Rheumatic heart disease: current status of diagnosis and therapy

Incidence and Pathology of Aortic Regurgitation

Aortic regurgitation (AR) is the third most common valvular heart disease, with its prevalence and severity increasing with age. AR can arise from degenerative, congenital, inflammatory and infectious aetiologies, manifesting as primary AR with intrinsic leaflet disease, secondary AR due to aortopathy or annular dilatation, or a combination. Furthermore, AR can be acute, as observed in endocarditis and aortic dissection, or chronic, as seen in calcific aortic valve disease, connective tissue disorders, or bicuspid valve phenotypes. This review discusses the aetiopathology of these various AR manifestations (primary, secondary, acute and chronic AR), highlighting diagnostic challenges and implications for aortic valve replacement and transcatheter aortic valve implantation.

Polymeric Heart Valves: Do They Represent a Reliable Alternative to Current Prosthetic Devices?

With the increasing number of people suffering from heart valve diseases (e.g., stenosis and/or insufficiency), the attention paid to prosthetic heart valves has grown significantly. Developing a prosthetic device that fully replaces the functionality of the native valve remains a huge challenge. Polymeric heart valves (PHVs) represent an appealing option, offering the potential to combine the robustness of mechanical valves with the enhanced biocompatibility of bioprosthetic ones. Over the years, novel biomaterials (such as promising new polymers and nanocomposites) and innovative designs have been explored for possible applications in manufacturing PHVs. This work provides a comprehensive overview of PHVs' evolution in terms of materials, design, and fabrication techniques, including in vitro and in vivo studies. Moreover, it addresses the drawbacks associated with PHV implementation, such as their limited biocompatibility and propensity for sudden failure in vivo. Future directions for further development are presented. Notably, PHVs can be particularly relevant for transcatheter application, the most recent minimally invasive approach for heart valve replacement. Despite current challenges, PHVs represent a promising area of research with the potential to revolutionize the treatment of heart valve diseases, offering more durable and less invasive solutions for patients.

Direct Oral Anticoagulants for Rheumatic Heart Disease-Associated Atrial Fibrillation Post-Bioprosthetic Mitral Valve Replacement

BACKGROUND

The efficacy of direct oral anticoagulants (DOACs) in preventing ischemic and thromboembolic events may be suboptimal in atrial fibrillation (AF) patients with rheumatic mitral stenosis. However, their safety and effectiveness after mitral valve replacement (MVR) using bioprosthetic valves is unclear.

OBJECTIVES

This study sought to evaluate the safety and effectiveness of DOACs vs warfarin among patients with rheumatic heart disease (RHD)-associated AF after bioprosthetic MVR.

METHODS

We performed an observational analysis identifying patients with RHD and AF who underwent bioprosthetic MVR. Primary effectiveness and safety outcomes were ischemic events and major bleeding, respectively. Secondary outcomes included all-cause mortality, cardiac thrombosis, myocardial infarction, and all-cause hospitalization. Propensity score matching was performed to account for the differences in baseline characteristics and comorbidities.

RESULTS

A total of 3,950 patients were identified; 76% were on warfarin and 24% on DOAC post-MVR. The DOAC group had a higher burden of baseline comorbidities and prior cardiovascular procedures compared with the warfarin group. The propensity score matching balanced baseline characteristics in 1,832 patients (916 in each group), with a mean age of 69 years. At the 5-year follow-up, DOACs were associated with a lower incidence of major bleeding compared with warfarin (HR: 0.76; 95% CI: 0.62-0.94), with no significant difference in ischemic events, mortality, cardiac thrombosis, myocardial infarction, or hospitalization.

CONCLUSIONS

Among patients with RHD-associated AF patients post-bioprosthetic MVR, DOACs are associated with lower major bleeding and comparable effectiveness, indicating a potential alternative to warfarin. Further randomized controlled trials are warranted to validate these findings in this population.

Machine learning and artificial intelligence within pediatric autoimmune diseases: applications, challenges, future perspective

INTRODUCTION

Autoimmune disorders affect 4.5% to 9.4% of children, significantly reducing their quality of life. The diagnosis and prognosis of autoimmune diseases are uncertain because of the variety of onset and development. Machine learning can identify clinically relevant patterns from vast amounts of data. Hence, its introduction has been beneficial in the diagnosis and management of patients.

