Biological Valve Research Articles

Chemical bonding of biological valve leaflets with an aminated zwitterionic copolymer for long-term anticoagulation and improved anti-calcification

Glutaraldehyde cross-linked pericardium (GLUT), mostly used in Bioprosthetic heart valves (BHVs) clinically, still has problems of valve thrombus, cytotoxicity, and calcification. Although many new crosslinking approaches have been explored to obtain certain biological achievements, their clinical applications are still some way off, which might be ascribed to the limitations of preservation and sterilization. In this study, a novel post-crosslinking of GLUT was developed using a zwitterionic copolymer. The copolymer imitating the molecular structure of phospholipids was composed of the copolymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC), N-(3-Aminopropyl) methacrylamide hydrochloride (APMA), and Lauryl methacrylate (LMA). With the introduction of primary amines, the zwitterionic copolymer could be effectively utilized in the post-crosslinking of GLUT. Meanwhile, the anticoagulation properties of valve leaflets could be adjusted by combining aminated zwitterionic copolymers with different molecular weights. The valve leaflets modified with aminated zwitterionic copolymer not only maintained original mechanical property and structural integrity, but also significantly improved the long-term anti-coagulation and stability in vitro and ex vivo. The subcutaneous implantation confirmed that the modified leaflets possessed great resistance to calcification along with reduced inflammatory response. Besides, the modified leaflets could be further stored in glutaraldehyde solution (a storage formula for commercial valves) and still retained great anti-coagulant and anti-calcification properties. The study demonstrated a better clinical potential of the modified leaflets via the post-crosslinking of glutaraldehyde treated leaflets with the aminated zwitterionic copolymer.

Report on outcomes of valve-in-valve transcatheter aortic valve implantation and redo surgical aortic valve replacement in the Netherlands.

ObjectiveWe sought to investigate real-world outcomes of patients with degenerated biological aortic valve prostheses who had undergone valve-in-valve transcatheter aortic valve implantation (ViV-TAVI) or reoperative surgical aortic valve replacement (redo-SAVR) in the Netherlands.MethodsPatients who had undergone ViV-TAVI or redo-SAVR for a degenerated biological aortic valve prosthesis in the Netherlands between January 2014 and December 2018 were eligible for this retrospective study. Patients with a prior homograft, active endocarditis or mechanical aortic valve prosthesis were excluded. Patients were matched using the propensity score. The primary endpoint was a composite of 30-day all-cause mortality and in-hospital postoperative stroke. Secondary endpoints were all-cause mortality at different time points, in-hospital postoperative stroke, pacemaker implantation and redo procedures within one year. Baseline characteristics and outcome data were collected from the Netherlands Heart Registration.ResultsFrom 16 cardiac centres, 653 patients were included in the study (374 ViV-TAVI and 279 redo-SAVR). European System for Cardiac Operative Risk Evaluation I (EuroSCORE I) was higher in ViV-TAVI patients (19.4, interquartile range (IQR) 13.3–27.9 vs 13.8, IQR 8.3–21.9, p < 0.01). After propensity score matching, 165 patients were matched with acceptable covariate balance. In the matched cohorts, the primary endpoint was not significantly different for ViV-TAVI and redo-SAVR patients (odds ratio 1.30, 95% confidence interval 0.57–3.02). Procedural, 30-day and 1‑year all-cause mortality rates, incidence of in-hospital postoperative stroke, pacemaker implantation and redo procedures within one year were also similar between cohorts.ConclusionPatients with degenerated aortic bioprostheses treated with ViV-TAVI or redo-SAVR have similar mortality and morbidity.Supplementary InformationThe online version of this article (10.1007/s12471-021-01608-0) contains supplementary material, which is available to authorized users.

Structural valve degeneration in the transcatheter mitral valve implantation era.

Structural valve degeneration of biological valves continues to be a persistent problem and has assumed greater importance with the advent of transcatheter valve implantation techniques. Considerable variability exists among different studies in reporting the incidence of structural valve degeneration and differentiation with nonstructural valve degeneration and bio-prosthetic valve failures is important. Moreover, the pathological basis of structural valve degeneration is still not completely understood. Theoretically, trans-catheter implanted valves may be more prone to degeneration compared to surgically implanted biological valves. Measures to reduce structural valve degeneration are imperative, irrespective of the technique of valve implantation.

