The American Heart Association's Call to Action for Reducing the Global Burden of Rheumatic Heart Disease: A Policy Statement From the American Heart Association

Anti-IL-17 Inhibits PINK1/Parkin Autophagy and M1 Macrophage Polarization in Rheumatic Heart Disease

Rheumatic heart disease (RHD) is an important and preventable cause of cardiovascular death and disability, but the lack of clarity about its exact mechanisms makes it more difficult to find alternative methods or prevention and treatment. We previously demonstrated that increased IL-17 expression plays a crucial role in the development of RHD-related valvular inflammatory injury. Macrophage autophagy/polarization may be a pro-survival strategy in the initiation and resolution of the inflammatory process. This study investigated the mechanism by which IL-17 regulates autophagy/polarization activation in macrophages. A RHD rat model was generated, and the effects of anti-IL-17 and 3-methyladenine (3-MA) were analyzed. The molecular mechanisms underlying IL-17-induced macrophage autophagy/polarization were investigated via in vitro experiments. In our established RHD rat model, the activation of the macrophage PINK1/Parkin autophagic pathway in valve tissue was accompanied by M1 macrophage infiltration, and anti-IL-17 treatment inhibited autophagy and reversed macrophage inflammatory infiltration, thereby attenuating endothelial-mesenchymal transition (EndMT) in the valve tissue. The efficacy of 3-MA treatment was similar to that of anti-IL-17 treatment. Furthermore, in THP-1 cells, the pharmacological promotion of autophagy by IL-17 induced M1-type polarization, whereas the inhibition of autophagy by 3-MA reversed this process. Mechanistically, silencing PINK1 in THP-1 blocked autophagic flux. Moreover, IL-17-induced M1-polarized macrophages promoted EndMT in HUVECs. This study revealed that IL-17 plays an important role in EndMT in RHD via the PINK1/Parkin autophagic pathway and macrophage polarization, providing a potential therapeutic target.

Rheumatic heart valve disease: navigating the challenges of an overlooked autoimmune disorder

Despite being a leading cause of morbidity and mortality among young people, affecting predominantly women, rheumatic heart disease (RHD) remains neglected and understudied. This autoimmune condition arises from a complex continuum that begins with repeated Group A Streptococcal (GAS) pharyngitis, leading to acute rheumatic fever (ARF) that eventually results in damage to the heart, mainly affecting the mitral valve. While RHD has been nearly eradicated in high-income countries, it continues to be a significant and active health issue in low- and middle-income countries. The resolution of this disease faces several challenges, including the difficulty of diagnosis and the lack of access to preventive measures in resource-poor communities. Addressing these issues will require a global health collaboration involving healthcare professionals, policymakers, and advocacy groups. However, over the past two decades, there has been a revival of scientific interest, fostering optimism for the future. Recent research has significantly advanced our understanding of RHD, shedding light on the immune-to-autoimmune transition, neoangiogenesis, and lymphangiogenesis processes. Additionally, perspectives of discoveries in biomarkers and the development of genetic, transcriptomic, and provide a solid foundation for further advancements in the field.

Review: Known, Emerging, and Remerging Pharyngitis Pathogens

Pharyngitis is an inflammatory condition of the pharynx and/or tonsils commonly seen in both children and adults. Viruses and bacteria represent the most common encountered etiologic agents-yeast/fungi and parasites are infrequently implicated. Some of these are predominantly observed in unique populations (eg, immunocompromised or unvaccinated individuals). This article (part 1 of 3) summarizes the impact of acute pharyngitis on the health care system and reviews the etiologic agents of acute pharyngitis, including both emerging and reemerging pathogens that health care providers should consider when evaluating their patients. Finally, it sets the stage for parts 2 and 3, which discuss the current and evolving state of diagnostic testing for acute pharyngitis.

Acute rheumatic fever and rheumatic heart disease: updates in diagnosis and treatment

PURPOSE OF REVIEW

To summarize the latest developments in rheumatic fever and rheumatic heart disease (RHD) prevention, (early) diagnosis, and treatment.

