Mechanical Aortic Valve Dehiscence and Aortic Root Aneurysm: An Interesting Case With a Timely Diagnosis and Intervention.

Prosthetic aortic valve dehiscence is a rare but potentially life-threatening complication that can occur after aortic valve replacement surgery. This condition occurs when the prosthetic valve becomes detached or dislodged from its original position leading to aortic valve regurgitation and congestive heart failure. The most common risk factors for prosthetic valve dehiscence include infective endocarditis, ascending aortic aneurysm, and severe calcification of the aortic valve. Ankylosing spondylitis, non-infectious aortitis, and accompanying vasculitis can also cause aortic valve dehiscence. Transthoracic echocardiography and transesophageal echocardiography usually reveal an unstable prosthesis with rocking motion and paravalvular regurgitation. Fluoroscopy and cardiac computed tomography (CT) are useful complementary tests, especially in patients with significant artifacts related to a valve prosthesis. Patients with prosthetic valve dehiscence and paravalvular regurgitation eventually develop heart failure and circulatory collapse. Timely diagnosis and early surgical intervention in these patients are crucial to achieve good long-term outcomes.

Surgery compared to fibrinolytic therapy for symptomatic left-sided prosthetic heart valve thrombosis (SAFE-PVT): Rationale and design of a randomized controlled trial.

BACKGROUND: Left-sided mechanical prosthetic heart valve thrombosis (PVT) occurs because of suboptimal anticoagulation and is common in low-resource settings. Urgent surgery and fibrinolytic therapy (FT) are the two treatment options available for this condition. Urgent surgery is a high-risk procedure but results in successful restoration of valve function more often and is the treatment of choice in developed countries. In low-resource countries, FT is used as the default treatment strategy, though it is associated with lower success rates and a higher rate of bleeding and embolic complications. There are no randomized trials comparing the two modalities. METHODS: We performed a single center randomized controlled trial comparing urgent surgery (valve replacement or thrombectomy) with FT (low-dose, slow infusion tissue plasminogen activator, tPA) in patients with symptomatic left-sided PVT. The primary outcome was the occurrence of a complete clinical response, defined as discharge from hospital with completely restored valve function, in the absence of stroke, major bleeding or non-CNS systemic embolism. Outcome assessment was done by investigators blinded to treatment allocation. The principal safety outcome was the occurrence of a composite of in-hospital death, non-fatal stroke, non-fatal major bleed or non-CNS systemic embolism. Outcomes will be assessed both in the intention-to-treat, and in the as-treated population. We will also report outcomes at one year of follow-up. The trial has completed recruitment. CONCLUSION: This is the first randomized trial to compare urgent surgery with FT for the treatment of left-sided PVT. The results will provide evidence to help clinicians make treatment choices for these patients. (Clinical trial registration: CTRI/2017/10/010159).

Kocuria kristinae-Induced Infective Endocarditis: Unveiling an Emerging Threat in Clinical Practice.

Infective endocarditis (IE) remains a formidable challenge in clinical practice due to several causative agents, each presenting with unique diagnostic and therapeutic dilemmas. Kocuria kristinae, a coagulase-negative, catalase-positive Gram-positive coccus, has recently emerged as an uncommon but increasingly recognized pathogen in the cause of IE. This case report highlights the clinical characteristics, risk factors, and challenges associated with Kocuria kristinae-induced IE. We conducted a comprehensive literature review and identified several case reports on Kocuria kristinae as a causative agent. Due to its indolent nature and the subtle presentation of symptoms, along with its ability to form biofilms, delayed diagnosis of Kocuria is often seen, thereby emphasizing the need for heightened clinical suspicion. The predisposing factors for Kocuria kristinae infection include underlying cardiac abnormalities, prosthetic heart valves, and immunocompromised states. Additionally, antimicrobial susceptibility patterns and optimal treatment strategies remain unclear, warranting further investigation. This abstract presents the case of a 75-year-old male with IE secondary to Kocuria kristinae on a prosthetic mitral valve. We aim to highlight the need for increased awareness among clinicians to facilitate early recognition and prompt initiation of targeted therapeutic interventions. Unraveling the intricacies of Kocuria kristinae's pathogenicity is crucial for refining diagnostic approaches and optimizing patient outcomes.

