Antithrombotic Treatment After Surgical and Transcatheter Heart Valve Repair and Replacement

Experimental Investigation of the Effect of a MitraClip on Left Ventricular Flow Dynamics

PURPOSE

The MitraClip device has emerged as an effective treatment option for patients with mitral regurgitation. However, implementing a MitraClip alters the mitral valve structure and left ventricular flow dynamics. In this study, we experimentally investigate the effects of the MitraClip and the resulting twin pulsed jets on flow dynamics within the left ventricle.

METHODS

A custom-made left heart pulse duplicator was utilized, considering three different configurations: (1) a healthy mitral valve; (2) a regurgitant mitral valve; and (3) a repaired mitral valve with a MitraClip device. The flow field within the left ventricle was examined using time-resolved particle image velocimetry across different planes. Of particular interest was the analysis of flow structures, viscous energy dissipation and the accumulation of viscous shear stresses in the left ventricle.

RESULTS

The results indicate that mitral valve regurgitation increases both viscous energy dissipation and the accumulation of viscous shear stresses in the left ventricle along with a 45% increase in peak velocity compared to the case with a normal mitral valve. Moreover, while mitral valve repair with a MitraClip alters the flow dynamics in the left ventricle, generating twin pulsed jets, it effectively reduces viscous energy dissipation (by 25 and 36% in the lateral and side planes, respectively) and shear stress accumulation compared to the regurgitant valve. However, these improvements do not fully restore the levels observed in a healthy mitral valve.

CONCLUSION

MitraClip mitigates the adverse effects of mitral regurgitation by restoring key hemodynamic parameters closer to healthy levels, highlighting its potential as a promising treatment.

Association between Stroke History and Clinical Events in Atrial Fibrillation Patients after Valve Replacement

Background

The association between stroke history and clinical events after valve replacement in patients with atrial fibrillation (AF) combined with valvular heart disease (VHD) is unclear. Thus, we sought to investigate the relationship between stroke history and clinical events in patients with AF after valve replacement.

Methods

This retrospective cohort study enrolled 746 patients with AF who underwent valve replacement between January 2018 and December 2019 at the Wuhan Asia Heart Hospital. Patient information was collected from the hospital's electronic medical record system. Patients were categorized based on their stroke history and followed through outpatient visits or by telephone until the occurrence of an endpoint event; the maximum follow-up period was 24 months. Endpoint events included thrombotic events, bleeding, and all-cause mortality. The frequency of thrombotic, hemorrhagic, and fatal events during the follow-up period was compared between the two groups. Independent risk factors for endpoint events were analyzed using multifactorial Cox regression.

Results

The analysis included 746 patients. Over a 24-month follow-up period, there were more total adverse events (hazard ratio (HR) = 2.08, 95% confidence interval (CI) 1.06-4.08, p = 0.018), thrombotic events (HR = 10.28, 95% CI 2.85-37.11, p < 0.001), and increased all-cause mortality (HR = 5.74, 95% CI 1.84-17.93, p < 0.001) in the stroke history group than in the non-stroke history group. Fewer bleeding events were observed in the group with a history of stroke (HR = 0.87, 95% CI 0.37-2.04, p = 0.757). A multifactorial Cox regression analysis revealed that a personal history of stroke was an independent risk factor for total adverse events, thrombotic events, and all-cause mortality.

Conclusions

Previous stroke history is significantly associated with adverse events in AF patients following valve replacement.

From Strep Infection to a Strepitous Heart Pattern in Rheumatic Fever: A Case Report

Rheumatic heart disease (RHD) is the leading cause of valvular heart disease globally, arising from acute rheumatic fever (ARF). It results from an abnormal immune response to group A streptococcal (GAS) infection, leading to myocardial injury. This is the case of a 65-year-old female with severe mitral regurgitation (MR) secondary to RHD disease who develops acute heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF), both de novo. It underscores the role of echocardiography in early diagnosis and severity assessment of RHD, antibiotic prophylaxis strategies, and the management of complications.

Non-vitamin K versus vitamin K antagonist oral anticoagulants in surgical mitral valve repair or bioprosthetic valve replacement in the first three months after surgery

INTRODUCTION AND OBJECTIVES

Oral anticoagulation (OAC) with non-vitamin K antagonist oral anticoagulants (NOACs) after surgical mitral valve repair (MVR) or bioprosthetic valve replacement (BVR) in mitral position remains a controversial topic among the cardiovascular community, in particular in the early postoperative period. This study aimed to evaluate the efficacy and safety of NOACs in the first three months after MVR or mitral BVR compared to vitamin K antagonists (VKAs).