RECENT FINDINGS

The revised Jones criteria have demonstrated increased sensitivity and specificity for rheumatic fever diagnosis in high-risk populations. The management of rheumatic fever remains symptom-based, with no treatment options proven to alter the disease course or prevent chronic RHD. The revised World Heart Federation (WHF) guidelines for the echocardiographic diagnosis of RHD encourage task-shifting of RHD screening, extending reach in endemic regions. These guidelines also present an A-D classification of RHD and provide recommendations for the management of early disease. Integrated models for RHD screening within existing health structures are emerging and automated intelligence is showing potential to support RHD screening and diagnosis. Innovative strategies to foster adherence and equitable access to secondary prophylaxis, such as re-examination of the efficacy of oral penicillin, trials of longer acting penicillin formulations and implants are underway. There is renewed interest and investment in a well tolerated and effective GAS vaccine.

SUMMARY

We are living in a time of possibility with global acceleration to address the prevailing burden of RHD. Together, we can ensure that RHD does not once again fall off the global health agenda, until equitable elimination has been achieved.

An acute rheumatic fever immune signature comprising inflammatory markers, IgG3, and Streptococcus pyogenes-specific antibodies

Understanding the immune profile of acute rheumatic fever (ARF), a serious post-infectious sequelae of Streptococcal pyogenes (group A Streptococcus [GAS]), could inform disease pathogenesis and management. Circulating cytokines, immunoglobulins, and complement were analyzed in participants with first-episode ARF, swab-positive GAS pharyngitis and matched healthy controls. A striking elevation of total IgG3 was observed in ARF (90% > clinical reference range for normal). ARF was also associated with an inflammatory triad with significant correlations between interleukin-6, C-reactive protein, and complement C4 absent in controls. Quantification of GAS-specific antibody responses revealed that subclass polarization was remarkably consistent across the disease spectrum; conserved protein antigens polarized to IgG1, while M-protein responses polarized to IgG3 in all groups. However, the magnitude of responses was significantly higher in ARF. Taken together, these findings emphasize the association of exaggerated GAS antibody responses, IgG3, and inflammatory cytokines in ARF and suggest IgG3 testing could beneficially augment clinical diagnosis.

Contemporary spectrum, characteristics, and outcomes of adult patients with rheumatic valvular disease in China: Insights from the China-VHD study

Background

Rheumatic valvular disease (RVD) represents a significant health concern in developing countries, yet a scarcity of detailed data exists. This study conducts a comprehensive examination of RVD patients in China, exploring aspects of the disease's spectrum, characteristics, investigation, management, and outcomes.

Methods

The China Valvular Heart Disease (China-VHD) study, a nationwide, multicenter, prospective observational study, enrolled 13,917 adults with moderate-to-severe valvular heart disease from April to June 2018. Among these, 2402 patients with native RVD (19.7% of native VHD patients) were analyzed.

Results

Among the RVD patients, the median age was 57 years (interquartile range 50-65), with 82.5% falling within the 40-70 age range; females were notably predominant (63.9%). Rheumatic etiology prevailed, particularly in southern regions (48.8%). Multivalvular involvement was observed in 47.4% of RVD cases, and atrial fibrillation emerged as the most common comorbidity (43.2%). Severe RVD affected 64.2% of patients. Valvular interventions were undertaken by 66.9% of RVD patients, predominantly involving surgical valve replacement (90.8%). Adverse events, encompassing all-cause mortality and heart failure hospitalization, occurred in 7.3% of patients during the 2-year follow-up. Multivariable analysis identified factors such as age, geographical region, low body mass index, renal insufficiency, left atrial diameter, and left ventricular ejection fraction <50% (all P < 0.05) associated with adverse events, with valvular intervention emerging as a protective factor (HR: 0.201; 95%CI: 0.139 to 0.291; p < 0.001).

Conclusions

This study delivers a comprehensive evaluation of RVD patients in China, shedding light on the spectrum, characteristics, investigation, management, and outcomes of this prevalent condition.