Analysis of Aetiological Agents in Infectious Endocarditis in the Central Military Emergency University Hospital "Dr. Carol Davila" Bucharest.

BACKGROUND: Infective endocarditis (IE) is a pathological condition caused by various microbial agents that can lead to severe complications affecting the heart. Accurate diagnosis is crucial for the effective management of patients with IE. Blood culture is the gold standard for identifying the primary infectious agents, which is a key factor in diagnosing IE using the modified Duke criteria. OBJECTIVE: The main objective of this study was to investigate the distribution of the etiological agents of IE and the most common secondary diagnoses associated with it. METHOD: A total of 152 patients aged 23-95 years with a diagnosis of IE and proven etiology (through blood cultures or serological tests) were included in this study. RESULTS: The most common etiological agent identified through blood tests was Enterococcus faecalis, which was detected in 39 patients (23.5%). Staphylococcus aureus was the second most common agent and was identified in 33 patients (19.9%), followed by Staphylococcus epidermidis, which was identified in 12 patients (13.1%). Nine patients (5.8%) had high levels of anti-Coxiella burnetti IgG phase I and II antibodies. CONCLUSIONS: IE is a leading cause of death in the Department of Infectious Diseases. Early and accurate diagnosis, along with interdisciplinary treatment, can significantly increase the chances of patient survival. Currently, Enterococcus faecalis and Staphylococcus aureus are the dominant etiological agents of IE, highlighting the need to revise protocols for prophylaxis, diagnosis, and initial treatment of this condition.

Management of prosthetic valve thrombosis with unfractionated heparin.

BACKGROUND: Prosthetic valve thrombosis (PVT) is a severe and life-threatening complication. Surgery and thrombolytic therapy (TT) carry a high risk, and in several circumstances, optimal anticoagulation with unfractionated heparin (UFH) infusion may be an alternative treatment. This study aimed to assess the results of UFH in patients diagnosed with both obstructive and non-obstructive PVT. METHODS: This observational retrospective study enrolled patients who had contraindications for TT and surgery underwent UFH therapy. RESULTS: A total of 136 patients were enrolled [male: 55 (40.4%), mean age: 50.3 ± 14.6 years] in the study. In the successful group, 66 patients (48,5%) showed >75% regression in the thrombus burden without facing death or major non-fatal complications.In the unsuccessful group, 56 had less than a 50% reduction in thrombus load and 14 (10.3%) suffered major complications. The presence of obstruction (27.1% vs. 12.1%; p = 0.028), thrombus area 1.1 cm2 vs. 0.8 cm2; p = 0.005] and the duration of UFH treatment (15.1 vs. 11.8 (days); p = 0.005) were significantly higher in the unsuccessful UFH group.In multivariate regression analyses the presence of obstruction (RR: 3.088, p = 0.020), increased thrombus area (RR: 2.400; p = 0.015), and increased duration of UFH therapy (RR: 1.073 95%, p = 0.012) were identified as independent predictive parameters for a failed UFH therapy. CONCLUSIONS: This study suggests that UFH therapy may be considered a relatively beneficial treatment strategy for some patients with PVT. The most significant factors affecting success are the obstructive nature and area of the thrombus.

A Fibrin-Thrombin Based In Vitro Perfusion System to Study Flow-Related Prosthetic Heart Valves Thrombosis.

Prosthetic heart valve (PHV) replacement has increased the survival rate and quality of life for heart valve-diseased patients. However, PHV thrombosis remains a critical problem associated with these procedures. To better understand the PHV flow-related thrombosis problem, appropriate experimental models need to be developed. In this study, we present an in vitro fibrin clot model that mimics clot accumulation in PHVs under relevant hydrodynamic conditions while allowing real-time imaging. We created 3D-printed mechanical aortic valve models that were inserted into a transparent glass aorta model and connected to a system that simulates human aortic flow pulse and pressures. Thrombin was gradually injected into a circulating fibrinogen solution to induce fibrin clot formation, and clot accumulation was quantified via image analysis. The results of valves positioned in a normal versus a tilted configuration showed that clot accumulation correlated with the local flow features and was mainly present in areas of low shear and high residence time, where recirculating flows are dominant, as supported by computational fluid dynamic simulations. Overall, our work suggests that the developed method may provide data on flow-related clot accumulation in PHVs and may contribute to exploring new approaches and valve designs to reduce valve thrombosis.