METHODS

This was a single-center retrospective study with prospectively collected peri-intervention outcomes between 2020 and 2021. Records were retrieved and all participants were contacted by telephone. Patients were divided into groups according to OAC strategy. The primary outcome was a composite of death, rehospitalization, myocardial infarction, stroke or transient ischemic attack, systemic embolism, mitral thrombosis, or bleeding during the first three months after surgery.

RESULTS

A total of 148 patients were enrolled, with a mean age of 65.5±12.2 years, 56.8% male. On discharge, 98 (66.2%) patients were on VKAs and 50 (33.8%) were on DOACs for at least three months. The primary outcome occurred in 22 (22.4%) patients in the VKA group and in three (6%) in the NOAC group (p=0.012), mainly driven by more bleeding events in the former. Independent predictors of the primary outcome were smoking (p=0.028) and OAC with VKAs at discharge, the latter predicting three times more events (p=0.046, OR 3.72, 95% CI 1.02-13.5).

CONCLUSIONS

NOACs were associated with fewer events, supporting their efficacy and safety during the first three months after surgical MVR or mitral BVR.

TriClip G4: A game-changer for tricuspid valve regurgitation treatment

Tricuspid valve regurgitation, or TR, is a difficult-to-manage condition. In addition to EVOQUE, percutaneous annuloplasty, and surgical repair, the TriClip G4 system has been added to the interventional therapeutic choices for TR. Recently, the Food and Drug Administration (FDA) approved the use of the TriClip G4 device to treat patients with symptomatic, severe TR who have received optimal medication therapy but are at intermediate or higher risk of surgery. This review attempts to offer a thorough examination of the procedural features, learning curves, results of the device and compares the TriClip G4 system to other interventional therapies for TR. TriClip G4 has shown to have promising results in pivotal clinical trials, be cost-effective, and improve the quality of life of patients. Furthermore, it has its unique advantages against other conventional techniques and devices.

Mechanical Aortic Valve Thrombosis During Anticoagulation Using Oral Rivaroxaban: A Case Report

Direct oral anticoagulants (DOACs) are widely used in cardiovascular medicine. Although rivaroxaban has potential benefits for anticoagulation in certain contexts, DOACs remain contraindicated in patients with mechanical heart valves. This case report highlights the life-threatening risks of rivaroxaban use in patients with mechanical aortic valves, underscoring the lack of proven efficacy and the necessity of adhering to established anticoagulation protocols with warfarin for this patient population. Here, we report a case of a 65-year-old man who had previously undergone aortic valve replacement and developed a thrombus in the mechanical aortic valve six months after switching from warfarin to rivaroxaban. The patient experienced a sudden loss of consciousness and chest discomfort. Echocardiography revealed a thrombus in the valve requiring urgent reoperation and replacement with a bioprosthetic valve. The postoperative recovery was uneventful.

Percutaneous pulmonary valve implantation in children and adults with an age and gender-specific analysis

BACKGROUND

There are limited studies with medium-term follow-up following percutaneous pulmonary valve implantation and no studies with a gender-specific analysis.

AIMS

To report clinical outcomes up to five years following percutaneous pulmonary valve implantation using the two most common balloon expandable valves in a mixed population of paediatric and adult patients with an age and gender-specific analysis.

METHODS

This was a single-centre retrospective observation study. Relevant data were obtained retrospectively from the case files. Age and gender- specific analysis was performed using SPSS.

RESULTS

Totally, 58 patients (13 children, 45 adults) underwent percutaneous pulmonary valve implantation. Statistically significant reduction in median right ventricular outflow tract flow velocity following valve implantation was maintained for the whole five years in adults but not in children. There were no gender-specific differences despite the study being adequately powered. Independent of valve type used, there was significant reduction of the right ventricular outflow tract flow velocity in the immediate post valve implantation period (Edwards P = 0.001, Melody P = 0.013). There was a significant negative correlation between implanted valve Z-score and subsequent right ventricular outflow tract gradient during the first two years following valve implantation.

CONCLUSION

Gender does not significantly affect valve function following percutaneous pulmonary valve implantation. It is important to consider patients' age and body surface area in relation to existing right ventricular outflow tract size during decisions for percutaneous pulmonary valve implantation.

