Biological Prosthetic Valves Research Articles

Clinical characteristics and outcomes of aortic prosthetic valve endocarditis: comparison between transcatheter and surgical bioprostheses

Abstract Purpose Most data regarding infective endocarditis (IE) after transcatheter aortic valve implantation (TAVI) comes from TAVI registries, rather than IE dedicated cohorts. The objective of our study was to compare the clinical and microbiological profile, imaging features and outcomes of patients with IE after SAVR with a biological prosthetic valve (IE-SAVR) and IE after TAVI (IE-TAVI) from 6 centres with an Endocarditis Team (ET) and broad experience in IE. Methods Retrospective analysis of prospectively collected data. From the time of first TAVI implantation in each centre to March 2021, all consecutive patients admitted for IE-SAVR or IE-TAVI were prospectively enrolled. Follow-up was monitored during admission and at 12 months after discharge. Results 169 patients with IE-SAVR and 41 with IE-TAVI were analysed. Early episodes were more frequent among IE-TAVI. Clinical course during hospitalization was similar in both groups, except for a higher incidence of atrioventricular block in IE-SAVR. The most frequently causative microorganisms were S. epidermidis, Enterococcus spp. and S. aureus in both groups. Periannular complications were more frequent in IE-SAVR. Cardiac surgery was performed in 53.6% of IE-SAVR and 7.3% of IE-TAVI (p=0.001), despite up to 54.8% of IE-TAVI patients had an indication. No differences were observed about death during hospitalization (32.7% vs 35.0%), and at 1-year follow-up (41.8% vs 37.5%), regardless of whether the patient underwent surgery or not. Conclusion Patients with IE-TAVI had a higher incidence of early prosthetic valve IE. Compared to IE-SAVR, IE-TAVI patients underwent cardiac surgery much less frequently, despite having surgical indications. However, in-hospital and 1-year mortality rate was similar between both groups.

Choice of the prosthetic valve in patients aged between 55 and 70 years

About 280 000 heart valve replacements are performed worldwide every year. Since the first prosthetic valve implantation in 1952 there have been notable developments. There are a lot of types of prosthetic valves that can be summarized into two categories: biological prosthetic valves or mechanical prosthetic valves. Biological prostheses, made of bovine or porcine pericardium, homografts, or autografts, degenerate over time becoming dysfunctional. Mechanical prostheses have a potentially unlimited lifespan but require oral anticoagulation which can affect patients' quality of life. Generally, biological prostheses are particularly suitable for elderly patients while mechanical prostheses for young people, with some distinctions. For example, in case of age <60 years, in the presence of preoperative oral anticoagulant therapy, metabolic syndrome, hemodialysis or hyperparathyroidism, a mechanical valve is the preference. The choice of the prosthesis in patients aged between 55 and 70 years is particularly challenging because the advantages and disadvantages of the two categories of prosthesis overlap in middle-aged patients. The choice of the prosthesis should be made after discussion with the surgeon, according to the patient's preferences, and keeping in mind the pros and cons of biological and mechanical prostheses.

The Association Between Ascending Aortic and Left Ventricular Dimensions in Patients After Aortic Valve Replacement.

Aortic valve replacement (AVR) is often recommended for patients with severe aortic stenosis or chronic aortic regurgitation. These conditions result in remodeling of the left ventricle, including increased interstitial fibrosis that may persist even after AVR. These structural changes impact left ventricular (LV) mechanics, causing compromised LV diameter to occur earlier than reduced LV ejection fraction (LVEF). The aim of this study was to examine the effect of left ventricular end-diastolic diameter (LVEDD) and its role in aortic expansion one year after AVR. Sixty-three patients who underwent AVR were evaluated. All patients underwent standard transthoracic echocardiography, which included measurements of the ascending aorta, aortic root, LVEF, and LVEDD before the surgery and one year postoperatively. Correlations between these variables were calculated. All patients underwent AVR with either a mechanical or biological prosthetic aortic valve. Following AVR, there was a significant decrease in the dimensions of the ascending aorta and aortic root (both P=0.001). However, no significant changes were observed in LVEDD and LVEF. Correlations were found between the preoperative ascending aortic size and the preoperative and one-year postoperative LVEDD (r=0.419, P=0.001 and r=0.320, P=0.314, respectively). Additionally, there was a correlation between the postoperative ascending aortic size and the preoperative and one-year postoperative LVEDD (r=0.320, P=0.003 and r=0.136, P=0.335, respectively). The study findings demonstrate a significant correlation between the size of the aortic root and ascending aorta, before and after AVR. Additionally, a notable correlation was observed between postoperative LVEDD and the size of the aortic root.