Perfect prosthetic heart valve: generative design with machine learning, modeling, and optimization.

Majority of modern techniques for creating and optimizing the geometry of medical devices are based on a combination of computer-aided designs and the utility of the finite element method This approach, however, is limited by the number of geometries that can be investigated and by the time required for design optimization. To address this issue, we propose a generative design approach that combines machine learning (ML) methods and optimization algorithms. We evaluate eight different machine learning methods, including decision tree-based and boosting algorithms, neural networks, and ensembles. For optimal design, we investigate six state-of-the-art optimization algorithms, including Random Search, Tree-structured Parzen Estimator, CMA-ES-based algorithm, Nondominated Sorting Genetic Algorithm, Multiobjective Tree-structured Parzen Estimator, and Quasi-Monte Carlo Algorithm. In our study, we apply the proposed approach to study the generative design of a prosthetic heart valve (PHV). The design constraints of the prosthetic heart valve, including spatial requirements, materials, and manufacturing methods, are used as inputs, and the proposed approach produces a final design and a corresponding score to determine if the design is effective. Extensive testing leads to the conclusion that utilizing a combination of ensemble methods in conjunction with a Tree-structured Parzen Estimator or a Nondominated Sorting Genetic Algorithm is the most effective method in generating new designs with a relatively low error rate. Specifically, the Mean Absolute Percentage Error was found to be 11.8% and 10.2% for lumen and peak stress prediction respectively. Furthermore, it was observed that both optimization techniques result in design scores of approximately 95%. From both a scientific and applied perspective, this approach aims to select the most efficient geometry with given input parameters, which can then be prototyped and used for subsequent in vitro experiments. By proposing this approach, we believe it will replace or complement CAD-FEM-based modeling, thereby accelerating the design process and finding better designs within given constraints. The repository, which contains the essential components of the study, including curated source code, dataset, and trained models, is publicly available at https://github.com/ViacheslavDanilov/generative_design.

A Case Report of Secondary Postpartum Hemorrhage in a Pregnant Woman With a Mechanical Mitral Valve: Challenges of Anticoagulation.

A pregnant woman with rheumatic heart disease always runs the risk of developing both thromboembolic and hemorrhagic symptoms, necessitating careful monitoring of her anticoagulation treatments both throughout pregnancy and after delivery. Postpartum haemorrhage, a hemorrhagic manifestation, can be challenging to control and presents a significant challenge when it comes to beginning anticoagulation after delivery. Thus, pregnancy in these patients is an extremely risky endeavour. Given that these women take anticoagulants, managing these women with artificial heart valves throughout pregnancy can be difficult. The diminished clotting ability in these women may be the cause of postpartum haemorrhage, and a multidisciplinary approach is necessary for a successful treatment. To manage this potentially fatal illness, a well-equipped institution with proper support systems is essential. We present a 23-year-old primigravida who was 39 weeks and three days pregnant and had a repaired aortic valve as well as a prosthetic mitral valve. She was taking warfarin to prevent clotting when she was pregnant.

Mycoplasma genitalium Endocarditis in Prosthetic Aortic Valve.

We report a case of Mycoplasma genitalium endocarditis in a prosthetic heart valve of a woman who sought care in Switzerland for acute aortic valve dysfunction 3 years after valve replacement. This unusual manifestation of infection with this bacterium was diagnosed using broad-range PCR despite suspicion of a mechanical disinsertion.

A contact model based on the coefficient of restitution for simulations of bio-prosthetic heart valves.

A new general contact model is proposed for preventing inter-leaflet penetration of bio-prosthetic heart valves (BHV) at the end of the systole, which has the advantage of applying kinematic constraints directly and creating smooth free edges. At the end of each time step, the impenetrability constraints and momentum exchange between the impacting bodies are applied separately based on the coefficient of restitution. The contact method is implemented in a rotation-free, large deformation, and thin shell finite-element (FE) framework based on loop's subdivision surfaces. A nonlinear, anisotropic material model for a BHV is employed which uses Fung-elastic constitutive laws for in-plane and bending responses, respectively. The contact model is verified and validated against several benchmark problems. For a BHV-specific validation, the computed strains on different regions of a BHV under constant pressure are compared with experimentally measured data. Finally, dynamic simulations of BHV under physiological pressure waveform are performed for symmetrical and asymmetrical fiber orientations incorporating the new contact model and compared with the penalty contact method. The proposed contact model provides the coaptation area of a functioning BHV during the closing phase for both of the fiber orientations. Our results show that fiber orientation affects the dynamic of leaflets during the opening and closing phases. A swirling motion for the BHV with asymmetrical fiber orientation is observed, similar to experimental data. To include the fluid effects, fluid-structure interaction (FSI) simulation of the BHV is performed and compared to the dynamic results.

