Cardiomyopathies and myocardial disorders in Africa: present status and the way forward

Heart Diseases of Uncertain Etiology: A New Definition of Heart Failure for Epidemiological Studies

It has been a long time since, in the spectrum of ischemic (IHD) or coronary (CHD) heart diseases, a differentiation was performed between the forms presenting with and those without pain [...].

National, regional, and global cardiomyopathy burden from 1990 to 2019

OBJECTIVE

To examine the incidence of cardiomyopathy including both alcoholic cardiomyopathy (AC) and other cardiomyopathy (OC) in 204 nations and regions over the 1990-2019 period.

METHODS

The present study was conducted using data derived from the GBD 2019 study coordinated by the Institute for Health Metrics and Evaluation (IHME). The GBD 2019 study included epidemiological data pertaining to 369 diseases/injuries, 286 causes of death, and 87 risk factors in 204 nations and regions. For this study, we adopt published estimates pertaining to the prevalence rates, mortality rates, and disability-adjusted life years (DALYs) associated with cardiomyopathy. The Bayesian mixed-effects DisMod-MR 2.1 meta-regression tool, which was designed to analyze GBD data, was used to estimate the prevalence of OC and AC. The GBD data are subdivided into 21 global regions based on characteristics such as geographical proximity and epidemiological similarity. The overall burden of cardiomyopathy was assessed by combining AC- and OC-related data, 95% confidence intervals were calculated based on standardized error values determined based upon the width of the 95% UI divided by 1.96 × 2.

RESULTS

Globally, there were an estimated 0.71 million (95% UI: 0.55-0.92) AC cases and 3.73 million (95% UI: 2.92-4.72) OC cases in 2019. The age-standardized cardiomyopathy, AC, and OC prevalence rates (per 100,000 persons) in 2019 were 56.0 (95% CI: 43.82-71.17), 8.51 (95% UI: 6.6-11.01), and 47.49 (95% UI: 37.22-60.16), respectively. In total, the respective numbers of global deaths attributed to AC and OC were 0.07 million (95% UI: 0.06-0.08) and 0.24 million (95% UI: 0.19-0.26). The age-standardized mortality rate for cardiomyopathy in 2019 was 3.97 (95% CI: 3.29-4.39), with respective mortality rates of 0.86 (95% UI: 0.72-0.99) and 3.11 (95% UI: 2.57-3.4) for AC and OC. At the global level in 2019, 2.44 million (95% UI: 2.04-2.78) DALYs were attributed to AC, while 5.72 million (95% UI: 4.89-6.33) DALYs were attributed to OC. From 1990 to 2019, cardiomyopathy age-standardized prevalence rates declined by -0.49% (95% CI: -0.57 to -0.41), with those for AC and OC having respectively declined by -0.32% (95% UI: -0.36 to -0.28) and -0.17% (95% UI: -0.21 to -0.13). The age-standardized AC and OC mortality rates declined by -0.36% (95% UI: -0.5 to -0.26) and -0.39% (95% UI: -0.44 to -0.29), despite 24.8 and 30.2% increases, respectively, in the numbers of AC- and OC-related deaths during the same period.

CONCLUSION

Previous studies have estimated the risk factors that influence the burden of multiple cardiovascular diseases (CVD). Among them, some studies related to the GBD database on cardiomyopathy data suggest that alcohol intake, gender are factors in the development of AC, and the burden of AC and OC is not limited to developed or less developed countries. Otherwise, this study mainly focused on cardiomyopathy, and analyzed multiple indicators from national, regional, and age-standard dimensions to identify potential risk factors including prevalence, deaths, years lived with Disability-adjusted life years (DALYs) that influence the development of AC and OC. To our knowledge, this study is the first to have systematically assessed the burden of AC and OC as of 2019 at the national, regional, and global levels and calculated DALYs to achieve a better evaluation of disease risk and quality of life of the population. The number of cases, deaths and DALYs of cardiomyopathy showed an overall increasing trend and obvious geographical differences in the past three decades. The burden of cardiomyopathy remains a persistent threat to global public health. These results provide an epidemiological foundation that can guide public health efforts and policymakers.