Numerical simulation of electrical network left ventricular circulatory system with biological valve motion model

This paper presents a new concentrated parameter model represented by an electrical network model for cardiovascular dynamics that includes an innovative model of biological heart valve dynamics. We obtained the hemodynamic waveform of the heart by solving the equations of state through programming. The results show that using the biological valve motion model can reflect the phenomenon of blood return flow that is not found in the ideal diode model. This model can simulate the biological characteristics of heart valve reasonably and accurately, and it is simple and easy to control.

CT Derived Perimeter Strain In Severe Aortic Regurgitation - Comparison With Speckle Tracking Echocardiography

Introduction: We assessed CT-derived left ventricular (LV) perimeter strain in a cohort of patients with severe regurgitation of the aortic valve or biological aortic valve prothesis and validated it against echocardiographic global longitudinal strain (GLS) derived by 2 dimensional speckle tracking echocardiography as the gold standard.

Cardiovascular Interventions in Patients with Hemophilia and Severe Von Willebrand Disease.

The management of cardiovascular interventions in patients with hemophilia and severe von Willebrand disease (VWD) is challenging. The procedure itself as well as the use of anti-platelet drugs and anticoagulants implies a risk of bleeding. On the other hand, factor replacement therapy as well as withdrawal of anti-platelet drugs or anticoagulants may increase the risk of cardiovascular events and thrombosis. Information on the management of such interventions is limited to very few case reports. Here, we report a retrospective analysis of 28 patients with hemophilia A (n=16), hemophilia B (n=4) or VWD (n=8, all with VWF:RCo <30 IU/dl), who underwent a total of 39 cardiovascular interventions including coronary angiography (CA, n=11), percutaneous coronary interventions (PCI, n=18), or cardiac surgery (CS, n=10) including coronary artery bypass grafting (CABG) and heart valve surgery with the use of cardiopulmonary bypass (CPB). Patients had a median age of 66 years (range 47–85) and had a median factor activity of 3 IU/dl (range <1–35). Six patients were on regular prophylaxis prior to the intervention. Patients undergoing CA received replacement therapy for a median of 2 days (range 1–15) with a median starting dose of 36 IU/kg (range 24–67). Minor bleeding at the site of puncture occurred in 5 of 11 patients. Major bleeding or bleeding requiring transfusion did not occur. Patients undergoing PCI received replacement therapy for a median of 4 days (range 1–41) with a starting dose of 40 IU/kg (range 12–63) given before or during the intervention. 12 of 14 patients receiving bare metal stents were on aspirin and clopidogrel for 4 to 6 weeks; 7 of these including all patients with severe hemophilia received prophylactic replacement therapy for the time of dual anti-platelet therapy. Two patients received shorter courses of single anti-platelet agents due to bleeding. Three patients receiving drug-eluting stents were on aspirin and clopidogrel for 8 to 12 weeks; 2 of these also received prophylactic replacement therapy, whereas one patient with mild hemophilia did not. Minor bleeding at the site of puncture occurred in 15 of 18 patients undergoing PCI; major bleeding at the site of puncture occurred in 1 patient and required transfusion. Major bleeding at distant sites occurred in 3 patients with 1 patient requiring transfusion. Two of these three patients received anti-platelet therapy without prophylactic factor replacement. No patient experienced stent thrombosis or other thromboembolic complications. Patients undergoing cardiac surgery received replacement therapy for a median of 23 days (range 11–46) with a median starting dose of 57 IU/kg (range 23–107). Unfractionated heparin was used for anticoagulation during CPB. Minor wound bleeding occurred in 8 of 10 patients. Four patients received transfusions of 2 to 5 units of packed red blood cells. Five of seven patients undergoing CABG received aspirin. One patient with VWD undergoing CABG and biological aortic valve replacement received oral anticoagulation and experienced gross hematuria; he was switched to aspirin after 6 weeks. A patient with mild hemophilia on long-term oral anticoagulation because of atrial fibrillation remained on oral anticoagulants without signs of bleeding. In summary, this is the largest cohort of patients with hemophilia and severe VWD undergoing cardiovascular interventions. Combining replacement therapy with anti-platelet agents or anticoagulants appears to be a safe strategy, despite of frequent minor bleeding. Major bleeding mainly occurred in patients on anti-platelet agents without concomitant prophylactic replacement therapy.