Strep A: challenges, opportunities, vaccine-based solutions, and economics

This collection of articles focuses on Streptococcus pyogenes (Strep A) vaccine research and innovation, with a focus on emerging efforts to understand and estimate the full societal value of Strep A vaccination.

Human Umbilical Cord Mesenchymal Stem Cells Repair Endothelial Injury and Dysfunction by Regulating NLRP3 to Inhibit Endothelial Cell Pyroptosis in Kawasaki Disease

Vascular endothelial inflammation and endothelial dysfunction are the main causes of endothelial injury in Kawasaki disease (KD). Human umbilical cord-derived mesenchymal stem cells (Huc-MSCs) have multiple functions in immune regulation. This study examined whether Huc-MSCs inhibited endothelial inflammation and improved endothelial function in KD through constructing cell and in vivo animal KD vasculitis models. The pyroptosis factor NOD-like receptor protein 3 (NLRP3) was involved in the inflammatory process in the acute phase of KD. After tail vein injection of Huc-MSCs, inflammatory cell infiltration and the expression of pyroptosis-related proteins in the LCWE-induced KD mouse vasculitis model were significantly reduced. In vitro, NLRP3-dependent pyroptosis successfully induced human umbilical vein endothelial cell (HUVEC) damage. Huc-MSCs effectively increased the abilities of impaired HUVECs to proliferate, migrate, invade, and form vessel-like tubes, while inhibiting their apoptosis, suggesting that Huc-MSCs can reduce inflammation and improve vascular endothelial function by inhibiting the NLRP3-dependent pyroptosis pathway in KD, providing a possibility and novel target for KD endothelial injury and dysfunction.

A Case of Group A Streptococcus Bacteremia and Infective Endocarditis Caused by Right Ovarian Tube Endometriosis Where the Patient's Perspective Was Key to the Diagnostic Process

Group A streptococcus pyogenes (GAS) is a common organism that can cause upper respiratory infections. We encountered a case where GAS caused infective endocarditis (IE) due to an entry from the vagina. In this case, although echocardiography was negative, we were able to make a diagnosis of IE based on the 2023 Duke International Society for Cardiovascular Infectious Diseases Criteria, and we started antimicrobial therapy for IE. However, the patient subsequently developed persistent abdominal pain, which was atypical; hence, we reviewed the differential diagnosis. It is difficult to locate the primary site of infection because GAS rarely causes vaginal infections, and vaginal infections rarely cause IE. This case highlights the significance of revisiting medical history and the value of using a system 3 approach to refine diagnostic directions.

The full health, economic, and social benefits of prospective Strep A vaccination

Recent research has documented a wide range of health, economic, and social benefits conferred by vaccination, beyond the direct reductions in morbidity, mortality, and future healthcare costs traditionally captured in economic evaluations. In this paper, we describe the societal benefits that would likely stem from widespread administration of safe and effective vaccines against Streptococcus pyogenes (Strep A), which was estimated to be the fifth-leading cause of infectious disease deaths globally prior to the COVID-19 pandemic. We then estimate the global societal gains from prospective Strep A vaccination through a value-per-statistical-life approach. Estimated aggregate lifetime benefits for 30 global birth cohorts range from $1.7 to $5.1 trillion, depending on the age at which vaccination is administered and other factors. These results suggest that the benefits of Strep A vaccination would be large and justify substantial investment in the vaccines' development, manufacture, and delivery.

Research opportunities for the primary prevention and management of acute rheumatic fever and rheumatic heart disease: a National Heart, Lung, and Blood Institute workshop report