Cardiovascular diseases in Africa in the twenty-first century: Gaps and priorities going forward

In 2015, the United Nations set important targets to reduce premature cardiovascular disease (CVD) deaths by 33% by 2030. Africa disproportionately bears the brunt of CVD burden and has one of the highest risks of dying from non-communicable diseases (NCDs) worldwide. There is currently an epidemiological transition on the continent, where NCDs is projected to outpace communicable diseases within the current decade. Unchecked increases in CVD risk factors have contributed to the growing burden of three major CVDs-hypertension, cardiomyopathies, and atherosclerotic diseases- leading to devastating rates of stroke and heart failure. The highest age standardized disability-adjusted life years (DALYs) due to hypertensive heart disease (HHD) were recorded in Africa. The contributory causes of heart failure are changing-whilst HHD and cardiomyopathies still dominate, ischemic heart disease is rapidly becoming a significant contributor, whilst rheumatic heart disease (RHD) has shown a gradual decline. In a continent where health systems are traditionally geared toward addressing communicable diseases, several gaps exist to adequately meet the growing demand imposed by CVDs. Among these, high-quality research to inform interventions, underfunded health systems with high out-of-pocket costs, limited accessibility and affordability of essential medicines, CVD preventive services, and skill shortages. Overall, the African continent progress toward a third reduction in premature mortality come 2030 is lagging behind. More can be done in the arena of effective policy implementation for risk factor reduction and CVD prevention, increasing health financing and focusing on strengthening primary health care services for prevention and treatment of CVDs, whilst ensuring availability and affordability of quality medicines. Further, investing in systematic country data collection and research outputs will improve the accuracy of the burden of disease data and inform policy adoption on interventions. This review summarizes the current CVD burden, important gaps in cardiovascular medicine in Africa, and further highlights priority areas where efforts could be intensified in the next decade with potential to improve the current rate of progress toward achieving a 33% reduction in CVD mortality.

Genetic predisposition study of heart failure and its association with cardiomyopathy

Heart failure (HF) is a clinical condition distinguished by structural and functional defects in the myocardium, which genetic and environmental factors can induce. HF is caused by various genetic factors that are both heterogeneous and complex. The incidence of HF varies depending on the definition and area, but it is calculated to be between 1 and 2% in developed countries. There are several factors associated with the progression of HF, ranging from coronary artery disease to hypertension, of which observed the most common genetic cause to be cardiomyopathy. The main objective of this study is to investigate heart failure and its association with cardiomyopathy with their genetic variants. The selected novel genes that have been linked to human inherited cardiomyopathy play a critical role in the pathogenesis and progression of HF. Research sources collected from the human gene mutation and several databases revealed that numerous genes are linked to cardiomyopathy and thus explained the hereditary influence of such a condition. Our findings support the understanding of the genetics aspect of HF and will provide more accurate evidence of the role of changing disease accuracy. Furthermore, a better knowledge of the molecular pathophysiology of genetically caused HF could contribute to the emergence of personalized therapeutics in future.

Associations of Race and Ethnicity With Presentation and Outcomes of Hypertrophic Cardiomyopathy: JACC Focus Seminar 6/9

Significant racial and ethnicity-based disparities in clinical presentation, management, and outcome of hypertrophic cardiomyopathy (HCM) are reported. Black patients with HCM are more likely to present with heart failure but are less commonly referred for symptom management, sudden cardiac death stratification, surgical septal myectomy, or for implantable cardioverter-defibrillators, all interventions that increase survival. Prevalence of bystander cardiopulmonary resuscitation is lower for Black patients than for White patients. Black patients with HCM have decreased survival after hospital discharge following out-of-hospital cardiac arrest. Biomedical and social interventions are urgently needed to reduce ethnicity-based disparities, which have an impact on outcomes in HCM and other cardiovascular diseases. There is also a need to focus on implementation science to support durable adoption of evidence-based therapies in Black patients and communities.

