Bioprosthetic Aortic Valve Replacement Research Articles

A tale of 2 conversions: Dichotomous decision in the spectrum of Shone syndrome is still a dilemma

A tale of 2 conversions: Dichotomous decision in the spectrum of Shone syndrome is still a dilemma

Mechanical versus Bioprosthetic Aortic Valve Replacement in Middle-Aged Adults: A Systematic Review and Meta-Analysis.

Mechanical prostheses and bioprosthetic prostheses have their own advantages and disadvantages. Mechanical ones are recommended for younger patients (<50 years old), and bioprosthetic ones are recommended for older patients (>70 years old). There is still debate regarding which kind of prosthesis is better for middle-aged patients (50 to 70 years old) receiving aortic valve replacement (AVR). To solve this problem, we conducted this meta-analysis. Given that only one randomized controlled trial (RCT) study was included, we conducted a subgroup analysis of RCT and propensity score matching (PSM) retrospective studies to reduce the bias. We systematically searched articles related to clinical outcomes of mechanical and bioprosthetic prostheses in middle-aged patients receiving AVR in the PubMed, Cochrane Library, and China National Knowledge Infrastructure (CNKI) databases. The published date was up to 1 October 2022. Studies were excluded if not only middle-aged patients were included, or if they lacked direct comparisons between mechanical and bioprosthetic prostheses. In total, 22 studies with 32,298 patients were included in the final analysis. The results show that patients aged between 50 and 70 receiving AVR with mechanical prostheses achieved better long-term survival and fewer reoperations and valve-related events but suffered more with bleeding events. No significant difference could be found in terms of early mortality and long-term cardiac death. The same results could be observed in the subgroup analysis of RCT and PSM retrospective studies. Both mechanical and bioprosthetic prostheses are beneficial to middle-aged patients undertaking AVR procedures. However, mechanical prostheses show better clinical outcomes in long-term survival and comorbidities. Individual recommendation is still necessary.

Circulating Progenitor Cells Are Associated With Bioprosthetic Aortic Valve Deterioration: A Preliminary Study.

Background Mechanisms underlying bioprosthetic valve deterioration are multifactorial and incompletely elucidated. Reparative circulating progenitor cells, and conversely calcification-associated osteocalcin expressing circulating progenitor cells, have been linked to native aortic valve deterioration. However, their role in bioprosthetic valve deterioration remains elusive. This study sought to evaluate the contribution of different subpopulations of circulating progenitor cells in bioprosthetic valve deterioration. Methods and Results This single-center prospective study enrolled 121 patients who had peripheral blood mononuclear cells isolated before bioprosthetic aortic valve replacement and had an echocardiographic follow-up ≥2 years after the procedure. Using flow cytometry, fresh peripheral blood mononuclear cells were analyzed for the surface markers CD34, CD133, and osteocalcin. Bioprosthetic valve deterioration was evaluated by hemodynamic valve deterioration (HVD) using echocardiography, which was defined as an elevated mean transprosthetic gradient ≥30 mm Hg or at least moderate intraprosthetic regurgitation. Sixteen patients (13.2%) developed HVD during follow-up for a median of 5.9 years. Patients with HVD showed significantly lower levels of reparative CD34+CD133+ cells and higher levels of osteocalcin-positive cells than those without HVD (CD34+CD133+ cells: 125 [80, 210] versus 270 [130, 420], P=0.002; osteocalcin-positive cells: 3060 [523, 5528] versus 670 [180, 1930], P=0.005 respectively). Decreased level of CD34+CD133+ cells was a significant predictor of HVD (hazard ratio, 0.995 [95% CI, 0.990%-0.999%]). Conclusions Circulating levels of CD34+CD133+ cells and osteocalcin-positive cells were significantly associated with the subsequent occurrence of HVD in patients undergoing bioprosthetic aortic valve replacement. Circulating progenitor cells might play a vital role in the mechanism, risk stratification, and a potential therapeutic target for patients with bioprosthetic valve deterioration.