Transcatheter mitral paravalvular closure: a single centre experience with techniques and outcomes

Background In patients with symptomatic mitral PVL, successful transcatheter reduction of the PVL to less than mild is associated with significant improvement in short- and midterm survival. Objectives In this study, we present our single-centre, same operators’ experience on percutaneous paravalvular leak closure with techniques and outcomes. Methods In this retrospective observational designed study, we retrieved hospital records of patients with a surgical history of mechanical or biological prosthetic valve replacement and who subsequently underwent transcatheter mitral paravalvular leak closure (TMPLC). All procedures were performed by the same operators. Results A total of 45 patients with 58 PVDs underwent TMPLC using 60 devices. All patients had moderate or severe mitral paravalvular regurgitation associated with symptomatic HF (15.6%), clinically significant haemolytic anaemia (57.8%) or both (26.7%). The technical success rate was 91.4%, with 53 defects successfully occluded. The clinical success rate was 75.6%. Among the clinical success parameters, the preprocedural median ejection fraction increased from 45% (35–55) to 50% (40–55) (p = .04). Mitral gradients decreased from max/mean 18/8 mmHg to max/mean 16/7 mmHg; p = .02). Haemoglobin levels increased from 9.9 (8.5–11.1) to 11.1 (3–13); p = .003. LDH levels decreased from 875 (556–1125) to 435 (314–579); p: <.001. All-cause 30-day and in-hospital mortality rates were the same at 8.9%. Conclusion This single-centre study with a limited number of patients confirmed that TMPLC is a safe and effective procedure to improve symptoms and severity of PVL.

Trends in SAVR with biological vs. mechanical valves in middle-aged patients: results from a French large multi-centric survey.

Currently, despite continued issues with durability ( 1), biological prosthetic valves are increasingly chosen over mechanical valves for surgical aortic valve replacement (SAVR) in adult patients of all ages, at least in Western countries. For younger patients, this choice means assuming the risks associated with a redo SAVR or valve-in-valve procedure. To assess the use of mechanical vs. biological valve prostheses for SAVR relative to patient's age and implant time in a large population extracted from the French National Database EPICARD. Patients in EPICARD undergoing SAVR from 2007 to 2022 were included from 22 participating public or private centers chosen to represent a balanced representation of centre sizes and geographical discrepancies. Patients with associated pathology of the aorta (aneurysm or dissection) and requiring a vascular aortic prosthesis were excluded. Comparisons were made amongst centers, valve choice, implant date range, and patient age. We considered 101,070 valvular heart disease patients and included 72,375 SAVR (mean age 71.4 ± 12.2 years). We observed a mechanical vs. biological prosthesis ratio (MBPR) of 0.14 for the overall population. Before 50 years old (y-o), MBPR was >1.3 (p < 0.001) while patients above 60 years-old received principally biological SAVR (p < 0.0001). Concerning patients between 50 and 60 years-old patients, MPVR was 1.04 (p = 0.03). Patients 50-60 years-old from the first and second study duration quartile (before August 2015) received preferentially mechanical SAVR (p < 0.001). We observed a shift towards more biological SAVR (p < 0.001) for patients from the third and fourth quartile to reach a MBPR at 0.43 during the last years of the series. Incidentally, simultaneous mitral valve replacement were more common in case of mechanical SAVR (p < 0.0001), while associated CABGs were more frequent in case of biological SAVR (p < 0.0001). In a large contemporary French patient population, real world practice showed a recent shift towards a lower age-threshold for biological SAVR as compared to what would suggest contemporary guidelines.

Pulmonary valve-in-valve procedure after fractured biological prosthetic valve

Pulmonary valve-in-valve procedure after fractured biological prosthetic valve

A New Decellularization Protocol of Porcine Aortic Valves Using Tergitol to Characterize the Scaffold with the Biocompatibility Profile Using Human Bone Marrow Mesenchymal Stem Cells.