Global, Regional, and National Burden of Myocarditis and Cardiomyopathy, 1990-2017

Objective: To estimate the burden of myocarditis (MC), alcoholic cardiomyopathy (AC), and other cardiomyopathy (OC) for 195 countries and territories from 1990 to 2017. Methods: We collected detailed information on MC, AC, and OC between 1990 and 2017 from the Global Burden of Disease study 2017, which was designed to provide a systematic assessment of health loss due to diseases and injuries in 21 regions, covering 195 countries and territories. Estimates of MC, AC, and OC burden were produced using a standard Cause of Death Ensemble model and a Bayesian mixed-effects meta-regression tool, and included prevalence, deaths, years lived with disability (YLDs), and years of life lost (YLLs). All estimates were presented as counts, age-standardized rates per 100,000 people and percentage change, with 95% uncertainty intervals (UIs). Results: Worldwide, there were 1.80 million (95% UI 1.64-1.98) cases of MC, 1.62 million (95% UI 1.37-1.90) cases of AC and 4.21 million (95% UI 3.63-4.87) cases of OC, contributing to 46,486 (95% UI 39,709-51,824), 88,890 (95% UI 80,935-96,290), and 233,159 (95% UI 213,677-248,289) deaths in 2017, respectively. Furthermore, globally, there were 131,376 (95% UI 90,113-183,001) YLDs and 1.26 million (95% UI 1.10-1.42) YLLs attributable to MC, 139,087 (95% UI 95,134-196,130) YLDs and 2.84 million (95% UI 2.60-3.07) YLLs attributable to AC, and 353,325 (95% UI 237,907-493,908) YLDs and 5.51 million (95% UI 4.95-5.99) YLLs attributable to OC in 2017. At the national level, the age-standardized prevalence rates varied by 10.4 times for MC, 252.6 times for AC and 38.1 times for OC; the age-standardized death rates varied by 43.9 times for MC, 531.0 times for AC and 43.3 times for OC; the age-standardized YLD rates varied by 12.4 times for MC, 223.7 times for AC, and 34.1 times for OC; and the age-standardized YLL rates varied by 38.4 times for MC, 684.8 times for AC, and 36.2 times for OC. Between 1990 and 2017, despite the decreases in age-standardized rates, the global numbers of prevalent cases, deaths, YLDs, and YLLs have increased for all the diseases. Conclusion: Accurate assessment of the burden of MC, AC, and OC is essential for formulating effective preventative prevention and treatment programs and optimizing health system resource allocation. Our results suggest that MC, AC, and OC remain important global public health problems with increasing numbers of prevalent cases, deaths, YLDs, and YLLs over the past decades, and there are significant geographic variations in the burden of these diseases. Further research is warranted to expand our knowledge of potential risk factors and to improve the prevention, early detection and treatment of these diseases.

An Overview of Benefits and Challenges of Rare Disease Biobanking in Africa, Focusing on South Africa