Mechanical vs Bioprosthetic Aortic Valve Replacement in Patients on Dialysis: Long-term Outcomes

BackgroundUsing the Japan National Clinical Database and additional data, this study is an analysis of long-term survival of dialysis-dependent patients who underwent aortic valve replacement (AVR). MethodsDialysis-dependent patients who underwent de novo AVR between 2010 and 2012 and who were registered in the database were included. Concomitant aortic surgery and transcatheter aortic valve replacement were excluded. Additional data on the underlying kidney disease, the duration of dialysis, and clinical outcomes were registered between October 29, 2019, and August 30, 2020. The primary outcome was all-cause mortality. The secondary outcomes were cerebral infarction, cerebral bleeding, gastrointestinal bleeding, and prosthetic valve failure. ResultsAfter propensity score matching, 1016 cases (508 each in the bioprosthetic and mechanical valve groups) were matched. The median follow-up period was 3.29 years (interquartile range [IQR], 0.59 years, 6.25 years). The median survival time was 5.38 years (IQR, 1.20 and 9.26 years) in the mechanical valve group and 4.98 years (IQR, 1.69 and 9.62 years) in the bioprosthetic valve group. The Cox regression model showed no significant difference in long-term survival between the groups (mechanical valve: hazard ratio [HR], 0.895; 95% CI, 0.719-1.113; P = .318). The incidences of cerebral infarction and prosthetic valve failure requiring admission were similar between the groups. Cerebral bleeding (HR, 2.143; 95% CI, 1.125-4.080; P = .002) and gastrointestinal bleeding (HR, 2.071; 95% CI, 1.243-3.451; P = .0005) were more frequent in the mechanical valve group. ConclusionsLong-term survival of dialysis-dependent patients was similar regardless of whether mechanical valves or bioprosthetic valves were implanted. The incidences of cerebral and gastrointestinal bleeding were 2-fold higher in the mechanical valve group.

Hypertrophic Obstructive Cardiomyopathy Associated with Moderate Aortic Stenosis in Symptomatic 75-Year-Old Female: A Case Report

A 72-year-old female was found to have symptomatic hypertrophic obstructive cardiomyopathy associated with significant aortic stenosis. She was found to have severe left ventricular outflow tract obstruction, asymmetric septal hypertrophy, significant systolic anterior motion of the anterior mitral valve leaflet, and mitral regurgitation. She was also found to have moderate aortic stenosis that made the obstruction even worse which made the patient progressively symptomatic not responding to medical therapy. She eventually underwent cardiac surgery in form of left ventricular septal myomectomy and bioprosthetic aortic valve replacement (tissue AVR) with a size 23 tissue valve, aortic root enlargement with bovine pericardial patch. She is currently stable on optimal medical therapy, feels much better and stable cardiac-wise with much better quality of life.

Ross Procedure Versus Mechanical Versus Bioprosthetic Aortic Valve Replacement: A Network Meta-Analysis.

Background The Ross operation appears to restore normal survival in young and middle-aged adults with aortic valve disease. However, there are limited data comparing it with conventional aortic valve replacement. Herein, we compared outcomes of the Ross procedure with mechanical and bioprosthetic aortic valve replacement (M-AVR and B-AVR, respectively). Methods and Results MEDLINE and EMBASE were searched through March 2022 to identify randomized controlled trials and propensity score-matched studies that investigated outcomes of patients aged ≥16 years undergoing the Ross procedure, M-AVR, or B-AVR. The systematic literature search identified 2 randomized controlled trials and 8 propensity score-matched studies involving a total of 4812 patients (Ross: n=1991; M-AVR: n=2019; and B-AVR: n=802). All-cause mortality was significantly lower in the Ross procedure group compared with M-AVR (hazard ratio [HR] [95% CI], 0.58 [0.35-0.97]; P=0.035) and B-AVR (HR [95% CI], 0.32 [0.18-0.59]; P<0.001) groups. The reintervention rate was lower after the Ross procedure and M-AVR compared with B-AVR, whereas it was higher after the Ross procedure compared with M-AVR. Major bleeding rate was lower after the Ross procedure compared with M-AVR. Long-term stroke rate was lower following the Ross procedure compared with M-AVR and B-AVR. The rate of endocarditis was also lower after the Ross procedure compared with B-AVR. Conclusions Improved long-term outcomes of the Ross procedure are demonstrated compared with conventional M-AVR and B-AVR options. These results highlight a need to enhance the recognition of the Ross procedure and revisit current guidelines on the optimal valve substitute for young and middle-aged patients.