A multi-in-one strategy with glucose-triggered long-term antithrombogenicity and sequentially enhanced endothelialization for biological valve leaflets

Bioprosthetic heart valves are commonly applied in heart valve replacement, while the effectiveness is limited by inflammation, calcification and especially thrombosis. Surface modification is expected to endow the biological valves with versatility. Herein, a multi-in-one strategy was established to modify biological valves with long-term antithrombogenicity and sequentially enhanced endothelialization triggered by glucose, in which the direct thrombin inhibitor rivaroxaban (RIVA)-loaded nanogels were embedded and the detachable polyethylene glycol (PEG) was grafted. These two anticoagulant strategies were connected by glucose oxidase (GOx), which catalyzed the oxidation of glucose to produce hydrogen peroxide (H2O2) and local acidic environment. The generated H2O2 stimulated H2O2-responsive nanogels release RIVA to obtain continuous antithrombogenicity. Meanwhile, PEG was attached to the surface via pH-sensitive bonds, which prevented thrombus formation by resisting the serum proteins and platelets adhesion at the initial stage of material/blood contact. Sequentially, PEG gradually peeled off under the local weak acidic environment, which ultimately resulted in the endothelialization enhancement. Within such multi-in-one strategy, the biological valve leaflets induced long-term anticoagulant performance, gradually enhanced endothelialization and improved tissue affinity, including anti-calcification and anti-inflammation, indicating the potential of the response sequence matching between materials and tissues after implantation, which might improve performance of biological heart valves.

Anticoagulation Therapy After Biologic Aortic Valve Replacement.

Objectives: Thromboembolism prophylaxis after biologic aortic valve replacement (BAVR) is recommended for 3 months postoperatively. We examined the continuation of oral anticoagulation (OAC) treatment and its effect on the long-term prognosis after BAVR.Methods: We used nation-wide register data from 4,079 individuals who underwent BAVR. We examined the association between warfarin and the non-vitamin K antagonist oral anticoagulant use with death, stroke and major bleeding in 2010 – 2016.Results: The risk of stroke was higher (HR 2.39, 95% CI 1.62 – 3.53, p < 0.001) and the risk of death was lower (HR 0.79, 95% CI 0.65 – 0.96, p = 0.016) in OAC-users compared to individuals without OAC. We observed no significant associations between OAC use and bleeding risk.Conclusion: OAC use after BAVR was associated with increased risk of stroke and decreased risk of death. These observational findings warrant validation in randomized controlled trials before any clinical conclusions can be drawn.

Prosthesis choice for surgical treatment of left-sided native valve infective endocarditis: Determinants and impact on outcomes

Surgical treatment is required in approximately half of the patients with infective endocarditis (IE) because of severe complications. To date there is no recommendation favoring a specific valve substitute for IE treatment and accordingly there is a wide variation in routine surgical management of these patients. The purpose of this study is to describe surgical practices in our center and to investigate the impact on clinical outcomes. All patients with native valve left-sided IE, who underwent valve replacement surgery with a mechanical or biological prosthesis in our institution between 1 January 2006 and 31 December 2018 were enrolled in this retrospective study. A total of 303 patients were included (mean age = 58 years, 80% men). Patients in whom a biological valve was chosen (64%, n = 194) were older and had more comorbid conditions compared to patients who received a mechanical valve (36%, n = 109). In hospital mortality was respectively 19% ( n = 36) in the bioprosthesis group avec 3% ( n = 3) in the mechanical valve group ( P < 0.0001). The mortality rates at 1 and 3 years were 35% and 41% in the biological valve group, these rates were 8% and 15% in the mechanical valve group. Factors associated to in hospital and mid term mortality were age, comorbid conditions, hemodynamic failure, a double valve replacement or associated bypass surgery. The type of the implanted valve substitute was not independently associated with mortality. For surgical management of IE, a biological valve is the most used valve substitute in our institution. Mechanical valves seem to be implanted in a very selected and low-risk patient subgroup. The valve substitute does not appear to be related to in hospital nor to midterm mortality rates.