Dementia Development during Long-Term Follow-Up after Surgical Aortic Valve Replacement with a Biological Prosthesis in a Geriatric Population

Surgical aortic valve replacement (SAVR) with a biological heart valve prosthesis (BHV) is often used as a treatment in elderly patients with symptomatic aortic valve disease. This age group is also at risk for the development of dementia in the years following SAVR. The research question is "what are the predictors for the development of dementia?". In 1500 patients undergoing SAVR with or without an associated procedure, preoperative (demographic, cardiac and non-cardiac comorbid conditions), perioperative (associated procedures, cross-clamp and cardiopulmonary bypass time) and postoperative 30-day adverse events (bleeding, thromboembolism, heart failure, conduction defects, arrhythmias, delirium, renal and pulmonary complications) were investigated for their effect on the occurrence of dementia by univariate analyses. Significant factors were entered in a multivariate analysis. The sum of the individual follow-up of the patients was 10,182 patient-years, with a mean follow-up of 6.8 years. Data for the development of dementia could be obtained in 1233 of the 1406 patients who left the hospital alive. Dementia during long-term follow-up developed in 216/1233 (17.2%) of the patients at 70 ± 37 months. Development of dementia reduced the mean survival from 123 (119-128) to 109 (102-116) months (p < 0.001). Postoperative delirium was the dominant predictor (OR = 3.55 with a 95%CI of 2.41-4.93; p < 0.00), followed by age > 80 years (2.38; 1.78-3.18; p < 0.001); preoperative atrial fibrillation (1.47; 1.07-2.01; p = 0.018); cardiopulmonary bypass time > 120 min (1.34; 1.02-1.78; p = 0.039) and postoperative thromboembolism (1.94; 1.02-3.70; p = 0.044). Postoperative delirium, as a marker for poor condition, and an age of 80 or more were the dominant predictors.

Direct Oral Anticoagulant Use Early After Cardiac Surgery: A Retrospective Cohort Study

Background

There is limited literature guiding the prescribing of direct oral anticoagulants (DOACs) early after cardiac surgery as this population has been excluded from landmark randomized controlled trials. This study aims to determine the rate of in-hospital DOAC use compared with warfarin early after cardiac surgery, evaluate factors associated with DOAC use, determine difference in postoperative length of stay, and characterize bleeding events.

Methods

A retrospective cohort study was conducted in adult patients with indications for anticoagulation and receiving either a DOAC or warfarin after cardiac surgery during their index hospitalization. Patients were excluded if they had any contraindications to DOAC use. The primary outcome was the proportion of patients discharged on a DOAC compared with warfarin.

Results

Of included 210 patients, 30% received DOACs and 70% received warfarin on discharge. The most common DOAC used was apixaban (74.6%), and median postoperative day of initiation was 5 days. Patients receiving DOACs were older (70.8 vs 68.0 years), had less valvular heart disease (38.1% vs 63.9%), were more likely to be on DOACs preoperatively (50.8% vs 31.3%), and were more likely to have undergone coronary artery bypass graft alone (54.0% vs 24.5%) compared with those on warfarin. Postoperative length of stay (7 vs 9 days; P = 0.59) and in-hospital bleeding (1.6% vs 2.0%; P = 1.00) did not differ between DOAC and warfarin groups.

Conclusions

At a quaternary referral centre for cardiac surgery, DOACs were used in approximately one-third of patients with an indication for anticoagulation early after cardiac surgery.

Advances in diagnosis and treatment of mechanical hemolysis following percutaneous interventional for valvular heart diseases

Valvular heart disease is one of the common heart diseases in clinical practice, characterized by valve stenosis and/or incomplete closure. At present, drug therapy, surgery, and emerging percutaneous intervention therapy are the main treating methods for heart valve disease. Although the research and development of percutaneous intervention therapy devices is relatively mature, there are still problems such as postoperative mechanical hemolysis. The occurrence of mechanical hemolysis is associated with factors such as excessive shear stress experienced by red blood cells, direct interaction between red blood cells and the heart and valve surfaces, and thrombus formation. Furthermore, the presence of postoperative infection and other hemolytic diseases can also affect the occurrence of mechanical hemolysis. Although most patients are asymptomatic when hemolysis occurs, there are still critical cases. This type of hemolysis can accelerate the deterioration of the condition, and even endanger life in severe cases. Therefore, elucidating the background, pathogenesis, epidemiology, and related clinical research progress of mechanical hemolysis after percutaneous intervention therapy for valvular heart disease is of great significance for guiding the standardized diagnosis and treatment of the disease.

