). However, the dynamic hemodynamic changes and cardiac performances during each dialytic session have been rarely explored in patients having IDH. Methods: Seventy-six HD patients (IDH = 40, controls = 36) were enrolled. Echocardiography examinations were performed in all patients at the pre-HD, during-HD and post-HD phases of a single HD session. A two-way analysis of variance was applied to compare differences of echocardiographic parameters between IDH and controls over time. The risk association was estimated by using a logistic regression analysis. Results: The IDH patients had a higher ejection fraction during HD followed by a greater reduction at the post-HD phase than the controls. Significant decreases in septal ratios of transmitral flow velocity to annular velocity (E/e’) over times were detected between IDH patients and controls after adjusting for gender, age and ultrafiltration (p = 0.016). A lower septal E/e’ ratio was independently associated with IDH (OR = 0.040; 95% CI = 0.003–0.606; p = 0.02). In contrast, significant systolic and diastolic dysfunctions over time were found in diabetic IDH compared to non-diabetic counterparts. Conclusion: The septal E/e’ ratio was a significant predictor for IDH.

A Comparative Study on the Hemodynamic Performance Within Cross and Non-cross Stent-Grafts for Abdominal Aortic Aneurysms With an Angulated Neck.

Objectives: Cross-limb stent grafts for endovascular aneurysm repair (EVAR) are often employed for abdominal aortic aneurysms (AAAs) with significant aortic neck angulation. Neck angulation may be coronal or sagittal; however, previous hemodynamic studies of cross-limb EVAR stent grafts (SGs) primarily utilized simplified planar neck geometries. This study examined the differences in flow patterns and hemodynamic parameters between crossed and non-crossed limb SGs at different spatial neck angulations.Methods: Ideal models consisting of 13 cross and 13 non-cross limbs were established, with coronal and sagittal angles ranging from 0 to 90°. Computational fluid dynamics (CFD) was used to capture the hemodynamic information, and the differences were compared.Results: With regards to the pressure drop index, the maximum difference caused by the configuration and angular direction was 4.6 and 8.0%, respectively, but the difference resulting from the change in aneurysm neck angle can reach 27.1%. With regards to the SAR-TAWSS index, the maximum difference caused by the configuration and angular direction was 7.8 and 9.8%, respectively, but the difference resulting from the change in aneurysm neck angle can reach 26.7%. In addition, when the aneurysm neck angle is lower than 45°, the configuration and angular direction significantly influence the OSI and helical flow intensity index. However, when the aneurysm neck angle is greater than 45°, the hemodynamic differences of each model at the same aneurysm neck angle are reduced.Conclusion: The main factor affecting the hemodynamic index was the angle of the aneurysm neck, while the configuration and angular direction had little effect on the hemodynamics. Furthermore, when the aneurysm neck was greatly angulated, the cross-limb technique did not increase the risk of thrombosis.

Chronic haemodynamic performance of a biorestorative transcatheter heart valve in an ovine model.

The Xeltis biorestorative transcatheter heart valve (BTHV) leaflets are made from an electrospun bioabsorbable supramolecular polycarbonate-urethane and are mounted on a self-expanding nitinol frame. The acute haemodynamic performance of this BTHV was favourable. We sought to demonstrate the preclinical feasibility of a novel BTHV by evaluating the haemodynamic performances of five pilot valve designs up to 12 months in a chronic ovine model. Five design iterations (A, B, B', C, and D) of the BTHV were transapically implanted in 46 sheep; chronic data were available in 39 animals. Assessments were performed at implantation, 3, 6, and 12 months including quantitative aortography, echocardiography, and histology. At 12 months, greater than or equal to moderate AR on echocardiography was seen in 0%, 100%, 33.3%, 100%, and 0% in the iterations A, B, B', C, and D, respectively. Furthermore, transprosthetic mean gradients on echocardiography were 10.0±2.8 mmHg, 19.0±1.0 mmHg, 8.0±1.7 mmHg, 26.8±2.4 mmHg, and 11.2±4.1 mmHg, and effective orifice area was 0.7±0.3 cm2, 1.1±0.3 cm2, 1.5±1.0 cm2, 1.5±0.6 cm2, and 1.0±0.4 cm2 in the iterations A, B, B', C, and D, respectively. On pathological evaluation, the iteration D demonstrated generally intact leaflets and advanced tissue coverage, while different degrees of structural deterioration were observed in the other design iterations. Several leaflet material iterations were compared for the potential to demonstrate endogenous tissue restoration in an aortic valve in vivo. The most promising iteration showed intact leaflets and acceptable haemodynamic performance at 12 months, illustrating the potential of the BTHV.