Primary prevention of acute rheumatic fever (ARF) and rheumatic heart disease (RHD) encompasses the timely diagnosis and adequate treatment of the superficial group A Streptococcus (GAS) infections pharyngitis and impetigo. GAS is the only known inciting agent in the pathophysiology of the disease. However, sufficient evidence indicates that the uptake and delivery of primary prevention approaches in RHD-endemic regions are significantly suboptimal. This report presents expert deliberations on priority research and implementation opportunities for primary prevention of ARF/RHD that were developed as part of a workshop convened by the US National Heart, Lung, and Blood Institute in November 2021. The opportunities identified by the Primary Prevention Working Group encompass epidemiological, laboratory, clinical, implementation and dissemination research domains and are anchored on five pillars including: (A) to gain a better understanding of superficial GAS infection epidemiology to guide programmes and policies; (B) to improve diagnosis of superficial GAS infections in RHD endemic settings; (C) to develop scalable and sustainable models for delivery of primary prevention; (D) to understand potential downstream effects of the scale-up of primary prevention and (E) to develop and conduct economic evaluations of primary prevention strategies in RHD endemic settings. In view of the multisectoral stakeholders in primary prevention strategies, we emphasise the need for community co-design and government engagement, especially in the implementation and dissemination research arena. We present these opportunities as a reference point for research organisations and sponsors who aim to contribute to the increasing momentum towards the global control and prevention of RHD.

Tertiary prevention and treatment of rheumatic heart disease: a National Heart, Lung, and Blood Institute working group summary

Although entirely preventable, rheumatic heart disease (RHD), a disease of poverty and social disadvantage resulting in high morbidity and mortality, remains an ever-present burden in low-income and middle-income countries (LMICs) and rural, remote, marginalised and disenfranchised populations within high-income countries. In late 2021, the National Heart, Lung, and Blood Institute convened a workshop to explore the current state of science, to identify basic science and clinical research priorities to support RHD eradication efforts worldwide. This was done through the inclusion of multidisciplinary global experts, including cardiovascular and non-cardiovascular specialists as well as health policy and health economics experts, many of whom also represented or closely worked with patient-family organisations and local governments. This report summarises findings from one of the four working groups, the Tertiary Prevention Working Group, that was charged with assessing the management of late complications of RHD, including surgical interventions for patients with RHD. Due to the high prevalence of RHD in LMICs, particular emphasis was made on gaining a better understanding of needs in the field from the perspectives of the patient, community, provider, health system and policy-maker. We outline priorities to support the development, and implementation of accessible, affordable and sustainable interventions in low-resource settings to manage RHD and related complications. These priorities and other interventions need to be adapted to and driven by local contexts and integrated into health systems to best meet the needs of local communities.

Modalities of group A streptococcal prevention and treatment and their economic justification

Infection by group A Streptococcus (Strep A) results in a diverse range of clinical conditions, including pharyngitis, impetigo, cellulitis, necrotising fasciitis, and rheumatic heart disease. In this article, we outline the recommended strategies for Strep A treatment and prevention and review the literature for economic evaluations of competing treatment and prevention strategies. We find that most economic evaluations focus on reducing the duration of illness or risk of rheumatic fever among people presenting with sore throat through diagnostic and/or treatment strategies. Few studies have evaluated strategies to reduce the burden of Strep A infection among the general population, nor have they considered the local capacity to finance and implement strategies. Evaluation of validated costs and consequences for a more diverse range of Strep A interventions are needed to ensure policies maximise patient outcomes under budget constraints. This should include attention to basic public health strategies and emerging strategies such as vaccination.

American Heart Association's Children's Strategically Focused Research Network Experience

The American Heart Association's Strategically Focused Children's Research Network started in July 2017 with 4 unique programs at Children's National Hospital in Washington, DC; Duke University in Durham, North Carolina; University of Utah in Salt Lake City, Utah; and Lurie Children's Hospital/Northwestern University in Chicago, Illinois. The overarching goal of the Children's National center was to develop evidence-based strategies to strengthen the health system response to rheumatic heart disease through synergistic basic, clinical, and population science research. The overall goals of the Duke center were to determine risk factors for obesity and response to treatment including those that might work on a larger scale in communities across the country. The integrating theme of the Utah center focused on leveraging big data-science approaches to improve the quality of care and outcomes for children with congenital heart defects, within the context of the patient and their family. The overarching hypothesis of the Northwestern center is that the early course of change in cardiovascular health, from birth onward, reflects factors that result in either subsequent development of cardiovascular risk or preservation of lifetime favorable cardiovascular health. All 4 centers exceeded the original goals of research productivity, fellow training, and collaboration. This article describes details of these accomplishments and highlights challenges, especially around the COVID-19 pandemic.