The most common aortic valve diseases in adults are stenosis due to calcification and regurgitation. In pediatric patients, aortic pathologies are less common. When a native valve is surgically replaced by a prosthetic one, it is necessary to consider that the latter has a limited durability. In particular, current bioprosthetic valves have to be replaced after approximately 10 years; mechanical prostheses are more durable but require the administration of permanent anticoagulant therapy. With regard to pediatric patients, both mechanical and biological prosthetic valves have to be replaced due to their inability to follow patients’ growth. An alternative surgical substitute can be represented by the acellular porcine aortic valve that exhibits less immunogenic risk and a longer lifespan. In the present study, an efficient protocol for the removal of cells by using detergents, enzyme inhibitors, and hyper- and hypotonic shocks is reported. A new detergent (Tergitol) was applied to replace TX-100 with the aim to reduce toxicity and maximize ECM preservation. The structural integrity and efficient removal of cells and nuclear components were assessed by means of histology, immunofluorescence, and protein quantification; biomechanical properties were also checked by tensile tests. After decellularization, the acellular scaffold was sterilized with a standard protocol and repopulated with bone marrow mesenchymal stem cells to analyze its biocompatibility profile.

44 Early and Long-Term Outcomes of Re-Sternotomy Aortic Valve Replacement (AVR) With Previous Coronary Artery Bypass Grafts (CABG)

Abstract Introduction With the wider use of biological prosthetic valves and increasing life expectancy, the number of patients requiring redo surgery for aortic valve replacement (AVR) is increasing. This carries its own risks particularly in those with previous cardiac surgery - from graft injury and myocardial jeopardy. Transcatheter valve replacement provides a safer option for high-risk patients that do not require any additional cardiac surgery. This project aims to evaluate the early and long-term outcomes of redo-sternotomy AVR after previous CABG. Method Retrospective study of patients that underwent redo sternotomy AVR with (Group 1) or without (Group 2) concomitant cardiac procedure(s) from 2000–2019. Pre-operative, operative and post-operative data collected for each patient. Statistical analysis done with significance p-value &amp;lt;0.15. Results 178 patients included during this time-period (Group 1 = 90 and Group 2 = 88). Mean age of 75 years and EuroSCORE of 17. In hospital-mortality was 7.8% with key contributing factors of heart failure (NYHA III-V), perioperative IABP insertion and cardiovascular injury - 12% of cases and most commonly effecting the left internal mammary artery (LIMA). Survival at 5 years in both groups is significantly worse for patients with post-operative complications and cardiovascular injury. However, long-term survival is better in Group 1 than in Group 2. Conclusions Risk of injury to LIMA increases operative mortality. Peripheral cannulation and pre-sternotomy cardiopulmonary bypass can help manage this - although numbers in this study too small. Alternatives to redo valve surgery are to be considered in high-risk patients and a multidisciplinary approach continued to be adopted for each case.

Valve deterioration: A victim of construct over time?

Surgical aortic valve replacement (sAVR) remains one of the most common cardiac operations performed globally on an annual basis. Biological and mechanical valves comprise the two classes of prosthetic valves available to surgeons. Biological prosthetic valves can be prone to failure and structural valve deterioration (SVD), which may necessitate reintervention. Recent literature suggests that the Trifecta heart valve is susceptible to early failure. In this retrospective study, Yount et al. use institutional data to assess the longevity of the Trifecta heart valve. The investigators included patients who had undergone sAVR and had received either a Trifecta prosthetic heart valve or a Magna/Magna Ease heart valve. While there were some baseline differences between the patient groups, the study found that those who had received a Trifecta valve had higher rates of valve failure. This is an important study that adds valuable evidence pertaining to the incidence of failure and SVD with the Trifecta heart valve. Although further studies may shed light on the precise mechanisms that drive valve failure and deterioration, surgeons should be aware of the mounting clinical data in this area.

The Role of Multimodality Imaging in Left-Sided Prosthetic Valve Dysfunction.