Management Challenges in Patients Younger Than 65 Years With Severe Aortic Valve Disease

The management of aortic valve disease, including aortic stenosis and aortic regurgitation (AR), in younger adult patients (age <65 years) is complex, and the optimal strategy is often unclear, contingent on multiple anatomic and holistic factors. Traditional surgical approaches carry significant considerations, including compulsory lifelong anticoagulation for patients who receive a mechanical aortic valve replacement (AVR) and the risk of structural valvular deterioration and need for subsequent valve intervention in those who receive a bioprosthetic AVR. These factors are magnified in young adults who are considering pregnancy, for whom issues of anticoagulation and valve longevity are heightened. The Ross procedure has emerged as a promising alternative; however, its adoption is limited to highly specialized centers. Valve repair is an option for selected patients with AR. These treatment options offer varying degrees of durability and are associated with different risks and complications, especially for younger adult patients. Patient-centered care from a multidisciplinary valve team allows for discussion of the optimal timing of intervention and the advantages and disadvantages of the various treatment options. The management of severe aortic valve disease in adults younger than 65 years is complex, and there are numerous considerations with each management decision. While mechanical AVR and bioprosthetic AVR have historically been the standards of care, other options are emerging for selected patients but are not yet generalizable beyond specialized surgical centers. A detailed discussion by members of the multidisciplinary heart team and the patient is an integral part of the shared decision-making process.

902: A MIX OF FUNGI, AIR, BLEED, AND CLOTS WITHIN A LUNG

Introduction: Spontaneous hemothorax is a rare condition known to be associated with anticoagulation. We describe a case of fatal hemothorax associated with 2 different fungi that presented a therapeutic dilemma. Description: A 74-year-old female with past medical history significant for hyperhomocysteinemia secondary to MTHFR gene mutation, bioprosthetic aortic valve replacement, deep venous thrombosis, pulmonary embolism and paroxysmal atrial fibrillation on therapeutic anticoagulation presented with fever, dyspnea and hemoptysis. CT of the chest showed an actively extravasating left lung hematoma extending into the pleural space with moderate hemothorax and a small focus of gas within the collection and underlying multifocal pneumonia. Systemic anticoagulation was held and she received antibiotics for pneumonia despite which hypoxia worsened and she was intubated. She required pressors secondary to septic shock. She underwent multiple bronchoscopies and chest tube placement despite which she continued to have recurrent hemothorax suspected secondary to an actively hemorrhagic lung abscess. While in the operating room for video-assisted thoracoscopic surgery (VATS) she suffered cardiac arrest with return of spontaneous circulation in 2 minutes that resulted in multiorgan dysfunction. VATS was aborted. Cultures from previous bronchoscopy resulted in growth of Penicillium and Aspergillus species and she was started on antifungal therapy. However, she subsequently developed multiple pulmonary emboli and embolic brain infarcts. In light of clinical deterioration and grim prognosis, the family opted for comfort measures. Discussion: Despite its association with hemoptysis, there are limited studies describing the occurrence of massive spontaneous hemothorax in aspergillosis. Our case is made additionally interesting by the co-infection with Aspergillus and Penicillium species simultaneously. The patient’s hyperhomocysteinemia predisposes her to a prothrombotic state, compounded by atrial fibrillation that was likely the cause of multiple embolic infarcts in paradox to her actively hemorrhagic abscess that precluded systemic anticoagulation. The therapeutic dilemma and rapid clinical deterioration raise the need for further investigation into the condition to augment early diagnosis and intervention.