Valvular Heart Disease: New Concepts in Pathophysiology and Therapeutic Approaches

This review discusses recent advancements in the field of valvular heart disease. Topics covered include recognition of the impact of atrial fibrillation on development and assessment of valvular disease, strategies for global prevention of rheumatic heart disease, understanding and management of secondary mitral regurgitation, the updated classification of bicuspid aortic valve disease, recognition of heightened cardiovascular risk associated with moderate aortic stenosis, and a growing armamentarium of transcatheter therapies.

Correlates of immunity to Group A Streptococcus: a pathway to vaccine development

Understanding immunity in humans to Group A Streptococcus (Strep A) is critical for the development of successful vaccines to prevent the morbidity and mortality attributed to Strep A infections. Despite decades of effort, no licensed vaccine against Strep A exists and immune correlates of protection are lacking; a major impediment to vaccine development. In the absence of a vaccine, we can take cues from the development of natural immunity to Strep A in humans to identify immune correlates of protection. The age stratification of incidence of acute Strep A infections, peaking in young children and waning in early adulthood, coincides with the development of specific immune responses. Therefore, understanding the immune mechanisms involved in natural protection from acute Strep A infection is critical to identifying immune correlates to inform vaccine development. This perspective summarises the findings from natural infection studies, existing assays of immunity to Strep A, and highlights the gaps in knowledge to guide the development of Strep A vaccines and associated correlates of protection.

Harmonizing Surveillance Methodologies for Group A Streptococcal Diseases

Group A Streptococcus (Strep A) is responsible for a significant global health and economic burden. The recent prioritization of Strep A vaccine development by the World Health Organization has prompted global research activities and collaborations. To progress this prioritization, establishment of robust surveillance for Strep A to generate updated regional disease burden estimates and to establish platforms for future impact evaluation is essential. Through the activities of the Strep A Vaccine Global Consortium (SAVAC), we have refined and harmonized surveillance protocols for 7 Strep A disease endpoints with a view that these will form part of surveillance standards for ongoing research and public health activities.

The global burden of sore throat and group A Streptococcus pharyngitis: A systematic review and meta-analysis

BACKGROUND

Contemporary data for the global burden of sore throat and group A Streptococcus (Strep A) pharyngitis are required to understand the frequency of disease and develop value propositions for Strep A vaccines.

METHODS

We used Clarivate Analytics' Web of Science platform to search WoS core collection, PubMed, Medline, data citation index, KCI-Korean Journal Database, Russian Science Citation Index, and the SciELO Citation Index for articles published between Jan 1, 2000, and Feb 15, 2021, from any country and in any language. The risk of bias was assessed using the JBI critical appraisal checklist. We used random-effects meta-analyses to pool sore throat and Strep A sore throat incidence rates from community-based studies. Our study was registered with PROSPERO (CRD42020181103).

FINDINGS

Of 5,529 articles identified by the search strategy, 26 studies met the inclusion criteria, but only two included data to determine incidence among adults. The pooled incidence rate, calculated for children only, was 82.2 episodes per 100 child-years (95% CI 25.2-286.3, I² = 100%) for sore throat (7 studies; 7,964 person years) and 22.1 episodes per 100 child-years (95% CI 14.7-33.1, I² = 98%) for Strep A sore throat (9 studies; 15,696 person years). The pooled cumulative incidence rate of sore throat from five studies was 31.9 per 100 children. There was significant methodological and statistical heterogeneity among studies, and five of 26 studies had a risk of bias score less than five (range: nine [maximum score] to one).

INTERPRETATION

Strep A sore throat has a considerable global burden. However, methodologically standardised studies are required to quantify that burden, analyse differences in rates between populations, and evaluate the likely impact of future Strep A vaccines.

FUNDING

This study was funded by Wellcome Trust 215,490/Z/19/Z.