The North-West University's Centre for Human Metabolomics (CHM) is in the process of establishing the first rare disease (RD) biobank in South Africa and Africa. The CHM Biobank's main focus is on the collection of samples and information for rare congenital disorders. Approximately 72% of all RDs have a genetic origin, of which 70% have an exclusive pediatric onset. The need for such a biobank was identified by the CHM diagnostic laboratory. Feedback toward this initiative was overwhelmingly positive at the first stakeholder meeting in August 2019. However, gaining support from the public sector and recruiting of participants have proven to be challenging. Problems experienced to date include lack of support from government and clinicians; lack of knowledge on RDs (patients and clinicians); public health care focus not directed toward RDs; patients not returning for follow-up visits; and unwillingness to participate due to fear of exploitation. The CHM Biobank's vision and goals are aligned to address a national and international research need: it will provide a valuable resource for scientists to improve what is known about these diseases; to better understand the natural history and pathophysiology; to optimize diagnostic methods; and to potentially develop treatments. The genetic variability of the South African population provides added value to the RD biobank. This review provides a brief overview of the literature on the challenges and benefits of an RD biobank and how this relates to low- and middle-income countries (LMIC) like South Africa. The aim of the review is to draw attention to the potential benefits of such an undertaking and to create awareness, at both local and global level, toward some of the unique collective considerations that an RD biobank in LMIC (also unique South African challenges) faces on an operational, collaborate, and sustainability level.

Genetics of inherited cardiomyopathies in Africa

In sub-Saharan Africa (SSA), the burden of noncommunicable diseases (NCDs) is rising disproportionately in comparison to the rest of the world, affecting urban, semi-urban and rural dwellers alike. NCDs are predicted to surpass infections like human immunodeficiency virus, tuberculosis and malaria as the leading cause of mortality in SSA over the next decade. Heart failure (HF) is the dominant form of cardiovascular disease (CVD), and a leading cause of NCD in SSA. The main causes of HF in SSA are hypertension, cardiomyopathies, rheumatic heart disease, pericardial disease, and to a lesser extent, coronary heart disease. Of these, the cardiomyopathies deserve greater attention because of the relatively poor understanding of mechanisms of disease, poor outcomes and the disproportionate impact they have on young, economically active individuals. Morphofunctionally, cardiomyopathies are classified as dilated, hypertrophic, restrictive and arrhythmogenic; regardless of classification, at least half of these are inherited forms of CVD. In this review, we summarise all studies that have investigated the incidence of cardiomyopathy across Africa, with a focus on the inherited cardiomyopathies. We also review data on the molecular genetic underpinnings of cardiomyopathy in Africa, where there is a striking lack of studies reporting on the genetics of cardiomyopathy. We highlight the impact that genetic testing, through candidate gene screening, association studies and next generation sequencing technologies such as whole exome sequencing and targeted resequencing has had on the understanding of cardiomyopathy in Africa. Finally, we emphasise the need for future studies to fill large gaps in our knowledge in relation to the genetics of inherited cardiomyopathies in Africa.

Arrhythmia care in Africa

Data on cardiovascular disease, including arrhythmias, in Africa is limited. However, the burden of cardiovascular disease appears to be on the rise. Recent global data suggests an increase in atrial fibrillation rates despite declining rates of rheumatic heart disease. Atrial fibrillation is also associated with increased mortality in Africa. Current management with medical therapy is sub-optimal and ablation procedures, inaccessible. Atrial fibrillation is also an independent risk factor for death in patients with rheumatic heart disease. Sudden cardiac deaths from ventricular arrhythmias are under-recognized and inadequately treated with very high rates out of hospital cardiac arrest due to poor education of the general public on cardiopulmonary resuscitation skills and lack of essential healthcare infrastructure. Use of cardiac devices such as implantable defibrillators and pacemakers is low with significant regional variations and is almost non-existent in sub-Saharan Africa. There is a great unmet need for arrhythmia diagnosis and management in Africa. Governments and healthcare stakeholders need to include cardiovascular disease as a healthcare priority given the rising burden of disease and associated mortality.

Quantifying the contribution of alcohol to cardiomyopathy: A systematic review

Alcohol has a direct toxic impact on the heart, and while there is an ICD code for alcoholic cardiomyopathy, the burden of alcohol-attributable cardiomyopathy is not clear. For the usual estimation of this burden via population-attributable fractions, one would need to determine the risk relationships, i.e., average risk associated with different dimensions of alcohol exposure. The most important among these risk relationships is the dose-response relationship with different levels of average alcohol consumption. To establish risk relationships, we systematically searched for all studies on dose-response relationships, directly and indirectly, via reviews. The results did not permit computation of pooled estimates through meta-analyses. There were clear indications that heavy drinking (≥80 g per day) over several years was linked to high risk of cardiomyopathy, with greater lifetime exposure of alcohol linked to higher risks. Some studies indicated potential effects of patterns of drinking as well. As such, the global quantification of alcohol-attributable cardiomyopathy will have to rely on other methods than those used conventionally.