AREAS COVERED

This narrative review was conducted through searching various electronic databases, including PubMed, Scopus, and Web of Science. This study thoroughly explores the current knowledge and identifies the remaining gaps in the applications of machine learning specifically in the context of pediatric autoimmune and related diseases.

EXPERT OPINION

Machine learning algorithms have the potential to completely change how pediatric autoimmune disorders are identified, treated, and managed. Machine learning can assist physicians in making more precise and fast judgments, identifying new biomarkers and therapeutic targets, and personalizing treatment strategies for each patient by utilizing massive datasets and powerful analytics.

Clinical outcome of patients with rheumatic tricuspid valve disease: matched cohort study

Rheumatic heart disease (RHD) is still a major health problem, especially in low- to mid-income countries, leading premature deaths owing to valvular disease. Although left-sided valvular involvement is most commonly seen in RHD, the tricuspid valve can also be affected. However, there is a lack of information about the prognostic value of primary tricuspid valve (TV) disease in RHD. This study aimed to determine the impact of TV disease on clinical outcome in RHD. This prospective study enrolled patients with rheumatic mitral valve disease (MVD) referred to a tertiary center for management of heart valve disease. Primary rheumatic TV disease was defined by echocardiographic features including thickening of leaflets associated with some degree of restricted mobility. Patients with rheumatic TV disease were matched to patients with MVD using 1:1 genetic matching algorithm that maximized balance of baseline covariates prior to exploring outcome differences. The main outcome was either need for MV replacement or death. Among 694 patients eligible for the study, age of 47 ± 13 years, 84% female, 39 patients (5.6%) had rheumatic TV disease. After excluding patients with incomplete data, 33 patients with TV disease were matched to 33 controls based on age, right-sided heart failure, atrial fibrillation, and MV area. During a mean follow-up of 42 months (median 28, IQR 8 to 71 months), 32 patients (48.5%) experienced adverse events, including 6 cardiovascular deaths and 26 patients who underwent surgery for mitral valve replacement. The adjusted analysis demonstrated a significant association between TV disease and the outcome, with a hazard ratio (HR) of 3.386 (95% CI 1.559-7.353; P = 0.002) in the genetic matched cohort with balance on baseline covariates of interest. The model exhibited good discriminative ability, as indicated by a C-statistic of 0.837. In patients with rheumatic mitral valve disease, rheumatic TV disease significantly increased risk of adverse events compared with matched controls. The involvement of TV may express overall disease severity that adversely affects clinical outcome.

Plant Antioxidants: Therapeutic Potential in Cardiovascular Diseases

Cardiovascular diseases (CVDs) are a global health problem. The mortality associated with them is one of the highest. Essentially, CVDs occur when the heart or blood vessels are damaged. Oxidative stress is an imbalance between the production of reactive oxygen species (free radicals) and antioxidant defenses. Increased production of reactive oxygen species can cause cardiac and vascular injuries, leading to CVDs. Antioxidant therapy has been shown to have beneficial effects on CVDs. Plants are a rich source of bioactive antioxidants on our planet. Several classes of these compounds have been identified. Among them, carotenoids and phenolic compounds are the most potent antioxidants. This review summarizes the role of some carotenoids (a/β-carotene, lycopene and lutein), polyphenols such as phenolic acids (caffeic, p-coumaric, ferulic and chlorogenic acids), flavonoids (quercetin, kaempferol and epigallocatechin gallate), and hydroxytyrosol in mitigating CVDs by studying their biological antioxidant mechanisms. Through detailed analysis, we aim to provide a deeper understanding of how these natural compounds can be integrated into cardiovascular health strategies to help reduce the overall burden of CVD.