Prosthetic valve (PV) dysfunction (PVD) is a complication of mechanical or biological PV. Etiologic mechanisms associated with PVD include fibrotic pannus ingrowth, thrombosis, structural valve degeneration, and endocarditis resulting in different grades of obstruction and/or regurgitation. PVD can be life threatening and often challenging to diagnose due to the similarities between the clinical presentations of different causes. Nevertheless, identifying the cause of PVD is critical to treatment administration (thrombolysis, surgery, or percutaneous procedure). In this report, we review the role of multimodality imaging in the diagnosis of PVD. Specifically, this review discusses the characteristics of advanced imaging modalities underlying the importance of an integrated approach including 2D/3D transthoracic and transesophageal echocardiography, fluoroscopy, and computed tomography. In this scenario, it is critical to understand the strengths and weaknesses of each modality according to the suspected cause of PVD. In conclusion, for patients with suspected or known PVD, this stepwise imaging approach may lead to a simplified, more rapid, accurate and specific workflow and management.

Aortic biological prosthetic valve dysfunction secondary to endocarditis: Is percutaneous valve-in-valve an option?

We present the case of a 69-year-old man with an aortic biological prosthetic valve. In May 2019, the patient experienced increasing dyspnea and fatigue: A diagnosis of prosthetic aortic valve dysfunction was made, leading to severe valvular insufficiency. The dysfunction of the prosthetic valve seemed to be linked to a previous infective endocarditis: after ruling out active endocarditis, the patient was treated with an off-label valve-in-valve transcatheter aortic valve implantation.

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.

Pregnancy outcomes in women with mechanical heart valves

Abstract Background Mechanical heart valves (MHV) and their absolute need for adequate anticoagulation poses a challenge for pregnancy, either due to warfarin fetotoxicity or an increased risk of maternal thromboembolism. This represents a unique patient (P) group where data is scarce and maternal and fetal risks and benefits must be carefully weighed. Purpose To assess maternal and perinatal outcomes in women with MHV on different anticoagulant regimens and compare them with patients with other types of valvular heart disease (VHD). Methods A retrospective analysis of 131 pregnancies in 83 women with VHD (mean age 26.5±5.6 years) was carried out in a tertiary referral centre from 2000 to 2019. 92 pregnancies with VHD, including 11 with biological prosthetic valves, and 39 pregnancies in 22 P with MHV were identified. The main outcome measures were major maternal complications and perinatal outcome. Results MHV implanted were in mitral position (89.7%), aortic (2.6%), or both (7.7%). History of rheumatic heart disease was identified in 16 P (72.7%) and a congenital etiology was present in 2 P (9.1%). 9 P (40.9%) were on warfarine and 13 P (59.1%) on acenocumarol. Regarding anticoagulation strategy, 21 P (65.6%) remained on oral anticoagulation and 10 P (31.3%) had been switched to some form of heparin during part or the entire pregnancy. Mechanical valve thrombosis complicated pregnancy in 4 patients (10.2%), all cases on heparin, and resulted in maternal death in 1 P. MHV P had more hemorrhagic complications (15.4 vs 2.2%, p=0.004) requiring transfusion or surgical revision. MHV P tended to experience more NHYA class worsening demanding initiation or intensification of cardiac medication (17.9 vs 5.4%, p=0.023). Also in the MHV group there was a higher incidence of miscarriage (46.2 vs 12.0%, p≤0.0005), comprising spontaneous abortion (31.6 vs 7.6%, p&amp;lt;0.0005) and fetal malformations (18.4 vs 5.4%, p=0.028), including warfarin embryopathy (10.3 vs 1.1%, p=0.012). The live birth rate was higher in women on heparin compared with those on warfarin (85.9 vs 79.2%, p=0.002). The presence of multivalve disease (p=0.04), mechanical protheses (p&amp;lt;0.001), ACO (p&amp;lt;0.001) and previous impaired LVEF (p=0.02) were related to miscarriage. In multivariate analysis, ACO was the unique independent predictor of unsuccessful pregnancy (p=0.01). Only 29% of the patients with an MHV had a pregnancy free of serious adverse events compared with other types of VHD (81.5%, p&amp;lt;0.0005). Conclusions MHV remains a challenging condition for pregnancy with only 29% chance of experiencing an uncomplicated pregnancy with a live birth. The increased morbimortality warrant extensive prepregnancy counseling with prosthesis type discussion,centralization of care and further larger studies to come up with evidence-based recommendations. Funding Acknowledgement Type of funding source: None

