Search

Current guidelines exclusively recommend vitamin-K-antagonists (VKA) as anticoagulation for patients after mechanical aortic valve replacement due to the increased postoperative risk of valve thrombosis and thrombo-embolism. Strict and regular assessments are mandatory during VKA therapy to ensure a potent anticoagulatory effect within the desired range. From the patients' perspective, VKA are associated with relevant interactions and side effects reducing the quality of life and contributing to a high number of patients not achieving the optimal therapeutic target. Direct oral anticoagulants (DOAC) have replaced VKA therapy in the past for several indications, e.g., atrial fibrillation. However, it is still unclear if DOACs could replace VKA therapy in patients after mechanical aortic valve replacement. While the PROACT-Xa study did not show a sufficient anticoagulatory effect of apixaban plus aspirin compared to VKA therapy in patients after mechanical aortic valve replacement, the direct thrombin inhibitor dabigatran and the oral factor Xa inhibitors apixaban and rivaroxaban showed promising results in comparable patient cohorts in smaller studies and case reports. Factor Xa inhibitors were able to prevent thrombosis and thrombo-embolic events in patients after mechanical aortic valve replacement. Therefore, factor Xa inhibitors or factor XI inhibitors could provide a potent alternative to VKA for patients after a mechanical aortic valve replacement. [ABSTRACT FROM AUTHOR]

Background To date, vitamin K anticoagulants are the only recommended long-term therapy for mechanical heart valves. Bleeding episodes, thromboembolic events, and international normalized ratio monitoring are difficult and prevalent complications for these patients. This report reflects the late mechanical aortic valve dysfunction after long-term low molecular weight heparin therapy. Case summary A 66-year-old male patient underwent mechanical aortic valve replacement in 2007. He was administered therapeutic doses of enoxaparin for nearly 12 years due to warfarin-related bleeding complications and labile international normalized ratios. However, he experienced multiple cardiovascular and cerebrovascular thromboembolic events, including an anterolateral ST-elevation myocardial infarction with left anterior descending artery thrombus, treated with thrombus aspiration and stenting. The patient was eventually admitted with symptoms and signs of acute heart failure, and echocardiography, fluoroscopy, and a cardiac computed tomography detected mechanical aortic valve prosthesis dysfunction, with an immobile leaflet and pannus. The patient demonstrated no improvement despite switching to unfractionated heparin, and he ultimately underwent redo aortic bioprosthetic valve surgery with a favourable outcome. Discussion Low molecular weight heparin is prescribed for patients with aortic mechanical valves who are intolerant to vitamin K antagonists or as bridging in certain situations. Anti-Xa factor monitoring should be considered for long-term prescriptions. [ABSTRACT FROM AUTHOR]

Over the last years computer modelling and simulation has emerged as an effective tool to support the total product life cycle of cardiovascular devices, particularly in the device preclinical evaluation and post-market assessment. Computational modelling is particularly relevant for heart valve prostheses, which require an extensive assessment of their hydrodynamic performance and of risks of hemolysis and thromboembolic complications associated with mechanicallyinduced blood damage. These biomechanical aspects are typically evaluated through a fluid-structure interaction (FSI) approach, which enables valve fluid dynamics evaluation accounting for leaflets movement. In this context, the present narrative review focuses on the computational modelling of bileaflet mechanical aortic valves through FSI approach, aiming to foster and guide the use of simulations in device total product life cycle. The state of the art of FSI simulation of heart valve prostheses is reviewed to highlight the variety of modelling strategies adopted in the literature. Furthermore, the integration of FSI simulations in the total product life cycle of bileaflet aortic valves is discussed, with particular emphasis on the role of simulations in complementing and potentially replacing the experimental tests suggested by international standards. Simulations credibility assessment is also discussed in the light of recently published guidelines, thus paving the way for a broader inclusion of in silico evidence in regulatory submissions. The present narrative review highlights that FSI simulations can be successfully framed within the total product life cycle of bileaflet mechanical aortic valves, emphasizing that credible in silico models evaluating the performance of implantable devices can (at least) partially replace preclinical in vitro experimentation and support post-market biomechanical evaluation, leading to a reduction in both time and cost required for device development. [ABSTRACT FROM AUTHOR]