The five-year trends in antibiotic prescription by dentists and antibiotic prophylaxis for tooth extraction: a region-wide claims study in Japan.

BACKGROUND: Antimicrobial stewardship in dentistry and antibiotic prophylaxis for tooth extraction have been areas of concern in Japan, with limited research available. METHODS: This cross-sectional study utilized the regional health insurance claims database in Japan to examine antibiotic prescription trends by dentists, including antibiotic regimens, timing of prescription, and days of supply for prophylactic antibiotic use during tooth extraction. Antibiotic prophylaxis for patients with prosthetic heart valves was also investigated. FINDINGS: Antibiotic prescriptions by dentists decreased by 7% in 2019 compared to those in 2015, with third-generation cephalosporins still accounting for 48.5% in 2019. Amoxicillin prescription increased 3.9 times in 2019, although it only accounted for 8.4% of all antibiotic prescriptions. In 2019, amoxicillin was prescribed for 17.1% of all prophylactic antibiotics associated with tooth extraction, and 80% of prophylactic antibiotics were prescribed for 3 days or more, with 85% prescribed on the day of the procedure. However, only 60-70% of patients with prosthetic heart valves received antibiotic prophylaxis. INTERPRETATION: Despite the increasing trend after the implementation of the National Action Plan on antimicrobial resistance, the proportion of amoxicillin prescriptions in dentistry remains low. Antimicrobial stewardship issues related to long-term prescription and timing of administration of prophylactic antibiotics for tooth extraction should be addressed. Dentists must recognize the risks associated with high-risk patients with prosthetic heart valves who require antibiotic prophylaxis, and physicians providing valve replacement therapy should inform patients of the requirement for prophylaxis before invasive dental procedures.

Left-Sided Prosthetic Valve Dysfunction and Gastrointestinal Bleeding.

Introduction We sought to investigate the association between left-sided prosthetic valve dysfunction and gastrointestinal (GI) bleeding. Methods In a retrospective cohort of patients with left-sided prostheses, we identified those who experienced one or more GI bleeds. The latest or chronologically closest echocardiogram to the GI bleed was analyzed by a blinded investigator for prosthetic valve dysfunction. Results Among 334 unique patients, 166 had aortic prostheses, 127 had mitral prostheses, and 41 had both. A total of 58 (17.4%) subjects had GI bleeding events. Patients in the "GI Bleed" group had higher mean ejection fraction (56±14% vs. 49±15%; P = 0.003) and higher prevalence of hypertension, end-stage renal disease, and liver cirrhosis compared to the "No GI Bleed" group. There was a higher prevalence of moderate or severe prosthetic valve regurgitation in the GI Bleed vs. No GI Bleed group (8.6% vs. 2.2%; P = 0.027). Moderate or severe prosthetic valve regurgitation was independently associated with GI bleeding (odds ratio, 6.18; 95% confidence interval, 1.27-30.05; P = 0.024), after adjusting for ejection fraction, hypertension, end-stage renal disease and liver cirrhosis. Paravalvular regurgitation was associated with a higher incidence of GI bleeding compared to transvalvular regurgitation (35.7% vs. 11.9%; P = 0.044). The prevalence of prosthetic valve stenosis was similar between the GI Bleed and No GI Bleed groups (6.9% vs. 5.8%; P = 0.761). Conclusion In a cohort of patients with predominantly surgically placed prosthetic valves, moderate to severe left-sided prosthetic valve regurgitation was independently associated with GI bleeding.

Usefulness of cardiac computed tomography in prosthetic heart valve dysfunction.