Strategies for Development of Synthetic Heart Valve Tissue Engineering Scaffolds

The current clinical solutions, including mechanical and bioprosthetic valves for valvular heart diseases, are plagued by coagulation, calcification, nondurability, and the inability to grow with patients. The tissue engineering approach attempts to resolve these shortcomings by producing heart valve scaffolds that may deliver patients a life-long solution. Heart valve scaffolds serve as a three-dimensional support structure made of biocompatible materials that provide adequate porosity for cell infiltration, and nutrient and waste transport, sponsor cell adhesion, proliferation, and differentiation, and allow for extracellular matrix production that together contributes to the generation of functional neotissue. The foundation of successful heart valve tissue engineering is replicating native heart valve architecture, mechanics, and cellular attributes through appropriate biomaterials and scaffold designs. This article reviews biomaterials, the fabrication of heart valve scaffolds, and their in-vitro and in-vivo evaluations applied for heart valve tissue engineering.

The Complex Relationship between Hypoxia Signaling, Mitochondrial Dysfunction and Inflammation in Calcific Aortic Valve Disease: Insights from the Molecular Mechanisms to Therapeutic Approaches

Calcific aortic valve stenosis (CAVS) is among the most common causes of cardiovascular mortality in an aging population worldwide. The pathomechanisms of CAVS are such a complex and multifactorial process that researchers are still making progress to understand its physiopathology as well as the complex players involved in CAVS pathogenesis. Currently, there is no successful and effective treatment to prevent or slow down the disease. Surgical and transcatheter valve replacement represents the only option available for treating CAVS. Insufficient oxygen availability (hypoxia) has a critical role in the pathogenesis of almost all CVDs. This process is orchestrated by the hallmark transcription factor, hypoxia-inducible factor 1 alpha subunit (HIF-1α), which plays a pivotal role in regulating various target hypoxic genes and metabolic adaptations. Recent studies have shown a great deal of interest in understanding the contribution of HIF-1α in the pathogenesis of CAVS. However, it is deeply intertwined with other major contributors, including sustained inflammation and mitochondrial impairments, which are attributed primarily to CAVS. The present review aims to cover the latest understanding of the complex interplay effect of hypoxia signaling pathways, mitochondrial dysfunction, and inflammation in CAVS. We propose further hypotheses and interconnections on the complexity of these impacts in a perspective of better understanding the pathophysiology. These interplays will be examined considering recent studies that shall help us better dissect the molecular mechanism to enable the design and development of potential future therapeutic approaches that can prevent or slow down CAVS processes.

First Ex Vivo Animal Study of a Biological Heart Valve Prosthesis Sensorized with Intravalvular Impedance

IntraValvular Impedance (IVI) sensing is an innovative concept for monitoring heart valve prostheses after implant. We recently demonstrated IVI sensing feasible in vitro for biological heart valves (BHVs). In this study, for the first time, we investigate ex vivo the IVI sensing applied to a BHV when it is surrounded by biological tissue, similar to a real implant condition. A commercial model of BHV was sensorized with three miniaturized electrodes embedded in the commissures of the valve leaflets and connected to an external impedance measurement unit. To perform ex vivo animal tests, the sensorized BHV was implanted in the aortic position of an explanted porcine heart, which was connected to a cardiac BioSimulator platform. The IVI signal was recorded in different dynamic cardiac conditions reproduced with the BioSimulator, varying the cardiac cycle rate and the stroke volume. For each condition, the maximum percent variation in the IVI signal was evaluated and compared. The IVI signal was also processed to calculate its first derivative (dIVI/dt), which should reflect the rate of the valve leaflets opening/closing. The results demonstrated that the IVI signal is well detectable when the sensorized BHV is surrounded by biological tissue, maintaining the similar increasing/decreasing trend that was found during in vitro experiments. The signal can also be informative on the rate of valve opening/closing, as indicated by the changes in dIVI/dt in different dynamic cardiac conditions.

Innovative IntraValvular Impedance Sensing Applied to Biological Heart Valve Prostheses: Design and In Vitro Evaluation

Subclinical valve thrombosis in heart valve prostheses is characterized by the progressive reduction in leaflet motion detectable with advanced imaging diagnostics. However, without routine imaging surveillance, this subclinical thrombosis may be underdiagnosed. We recently proposed the novel concept of a sensorized heart valve prosthesis based on electrical impedance measurement (IntraValvular Impedance, IVI) using miniaturized electrodes embedded in the valve structure to generate a local electric field that is altered by the cyclic movement of the leaflets. In this study, we investigated the feasibility of the novel IVI-sensing concept applied to biological heart valves (BHVs). Three proof-of-concept prototypes of sensorized BHVs were assembled with different size, geometry and positioning of the electrodes to identify the optimal IVI-measurement configuration. Each prototype was tested in vitro on a hydrodynamic heart valve assessment platform. IVI signal was closely related to the electrodes' positioning in the valve structure and showed greater sensitivity in the prototype with small electrodes embedded in the valve commissures. The novel concept of IVI sensing is feasible on BHVs and has great potential for monitoring the valve condition after implant, allowing for early detection of subclinical valve thrombosis and timely selection of an appropriate anticoagulation therapy.