Precision Medicine in Congenital Heart Disease, Rheumatic Heart Disease, and Kawasaki Disease of Children: An Overview of Literature

Congenital heart disease and common acquired heart diseases like Kawasaki disease and rheumatic heart disease are prevalent cardiovascular conditions in children worldwide. Despite the availability of treatment options, they continue to be significant contributors to morbidity and mortality. Advancements in early diagnosis, improvements in treatment approaches, and overcoming resistance to available treatments are crucial to reduce morbidity. Researchers have turned to precision medicine to tackle these challenges. We aimed to analyze the existing literature concerning the utilization of precision medicine in congenital heart disease, rheumatic heart disease, and Kawasaki disease. The emphasis is placed on comprehending the key themes explored in these studies and evaluating the present state of their clinical integration. The central theme of most studies revolves around the examination of genetic factors. Despite promising research outcomes, limitations in these studies indicate that the clinical implementation of precision medicine in these conditions remains a distant prospect, necessitating additional exploration and attention to confounding factors.

Comparison of short-term efficacy of two bipolar radiofrequency ablation forceps for rheumatic heart disease concomitant with atrial fibrillation

Background

Currently, the bipolar radiofrequency ablation forceps manufactured by AtriCure are the main instrument for surgical ablation in patients with rheumatic heart disease (RHD) concomitant with atrial fibrillation (AF). The bipolar radiofrequency ablation forceps by Med-Zenith has a greater advantage in price compared with AtriCure. However, few studies have been reported on the comparison of their clinical efficacy. The aim of this study is to compare the short-term clinical efficacy of the two ablation forceps for RHD concomitant with AF.

Methods

Clinical data of 167 patients with RHD concomitant with AF admitted to the Department of Cardiac Major Vascular Surgery, Affiliated Hospital of North Sichuan Medical College, were retrospectively analyzed, and the restoration efficacy of sinus rhythm (SR) and cardiac function after surgery were compared with two ablation forceps.

Results

The end-systolic diameter of the right atrium and the end-systolic diameter of the left atrium in the patients of both groups at each postoperative time point decreased compared with that of the preoperative period (P < 0.05), and the left ventricular ejection fraction started to improve significantly at 6 months after surgery compared with that of the preoperative period (P < 0.05). There was no difference between the two groups of patients in the comparison of the aforementioned indicators at different points in time (P > 0.05). At 12 months postoperatively, the SR maintenance rate in using the ablation forceps by Med-Zenith (73.3%) was lower than that for AtriCure (86.4%) and the cumulative recurrence rate of AF in using the Med-Zenith ablation forceps was greater than that for AtriCure.

Conclusions

The two bipolar radiofrequency ablation forceps compared in the study are safe and effective in treating patients of RHD concomitant with AF, and the ablation forceps by AtriCure may be more effective in restoring SR in the short term.

Innovation and disruptive science determine the future of cardiothoracic surgery

One of the currently most asked questions in the field of medicine is how any specialty in the future will evolve to ensure better health for the patients by using current, unparalleled developments in all areas of science. This article will give an overview of new and evolving strategies for cardiothoracic (CT) surgery that are available today and will become available in the future in order to achieve this goal. In the founding era of CT surgery in the 1950s and 1960s, there was tremendous excitement about innovation and disruptive science, which eventually resulted in a completely new medical specialty, i.e. CT surgery. Entirely new treatment strategies were introduced for many cardiovascular diseases that had been considered incurable until then. As expected, alternative techniques have evolved in all fields of science during the last few decades, allowing great improvements in diagnostics and treatment in all medical specialties. The future of CT surgery will be determined by an unrestricted and unconditional investment in innovation, disruptive science and our own transformation using current achievements from many other fields. From the multitude of current and future possibilities, I will highlight 4 in this review: improvements in our current techniques, bringing CT surgery to low- and middle-income countries, revolutionizing the perioperative period and treating as yet untreatable diseases. These developments will allow us a continuation of the previously unheard-of treatment possibilities provided by ingenious innovations based on the fundamentals of CT surgery.

Social Drivers of Health and Pediatric Extracorporeal Membrane Oxygenation Outcomes

BACKGROUND

Relationships between social drivers of health (SDoH) and pediatric health outcomes are highly complex with substantial inconsistencies in studies examining SDoH and extracorporeal membrane oxygenation (ECMO) outcomes. To add to this literature with emerging novel SDoH measures, and to address calls for institutional accountability, we examined associations between SDoH and pediatric ECMO outcomes.