Over the last years computer modelling and simulation has emerged as an effective tool to support the total product life cycle of cardiovascular devices, particularly in the device preclinical evaluation and post-market assessment. Computational modelling is particularly relevant for heart valve prostheses, which require an extensive assessment of their hydrodynamic performance and of risks of hemolysis and thromboembolic complications associated with mechanically-induced blood damage. These biomechanical aspects are typically evaluated through a fluid-structure interaction (FSI) approach, which enables valve fluid dynamics evaluation accounting for leaflets movement. In this context, the present narrative review focuses on the computational modelling of bileaflet mechanical aortic valves through FSI approach, aiming to foster and guide the use of simulations in device total product life cycle. The state of the art of FSI simulation of heart valve prostheses is reviewed to highlight the variety of modelling strategies adopted in the literature. Furthermore, the integration of FSI simulations in the total product life cycle of bileaflet aortic valves is discussed, with particular emphasis on the role of simulations in complementing and potentially replacing the experimental tests suggested by international standards. Simulations credibility assessment is also discussed in the light of recently published guidelines, thus paving the way for a broader inclusion of in silico evidence in regulatory submissions. The present narrative review highlights that FSI simulations can be successfully framed within the total product life cycle of bileaflet mechanical aortic valves, emphasizing that credible in silico models evaluating the performance of implantable devices can (at least) partially replace preclinical in vitro experimentation and support post-market biomechanical evaluation, leading to a reduction in both time and cost required for device development.

Muhannad Ababneh,1 Abdullah Al-Kasasbeh,1 Emad Algorani2 1Division of Cardiology, Department of Internal Medicine, Faculty of Medicine, Jordan University of Science and Technology, Irbid, Jordan; 2Department of Internal Medicine, Faculty of Medicine, Jordan University of Science and Technology, Irbid, JordanCorrespondence: Muhannad Ababneh, Division of Cardiology, Department of Internal Medicine, Faculty of Medicine, Jordan University of Science and Technology, Irbid, Jordan, Tel +9622 799964654, Email mjababneh@just.edu.joBackground: The use of anticoagulation is mandatory for prevention of prosthetic valve thrombosis (PVT) worldwide, regardless of the valve type or position in the heart. In case a thrombosis causes symptomatic dysfunction, treatment usually includes the use of thrombolytic therapy or surgery. We report a case of PVT involving a patient with a mechanical aortic valve which was treated entirely with the use of anticoagulation therapy (warfarin).Case Presentation: A 58-year-old man had an aortic valve replacement using a Carbomedics® mechanical valve due to severe aortic stenosis as a result of a calcific bicuspid native aortic valve. He was commenced on warfarin after surgery which was continued thereafter. He presented to our hospital after three years with shortness of breath at rest. On clinical examination, his condition was poor with a New York Heart Association functional classification of IV. He was in sinus rhythm and had an enlarged heart shadow on chest X-ray. Transesophageal echocardiography (TEE) revealed aortic valve regurgitation with vegetations on the anterior valve leaflet causing reduced hemi leaflet motility and a mean pressure gradient of 50 mmHg. Cinefluoroscopy revealed a dysfunctional mechanical valve leaflet. Surgery was at high risk of mortality due to the patient’s clinical status and he was continued on warfarin therapy with close monitoring. Cinefluoroscopy and echocardiography done six months later revealed complete dissolution of thrombus and a normally functioning mechanical aortic valve.Conclusion: Only a few cases of symptomatic, thrombotic mechanical aortic valve were entirely treated with anticoagulation only. Our patient is one such case who had resolution of symptoms and improvement on NYHA functional classification (IV to I).Keywords: prosthetic valve thrombosis, PVT, anticoagulation, mechanical aortic valve, PVT management