Sanitation for all: the global opportunity to increase transgenerational health gains and better understand the link between NCDs and NTDs, a scoping review

The global sanitation divide is narrowing. However, in many countries in Asia and Africa, the gap between rural and urban sanitation coverage is rather widening. Moreover, there is an increase in the burden of non-communicable diseases (NCDs), notwithstanding to the already high burden of neglected tropical diseases (NTDs). A scientific query is building on how the global 'sanitation for all' goal will address the dual burden of NTDs and NCDs, and help further understand the link between the two. This paper aims to discuss the link between i) sanitation and NTDs, and ii) sanitation and NCDs through a scoping review of the literature.

Clinical and echocardiographic characteristics and outcomes in congestive heart failure at the Hospital of The State University of Haiti

BACKGROUND

This study aimed to evaluate the clinical and epidemiologic profile of congestive heart failure at the principal free-care hospital in Haiti. Cardiovascular disease represents the most prevalent cause of admissions to the medical service of the University Hospital of the State of Haiti. No previous study has examined the demographics of congestive heart failure in urban Haiti.

METHODS

Two hundred forty-seven patients presented to the inpatient service between May 2011 and May 2013. Evaluation included history and physical, CBC, renal/metabolic profile, serum glucose, anti-HIV antibody, ECG, chest radiograph and echocardiogram. Treatment included angiotensin converting enzyme inhibitors, furosemide and spironolactone, carvedilol, digoxin and anticoagulation.

RESULTS

Women (62.4%) outnumbered men; patients were relatively young (mean age 50.1) and from the lowest socio-economic levels of the population. Nearly all (98.8%) presented with NYHA III-IV status, with correspondingly high mortality (23.3%). Echocardiography showed 73% dilated cardiomyopathy; 83% showed moderate to severe LV systolic dysfunction (mean EF 36.5 +/- 15%) and 17% preserved LV systolic function. The three principal etiologies were dilated cardiomyopathy (29%) hypertensive cardiomyopathy (27%) and peripartum cardiomyopathy (20%). Ischemic cardiomyopathy was rare (3.4%). At 27 months follow-up, 76.7% of the patients were alive and well. Among those who died, mean survival time was 113 days. Readmission carried a poor prognosis.

CONCLUSIONS

This congestive heart failure study from Haiti shows an unusually high proportion of young women, primarily due to peripartum cardiomyopathy. Ischemic cardiomyopathy is rare, as in Africa. Further study is warranted to address the particular problem of the high frequency of peripartum cardiomyopathy in this population.

Neglected chronic disease: The WHO framework on non-communicable diseases and implications for the global poor

The current global framework on noncommunicable disease (NCD), as exemplified by the WHO Action Plan of 2012, neglects the needs of the global poor. The current framework is rooted in an outdated pseudo-evolutionary theory of epidemiologic transition, which weds NCDs to modernity, and relies on global aggregate data. It is oriented around a simplistic causal model of behaviour, risk and disease, which implicitly locates 'risk' within individuals, conveniently drawing attention away from important global drivers of the NCD epidemic. In fact, the epidemiologic realities of the bottom billion reveal a burden of neglected chronic diseases that are associated with 'alternative' environmental and infectious risks that are largely structurally determined. In addition, the vertical orientation of the framework fails to centralise health systems and delivery issues that are essential to chronic disease prevention and treatment. A new framework oriented around a global health equity perspective would be able to correct some of the failures of the current model by bringing the needs of the global poor to the forefront, and centralising health systems and delivery. In addition, core social science concepts such as Bordieu's habitus may be useful to re-conceptualising strategies that may address both behavioural and structural determinants of health.