At the Crossroads of Minimally Invasive Mitral Valve Surgery—Benching Single Hospital Experience to a National Registry: A Plea for Risk Management Technology

Almost 30 years after the first endoscopic mitral valve repair, Minimally Invasive Mitral Valve Surgery (MIMVS) has become the standard at many institutions due to optimal clinical results and fast recovery. The question that arises is can already good results be further improved by an Institutional Risk Management Performance (IRMP) system in decreasing risks in minimally invasive mitral valve surgery (MIMVS)? As of yet, there are no reports on IRMP and learning systems in the literature. (2) Methods: We described and appraised our five-year single institutional experience with MIMVS in isolated valve surgery included in the Netherlands Heart Registry (NHR) and investigated root causes of high-impact complications. (3) Results: The 120-day and 12-month mortality were 1.1% and 1.9%, respectively, compared to the average of 4.3% and 5.3% reported in the NHR. The regurgitation rate was 1.4% compared to 5.2% nationwide. The few high-impact complications appeared not to be preventable. (4) Discussion: In MIMVS, freedom from major and minor complications is a strong indicator of an effective IRMP but remains concealed from physicians and patients, despite its relevance to shared decision making. Innovation adds to the complexity of MIMVS and challenges surgical competence. An IRMP system may detect and control new risks earlier. (5) Conclusion: An IRMP system contributes to an effective reduction of risks, pain and discomfort; provides relevant input for shared decision making; and warrants the safe introduction of new technology. Crossroads conclusions: investment in machine learning and AI for an effective IRMP system is recommended and the roles for commanding and operating surgeons should be considered.

A successful double valve repair on an interesting background: Case report

Aortic regurgitation in a bicuspid aortic valve is a complex entity that involves not only the semilunar valve but also the structure of the aortic root which is functionally and pathologically in a very close relationship to it. Considering repairing a bicuspid valve mandates a mindful involvement of all related structures concurrently. Here, we report an interesting case of both bicuspid aortic valve and mitral valve regurgitation in a patient with a history of infective endocarditis, that was successfully managed by double valve repair.

The role of antiaggregant agents and anticoagulants in the prevention of aortic valve endocarditis: A double-cohort retrospective study

Objective

Antiaggregants (Ag) could prevent infective endocarditis (IE) in preclinical studies. In this study we investigated whether Ag or anticoagulants (Ac) were also protective in humans.

Methods

In part I we determined the incidence of IE of bioprosthetic aortic valves (PVE) in 333 consecutive patients who underwent aortic valve replacement for noninfective aortic insufficiency between 2009 and 2019. In part II we retrospectively analyzed data of 137 patients who had developed IE of the native aortic valve (NVE) between 2007 and 2015. Multivariable Fine–Gray and logistic regression models were used to investigate associations between Ag and Ac therapy and IE.

Results

Sixteen of 333 (4.8%) aortic valve replacement recipients developed PVE after a median of 3.72 years. There was no association between Ag and PVE, whereas Ac was associated with a higher IE occurrence (no association for vitamin K antagonists but significant for fondaparinux or low molecular-weight heparins; hazard ratio, 4.61; 95% CI, 1.01-21.9). In contrast, among the 137 patients in part II, vitamin K antagonists (odds ratio [OR], 7.52; 95% CI, 2.51-22.6), double antiplatelet therapy (OR, 44.3; 95% CI, 4.83-407), novel oral Ac (OR, 4.17; 95% CI, 1.15-15.1), and fondaparinux or low molecular-weight heparins (OR, 9.87; 95% CI, 1.81-53.9), but not acetylsalicylic acid, were associated with NVE.

Conclusions

Ac were associated with IE in both cohorts, whereas Ag were not associated with PVE. This might reflect differences in the studied populations, with Ag and Ac being prescribed for conditions associated with long-term IE risk in the NVE cohort. Therefore, determining the potential protective effect of Ag and Ac will necessitate further well–controlled studies.