Patients with a mechanical heart valve need a lifelong anticoagulation due to the increased risk of valve thrombosis and thrombo-embolism. Currently, vitamin K antagonists (VKA) are the only approved class of oral anticoagulants, but relevant interactions and side effects lead to a large number of patients not achieving the optimal therapeutic target international normalized ration (INR). Therefore, steady measurements of the INR are imperative to ensure potent anticoagulation within a distinctive range. Direct oral anticoagulants (DOACs) with newer agents could serve as a possible alternative to VKAs in this patient cohort. DOACs are approved for several indications, e.g., atrial fibrillation (AF). They only have a minor interaction potential, which is why monitoring is not needed. Thereby, DOACs improve the livability of patients in need of chronical anticoagulation compared with VKAs. In contrast to dual platelet inhibition using aspirin in combination with an ADP receptor antagonist and the direct thrombin inhibitor dabigatran, the oral factor Xa inhibitors apixaban and rivaroxaban show promising results according to current evidence. In small-scale studies, factor Xa inhibitors were able to prevent thrombosis and thrombo-embolic events in patients with mechanical heart valves. Finally, DOACs seem to represent a feasible treatment option in patients with mechanical heart valves, but further studies are needed to evaluate clinical safety. In addition to the ongoing PROACT Xa trial with apixaban in patients after aortic On-X valve implantation, studies in an all-comer collective with rivaroxaban could be promising. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to investigate outcomes after endovascular aortic arch repair in patients with a mechanical aortic valve where the valve needs to be crossed., Methods: An international, multicentre, retrospective observational study was undertaken including all consecutive patients who underwent endovascular arch repair with mechanical aortic valve crossing., Results: From March 2020 to August 2023, 12 patients were included in the study (median age 55 years, interquartile range 45, 67 years; 58% male). Five patients (42%) had a genetically confirmed connective tissue disorder (CTD) and three more had a high clinical suspicion of CTD. Most patients had a bileaflet valve (11/12; 92%) and one patient had a monoleaflet one. All patients had previously undergone surgical ascending aortic repair. Technical success was 100% with successful completion of the procedure with no valve damage. Two deaths (17%) were observed in the first 30 days post-operatively with no signs of valve malfunction: one patient died of major stroke due to excessive wire and sheath manipulation in the arch; and another due to cardiac arrest of unknown cause, with no valve damage being detected in the autopsy. No intra-operative technical difficulties regarding valve cannulation were observed. During a median follow up of eight months, one patient died fifteen months after the procedure owing to non-aortic related causes, and four endoleaks were present on the latest computed tomography angiography, none type I or III., Conclusion: Endovascular aortic arch repair in a selected group of patients with a mechanical aortic valve, treated in experienced high volume aortic centres, seems technically feasible and reasonably safe. These preliminary results underline the complexity of the procedure and should be validated by larger cohort studies. With careful patient selection and adequate physician experience, the presence of a mechanical aortic valve could potentially no longer pose a major contraindication to endovascular arch repair in the future., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Acute aortic dissections are considered surgical emergencies because they are catastrophic bleeding events. The risk of bleeding is further increased if the patient requires anticoagulation for other comorbidities, such as a mechanical heart valve.  This case study describes a 73-year-old gentleman who presented with massive hemoptysis due to an acute aortic dissection complicated by pulmonary hemorrhage in the context of previous aortic dissection with multiple repair surgeries and residual chronic aortic dissection. He was also on warfarin for a mechanical aortic valve complicated by supratherapeutic international normalized ratio. His acute aortic dissection was treated conservatively without surgery, and he survived. Concerning the risk of thromboembolism from the mechanical aortic valve, anticoagulation was reintroduced one week after his initial bleeding. We changed warfarin to enoxaparin, which was started at a small dose, 40 mg subcutaneously once a day, then gradually increased to the full therapeutic dose, 90 mg (1 mg/kg) twice daily over a week. He was not fully anticoagulated for two weeks. Fortunately, he did not develop any thrombosis. Hemoglobin and Factor Xa levels were closely monitored. He tolerated the enoxaparin without further bleeding.  This type of case is rare and has not been previously reported, considering the patient survived acute aortic dissection with conservative management, did not develop any thrombosis from the mechanical aortic valve when anticoagulation was withheld, and did not experience rebleeding when anticoagulation was restarted. Further research and guidelines are needed to assist clinicians in managing anticoagulation when facing the dilemmas of the risk of bleeding and the risk of thromboembolism. This is particularly important in complex scenarios, such as for patients with mechanical heart valves who subsequently develop contraindications such as aortic dissection or other life-threatening bleeding events., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Xia et al.)