A systematic framework for prioritising burden of disease data required for vaccine development and implementation: the case for group A streptococcal diseases

Vaccine development and implementation decisions need to be guided by accurate and robust burden of disease data. We developed an innovative systematic framework outlining the properties of such data that are needed to advance vaccine development and evaluation, and prioritize research and surveillance activities. We focus on 4 objectives—advocacy, regulatory oversight and licensure, policy and post-licensure evaluation, and post-licensure financing—and identify key stakeholders and specific requirements for burden of disease data aligned with each objective. We apply this framework to group A Streptococcus, a pathogen with an underrecognized global burden, and give specific examples pertinent to 8 clinical endpoints. This dynamic framework can be adapted for any disease with a vaccine in development and can be updated as vaccine candidates progress through clinical trials. This framework will also help with research and innovation priority setting of the Immunization Agenda 2030 (IA2030) and accelerate development of future vaccines.

Recent Advances in the Rheumatic Fever and Rheumatic Heart Disease Continuum

Nearly a century after rheumatic fever (RF) and rheumatic heart disease (RHD) was eradicated from the developed world, the disease remains endemic in many low- and middle-income countries (LMICs), with grim health and socioeconomic impacts. The neglect of RHD which persisted for a semi-centennial was further driven by competing infectious diseases, particularly the human immunodeficiency virus (HIV) pandemic. However, over the last two-decades, slowly at first but with building momentum, there has been a resurgence of interest in RF/RHD. In this narrative review, we present the advances that have been made in the RF/RHD continuum over the past two decades since the re-awakening of interest, with a more concise focus on the last decade's achievements. Such primary advances include understanding the genetic predisposition to RHD, group A Streptococcus (GAS) vaccine development, and improved diagnostic strategies for GAS pharyngitis. Echocardiographic screening for RHD has been a major advance which has unearthed the prevailing high burden of RHD and the recent demonstration of benefit of secondary antibiotic prophylaxis on halting progression of latent RHD is a major step forward. Multiple befitting advances in tertiary management of RHD have also been realized. Finally, we summarize the research gaps and provide illumination on profitable future directions towards global eradication of RHD.

Period Prevalence of Rheumatic Heart Disease and the Need for a Centralized Patient Registry in American Samoa, 2016 to 2018

Background

Rheumatic heart disease (RHD) is a severe, chronic complication of acute rheumatic fever, triggered by group A streptococcal pharyngitis. Centralized patient registries are recommended for RHD prevention and control, but none exists in American Samoa. Using existing RHD tracking systems, we estimated RHD period prevalence and the proportion of people with RHD documented in the electronic health record.

Methods and Results

RHD cases were identified from a centralized electronic health record system, which retrieved clinical encounters with RHD International Classification of Diseases, Tenth Revision, Clinical Modification (ICD‐10‐CM) codes, clinical problem lists referencing RHD, and antibiotic prophylaxis administration records; 3 RHD patient tracking spreadsheets; and an all‐cause mortality database. RHD cases had ≥1 clinical encounter with RHD ICD‐10‐CM codes, a diagnostic echocardiogram, or RHD as a cause of death, or were included in RHD patient tracking spreadsheets. Period prevalence per 1000 population among children aged <18 years and adults aged ≥18 years from 2016 to 2018 and the proportion of people with RHD with ≥1 clinical encounter with an RHD ICD‐10‐CM code were estimated. From 2016 to 2018, RHD was documented in 327 people (57.2%: children aged <18 years). Overall RHD period prevalence was 6.3 cases per 1000 and varied by age (10.0 pediatric cases and 4.3 adult cases per 1000). Only 67% of people with RHD had ≥1 clinical encounter with an RHD ICD‐10‐CM code.

Conclusions

RHD remains a serious public health problem in American Samoa, and the existing electronic health record does not include all cases. A centralized patient registry could improve tracking people with RHD to ensure they receive necessary care.

Mortality and years of life lost of cardiovascular diseases in China, 2005-2020: Empirical evidence from national mortality surveillance system

OBJECTIVES

Cardiovascular disease (CVD) is leading cause of death in China. We aimed to provide national and subnational estimates and its change of premature mortality burden of CVD during 2005-2020.

METHODS

Data from multi-source on the basis of national mortality surveillance system (NMSS) was used to estimate mortality and years of life lost (YLL) of total CVD and its subcategories in Chinese population across 31 provinces during 2005-2020.