BACKGROUND: Prosthetic heart valve (PHV) dysfunction is a serious complication. Echocardiography remains the first-line imaging investigation to assess PHV dysfunction. However, the role of Computed Tomography (CT) scanning in this type of case has not been thoroughly studied yet. The objective of our study was to determine if cardiac Computed Tomography (CT) had a potentially complementary role to play alongside echocardiography in diagnosing the mechanism of prosthetic valve dysfunction. METHODS AND RESULTS: This prospective cohort study was conducted on 54 patients with suspected PHV dysfunction. All patients underwent routine diagnosis work-up (transthoracic and transesophageal echocardiography) and additional cardiac CT. Cardiac CT showed findings that were not detected by echocardiography in seven patients (12%) namely aortic pannus (5) and pseudoaneurysm (2). An underlying thrombus was detected by echocardiography and missed by cardiac CT in 15 patients (27%). However, in these thrombotic cases, cardiac CT contributed to the functional evaluation of leaflets. CONCLUSION: This study demonstrates that an integrated approach including transthoracic, transesophageal echocardiography and computed tomography is useful in patients with suspected PHV dysfunction. While computed tomography is more accurate in the diagnosis of pannus formation and periannular complications, echocardiography is superior at detecting thrombus.

Dehiscent Prosthetic Aortic Valve and Aortic Root Pseudoaneurysm Complicated by Left Main Coronary Artery Compression.

Prosthetic aortic valve dehiscence is an uncommon complication of prosthetic valve endocarditis that may occur in patients who have undergone aortic valve replacement (AVR). The concurrent presence of aortic root pseudoaneurysm may further complicate the clinical presentation through the external compression of coronary arteries. Thus, patients may present with clinical features of coronary ischemia. Echocardiogram and coronary angiography are useful in establishing diagnosis. Treatment involves a multidisciplinary approach involving cardiologists, infectious disease specialists, and cardiothoracic surgeons. The authors of this study discuss a 51-year-old male who presented with anginal chest pain and was found to have a new left bundle branch block, elevated troponins, and left main coronary artery compression complicating aortic root aneurysm. He ended up requiring a re-do AVR, repair of the pseudoaneurysm, and coronary artery bypass graft.

Prosthetic Aortic Valve Endocarditis Creeping Into the Paravalvular Space.

Prosthetic valve endocarditis is a devastating infection with a challenging diagnosis and management. Despite advances in its diagnostic modalities, medical, and surgical interventions, prosthetic valve endocarditis still carries high morbidity and mortality rates. Here, we report a case of prosthetic aortic valve endocarditis that progressed to involve the paravalvular space and the importance of multimodality cardiac imaging in the early detection of paravalvular complications.

Causes and treatment strategies of unilateral leaflet escape of bileaflet mechanical prosthetic heart valves after surgery: a case series.

BACKGROUND: During the eleven years from 2010 to 2021, preliminary statistics have shown that Fuwai Hospital completed 23,571 mechanical valve replacements for various types of valves, and 1139 mechanical valve replacements were performed in Guangyuan First People's Hospital. Only two patients developed valve leaflet escape, so valve leaflet escape is a rare postoperative complication. CASE PRESENTATION: In 2010 and 2021, two patients were selected after they had unilateral leaflet escape after having mechanical valve replacements in Fuwai Hospital of Chinese Academy of Medical Sciences and Guangyuan First People's Hospital. Both patients underwent reoperations with the classic operation and the new bileaflet mechanical prosthetic heart valve was sutured. The treatment of detached single lobe and distal vessel was comprehensively determined, and the condition was treated according to the patient's symptoms, CT results, ultrasound results and other test results, as well as whether this detached lobe caused any abnormal hemodynamics of the distal vessel. The patient with mechanical aortic valve escape completed the 10-year follow-up, and patient with mechanical mitral valve escape completed the 3-month follow-up. there was no thrombosis or hematoma at the embolic site; the patient had no lower limb symptoms. CONCLUSIONS: The reason for the leaflet escape may be related to the valve design and the leaflet material. If the detached leaflets are damaged and if the distal blood vessels are affected, simultaneous surgical treatment is required. Those patients whose vessels were not damaged by the valve lobe should be carefully monitored.

Survival and Recurrence of Endocarditis following Mechanical vs. Biological Aortic Valve Replacement for Endocarditis in Patients Aged 40 to 65 Years: Data from the INFECT-Registry.