How Did We Get Here? Antithrombotic Therapy after Bioprosthetic Aortic Valve Replacement: A Review.

Aortic stenosis is the most common valvular disease, and more than 90% of patients who undergo aortic valve replacement receive a bioprosthetic valve. Yet optimal antithrombotic therapy after bioprosthetic aortic valve replacement remains uncertain, and guidelines provide contradictory recommendations. Randomized studies of antithrombotic therapy after bioprosthetic aortic valve replacement are small and underpowered. Observational data present opposing, and likely confounded, results. Historically, changes to guidelines have not been informed by high-quality new data. Current guidelines from different professional bodies provide contradictory recommendations despite citing the same evidence. Insufficient antithrombotic therapy after bioprosthetic aortic valve replacement has serious implications: ischemic stroke, systemic arterial thromboembolism, and clinical and subclinical valve thromboses. Unnecessarily intense antithrombotic therapy, however, increases risk of bleeding and associated morbidity and mortality. Professional bodies have used the current low-quality evidence and generated incongruent recommendations. Researchers should prioritize generating high-quality, randomized evidence evaluating the risks and benefits of antiplatelet versus anticoagulant therapy after bioprosthetic aortic valve replacement.

Treatment of Severe Aortic Valve Stenosis: Impact of Patient Sex and Life Expectancy on Treatment Choice.

In adults with severe aortic stenosis, sex and age differences in symptoms and diagnosis may lead to delays in intervention. Choice of intervention partly depends on expected longevity because bioprosthetic valves have limited durability, particularly in younger patients. Current guidelines recommend the following: a mechanical valve in younger adults (aged <50 years) if lifelong anticoagulation is possible and acceptable and a valve-sparing procedure is not possible; surgical mechanical or bioprosthetic aortic valve replacement (SAVR) in adults aged 50-65 years; and transcatheter aortic valve implantation (TAVI) for those aged >80 years based on lower mortality and morbidity compared to SAVR and adequate valve durability. For patients aged 65-80 years, the choice between TAVI and a bioprosthetic SAVR depends on expected longevity, which is greater in women than men, as well as associated cardiac and noncardiac conditions, valvular and vascular anatomy, estimated risk of SAVR versus TAVI and expected complications and patient preferences.

Bioprosthetic reoperative aortic valve replacement in patients under 50

A clinical decision report using: Chan V, Lam BK, Rubens FD, et al. Long-term evaluation of biological versus mechanical prosthesis use at reoperative aortic valve replacement. J Thorac Cardiovasc Surg. 2012;144(1):146-151. https://doi.org/10.1016/j.jtcvs.2011.08.041 for a patient considering reoperative aortic valve replacement.

Clinical performance of a novel bioprosthetic surgical aortic valve in a German high-volume center.

Bioprosthetic surgical aortic valve replacement (SAVR) is increasingly adopted in younger patients. We aimed to analyze mid-term follow-up data after SAVR to assess the performance of the prosthesis. Data were collected from a single-center series of 154 patients, who underwent SAVR with a bioprosthetic heart valve with the RESILIA tissue at our Heart Centre in Siegburg. All procedural and midterm patient outcomes were documented. Patients had a mean age of 56.8 ± 9.9 years, 35.7% were female, and the mean logistic European system for cardiac operative risk evaluation (EuroSCORE) was 3.4 ± 3.6%. Diabetes (12.3%), atrial fibrillation (10.4%), and chronic obstructive pulmonary disease (COPD) (5.8%) were common comorbidities. The mean surgery duration was 163.8 ± 73.4 min, with the 23 mm (34.4%) and 25 mm (33.8%) heart valves being most frequently implanted. At 3-year follow-up, mean pressure gradient was 13.9 ± 5.9 mmHg, peak gradient was 23.6 ± 7.7 mmHg, and effective orifice area (EOA) was 1.9 ± 0.4 cm². No patient died during the operation, 3 (2.1%) patients within 30 days, and 4 (2.7%) thereafter with an overall mortality of n = 7. Of the surviving patients, 97.8% were in New York Heart Association (NYHA) class I/II and none had structural valve deterioration (SVD). Results of our single-center study indicate favorable procedural outcomes. The safety outcomes confirm preliminary earlier results of this novel bioprosthesis but include more patients and a longer midterm follow-up.