Long-term survival after Carpentier-Edwards Perimount aortic valve replacement in Western Denmark: a multi-centre observational study

BackgroundThis study describes the long-term survival, risk of reoperation and clinical outcomes of patients undergoing solitary surgical aortic valve replacement (SAVR) with a Carpentier-Edwards Perimount (CE-P) bioprosthetic in Western Denmark. The renewed interest in SAVR is based on the questioning regarding the long-term survival since new aortic replacement technique such as transcatheter aortic-valve replacement (TAVR) probably have shorter durability, why assessment of long-term survival could be a key issue for patients.MethodsFrom November 1999 to November 2013 a cohort of a total of 1604 patients with a median age of 73 years (IQR: 69–78) undergoing solitary SAVR with CE-P in Western Denmark was obtained November 2018 from the Western Danish Heart Registry (WDHR). The primary endpoint was long-term survival from all-cause mortality. Secondary endpoints were survival free from major adverse cardiovascular and cerebral events (MACCE), risk of reoperation, cause of late death, patient-prothesis mismatch, risk of AMI, stroke, pacemaker or ICD implantation and postoperative atrial fibrillation (POAF). Time-to-event analysis was performed with Kaplan-Meier curve, cumulative incidence function was performed with Nelson-Aalen cumulative hazard estimates. Cox regression was applied to detect risk factors for death and reoperation.ResultsIn-hospital mortality was 2.7% and 30-day mortality at 3.4%. The 5-, 10- and 15-year survival from all-cause mortality was 77, 52 and 24%, respectively. Survival without MACCE was 80% after 10 years. Significant risk factors of mortality were small valves, smoking and EuroSCORE II ≥4%. The risk of reoperation was < 5% after 7.5 years and significant risk factors were valve prosthesis-patient mismatch and EuroSCORE II ≥4%.ConclusionsPatients undergoing aortic valve replacement with a Carpentier-Edwards Perimount valve shows a very satisfying long-term survival. Future research should aim to investigate biological valves long-term durability for comparison of different SAVR to different TAVR in long perspective.

Effect of Aortic Valve Type on Patients Who Undergo Type A Aortic Dissection Repair

Aortic valve replacement (AVR) is common in the setting of type A aortic dissection (TAAD) repair. Here, we evaluated the association between prosthesis choice and patient outcomes in an international patient cohort. We reviewed data from the International Registry of Acute Aortic Dissection (IRAD) interventional cohort to examine the relationship between valve choice and short- and mid-term patient outcomes. Between January 1996 and March 2016, 1290 surgically treated patients with TAAD were entered into the IRAD interventional cohort. Of those, 364 patients undergoing TAAD repair underwent aortic valve replacement (AVR; mean age, 57 years). The mechanical valve cohort consisted of 189 patients, of which 151 (79.9%) had a root replacement. The nonmechanical valve cohort consisted of 5 patients who received homografts and 160 patients who received a biologic AVR, with a total of 118 (71.5%) patients who underwent root replacements. The mean follow-up time was 2.92 ± 1.75 years overall (2.46 ± 1.69 years for the mechanical valve cohort and 3.48 ± 1.8 years for the nonmechanical valve cohort). After propensity matching, Kaplan-Meier estimates of 4-year survival rates after surgery were 64.8% in the mechanical valve group compared with 74.7% in the nonmechanical valve group (p = 0.921). A stratified Cox model for 4-year mortality showed no difference in hazard between valve types after adjusting for the propensity score (p = 0.854). A biologic valve is a reasonable option in patients with TAAD who require AVR. Although this option avoids the potential risks of anticoagulation, long-term follow up is necessary to assess the effect of reoperations or transcatheter interventions for structural valve degeneration.

Transcatheter aortic valve implantation for degenerated aortic valves: Experience with a new supra-annular device. The Spanish Allegra valve-in-valve (SAVIV) registry.