Early Results after Aortic Valve Replacement Using Last Generation Bioprosthetic Aortic Valve.

Few data are available about the newest generation surgical bioprosthesis. We aimed to evaluate early clinical and hemodynamic outcomes after using the INSPIRIS RESILIA aortic valve (Edwards Lifesciences, Irvine, California, USA). Between July 2018 and April 2021, 80 patients underwent aortic valve replacement receiving the INSPIRIS RESILIA aortic valve at our institution. Primary outcomes were the composite of early mortality, stroke, and myocardial infarction. Secondary outcomes were hemodynamic performances of the valve, paravalvular leakage, and new pacemaker implantation. The mean age of the study population was 60.6 ± 8.3 years. The mean Society of Thoracic Surgery-Predicted Risk of Mortality score was 2.9 ± 1.7%. In 43.7% of the patients, concomitant surgery was performed. The in-hospital mortality, all-stroke, and myocardial infarction rates were 2.5%, 1.2%, and 1.2%, respectively. No valve was explanted and no redo was performed. The mean postoperative trans-prosthetic gradient at discharge was 10.2 ± 4.1 mm Hg. There was no need for new pacemaker implantation. We registered only two cases with minimal (trace) paravalvular leakage. The use of the INSPIRIS RESILIA aortic valve in a young, low-risk population is safe and associated with very good early clinical and hemodynamic outcomes.

Preliminary Results With a Novel Expanded Polytetrafluoroethylene-based Pulmonary Valved Conduit

BackgroundA novel polymeric pulmonary valved conduit, resistant to calcification and structural valve deterioration, may provide a more durable therapy option for the pediatric population by preventing loss of right ventricular function and increasing freedom from valve-related reintervention and mortality. MethodsThis was a prospective, multicenter, single-arm study evaluating safety and performance of an investigational novel expanded polytetrafluoroethylene–based valve. Patients met study inclusion/exclusion criteria, had a signed informed consent, had pre- and postoperative evaluation via transthoracic echocardiography, and 6-month cardiac magnetic resonance imaging. ResultsSeventeen patients were enrolled from 3 sites. Median age was 12 years (range, 6-17 years) with 52.9% male. Body surface area ranged from 0.82 to 1.57 m2. There has been no mortality and 100% freedom from device related reinterventions. Baseline compared with 6-month cardiac magnetic resonance imaging (in 11 of 16 patients with available data) suggests favorable right ventricular remodeling (right ventricular end-diastolic volume, 123 ± 37 to 94 ± 25 mL/m2) with no significant change in ejection fraction. Through current follow-up, no patient has a right ventricular outflow tract gradient >20 mm Hg (mean, 11.2 ± 4.3 mm Hg). No evidence of worsening valvular insufficiency was observed throughout postoperative serial transthoracic echocardiogram evaluations. No pulmonary regurgitation above baseline (≤ mild) was observed. No patient developed endocarditis. No thrombus or calcification was identified. ConclusionsThis preliminary evaluation of a novel expanded polytetrafluoroethylene–based valved conduit suggests promising valve function with no thromboembolic or infectious complications, no valve related reinterventions, no valve-related adverse events or unexpected findings, improved right ventricular volumes, and encouraging hemodynamic performance through current follow-up.

Biological Equivalence of GGTA-1 Glycosyltransferase Knockout and Standard Porcine Pericardial Tissue Using 90-Day Mitral Valve Implantation in Adolescent Sheep