METHODS

This single-center retrospective cohort study included children (<18 years) supported on ECMO (2012-2021). SDoH included Child Opportunity Index (COI), race, ethnicity, payer, interpreter requirement, urbanicity, and travel-time to hospital. COI is a multidimensional estimation of SDoH incorporating traditional (eg, income) and novel (eg, healthy food access) neighborhood attributes ([range 0-100] higher indicates healthier child development). Outcomes included in-hospital mortality, ECMO run duration, and length of stay (LOS).

RESULTS

540 children on ECMO (96%) had a calculable COI. In-hospital mortality was 44% with median run duration of 125 hours and ICU LOS 29 days. Overall, 334 (62%) had cardiac disease, 92 (17%) neonatal respiratory failure, 93 (17%) pediatric respiratory failure, and 21 (4%) sepsis. Median COI was 64 (interquartile range 32-81), 323 (60%) had public insurance, 174 (34%) were from underrepresented racial groups, 57 (11%) required interpreters, 270 (54%) had urban residence, and median travel-time was 89 minutes. SDoH including COI were not statistically associated with outcomes in univariate or multivariate analysis.

CONCLUSIONS

We observed no significant difference in pediatric ECMO outcomes according to SDoH. Further research is warranted to better understand drivers of inequitable health outcomes in children, and potential protective mechanisms.

Health-related quality of life and healthcare consultations among adult patients before and after diagnosis with rheumatic heart disease in Namibia

BACKGROUND

Rheumatic Heart Disease (RHD) causes high morbidity and mortality rates among children and young adults, impacting negatively on their health-related quality of life (HRQoL). This study aimed to evaluate the HRQoL and healthcare consultations of adult patients with RHD in Namibia.

METHODS

From June 2019 to March 2020, a questionnaire was administered to 83 RHD patients during routine follow-ups. The EQ-5D-5L instrument was used to assess the health-related quality of life before diagnosis and at the time of the survey. The Ethiopian value set for EQ-5D-5L was used to calculate Quality-Adjusted Life Years (QALY).

RESULTS

Most respondents were women (77%), young adults below the age of 30 years (42%), and individuals who grew up in rural areas (87%). The mean QALY statistically significantly improved from 0.773 pre-diagnosis to 0.942 in the last 12 months (p < 0.001). Sixty-six patients who had surgery reported a better QALY. Healthcare visits statistically significantly increased from on average 1.6 pre-diagnosis to 2.7 days in the last 12 months (p < 0.001). The mean distance to the nearest facility was 55 km, mean cost of transport was N$65, and mean time spent at the clinic was 3.6 h. The median time from diagnosis to the survey was 7 years (quartiles 4 and 14 years).

CONCLUSION

Treatment and surgery can improve HRQoL substantially among RHD patients. Being diagnosed with RHD affects patients living in socioeconomically disadvantaged rural areas through cost and time for healthcare visits. It would be valuable with further research to understand differences between disease severities.

A Case Report: Acute Rheumatic Fever or Something More?

Acute rheumatic fever (ARF) is an autoimmune response that may occur after a group A Streptococcus (GAS) infection. Subcutaneous nodules are considered a rare manifestation of acute rheumatic fever with an incidence of 0%-10%. We present a case study of a 13-year-old girl who presented to us with subcutaneous nodules and articular involvement described as a non-migratory polyarticular joint pain involving the small joints of the hands, wrist, elbows, knees, and ankles for three months with poor response to the non-steroidal anti-inflammatory drug (NSAID) Ibuprofen. Accompanied with the presence of carditis, the patient fulfilled three major and two minor criteria of the revised Jones criteria 2015. Therefore, a diagnosis of acute rheumatic fever was made. The child was asymptomatic on subsequent visits, and although the subcutaneous nodules subsided, she will continue to receive penicillin every month for five years. We describe the successful diagnosis and management of a patient with ARF.