The objective was to evaluate the results of valve-in-valve procedures performed with the Allegra device. Transcatheter aortic valve implantation to treat degenerated biological aortic valves (valve-in-valve) is an established procedure in most catheterization laboratories, but the results are poorer than procedures done in native aortic stenosis. The Allegra device (Biosensors, Morges, Switzerland) has an excellent design to treat these patients. All patients with severely degenerated biological aortic valve treated with the Allegra device in centers from Spain until December 2020 were included (n= 29). Hemodynamic results and 30-day clinical outcomes were evaluated. The predominant hemodynamic failure was stenosis in 15, regurgitation in 11, and a combination of both in 3 cases. Time from aortic valve replacement to valve-in-valve procedure was 8.4 ± 3.9 years (range 3.3-22.1). After the procedure, maximum and mean trans-valvular gradients were 17.4 ± 12.3 and 8.4 ± 6.1 mmHg, respectively. Device success was obtained in 28 patients (96.6%). In one patient with a degenerated 19 mm prosthetic valve, mean gradient after the procedure was 22 mmHg. No patients had a para-valvular leak grade >1. There were no deaths during the hospitalization or at 30 days and one patient suffered a stroke. The Allegra trans-catheter aortic valve offers optimal hemodynamic results in patients with severely degenerated biological aortic valve.

Transcatheter Aortic Valve Replacement in Aortic Stenosis: a Clinical Case

Background. Aortic valve stenosis is common with prevalence of about 0.5 %, peaking in people aged over 70 years mostly due to age-related valve calcification. The year 2002 was marked by the invention and use of the endovascular aortic replacement valve by an A. Cribier’s group of French surgeons. Russian endovascular surgery introduced transcatheter aortic valve replacement in 2009, having since built an extensive experience in this practice. Perioperative mortality in patients under 70 years with no serious comorbidity ranges from 1 to 3 %, however, reaching two-fold 4–8 % in elderly patients. The emergence of minimally invasive technologies offered cure to critical patients, who would merely not get over an open surgery.Materials and methods. This case study provides video recordings of transcatheter aortic valve replacement (Accurate Neo) in transfemoral approach performed for the first time in the Republic of Bashkortostan. Patient K., 70 yo, diagnosis: Atherosclerosis. Aortic valve stenosis. FC III. Complications: aortic valve calcification st. III, CHF II A, FC III, persistent atrial fibrillation, tachysystole. Comorbid: CHD. Exertional angina. FC III. CHF II A, FC III.Results and discussion. Improving the transcatheter valve type facilitates an optimal individual aortic valve selection. Pre-replacement valvuloplasty was performed in all patients. The valve replacement is followed by transoesophageal echocardiography to justify possible aortic valve post-dilatation upon marked paravalvular regurgitation. The implant positioning relative to the aortic valve fibrous crown and mitral valve flaps is precisely controlled with ultrasound.Conclusion. Interventional radiology currently provides high-quality, effective, minimally invasive medical aid even in aortic stenosis patients with multiple comorbidity. In the patient’s denial of open surgery, transcatheter aortic valve replacement represents a sole alternative treatment, also increasing the life expectancy and quality. A wider diversity of available transcatheter devices enables a better personalisation of the biological valve replacement procedure.

Post hoc patient satisfaction with the choice of valve prosthesis for aortic valve replacement: results of a single-centre survey.

Our goal was to examine post hoc patient satisfaction and the decision-making process of choosing a prosthesis for aortic valve replacement (AVR). We surveyed 113 patients who were operated on for AVR at 60-70 years of age, including 74 patients with a mechanical valve (MECH) and 39 with a bioprosthesis (BIO). The study focused on quality of life and the decision pathway in relation to prosthesis choice and valve-related complications. Decisional conflict was defined as the post hoc uncertainty perceived by patients regarding their choice of prosthesis. The survey was performed at a median of 5.2 (3.2-8.1) years after the AVR. Patients with a biological valve were older (BIO: 68.4 years [66.2-69.4] vs MECH: 63.9 [61.9-66.7]; P < 0.001). Global post hoc satisfaction with prosthesis choice was high in both groups (MECH: 95.9%; BIO: 100%), and 85.1% (MECH) and 92.3% (BIO) of them would repeat their choice. Conflict about their decision was equal (MECH: 30.3%; BIO: 32.6%) for different reasons: MECH patients experienced more anticoagulation-related inconvenience (25.9% vs 0%), fear of bleeding (31.1% vs 0%) and prosthesis noise (26.2% vs 0%), whereas more BIO patients feared prosthesis failure (39.7% vs 17.4%) or reoperation (43.5% vs 18.1%). Active involvement in the decision (odds ratio 0.37, 95% confidence interval 0.16-0.85; P = 0.029) and adequate information about the prosthesis (odds ratio 0.34, 95% confidence interval 0.14-0.86; P = 0.020) decreased the risk of conflict about the decision. Although 30% of the responders showed a decisional conflict related to prosthesis-specific interferences, global patient satisfaction with the prosthesis choice for AVR is excellent. Increasing the patient's involvement in the prosthesis choice through shared accountability and improved information is recommended to decrease the choice-related uncertainty.