Abstract Background Mechanical aortic valve dysfunction is a rare but potentially fatal complication. It is usually caused by thrombosis, vegetation, and pannus overgrowth. However, it very rarely occurs immediately after the cardiopulmonary bypass weaning period. Case presentation We describe a case of stuck leaflet after the implantation of a mechanical aortic valve because of residual suture materials interfering with mechanical aortic valve leaflet closure, which is a very rare cause and has not been reported until now. Conclusion The residual suture materials for mechanical aortic valve replacement could cause mechanical valve dysfuction indicated as stuck leafet.

Abstract Background This study aimed to confirm the safety and feasibility of simple pannus removal in patients with mechanical aortic valve dysfunction for pannus overgrowth by evaluating its early clinical outcomes. Methods From March 2015 to April 2019, 24 consecutive patients with mechanical aortic valve dysfunction due to subaortic pannus underwent reoperation. In 12 patients the repeat aortic valve replacement (AVR) was performed, and 12 received the simple pannus removal to preserve the previously implanted prosthesis. Results There was only 1 in-hospital death in simple pannus removal group. Significant differences were obtained between procedures in cardiopulmonary bypass (CPB) and aortic cross-clamp time (128.7 vs 179.7 and 74.2 vs 132.7 mins, respectively, P 0.05) in echocardiography 1 week after operation. In addition, the aortic transvalvular peak velocity and TMPG in echocardiography 1 week after operation in pannus removal group between the repeat and initial surgery were not statistically significant (2.6 ± 0.4 vs. 2.5 ± 0.3 m/s, 13.2 ± 3.6 vs. 13.0 ± 3.5 mmHg, P > 0.05). Conclusions Simple pannus removal was a safe and effective procedure with satisfied early clinical outcomes for pannus overgrowth in mechanical aortic valve. However, further randomized and long-term follow-up studies were warranted to determine the clinical effects of the simple aortic pannus removal.

Purpose: To present a novel technique to successfully cross a mechanical aortic valve prosthesis.Technique: A 55-year-old female patient with genetically verified Marfan syndrome presented with a 5-cm anastomotic aneurysm of the proximal aortic arch after previous ascending aortic replacement due to a type A aortic dissection in 2007. The patient also underwent mechanical aortic valve replacement in 1991. A 3-stage hybrid repair was planned. The first 2 steps included debranching of the supra-aortic vessels. In the third procedure, a custom-made double branched endovascular stent-graft with a short 35-mm introducer tip was implanted. The mechanical valve was passed with the tip of the dilator on the lateral site of the leaflet, without destructing the valve and with only mild symptoms of aortic insufficiency, as one leaflet continued to work. This allowed the implantation of the stent-graft directly distally of the coronary arteries. Postoperative computed tomography angiography showed no endoleaks and patent coronary and supra-aortic vessels.Conclusion: Passing a mechanical aortic valve prosthesis at the proper position is feasible and allows adequate endovascular treatment in complex arch anatomy. However, caution should be taken during positioning of the endovascular graft as the tip may potentially damage the valve prosthesis. [ABSTRACT FROM AUTHOR]

Background: Cardiovascular diseases are the leading cause of morbidity and mortality in pregnant women. On the other hand, cardiac surgery is not so common for pregnant women. Case report: We present the case of a pregnant woman with diagnosed thrombosis of the mechanical aortic valve in the 12th gestational week. The patient underwent surgery, and successfully completed her pregnancy till the 37th gestational week. Conclusion: We showed that, despite general anaesthesia during the first trimester of pregnancy, the application of the nonpulsatile flow of extracorporeal circulation and mild hypothermia, the operation was successfully completed and that both mother and fetus survived. [ABSTRACT FROM AUTHOR]