Cardiac imaging in rheumatic heart disease and future developments

Rheumatic heart disease (RHD) is the most common cause of valvular heart disease worldwide, affecting millions, especially in low- and middle-income countries. Multiple imaging modalities such as cardiac CT, cardiac MRI, and three-dimensional echocardiography may be utilized in diagnosing, screening, and managing RHD. However, two-dimensional transthoracic echocardiography remains the cornerstone of imaging in RHD. Criteria developed by the World Heart Foundation in 2012 sought to unify the diagnostic imaging criteria for RHD, but concerns remain regarding their complexity and reproducibility. In the intervening years, further measures have been developed to find a balance between simplicity and accuracy. Nonetheless, there remain significant unresolved problems within imaging in RHD, including the development of a practical and sensitive screening tool to identify patients with RHD. The emergence of handheld echocardiography has the potential to revolutionize RHD management in resource-poor settings, but its role as a screening or diagnostic tool is yet to be fully established. The dramatic evolution of imaging modalities over the last few decades has not addressed RHD compared to other forms of structural heart disease. In this review, we examine the current and latest developments concerning cardiac imaging and RHD.

Procedural complications associated with percutaneous mitral balloon valvotomy: A systematic review

BACKGROUND

As Percutaneous mitral balloon valvotomy (PMBV) remains the keystone in treating mitral stenosis, we conducted this review to elucidate the cumulative frequency and predictors of complications following PMBV and their occurrence in various patient populations.

AREAS COVERED

We searched digital databases for relevant studies covering complications of PMBV and retrieved articles using the Medical Subject Heading (MeSH) keywords.

EXPERT OPINION

A total of 37 articles (8 RCTs, 7 nonrandomized clinical trials, 22 observational studies) were selected for qualitative analysis. A total of 11,803 patients undergoing PMBV among 37 studies were included, with a mean success rate of 84.54%. The most common complication was mitral regurgitation (8.2%) followed by an atrial septal defect (2.4%). Other relevant complications like stroke, pericardial tamponade, rupture of mitral leaflets, and conduction abnormalities were present in <1% of the patients.

New insight into the role of lipid metabolism-related proteins in rheumatic heart valve disease

PURPOSE

The aim of this study was to determine the expression of lipid metabolism-related proteins in rheumatic heart valve disease (RHVD).

METHODS

This retrospective study involved a total of 20 cases of moderate or severe rheumatic mitral valve stenosis and 4 cases of mitral regurgitation due to secondary causes from September 2018 to September 2021. The patients enrolled included 12 males and 12 females who underwent surgical excision of the mitral valve at the cardiac surgery department of Hainan General Hospital. The samples of mitral valve were collected during surgery treatment as the study group, and mitral valves collected from patients with ischemic heart disease were allocated into the control group. Hematoxylin-eosin (HE), oil red staining and immunohistochemical (IHC) staining were conducted to compare the expression of lipid metabolism-related proteins (ATP-binding cassette transporter A1 and acyl-coenzyme A: cholesterol acyltransferase-1), and real-time polymerase chain reaction (RT-PCR) was applied to compare the mRNA levels of ABCA1, ACAT1, and the inflammatory cytokines TNF-α, IL-10, and MCP-1.

RESULTS

In general, the rheumatic mitral valve showed leaflet thickening along with border adhesions and visible yellow fats. Oil red O staining also revealed the abovementioned results as well as fat cells. Both ABCA1 and ACAT1 were expressed in the rheumatic mitral valve via IHC, whereas only ACAT1 showed a faint level of expression in the ischemic mitral valve with no expression of ABCA1. In addition, compared with the ischemic mitral valve, RT-PCT showed increased mRNA expression levels of ABCA1, ACAT1, and the inflammatory cytokines TNF-α, IL-10, and MCP-1 (P < 0.05). After dividing the RMs into two groups for RT-PCR, we found that the higher the expression of ABCA1 and ACAT1 was, the lower the relative expression of inflammatory factors.

CONCLUSION

This study showed that adipose tissue, adipose cells, and lipid transport-related proteins were expressed strongly in the rheumatic mitral valve, suggesting that adipose tissue formation might be one of the important pathways in the pathology of rheumatic heart disease. In addition, adipose tissue and adipocytes were also involved in the inflammatory process. These data provide new insight into pathological mechanisms in rheumatic heart disease.