Alternative and Safe Technique to Tie Down a Biologic Aortic Valve in Small Aortic Roots

Biologic aortic valves are constructed with 3 stents corresponding to the commissures, which sit in the aortic root. When implanted using interrupted sutures, these stents may make the valve difficult to tie down safely in patients with small, calcified aortic roots. We present an easily reproducible technique to make this valve tie down safer.

Comparison of the effective orifice area of prosthetic mitral valves using two-dimensional versus three-dimensional transesophageal echocardiography.

ObjectiveThis study compared the continuity equation-based effective orifice area (EOA) of prosthetic mitral valves between two-dimensional (2D) and 3D transesophageal echocardiography (TEE).MethodsThirty-four patients without major aortic valve abnormalities underwent mitral valve replacement surgery. The EOAs of prosthetic mitral valves were calculated using the continuity equation with 2D and 3D TEE. For 18/34 patients using a biological valve prosthesis, the EOA of the prosthesis was obtained from commercial records.ResultsThe EOA of prosthetic mitral valves significantly varied between the 2D and 3D methods (2.22 ± 0.71 vs 2.35 ± 0.70 cm2, n = 34). The area of the diameter of the left ventricular outflow tract as determined by the 3D method was significantly higher than that by the 2D method (mean difference: −0.14 ± 0.20 cm2), with 95% coherence boundaries of −0.53 and 0.25 cm2. The regression equation for the EOA by 3D and 2D TEE was y = 0.27 + 0.94x, with a good correlation.ConclusionsThe EOA of prosthetic mitral valves is underestimated using the 2D TEE method compared with the 3D TEE method. The 3D-TEE method has the advantage of higher precision over the 2D TEE method, and it may be helpful for better assessment of prosthetic mitral valves intraoperatively.

Long-Term Outcomes of Patients Undergoing the Ross Procedure

BackgroundTreatment of aortic-valve disease in young patients still poses challenges. The Ross procedure offers several potential advantages that may translate to improved long-term outcomes. ObjectivesThis study reports long-term outcomes after the Ross procedure. MethodsAdult patients who were included in the Ross Registry between 1988 and 2018 were analyzed. Endpoints were overall survival, reintervention, and major adverse events at maximum follow-up. Multivariable regression analyses were performed to identify risk factors for survival and the need of Ross-related reintervention. ResultsThere were 2,444 adult patients with a mean age of 44.1 ± 11.7 years identified. Early mortality was 1.0%. Estimated survival after 25 years was 75.8% and did not statistically differ from the general population (p = 0.189). The risk for autograft reintervention was 0.69% per patient-year and 0.62% per patient-year for right-ventricular outflow tract (RVOT) reintervention. Larger aortic annulus diameter (hazard ratio [HR]: 1.12/mm; 95% confidence interval [CI]: 1.05 to 1.19/mm; p < 0.001) and pre-operative presence of pure aortic insufficiency (HR: 1.74; 95% CI: 1.13 to 2.68; p = 0.01) were independent predictors for autograft reintervention, whereas the use of a biological valve (HR: 8.09; 95% CI: 5.01 to 13.08; p < 0.001) and patient age (HR: 0.97 per year; 95% CI: 0.96 to 0.99; p = 0.001) were independent predictors for RVOT reintervention. Major bleeding, valve thrombosis, permanent stroke, and endocarditis occurred with an incidence of 0.15% per patient-year, 0.07% per patient-year, 0.13%, and 0.36% per patient-year, respectively. ConclusionsThe Ross procedure provides excellent survival over a follow-up period of up to 25 years. The rates of reintervention, anticoagulation-related morbidity, and endocarditis were very low. This procedure should therefore be considered as a very suitable treatment option in young patients suffering from aortic-valve disease. (Long-Term Follow-up After the Autograft Aortic Valve Procedure [Ross Operation]; NCT00708409)

Imaging modalities in the planning of transcatheter aortic valve implantation (standardization of scanning, measurements and reporting protocols)

This review describes the state of the art on the role of various imaging modalities in pre-operative preparation to transcatheter implantation of biological aortic valve prosthesis, based on the literature data published from 2012 to 2020. One of the key source documents is the consensus of the European Society of Cardiovascular Radiology (ESCR) from 2019, providing the standardized protocols for scanning, measurements and description of the abnormalities identified. The final decision on the procedure of transcatheter aortic valve implantation should be based on the combination of all available diagnostic methods, clinical data and results of imaging by different modalities. Given the most comprehensive information content, the main diagnostic method is computed tomography. The radiologist and the multidisciplinary team should form a single entity, combining clinical and technical knowledge, discussing all the images and conclusions with other team members.