RESULTS

Estimated CVD deaths increased from 3.09 million in 2005 to 4.58 million in 2020; the age-standardized mortality rate (ASMR) decreased from 286.85 per 100,000 in 2005 to 245.39 per 100,000 in 2020. A substantial reduction of 19.27% of CVD premature mortality burden, as measured by age-standardized YLL rate, was observed. Ischemic heart disease (IHD), hemorrhagic stroke (HS) and ischemic stroke (IS) were leading 3 causes of CVD death. Marked differences were observed in geographical patterns for total CVD and its subcategories, and it appeared to be lower in areas with higher economic development. Population ageing was dominant driver contributed to CVD deaths increase, followed by population growth. And, age-specific mortality shifts contributed largely to CVD deaths decline in most provinces.

CONCLUSION

Substantial discrepancies were demonstrated in CVD premature mortality burden across China. Targeted considerations were needed to integrate primary care with clinical care through intensifying further strategies for reducing CVD mortality among specific subcategories, high risk population and regions with inadequate healthcare resources.

The Global Impact of Rheumatic Heart Disease

PURPOSE OF REVIEW

Rheumatic heart disease (RHD) is a neglected disease of poverty, which presents challenges for patients, communities, and health systems. These effects are magnified in low resource countries, which bear the highest disease burden. When considering the impact of RHD, it is imperative that we widen our lens in order to better understand how RHD impacts the over 40 million people currently living with this preventable condition and their communities. We aimed to perform an updated literature review on the global impact of RHD, examining a broad range of aspects from disease burden to impact on healthcare system to socioeconomic implications.

RECENT FINDINGS

RHD accounts for 1.6% of all cardiovascular deaths, resulting in 306,000 deaths yearly, with a much higher contribution in low- and middle-income countries, where 82% of the deaths occurred in 2015. RHD can result in severe health adverse outcomes, markedly heart failure, arrhythmias, stroke and embolisms, and ultimately premature death. Thus, preventive, diagnostic and therapeutic interventions are required, although insufficiently available in undersourced settings. As examples, anticoagulation management is poor in endemic regions - and novel oral anticoagulants cannot be recommended - and less than 15% of those in need have access to interventional procedures and valve replacement in Africa. RHD global impact remains high and unequally distributed, with a marked impact on lower resourced populations. This preventable disease negatively affects not only patients, but also the societies and health systems within which they live, presenting broad challenges and high costs along the pathway of prevention, diagnosis, and management.

Association of Novel Locus With Rheumatic Heart Disease in Black African Individuals: Findings From the RHDGen Study

Importance

Rheumatic heart disease (RHD), a sequela of rheumatic fever characterized by permanent heart valve damage, is the leading cause of cardiac surgery in Africa. However, its pathophysiologic characteristics and genetics are poorly understood. Understanding genetic susceptibility may aid in prevention, control, and interventions to eliminate RHD.

Objective

To identify common genetic loci associated with RHD susceptibility in Black African individuals.

Design, Setting, and Participants

This multicenter case-control genome-wide association study (GWAS), the Genetics of Rheumatic Heart Disease, examined more than 7 million genotyped and imputed single-nucleotide variations. The 4809 GWAS participants and 116 independent trio families were enrolled from 8 African countries between December 31, 2012, and March 31, 2018. All GWAS participants and trio probands were screened by use of echocardiography. Data analyses took place from May 15, 2017, until March 14, 2021.

Main Outcomes and Measures

Genetic associations with RHD.