Valvular Heart Disease Epidemiology

Valvular heart disease is a rapidly growing cause of global cardiovascular morbidity and mortality with diverse and evolving geographic distribution. The prevalence of rheumatic heart disease, the most common valvular heart disease (affecting approximately 41 million people), has been rising in developing nations, likely due to the expansion of the young adult population and the decrease in premature mortality that has resulted from improved access to antibiotics, microbiological testing, and echocardiography. Rheumatic heart disease has also been rising among the impoverished and, often, indigenous populations of developed nations, spurring public health initiatives that are aimed at alleviating healthcare disparities. Aortic valve stenotic disease is the most commonly occurring valvular pathology in developed nations (afflicting 9 million people worldwide) and its prevalence has been increasing with population aging and the increased prevalence of atherosclerosis. Aortic regurgitation is associated with diastolic, but not systolic, hypertension and it has likewise seen a rise in the developed world. Mitral regurgitation affects 24 million people worldwide, with great variability between and among nations. Primary mitral regurgitation arises as a consequence of myxomatous degeneration and mitral valve prolapse, which is largely due to genetic predispositions, while secondary mitral regurgitation accounts for 65% of cases and arises secondary to dilation and heart failure. Tricuspid regurgitation has become more prevalent in developed nations due to the increased usage of intracardiac pacemakers. Infective endocarditis prevalence has also grown in developed nations, likely due to population aging and the increased utilization of transcatheter valve replacement and prosthetic valves as interventions against the previously discussed valvular pathologies.

Rheumatic heart disease prevalence in Namibia: a retrospective review of surveillance registers

BACKGROUND

Rheumatic heart disease (RHD) is the most commonly acquired heart disease in children and young people in low and middle-income settings. Fragile health systems and scarcity of data persist to limit the understanding of the relative burden of this disease. The aims of this study were to estimate the prevalence of RHD and to assess the RHD-related health care systems in Namibia.

METHODS

Data was retrieved from outpatient and inpatient registers for all patients diagnosed and treated for RHD between January 2010 to December 2020. We used descriptive statistics to estimate the prevalence of RHD. Key observations and engagement with local cardiac clinicians and patients helped to identify key areas of improvement in the systems.

RESULTS

The outpatient register covered 0.032% of the adult Namibian population and combined with the cumulative incidence from the inpatient register we predict the prevalence of clinically diagnosed RHD to be between 0.05% and 0.10% in Namibia. Young people (< 18 years old) are most affected (72%), and most cases are from the north-eastern regions. Mitral heart valve impairment (58%) was the most common among patients. We identified weaknesses in care systems i.e., lack of patient unique identifiers, missing data, and clinic-based prevention activities.

CONCLUSION

The prevalence of RHD is expected to be lower than previously reported. It will be valuable to investigate latent RHD and patient follow-ups for better estimates of the true burden of disease. Surveillance systems needs improvements to enhance data quality. Plans for expansions of the clinic-based interventions must adopt the "Awareness Surveillance Advocacy Prevention" framework supported by relevant resolutions by the WHO.

Societies of Futures Past: Examining the History and Potential of International Society Collaborations in Addressing the Burden of Rheumatic Heart Disease in the Developing World

This paper explores the role and place of national, regional, and international society collaborations in addressing the major global burden of rheumatic heart disease (RHD). On the same order of HIV, RHD affects over 40 million people worldwide. In this article, we will outline the background and current therapeutic landscape for cardiac surgery in low- and middle-income countries (LMICs) including the resource-constrained settings within which RHD surgery often occurs. This creates numerous challenges to delivering adequate surgical care and post-operative management for RHD patients, and thus provides some context for a growing movement for and applicability of structural heart approaches, innovative valve replacement technologies, and minimally invasive techniques in this setting. Intertwined and building from this context will be the remainder of the paper which elaborates how national, regional, and international societies have collaborated to address rheumatic heart disease in the past (e.g., Drakensberg Declaration, World Heart Federation Working Group on RHD) with a focus on primary and secondary prevention. We then provide the recent history and context of the growing movement for how surgery has become front and center in the discussion of addressing RHD through the passing of the Cape Town Declaration.