Mechanical valve thrombosis is a rare but serious complication that requires rapid diagnosis and treatment. In most reported cases, inadequate anticoagulation or cessation of anticoagulation is the cause of the prosthesis thrombosis. We present a clinical case of a patient who underwent aortic valve replacement with a mechanical valve St. Jude Medical 10 years ago. Due to several sudden collapses and absence of the metallic click sound the patient was transported to our hospital. The patient was admitted in the cardiology department in severe general condition. We performed transthoracic echocardiography, transesophageal echocardiography, fluoroscopy and we established a dysfunction of mechanical aortic valve. Surgical treatment was undertaken: the dysfunctional aortic valve was removed and the new LivaNova Crown biological valve was implanted. The macroscopic surgical finding, a thrombosis in mechanical aortic valve, and the histology result proved the pattern of mixed thrombus. After the procedure patient presented with third-degree atrioventricular block which required the implantation of a permanent pacemaker St. Jude Medical, DDD mode. The patient was discharged on the tenth postoperative day in a good general condition. Although thrombosis of mechanical aortic valve prosthesis is a rare complication and most common in first year after implantation, all patients require lifelong follow-up by a cardiologist. [ABSTRACT FROM AUTHOR]

Introduction: Prosthetic valve endocarditis (PVE) is a serious condition commonly caused by bacterial microorganisms in patients with a mechanical or biological valve prosthesis that can lead to complications such as abscess, valve dehiscence, paravalvular regurgitation, heart failure, conduction disturbance, as well as embolic events and multiorgan failure.1,2 Case report: 52-year-old male, who had surgical aortic valve replacement with a mechanical prosthesis two years earlier due to complications of the bicuspid aortic valve, presented to the emergency department with shortness of breath at rest. During the last three weeks, he had fever, chills, cough, fatigue, myalgias, dyspnea, and exertion intolerance, along with weight loss. He was taking two antibiotics at home, but his condition was gradually worsening. Clinically, he was somnolent, pale, ortopnoic, hypotensive, and respiratory insufficient, with an auscultatory precordial diastolic murmur and mechanical valve sound, as well as bilateral lung crepitations and leg edema. The 12-lead electrocardiogram showed PR interval prolongation with a left bundle branch block. Laboratory findings indicated a septic condition with a myocardial injury. The chest radiography showed pulmonary edema with cardiomegaly. Echocardiography revealed severe prosthetic aortic paravalvular regurgitation with dehiscence greater than 50% of the prosthetic valve circumference (in aortic short-axis view). The left ventricle was dilated with an ejection fraction of 35%. The empirical antibiotic treatment for late PVE was administered promptly. All blood cultures were negative for bacterial infection. He was accepted for urgent valve replacement surgery, but his hemodynamic and neurological status rapidly deteriorated. The patient developed status epilepticus. A cranial CT scan revealed multiple acute and subacute ischemic lesions. Additionally, he had postictal respiratory failure, hypotension, bradycardia, and renal shutdown. Despite treatment measures, the patient died within 96 hours of admission in refractory cardiogenic and septic shock with respiratory insufficiency caused by mechanical and systemic complications of prosthetic valve endocarditis. Conclusion: PVE represents the most serious form of infective endocarditis.1,2 Embolism to the brain is a relatively frequent occurrence in patients with infective endocarditis that is associated with increased in-hospital mortality and morbidity as well as shortened long-term survival.1,3 [ABSTRACT FROM AUTHOR]

Background: Mechanical aortic valve dysfunction is a rare but potentially fatal complication. It is usually caused by thrombosis, vegetation, and pannus overgrowth. However, it very rarely occurs immediately after the cardiopulmonary bypass weaning period. Case presentation: We describe a case of stuck leaflet after the implantation of a mechanical aortic valve because of residual suture materials interfering with mechanical aortic valve leaflet closure, which is a very rare cause and has not been reported until now. Conclusion: The residual suture materials for mechanical aortic valve replacement could cause mechanical valve dysfuction indicated as stuck leafet. [ABSTRACT FROM AUTHOR]