Genetic profile of hypertrophic cardiomyopathy in Tunisia: Is it different?

We recently performed next generation sequencing (NGS) genetic screening in 11 consecutive and unrelated Tunisian HCM probands seen at Habib Thameur Hospital in Tunis in the first 6 months of 2014, as part of a cooperative study between our Institutions. The clinical diagnosis of HCM was made according to standard criteria. Using the Illumina platform, a panel of 12 genes was analyzed including myosin binding protein C (MYBPC3), beta-myosin heavy chain (MYH7), regulatory and essential light chains (MYL2 and MYL3), troponin-T (TNNT2), troponin-I (TNNI3), troponin-C (TNNC1), alpha-tropomyosin (TPM1), alpha-actin (ACTC1), alpha-actinin-2 (ACTN2) as well as alfa-galactosidase (GLA), 5′-AMP-activated protein (PKRAG2), transthyretin (TTR) and lysosomal-associated membrane protein-2 (LAMP2) for exclusion of phenocopies. Our preliminary data, despite limitations inherent to the small sample size, suggest that HCM in Tunisia may have a peculiar genetic background which privileges rare genes overs the classic HCM-associated MHY7 and MYBPC3 genes.

Cardiomyopathies: Evolution of pathogenesis concepts and potential for new therapies

Cardiomyopathies are defined as diseases of the myocardium with associated structural and functional abnormalities. Knowledge of these pathologies for a long period was not clear in clinical practice due to uncertainties regarding definition, classification and clinical diagnosis. In recent decades, major advances have been made in the understanding of the molecular and genetic issues, pathophysiology, and clinical and radiological assessment of the diseases. Progress has been made also in management of several types of cardiomyopathy. Advances in the understanding of these diseases show that cardiomyopathies represent complex entities. Here, special attention is given to evolution of classification of cardiomyopathies, with the aim of assisting clinicians to look beyond schematic diagnostic labels in order to achieve more specific diagnosis. Knowledge of the genotype of cardiomyopathies has changed the pathophysiological understanding of their etiology and clinical course, and has become more important in clinical practice for diagnosis and prevention of cardiomyopathies. New approaches for clinical and prognostic assessment are provided based on contemporary molecular mechanisms of contribution in the pathogenesis of cardiomyopathies. The genotype-phenotype complex approach for assessment improves the clinical evaluation and management strategies of these pathologies. The review covers also the important role of imaging methods, particularly echocardiography, and cardiac magnetic resonance imaging in the evaluation of different types of cardiomyopathies. In summary, this review provides complex presentation of current state of cardiomyopathies from genetics to management aspects for cardiovascular specialists.

Blood pressure, prevalence of hypertension and hypertension related complications in Nigerian Africans: A review

To review studies on hypertension in Nigeria over the past five decades in terms of prevalence, awareness and treatment and complications. Following our search on Pubmed, African Journals Online and the World Health Organization Global cardiovascular infobase, 1060 related references were identified out of which 43 were found to be relevant for this review. The overall prevalence of hypertension in Nigeria ranges from 8%-46.4% depending on the study target population, type of measurement and cut-off value used for defining hypertension. The prevalence is similar in men and women (7.9%-50.2% vs 3.5%-68.8%, respectively) and in the urban (8.1%-42.0%) and rural setting (13.5%-46.4%).The pooled prevalence increased from 8.6% from the only study during the period from 1970-1979 to 22.5% (2000-2011). Awareness, treatment and control of hypertension were generally low with attendant high burden of hypertension related complications. In order to improve outcomes of cardiovascular disease in Africans, public health education to improve awareness of hypertension is required. Further epidemiological studies on hypertension are required to adequately understand and characterize the impact of hypertension in society.