Results

This study included 4809 African participants (2548 RHD cases and 2261 controls; 3301 women [69%]; mean [SD] age, 36.5 [16.3] years). The GWAS identified a single RHD risk locus, 11q24.1 (rs1219406 [odds ratio, 1.65; 95% CI, 1.48-1.82; P = 4.36 × 10-8]), which reached genome-wide significance in Black African individuals. Our meta-analysis of Black (n = 3179) and admixed (n = 1055) African individuals revealed several suggestive loci. The study also replicated a previously reported association in Pacific Islander individuals (rs11846409) at the immunoglobulin heavy chain locus, in the meta-analysis of Black and admixed African individuals (odds ratio, 1.16; 95% CI, 1.06-1.27; P = 1.19 × 10-3). The HLA (rs9272622) associations reported in Aboriginal Australian individuals could not be replicated. In support of the known polygenic architecture for RHD, overtransmission of a polygenic risk score from unaffected parents to affected probands was observed (polygenic transmission disequilibrium testing mean [SE], 0.27 [0.16] SDs; P = .04996), and the chip-based heritability was estimated to be high at 0.49 (SE = 0.12; P = 3.28 × 10-5) in Black African individuals.

Conclusions and Relevance

This study revealed a novel candidate susceptibility locus exclusive to Black African individuals and an important heritable component to RHD susceptibility in African individuals.

Design of Broadly Cross-Reactive M Protein-Based Group A Streptococcal Vaccines

Group A streptococcal infections are a significant cause of global morbidity and mortality. A leading vaccine candidate is the surface M protein, a major virulence determinant and protective Ag. One obstacle to the development of M protein-based vaccines is the >200 different M types defined by the N-terminal sequences that contain protective epitopes. Despite sequence variability, M proteins share coiled-coil structural motifs that bind host proteins required for virulence. In this study, we exploit this potential Achilles heel of conserved structure to predict cross-reactive M peptides that could serve as broadly protective vaccine Ags. Combining sequences with structural predictions, six heterologous M peptides in a sequence-related cluster were predicted to elicit cross-reactive Abs with the remaining five nonvaccine M types in the cluster. The six-valent vaccine elicited Abs in rabbits that reacted with all 11 M peptides in the cluster and functional opsonic Abs against vaccine and nonvaccine M types in the cluster. We next immunized mice with four sequence-unrelated M peptides predicted to contain different coiled-coil propensities and tested the antisera for cross-reactivity against 41 heterologous M peptides. Based on these results, we developed an improved algorithm to select cross-reactive peptide pairs using additional parameters of coiled-coil length and propensity. The revised algorithm accurately predicted cross-reactive Ab binding, improving the Matthews correlation coefficient from 0.42 to 0.74. These results form the basis for selecting the minimum number of N-terminal M peptides to include in potentially broadly efficacious multivalent vaccines that could impact the overall global burden of group A streptococcal diseases.

Contemporary Diagnosis and Management of Rheumatic Heart Disease: Implications for Closing the Gap: A Scientific Statement From the American Heart Association

The global burden of rheumatic heart disease continues to be significant although it is largely limited to poor and marginalized populations. In most endemic regions, affected patients present with heart failure. This statement will seek to examine the current state-of-the-art recommendations and to identify gaps in diagnosis and treatment globally that can inform strategies for reducing disease burden. Echocardiography screening based on World Heart Federation echocardiographic criteria holds promise to identify patients earlier, when prophylaxis is more likely to be effective; however, several important questions need to be answered before this can translate into public policy. Population-based registries effectively enable optimal care and secondary penicillin prophylaxis within available resources. Benzathine penicillin injections remain the cornerstone of secondary prevention. Challenges with penicillin procurement and concern with adverse reactions in patients with advanced disease remain important issues. Heart failure management, prevention, early diagnosis and treatment of endocarditis, oral anticoagulation for atrial fibrillation, and prosthetic valves are vital therapeutic adjuncts. Management of health of women with unoperated and operated rheumatic heart disease before, during, and after pregnancy is a significant challenge that requires a multidisciplinary team effort. Patients with isolated mitral stenosis often benefit from percutaneous balloon mitral valvuloplasty. Timely heart valve surgery can mitigate the progression to heart failure, disability, and death. Valve repair is preferable over replacement for rheumatic mitral regurgitation but is not available to the vast majority of patients in endemic regions. This body of work forms a foundation on which a companion document on advocacy for rheumatic heart disease has been developed. Ultimately, the combination of expanded treatment options, research, and advocacy built on existing knowledge and science provides the best opportunity to address the burden of rheumatic heart disease.