Background: This study aimed to confirm the safety and feasibility of simple pannus removal in patients with mechanical aortic valve dysfunction for pannus overgrowth by evaluating its early clinical outcomes.Methods: From March 2015 to April 2019, 24 consecutive patients with mechanical aortic valve dysfunction due to subaortic pannus underwent reoperation. In 12 patients the repeat aortic valve replacement (AVR) was performed, and 12 received the simple pannus removal to preserve the previously implanted prosthesis.Results: There was only 1 in-hospital death in simple pannus removal group. Significant differences were obtained between procedures in cardiopulmonary bypass (CPB) and aortic cross-clamp time (128.7 vs 179.7 and 74.2 vs 132.7 mins, respectively, P < 0.05). The C-reactive protein (CRP) in simple pannus removal group was lower on the first day (0.13 ± 0.09 vs 0.31 ± 0.22 mg/dl, P < 0.05) and continued to be lower within 1 week after operation. There was no significant difference between procedures in aortic transvalvular peak velocity and transvalvular mean pressure gradient (TMPG) (2.6 ± 0.4 vs 2.5 ± 0.4 m/s and 13.2 ± 3.6 vs 11.6 ± 2.6 mmHg, respectively, P > 0.05) in echocardiography 1 week after operation. In addition, the aortic transvalvular peak velocity and TMPG in echocardiography 1 week after operation in pannus removal group between the repeat and initial surgery were not statistically significant (2.6 ± 0.4 vs. 2.5 ± 0.3 m/s, 13.2 ± 3.6 vs. 13.0 ± 3.5 mmHg, P > 0.05).Conclusions: Simple pannus removal was a safe and effective procedure with satisfied early clinical outcomes for pannus overgrowth in mechanical aortic valve. However, further randomized and long-term follow-up studies were warranted to determine the clinical effects of the simple aortic pannus removal. [ABSTRACT FROM AUTHOR]

Prosthetic heart valve (PHV) dysfunction is a rare but serious complication whose optimal management may be challenging and requires a multidisciplinary approach. Treatment success ultimately depends on determining the underlying mechanism of valve dysfunction by echocardiography. However, being able to establish the main etiology is not always straightforward. We present a difficult case of obstructive PHV dysfunction and discuss clinical and echocardiographic parameters to help differentiate thrombus from pannus formation. [ABSTRACT FROM AUTHOR]

Progressive ascending aortic dilatation has been observed after mechanical aortic valve replacement (mAVR), possibly due to altered blood flow and wall shear stress (WSS) patterns induced by their bileaflet design. We examined the effect of mAVR on WSS in the ascending aorta using time-resolved 4D flow MRI. Fifteen patients with mechanical aortic valve prostheses, 10 patients with bicuspid aortic valve disease and 10 healthy individuals underwent thoracic 4D flow MRI. Peak systolic hemodynamic parameters (velocity and WSS) and vessel diameters were assessed in the ascending aorta. In addition, three-dimensional per-voxel analysis was used to compare velocity and WSS between patient groups and healthy controls. Peak aortic diameters were significantly higher in mAVR and BAV patients compared to healthy controls (p = 0.011). Mean aortic diameters were comparable between mAVR and BAV patients. No differences in 4D flow MRI-derived mean blood flow velocity and peak WSS were found between the three groups. Compared to healthy controls, mean WSS was significantly lower in mAVR patients (p = 0.031). Per-voxel analysis revealed no increased WSS in the ascending aortic wall and significantly lower velocity and WSS values in mAVR patients compared to healthy controls. In contrast, regions of significantly increased outer lumen velocities and WSS in BAV patients compared to healthy controls were found. This study shows that there is no increased ascending aortic WSS after mAVR. Our results suggest that, in contrast to BAV patients, there is no indication for intensified follow-up of the ascending aorta after mAVR. [ABSTRACT FROM AUTHOR]