Abstract 13214: Circulating Progenitor Cells Are Associated With Bioprosthetic Aortic Valve Deterioration

Introduction: Mechanisms underlying bioprosthetic valve deterioration (BVD) are multifactorial and incompletely elucidated. Reparative circulating progenitor cells (CPCs), and conversely calcification-associated osteocalcin expressing CPCs (CPC-OCN), have been linked to native aortic valve deterioration. However, their role in BVD remains elusive. This study sought to evaluate the contribution of different subpopulations of CPCs in BVD. Methods: This prospective study enrolled 121 patients who had peripheral blood mononuclear cells (PBMC) isolated prior to bioprosthetic aortic valve replacement (surgical 104, transcatheter 17) and had an echocardiographic follow-up ≥2 years after the procedure. Using flow cytometry, fresh PBMC were analyzed for the surface markers CD34, CD133, and osteocalcin (OCN). BVD was evaluated by hemodynamic valve deterioration (HVD) using echocardiography, which was defined as an elevated mean transprosthetic gradient ≥30mmHg and/or at least moderate intraprosthetic regurgitation. Multivariable models were constructed to evaluate the association of each subpopulation of CPCs and other clinical characteristics with HVD. Results: Sixteen patients (13.2%) developed HVD during follow-up for a median of 5.9 years. Patients with HVD showed significantly lower levels of reparative CD34 + CD133 + cells and higher levels of OCN + cells than those without HVD (CD34 + CD133 + cells: 125 [80, 210] vs 270 [130, 420], P=0.002; OCN + cells: 3060 [523, 5528] vs 670 [180, 1930], P=0.005 respectively). Decreased level of CD34 + CD133 + cells was a significant predictor of HVD. Conclusions: Circulating levels of CD34 + CD133 + cells and OCN + cells were significantly associated with the subsequent occurrence of HVD in patients undergoing bioprosthetic aortic valve replacement. CPCs might play a vital role in the mechanism, risk stratification and a potential therapeutic target for patients with bioprosthetic valve deterioration.

Abstract 13847: The Ross Procedure versus Mechanical versus Bioprosthetic Aortic Valve Replacement: A Network Meta-Analysis

Background: The Ross operation appears to restore normal survival in young and middle-aged adults with aortic valve disease. However, there is limited data comparing it to conventional aortic valve replacement options. Objectives: To compare outcomes of the Ross procedure, mechanical and bioprosthetic aortic valve replacement (M-AVR, B-AVR). Methods: MEDLINE and EMBASE were searched through March 2022 to identifyrandomized controlled trials (RCTs) and propensity-score matched studies (PSMs) that investigated outcomes of patients ≥16-year-old undergoing the Ross procedure, M-AVR or B-AVR. Result: The systematic literature search identified 2 RCTs and 8 PSMs involving a total of 4,812 patients (Ross: n=1,991; M-AVR: n=2,019; B-AVR: n=802). All-cause mortality was significantly lower in the Ross procedure group compared with M-AVR (hazard rate (HR) [95% confidence interval (CI)]=0.58 [0.35-0.97], P=0.035) and BAVR (HR [95% CI]=0.32 [0.18-0.59], P &lt;0.001) groups. The reintervention rate was lower in the Ross and M-AVR groups compared with B-AVR (HR [95% CI] =0.31 [0.15-0.65], P=0.002, HR [95% 272 CI] =0.15 [0.05-0.41], P&lt; 0.001, respectively), while it was higher after the Ross procedure compared with M-AVR group (HR [95% CI] =2.12 [1.04-4.33], P=0.039). However, post-Ross reinterventions included both autograft and right ventricular outflow tract. Major bleeding rate was lower after the Ross procedure compared with M-AVR. Long-term stroke rate was lower following the Ross procedure compared with M-AVR and B-AVR. The rate of endocarditis was also lower after the Ross procedure compared with B-AVR. Conclusion: Improved long-term outcomes of the Ross procedure are demonstrated compared with conventional M-AVR and B-AVR options. These results highlight a need to enhance the recognition of the Ross procedure and revisit current guidelines regarding the optimal valve substitute for young and middle-aged patients.