BACKGROUND: Infective endocarditis (IE) is a serious disease, and in many cases, surgery is necessary. Whether the type of prosthesis implanted for aortic valve replacement (AVR) for IE impacts patient survival is a matter of debate. The aim of the present study is to quantify differences in long-term survival and recurrence of endocarditis AVR for IE according to prosthesis type among patients aged 40 to 65 years. METHODS: This was an analysis of the INFECT-REGISTRY. Trends in proportion to the use of mechanical prostheses versus biological ones over time were tested by applying the sieve bootstrapped t-test. Confounders were adjusted using the optimal full-matching propensity score. The difference in overall survival was compared using the Cox model, whereas the differences in recurrence of endocarditis were evaluated using the Gray test. RESULTS: Overall, 4365 patients were diagnosed and operated on for IE from 2000 to 2021. Of these, 549, aged between 40 and 65 years, underwent AVR. A total of 268 (48.8%) received mechanical prostheses, and 281 (51.2%) received biological ones. A significant trend in the reduction of implantation of mechanical vs. biological prostheses was observed during the study period (p < 0.0001). Long-term survival was significantly higher among patients receiving a mechanical prosthesis than those receiving a biological prosthesis (hazard ratio [HR] 0.546, 95% CI: 0.322-0.926, p = 0.025). Mechanical prostheses were associated with significantly less recurrent endocarditis after AVR than biological prostheses (HR 0.268, 95%CI: 0.077-0.933, p = 0.039). CONCLUSIONS: The present analysis of the INFECT-REGISTRY shows increased survival and reduced recurrence of endocarditis after a mechanical aortic valve prosthesis implant for IE in middle-aged patients.

Seguridad y eficacia de la bioprótesis de válvula cardiaca INC en humanos / Safety and efficacy of the INC bioprosthetic heart valve in humans

Resumen Introducción: Las bioprótesis de válvulas cardiacas son el estándar de oro para el reemplazo quirúrgico de la válvula aórtica en pacientes seleccionados. Objetivo: Evaluar la seguridad y eficacia de la válvula cardiaca bioprotésica del Instituto Nacional de Cardiología (INC) en humanos. Métodos: Estudio unicéntrico que incluyó 341 pacientes que se sometieron a reemplazo valvular quirúrgico único de válvula aórtica con válvula INC. Resultados: Se realizaron 318 implantes de novo (93 %) y 23 como segunda cirugía (7 %); las puntuaciones STS fueron de 1.4 y 1.8 % y el seguimiento de 42 y 46 meses, respectivamente. No existieron diferencias en las complicaciones ni en la tasa de implantación de marcapasos. Ambos grupos mantuvieron una FEVI normal. Se observó mejoría global en la clase funcional con empeoramiento solo en dos pacientes del grupo de novo. La disfunción de la prótesis INC que ameritó reintervención quirúrgica se observó en ocho pacientes (4.65 %) del grupo de novo versus un paciente (7.69 %) con segunda cirugía. Conclusiones: La válvula cardiaca INC es eficaz y segura, se asocia a baja tasa de complicaciones y mejoría de la clase funcional durante el seguimiento a largo plazo. Se necesitan estudios prospectivos comparativos de esta válvula.

Abstract Introduction: Heart valve bioprostheses are the gold standard for aortic valve surgical replacement in selected patients. Objective: To evaluate the safety and efficacy of the of the National Institute of Cardiology (INC) bioprosthetic heart alve of the National Institute of Cardiology (INC) bioprosthetic heart valve in humans. Methods: Single-center study that ncluded 341 patients who underwent single surgical aortic valve replacement with INC heart valve. Results: 318 implants were performed de novo (93%) and 23 as redo surgery (7%); STS scores were 1.4 and 1.8%, and follow-up was for 42 and 46 months, respectively. There were no differences in clinical complications or pacemaker implantation rate. Both groups maintained a normal LVEF. Overall improvement in functional class was observed, with worsening only in two patients of the de novo group. INC prosthesis dysfunction requiring surgical reintervention was observed in eight patients (4.65%) of the de novo group vs. one patient in the redo group. Conclusions: The INC heart valve is efficacious and safe, and is associated with a The INC heart valve is efficacious and safe, and is associated with a low rate of complications and functional class improvement during long-term follow-up. Prospective, comparative studies of this valve are required.