Objective: To review the current guidelines and published literature in order to identify the evidence-based international normalized ratio (INR) goal in patients with a mechanical aortic valve. Data Sources: Medline/PubMed, Cochrane and Google Scholar database searches for relevant articles from 1946 through March 2017 were executed using the key words "mechanical aortic valve" and "antithrombotic therapy or anticoagulation therapy or warfarin." Study Selection and Data Extraction: All English-language observational and interventional studies assessing INR goals in patients with a mechanical aortic valve were evaluated. Results: After low thrombogenic valves became standard in the practice, the INR goal decreased to 2 to 3 in low-risk recipients with most of bileaflet mechanical aortic valves. There is a paucity of data to justify the INR goal of 2 to 3 in high-risk patients. Until further higher evidence is available, it is reasonable to target an INR range of 2.5 to 3.5 in patients with risk factors for thromboembolism with low thrombogenic valves, except for On-X valve. The INR goal in high-risk On-X aortic valve recipients can be managed at 1.5 to 2.5 with low-dose aspirin 3 months after valve implantation. Conclusion: The INR goals of 2 to 3 for low risk and 2.5 to 3.5 for high risk should be considered for bileaflet mechanical aortic valve recipients. Additionally, a lower INR goal of 2 to 3 for the first 3 months after valve replacement followed by an INR goal of 1.5 to 2.5 in both low- and high-risk aortic On-X valve recipients may be considered. [ABSTRACT FROM AUTHOR]

Valvular heart disease is a common pathologic condition that affects 6 million people in the United States and more than 100 million worldwide. The most common valvular disorder is aortic stenosis. Current American and European guidelines recommend surgical management for symptomatic aortic stenosis with low risk of perioperative complications and endovascular intervention for high-risk patients with multiple comorbidities. Considering the increasing volume of aortic valve replacement (AVR) with biological valves, it is very important to select the appropriate anticoagulant after surgical AVR. In this article, we review the impact of anticoagulation on immediate and remote complications after AVR. [ABSTRACT FROM AUTHOR]

Transcatheter mitral valve replacement with the Tiara valve can be performed in inoperable patients with severe functional regurgitation. Risk of left ventricular outflow tract obstruction can be prevented using preoperative 3D imaging and 3D-printed models. However, in the case of mono-disk mechanical prostheses previously implanted in aortic position (Bjork-Shiley), there is an additional risk of mechanical interference leading to reduced leaflet motion and aortic valve dysfunction. Hereafter, we describe the case of a patient with a 27-mm mono-disk mechanical aortic valve implanted in 1978, a EuroSCORE II of 18%, and a Society of Thoracic Surgeon score (mortality) of 16% who successfully underwent a transapical Tiara valve implantation. [ABSTRACT FROM AUTHOR]

Cardiovascular syphilis manifests many years after primary infection. Here, we report the successful treatment of a patient who developed syphilitic aortitis with bilateral coronary ostial stenosis and aortic insufficiency. The patient underwent right coronary artery bypass grafting, left main coronary ostial "open" stent placement, and mechanical aortic valve placement during open-heart surgery.

This work focuses on the comparison between Newtonian and non-Newtonian blood flows through a bileaflet mechanical heart valve in the aortic root. The blood, in fact, is a concentrated suspension of cells, mainly red blood cells, in a Newtonian matrix, the plasma, and consequently its overall behavior is that of a non-Newtonian fluid owing to the action of the cells' membrane on the fluid part. The common practice, however, assumes the blood in large vessels as a Newtonian fluid since the shear rate is generally high and the effective viscosity becomes independent of the former. In this paper, we show that this is not always the case even in the aorta, the largest artery of the systemic circulation, owing to the pulsatile and transitional nature of the flow. Unexpectedly, for most of the pulsating cycle and in a large part of the fluid volume, the shear rate is smaller than the threshold level for the blood to display a constant effective viscosity and its shear thinning character might affect the system dynamics. A direct inspection of the various flow features has shown that the valve dynamics, the transvalvular pressure drop and the large-scale features of the flow are very similar for the Newtonian and non-Newtonian fluid models. On the other hand, the mechanical damage of the red blood cells (hemolysis), induced by the altered stress values in the flow, is larger for the non-Newtonian fluid model than for the Newtonian one. [ABSTRACT FROM AUTHOR]