Cirurgia cardíaca na endocardite infeciosa e preditores da mortalidade intra‐hospitalar

IntroductionInfective endocarditis (IE) is a serious disease with significant in‐hospital mortality (15‐30%) despite advances in medical and surgical therapy. AimsTo perform a clinical characterization of patients undergoing cardiac surgery for IE and to identify factors that predict in‐hospital mortality. MethodsWe retrospectively analyzed 145 patients with IE admitted between January 2006 and October 2017. ResultsThe median age was 72 years. IE was acquired mainly in the community (69%), and involved the native aortic valve in 54% of patients, biological prosthetic valves in 22.1% and mechanical valves in 10.3%. Staphylococcus spp. (31.0%) were the most frequent etiological agents. Cardiac surgery was emergent in 29 patients, urgent in 108, and elective in eight. The main indications were heart failure (57.9%), large vegetations (20%), systemic embolism (17.2%) and valve dysfunction (15.2%). Overall, biological valves were implanted in 62.1% of patients and mechanical valves in 37.2%. A total of 19 patients (13.1%) died. Predictors of mortality were preoperative atrial fibrillation and lower left ventricular ejection fraction, postoperative severe valve regurgitation associated with cardiogenic shock, sepsis, septic shock associated with cardiogenic shock, cardiac tamponade, need for renal replacement therapy and, although without statistical significance, emergent surgery. ConclusionsThere is a need for better indicators to enable early identification of surgical candidates for IE, implementation of a heart team, and better surgical strategies, including more rapid intervention, more specific postoperative care, and optimal antibiotic therapy.

Cardiac surgery in infective endocarditis and predictors of in-hospital mortality

Abstract Introduction Infective endocarditis (IE) is a serious disease with significant in-hospital mortality (15–30%) despite advances in medical and surgical therapy. Aims To perform a clinical characterization of patients undergoing cardiac surgery for IE and to identify factors that predict in-hospital mortality. Methods We retrospectively analyzed 145 patients with IE admitted between January 2006 and October 2017. Results The median age was 72 years. IE was acquired mainly in the community (69%), and involved the native aortic valve in 54% of patients, biological prosthetic valves in 22.1% and mechanical valves in 10.3%. Staphylococcus spp. (31.0%) were the most frequent etiological agents. Cardiac surgery was emergent in 29 patients, urgent in 108, and elective in eight. The main indications were heart failure (57.9%), large vegetations (20%), systemic embolism (17.2%) and valve dysfunction (15.2%). Overall, biological valves were implanted in 62.1% of patients and mechanical valves in 37.2%. A total of 19 patients (13.1%) died. Predictors of mortality were preoperative atrial fibrillation and lower left ventricular ejection fraction, postoperative severe valve regurgitation associated with cardiogenic shock, sepsis, septic shock associated with cardiogenic shock, cardiac tamponade, need for renal replacement therapy and, although without statistical significance, emergent surgery. Conclusions There is a need for better indicators to enable early identification of surgical candidates for IE, implementation of a heart team, and better surgical strategies, including more rapid intervention, more specific postoperative care, and optimal antibiotic therapy.