Rheumatic Heart Disease Screening Based on Phonocardiogram

Rheumatic heart disease (RHD) is one of the most common causes of cardiovascular complications in developing countries. It is a heart valve disease that typically affects children. Impaired heart valves stop functioning properly, resulting in a turbulent blood flow within the heart known as a murmur. This murmur can be detected by cardiac auscultation. However, the specificity and sensitivity of manual auscultation were reported to be low. The other alternative is echocardiography, which is costly and requires a highly qualified physician. Given the disease's current high prevalence rate (the latest reported rate in the study area (Ethiopia) was 5.65%), there is a pressing need for early detection of the disease through mass screening programs. This paper proposes an automated RHD screening approach using machine learning that can be used by non-medically trained persons outside of a clinical setting. Heart sound data was collected from 124 persons with RHD (PwRHD) and 46 healthy controls (HC) in Ethiopia with an additional 81 HC records from an open-access dataset. Thirty-one distinct features were extracted to correctly represent RHD. A support vector machine (SVM) classifier was evaluated using two nested cross-validation approaches to quantitatively assess the generalization of the system to previously unseen subjects. For regular nested 10-fold cross-validation, an f1-score of 96.0 ± 0.9%, recall 95.8 ± 1.5%, precision 96.2 ± 0.6% and a specificity of 96.0 ± 0.6% were achieved. In the imbalanced nested cross-validation at a prevalence rate of 5%, it achieved an f1-score of 72.2 ± 0.8%, recall 92.3 ± 0.4%, precision 59.2 ± 3.6%, and a specificity of 94.8 ± 0.6%. In screening tasks where the prevalence of the disease is small, recall is more important than precision. The findings are encouraging, and the proposed screening tool can be inexpensive, easy to deploy, and has an excellent detection rate. As a result, it has the potential for mass screening and early detection of RHD in developing countries.

Cardiovascular Diseases and Pharmacomicrobiomics: A Perspective on Possible Treatment Relevance

Cardiovascular diseases (CVDs), the most common cause of mortality in rich countries, include a wide variety of pathologies of the heart muscle and vascular system that compromise the proper functioning of the heart. Most of the risk factors for cardiovascular diseases are well-known: lipid disorders, high serum LDL cholesterol, hypertension, smoking, obesity, diabetes, male sex and physical inactivity. Currently, much evidence shows that: (i) the human microbiota plays a crucial role in maintaining the organism’s healthy status; and (ii) a link exists between microbiota and cardiovascular function that, if dysregulated, could potentially correlate with CVDs. This scenario led the scientific community to carefully analyze the role of the microbiota in response to drugs, considering this the right path to improve the effectiveness of disease treatment. In this review, we examine heart diseases and highlight how the microbiota actually plays a preponderant role in their development. Finally, we investigate pharmacomicrobiomics—a new interesting field—and the microbiota’s role in modulating the response to drugs, to improve their effectiveness by making their action targeted, focusing particular attention on cardiovascular diseases and on innovative potential treatments.

Diagnosing rheumatic heart disease: where are we now and what are the challenges?

INTRODUCTION

Rheumatic heart disease (RHD), a sequela of acute rheumatic fever (ARF), affects 40.5 million people worldwide. The burden of disease disproportionately falls on low- and middle-income countries (LMIC) and sub-populations within high-income countries (HIC). Advances have been made in earlier detection of RHD, though several barriers to ideal management persist.

AREAS COVERED

This article reviews the current burden of RHD, highlighting the disparate impact of disease. It also reviews the clinical and echocardiographic presentation of RHD, as some may present in late stages of disease with associated complications. Finally, we review the advances which have been made in echocardiographic screening to detect latent RHD, highlighting the challenges which remain regarding secondary prophylaxis management and uncertainty of best practices for treatment of latent RHD.

EXPERT OPINION

Advances in technology and validation of portable echocardiography have made screening and identifying latent RHD feasible in the most burdened regions. However, uncertainty remains around best management of those with latent RHD and best methods to ensure ideal secondary prophylaxis for RHD. Research regarding latent RHD management, as well as continued work on innovative solutions (such as group A streptococcal vaccine), are promising as efforts to improve outcomes of this preventable disease persist.