Anticalcification Potential of POSS-PEG Hybrid Hydrogel as a Scaffold Material for the Development of Synthetic Heart Valve Leaflets.

Calcification of bioprosthetics is a primary challenge in the field of artificial heart valves and a main reason for biological heart valve prostheses failure. Recent advances in nanomaterial science have promoted the development of polymers with advantageous properties that are likely suitable for artificial heart valves. In this work, we developed a nanocomposite polymeric biomaterial POSS-PEG (polyhedral oligomeric silsesquioxane-polyethylene glycol) hybrid hydrogel, which not only has improved mechanical and surface properties but also excellent biocompatibility. The results of atomic force microscopy and in vivo animal experiments indicated that the content of POSS in the PEG matrix plays an important role on the surface and contributes to its biological properties, compared to the decellularized porcine aortic valve scaffold. Additionally, this modification leads to enhanced protection of the hydrogel from thrombosis. Furthermore, the introduction of POSS nanoparticles also gives the hydrogel a better calcification resistance efficacy, which was confirmed through in vitro tests and animal experiments. These findings indicate that POSS-PEG hybrid hydrogel is a potential material for functional heart valve prosthetics, and the use of POSS nanocomposites in artificial valves may offer potential long-term performance and durability advantages.

Prosthesis-patient mismatch after aortic valve in valve procedure: incidence, predictors and clinical outcomes

Abstract Funding Acknowledgements Type of funding sources: None. Background. Transcatheter aortic valve-in-valve (TAVI ViV) implantation is an appealing treatment option for patients with degenerated bioprostheses. However, elevated residual gradients after TAVI ViV procedure are very common. These are an unwanted effects of prosthesis-patient mismatch (PPM). Currently, the actual incidenceof PPM, its predictors and its clinical outcomes have not been completely investigated. Purpose. The aims of this study was to investigate the incidence, predictors and clinical outcome of PPM and therefore of elevated gradients after TAVI ViV. Methods. 75 patients (age 78 ± 9 years, 36 male), who underwent TAVI-ViV due to failed aortic biological valve (60 stented, 15 stentless), were enrolled. Mechanism of bioprosthetic valve failure was stenosis (34 cases, 45%), regurgitation (24 cases, 32%) or combination (17 cases, 23%). Elevated residual gradients were defined as a mean DP&amp;gt; 20 mmHg. PPM was identified by the indexed effective orifice area (EOAi) measured by echocardiography (moderate PPM if 0.65 &amp;lt; EOAi &amp;lt; 0.85 cm²/m²; severe PPM if EOAi &amp;lt; 0.6 cm²/m²). Results. ViV TAVI was feasible in all patients, 33 patients (44%) were implanted with a balloon-expandable valve and 42 (56%) with a self-expandable valve. Post-procedural post-ballooning was performed in 16 out of 42 patients (38%) receiving a self-expandable valve. Post-operative mean DP&amp;gt; 20 mmHg was found in 35 patients (48%). Moderate PPM was found in 24 cases (33%) and severe PPM in 15 (20%). A logistic regression analyses identified small size of surgical prosthesis (size &amp;lt; 23 mm) [OR: 6.061(2.127-17.267), p = 0.001] and failed stented valve [OR: 20.727(2.522-170.364), p = 0.005] as independent predictors for the occurrence PPM. Interestingly PPM did not affect early and 1 years mortality (1 years mortality 1.3 %), while mortality was higher in pts with stentless prostheses (9%) Conclusions. PPM is a frequent finding after ViV procedures. Despite elevated residual gradients, TAVI ViV resolved prosthetic dysfunction and PPM did not affect mortality. Therefore, this procedure represents a promising new option for patients with failed biological prosthetic valves.