Abstract 13294: Role of Retrospective Cardiac Computed Tomography Angiography in the Detection of Prosthetic Valve Endocarditis

Case presentation A 47-year-old man was readmitted for evaluation of recurrent fevers, night sweats, and weight loss over a 3 month period. He had a history of bioprosthetic aortic and mitral valve replacements for rheumatic valve disease and heart failure with reduced ejection fraction due to non-ischemic cardiomyopathy. Physical examination was remarkable for a[LMD1] grade II/VI systolic murmur. Laboratory notable for neutrophilic leukocytosis elevated C-reactive protein and erythrocyte sedimentation rate. Blood cultures demonstrated Staphylococcus epidermidis . On transthoracic echocardiogram (TTE) performed in the current admission and transesophageal echocardiogram (TEE) done 2 months prior the prosthetic valves were not clearly visualized, but there was no regurgitation, stenosis or vegetation noted. Due to a high index of suspicion for prosthetic valve endocarditis (PVE), a retrospectively gated cardiac computed tomography angiography (CCTA) of the entire cardiac cycle was performed. It revealed a 13 mm mobile vegetation attached to the ventricular side of the left coronary cusp (Figure 1). Subsequently, the patient underwent a redo aortic valve replacement. Blood cultures cleared and the patient was discharged on hospital day 16 to complete 6 weeks of Cefazolin and Rifampin. Discussion: The modified Duke criteria play an important role in the diagnosis of native valve infective endocarditis (IE) (~ 80% sensitive), but it carries a lower diagnostic yield in the detection of PVE. While TEE carries high accuracy in the diagnosis of native valve endocarditis, approximately 30% of patients with PVE and/or intra-cardiac devices have inconclusive or normal echocardiographic findings. Inability to recognize IE in a timely fashion (&lt;4 days) leads to greater embolic events. We showed how CCTA can be used to expedite the diagnosis of PVE.

Outcomes of bovine versus porcine surgical aortic valve replacement.

There are no guidelines regarding the use of bovine pericardial or porcine valves for aortic valve replacement, and prior studies have yielded conflicting results. The current study sought to compare short- and long-term outcomes in propensity-matched cohorts of patients undergoing isolated aortic valve replacement(AVR) with bovine versus porcine valves. This was a retrospective study utilizing an institutional database of all isolated bioprosthetic surgical aortic valve replacements performed at our center from 2010 to 2020. Patients were stratified according to type of bioprosthetic valve (bovine pericardial or porcine), and 1:1 propensity-score matching was applied. Kaplan-Meier survival estimation and multivariable Cox regression for mortality were performed. Cumulative incidence functions were generated for all-cause readmissions and aortic valve reinterventions. A total of 1502 patients were identified, 1090 (72.6%) of whom received a bovine prosthesis and 412 (27.4%) of whom received a porcine prosthesis. Propensity-score matching resulted in 412 risk-adjusted pairs. There were no significant differences in clinical or echocardiographic postoperative outcomes in the matched cohorts. Kaplan-Meier survival estimates were comparable, and, on multivariable Cox regression, valve type was not significantly associated with long-term mortality (hazard ratio: 1.02, 95% confidence interval: 0.74, 1.40, p = .924). Additionally, there were no significant differences in competing-risk cumulative incidence estimates for all-cause readmissions (p = .68) or aortic valve reinterventions (p = .25) in the matched cohorts. The use of either bovine or porcine bioprosthetic aortic valves yields comparable postoperative outcomes, long-term survival, freedom from reintervention, and freedom from readmission.