Site-Specific Conjugation of Cell Wall Polyrhamnose to Protein SpyAD Envisioning a Safe Universal Group A Streptococcal Vaccine

Development of an effective vaccine against the leading human bacterial pathogen group A Streptococcus (GAS) is a public health priority. The species defining group A cell wall carbohydrate (GAC, Lancefield antigen) can be engineered to remove its immunodominant N-acetylglucosamine (GlcNAc) side chain, implicated in provoking autoimmune cross-reactivity in rheumatic heart disease, leaving its polyrhamnose core (GACPR). Here we generate a novel protein conjugate of the GACPR and test the utility of this conjugate antigen in active immunization. Instead of conjugation to a standard carrier protein, we selected SpyAD, a highly conserved GAS surface protein containing both B-cell and T-cell epitopes relevant to the bacterium that itself shows promise as a vaccine antigen. SpyAD was synthesized using the XpressTM cell-free protein expression system, incorporating a non-natural amino acid to which GACPR was conjugated by site-specific click chemistry to yield high molecular mass SpyAD-GACPR conjugates and avoid disruption of important T-cell and B-cell immunological epitopes. The conjugated SpyAD-GACPR elicited antibodies that bound the surface of multiple GAS strains of diverse M types and promoted opsonophagocytic killing by human neutrophils. Active immunization of mice with a multivalent vaccine consisting of SpyAD-GACPR, together with candidate vaccine antigens streptolysin O and C5a peptidase, protected against GAS challenge in a systemic infection model and localized skin infection model, without evidence of cross reactivity to human heart or brain tissue epitopes. This general approach may allow GAC to be safely and effectively included in future GAS subunit vaccine formulations with the goal of broad protection without autoreactivity.

A case report of isolated rheumatic tricuspid regurgitation and pericarditis

Rheumatic fever (RF) is a complex syndrome in which the human body develops antibodies against β-haemolytic streptococcus, and triggers inflammation in various organs. RF valvulitis mostly affects the mitral valve (MV) and, to a lesser extent, the aortic valve (AV). Isolated rheumatic tricuspid valve (TV) disease and pericarditis is extremely rare and is not well described in the RF guidelines. The current case demonstrates the echocardiographic findings of TV valvulitis of RF and describes the presentation and electrocardiogram (ECG) changes in pericarditis. We present the case of a 16-year-old male patient who developed upper respiratory tract infection followed by typical pericarditis chest pain. The patient had no history of joint pain or swelling, but was found to have a tricuspid regurgitation (TR) murmur upon examination. Laboratory investigations revealed an elevated erythrocyte sedimentation rate, and elevated C-reactive protein and antistreptolysin O titres. ECG showed a wide-spread 1.5 mm upward concave ST-segment elevation. In echocardiography, the TV opened well with markedly thickened leaflets and severe TR, while the MV and AV were normal in both structure and function. The diagnosis of RF was established and treatment with high-dose aspirin and antibiotics was initiated. The treatment led to resolution of the chest pain. Our case highlights that the physical and lab findings of rheumatic TR are similar to those of rheumatic mitral regurgitation, with the exception of a high-velocity jet. Similarly, the presentations of rheumatic pericarditis are similar to other types and may also respond to high-dose aspirin. Finally, physicians should be familiar with both the common and rare complications of RF because the guidelines have placed Middle East region among the high-risk countries.

Neglected cardiovascular diseases and their significance in the Global North

Due to increasing global migration, the spectrum of cardiovascular disease (CVD) is changing in developed countries. Up to 3% of migrants arriving in Europe have underlying CVD. Despite their high global prevalence, conditions such as rheumatic heart disease, Chagas disease, endomyocardial fibrosis, tuberculous pericarditis, peripartum cardiomyopathy, and pulmonary hypertension are often under-recognized, and, as a result, neglected in industrialized countries. Many of these conditions, and their causes, are often unfamiliar to the health-care providers in host countries. In this review, we summarize the epidemiology, etiology, clinical presentation, diagnostic work-up, and management of neglected CVDs that have an increasing prevalence in the Global North.