ObjectiveThere is growing interest in the application of genetically engineered reduced antigenicity animal tissue for manufacture of bioprosthetic heart valves (BHVs) to reduce antibody induced tissue calcification and accelerated structural valve degeneration (SVD). This study tested biological equivalence of valves made from Gal-knockout (GalKO) and standard porcine pericardium after 90-day mitral valve implantation in sheep.MethodsGalKO (n = 5) and standard (n = 5) porcine pericardial BHVs were implanted in a randomized and blind fashion into sheep for 90-days. Valve haemodynamic function was measured at 30-day intervals. After explantation, valves were examined for pannus, vegetation, inflammation, thrombus, and tissue calcification.ResultsNine of 10 recipients completed the study. There was no difference between study groups for haemodynamic performance and no adverse valve-related events. Explanted BHVs showed mild pannus integration and minimal thrombus, with no difference between the groups. Limited focal mineral deposits were detected by x-ray. Atomic spectroscopy analysis detected tissue calcium levels of 1.0 µg/mg ± 0.2 for GalKO BHVs and 1.9 µg/mg ± 0.9 for standard tissue BHVs (p = 0.4), considered to be both low and equivalent.ConclusionsThis is the first demonstration of biological equivalence between GalKO and standard pig pericardium. The GalKO mutation causes neither intrinsic detrimental biological nor functional impact on BHV performance. Commercial adaptation of GalKO tissue for surgical or transcatheter BHVs would remove the clinical disparity between patients producing anti-Gal antibody and BHVs containing the Gal antigen. GalKO BHVs may reduce accelerated tissue calcification and SVD, enhancing patient choices, especially for younger patients.Graphical

Flush Flow Behaviour Affected by the Morphology of Intravascular Endoscope: A Numerical Simulation and Experimental Study.

Background: Whilst intravascular endoscopy can be used to identify lesions and assess the deployment of endovascular devices, it requires temporary blockage of the local blood flow during observation, posing a serious risk of ischaemia.Objective: To aid the design of a novel flow-blockage-free intravascular endoscope, we explored changes in the haemodynamic behaviour of the flush flow with respect to the flow injection speed and the system design.Methods: We first constructed the computational models for three candidate endoscope designs (i.e., Model A, B, and C). Using each of the three endoscopes, flow patterns in the target vessels (straight, bent, and twisted) under three different sets of boundary conditions (i.e., injection speed of the flush flow and the background blood flowrate) were then resolved through use of computational fluid dynamics and in vitro flow experiments. The design of endoscope and its optimal operating condition were evaluated in terms of the volume fraction within the vascular segment of interest, as well as the percentage of high-volume-fraction area (PHVFA) corresponding to three cross-sectional planes distal to the microcatheter tip.Results: With a mild narrowing at the endoscope neck, Model B exhibited the highest PHVFA, irrespective of location of the cross-sectional plane, compared with Models A and C which, respectively, had no narrowing and a moderate narrowing. The greatest difference in the PHVFA between the three models was observed on the cross-sectional plane 2 mm distal to the tip of the microcatheter (Model B: 33% vs. Model A: 18%). The background blood flowrate was found to have a strong impact on the resulting volume fraction of the flush flow close to the vascular wall, with the greatest difference being 44% (Model A).Conclusion: We found that the haemodynamic performance of endoscope Model B outperformed that of Models A and C, as it generated a flush flow that occupied the largest volume within the vascular segment of interest, suggesting that the endoscope design with a diameter narrowing of 30% at the endoscope neck might yield images of a better quality.

One-Year Hemodynamic Performance of Three Cardiac Aortic Bioprostheses: A Randomized Comparative Clinical Trial

Background: We aimed to compare 1 year the hemodynamic in-vivo performance of three biological aortic prostheses (Carpentier Perimount Magna EaseTM, Crown PRTTM, and TrifectaTM). Methods: The sample used in this study comes from the “BEST-VALVE” clinical trial, which is a phase IV single-blinded randomized clinical trial with the three above-mentioned prostheses. Results: 154 patients were included. Carpentier Perimount Magna EaseTM (n = 48, 31.2%), Crown PRTTM (n = 51, 32.1%) and TrifectaTM (n = 55, 35.7%). One year after the surgery, the mean aortic gradient and the peak aortic velocity was 17.5 (IQR 11.3–26) and 227.1 (IQR 202.0–268.8) for Carpentier Perimount Magna EaseTM, 21.4 (IQR 14.5–26.7) and 237.8 (IQR 195.9–261.9) for Crown PRTTM, and 13 (IQR 9.6–17.8) and 209.7 (IQR 176.5–241.4) for TrifectaTM, respectively. Pairwise comparisons demonstrated improved mean gradients and maximum velocity of TrifectaTM as compared to Crown PRTTM. Among patients with nominal prosthesis sizes ≤ 21, the mean and peak aortic gradient was higher for Crown PRTTM compared with TrifectaTM, and in patients with an aortic annulus measured with metric Hegar dilators less than or equal to 22 mm. Conclusions: One year after surgery, the three prostheses presented a different hemodynamic performance, being TrifectaTM superior to Crown PRTTM.