95 A rare case of Lactobacillus Plantarum prosthetic valve endocarditis

Abstract INTRODUCTION Lactobacillus species are rare human pathogens but have been implicated in a variety of infections, including bacteremia and endocarditis, with Lactobacillus casei and Lactobacillus rhamnosus among the most frequently isolated species. Endocarditis due to Lactobacillus represents &amp;lt;0.5% of all cases of endocarditis and are associated with structural heart diseases, recent surgery, extended antibiotic and probiotic use and immuno-deficiency. We report a case of Lactobacillus plantarumendocarditis in a patient with biological aortic prosthetic valve. CASE REPORT Our patient is a 48 year-old male with a past medical history of surgical aortic replacement with a biological prosthetic valve in 2013. He reports the onset of symptoms 4 months before with worsening asthenia. The patient presented to a cardiologist after 3 months from symptoms beginning. A transesophageal echocardiogram (TEE) described marked fibro-plastic thickening of the cusps with two elongated vegetations (12 mm and 7 mm) causing a moderate-to-severe aortic steno-regurgitation. A few days later he came to our emergency department. On admission, the patient was afebrile, eupnoeic on room air. The cardiac examination revealed a regular rate and rhythm with a grade 4 of 6 holosystolic murmur loudest at the aortic and pulmonary focus. Three sets of blood cultures were drawn on admission. Hence, he was transferred to the Infectious Diseases Department where he started antibiotic therapy with Ceftriaxone and Gentamicin. A 18F-FDG PET-CT total body showed tracer accumulation close to the prosthetic aortic valve. Few days later Lactobacillus Plantarum was isolated from blood cultures and, according to the antibiogram results, therapy was adjusted using G Penicillin, Vancomicyn and Gentamicin. The TEE, performed during the hospitalization, showed one mobile vegetation, reduced in size (5 mm), adherent to the anterior aortic cusp, which prolapsed in the left ventricular outflow tract and commissural fusion, causing severe steno-regurgitation (Gmax 84 mmHg, Gmed 54 mmHg). During hospitalization the serial blood cultures resulted negative. Serial TEEs were also performed (3rdand 6thweek), showing a gradual reduction of the cusps thickening and disappearance of commissural fusion (Figure). In the last TEE no vegetations were described, and the transaortic mean gradient was reduced (Gmed 38 mmHg), persisting severe regurgitation. Hence the patient was discharged with oral antibiotic therapy (amoxicillin and clavulanic acid) and indication to redo aortic valve surgery. Written informed consent was obtained. CONCLUSIONS L. plantarum is a rare form of endocarditis. In our patient it caused fibro-plastic thickening of the bioprosthesis cusps and commissural fusion, determining severe steno-regurgitation. It also responded to targeted antibiotic therapy with improvement in cusp mobility but persistence of severe regurgitation. Abstract 95 Figure

Analysis of leaflet flutter in biological prosthetic heart valves using PIV measurements

The use of biological prosthetic valves has increased considerably in recent decades since they have several advantages over mechanical ones, but they still possess the great disadvantage of having a relatively short lifetime. An understudied phenomenon is the flutter effect that causes oscillations in the cusps, which is associated with regurgitation, calcification and fatigue, which can reduce even more the lifetime of bioproteses. In an experimental bench that simulates the cardiac flow, the behavior of a porcine and a bovine pericardium valves was recorded by a high-speed camera to quantify the oscillations of the cusps and an experiment using particle image velocimetry was conducted to study the velocity profiles and shear stresses and their relations with flutter. Results showed that the pericardial valve has lower values of frequencies and amplitudes compared to the porcine valve. Lower velocity values were found in the cusps that did not have flutter, but no relationship was observed between shear stress values and leaflet vibrations. These results may assist in future projects of biological prosthetic valves that have less flutter and longer lifespan.

Late Right Coronary Obstruction Following TAVR in a Degenerated Surgical Aortic Bioprosthetic Valve

We present a case of an 80-year-old woman with severe aortic insufficiency due to a degenerated 21-mm biological prosthetic aortic valve implanted 9 years earlier, treated by using a transcatheter aortic valve replacement valve-in-valve procedure and who experienced a delayed right coronary obstruction. (Level of Difficulty: Beginner.)

"A Tale of Two Cities": Anticoagulation Management in Patients with Atrial Fibrillation and Prosthetic Valves in the Era of Direct Oral Anticoagulants.

Valvular heart disease and atrial fibrillation often coexist. Oral vitamin K antagonists have represented the main anticoagulation management for antithrombotic prevention in this setting for decades. Novel direct oral anticoagulants (DOACs) are a new class of drugs and currently, due to their well-established efficacy and security, they represent the main therapeutic option in non-valvular atrial fibrillation. Some new evidences are exploring the role of DOACs in patients with valvular atrial fibrillation (mechanical and biological prosthetic valves). In this review we explore the data available in the medical literature to establish the actual role of DOACs in patients with valvular heart disease and atrial fibrillation.

Сравнительная оценка использования механических и биологических протезов в позиции аортального клапана у возрастных пациентов

Сравнительная оценка использования механических и биологических протезов в позиции аортального клапана у возрастных пациентов