Bioprosthetic aortic valve replacement: The right valve at the right patient by the right surgeon: The key to success.

Journal of Cardiac SurgeryVolume 37, Issue 12 p. 5254-5256 COMMENTARY Bioprosthetic aortic valve replacement: The right valve at the right patient by the right surgeon: The key to success Guglielmo Stefanelli MD, Corresponding Author Guglielmo Stefanelli MD [email protected] orcid.org/0000-0002-7789-0967 Department of Cardiac Surgery, Hesperia Hospital, Modena, Italy Correspondence: Guglielmo Stefanelli, MD, Department of Cardiac Surgery, Hesperia Hospital, Via Arquà 80/a, 41125, Modena, Italy. Email: [email protected]Search for more papers by this author Guglielmo Stefanelli MD, Corresponding Author Guglielmo Stefanelli MD [email protected] orcid.org/0000-0002-7789-0967 Department of Cardiac Surgery, Hesperia Hospital, Modena, Italy Correspondence: Guglielmo Stefanelli, MD, Department of Cardiac Surgery, Hesperia Hospital, Via Arquà 80/a, 41125, Modena, Italy. Email: [email protected]Search for more papers by this author First published: 02 November 2022 https://doi.org/10.1111/jocs.17077Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume37, Issue12December 2022Pages 5254-5256 RelatedInformation

Fluid-structure interaction analysis of eccentricity and leaflet rigidity on thrombosis biomarkers in bioprosthetic aortic valve replacements.

This work intends to study the effect of aortic annulus eccentricity and leaflet rigidity on the performance, thrombogenic risk and calcification risk in bioprosthetic aortic valve replacements (BAVRs). To address these questions, a two-way immersed fluid-structure interaction (FSI) computational model was implemented in a high-performance computing (HPC) multi-physics simulation software, and validated against a well-known FSI benchmark. The aortic valve bioprosthesis model is qualitatively contrasted against experimental data, showing good agreement in closed and open states. Regarding the performance of BAVRs, the model predicts that increasing eccentricities yield lower geometric orifice areas (GOAs) and higher normalized transvalvular pressure gradients (TPGs) for healthy cardiac outputs during systole, agreeing with in vitro experiments. Regions with peak values of residence time are observed to grow with eccentricity in the sinus of Valsalva, indicating an elevated risk of thrombus formation for eccentric configurations. In addition, the computational model is used to analyze the effect of varying leaflet rigidity on both performance, thrombogenic and calcification risks with applications to tissue-engineered prostheses. For more rigid leaflets it predicts an increase in systolic and diastolic TPGs, and decrease in systolic GOA, which translates to decreased valve performance. The peak shear rate and residence time regions increase with leaflet rigidity, but their volume-averaged values were not significantly affected. Peak solid stresses are also analyzed, and observed to increase with rigidity, elevating risk of valve calcification and structural failure. To the authors' knowledge this is the first computational FSI model to study the effect of eccentricity or leaflet rigidity on thrombogenic biomarkers, providing a novel tool to aid device manufacturers and clinical practitioners.

IMPROVED OUTCOMES FOLLOWING THE ROSS PROCEDURE COMPARED WITH BIOPROSTHETIC AORTIC VALVE REPLACEMENT

IMPROVED OUTCOMES FOLLOWING THE ROSS PROCEDURE COMPARED WITH BIOPROSTHETIC AORTIC VALVE REPLACEMENT

PROSTHETIC VALVE INFECTIVE ENDOCARDITIS CAUSED BY SERRATIA MARCESCENS IN A PATIENT WITH SURGICAL WOUND INFECTION

PROSTHETIC VALVE INFECTIVE ENDOCARDITIS CAUSED BY SERRATIA MARCESCENS IN A PATIENT WITH SURGICAL WOUND INFECTION