Understanding and controlling the increasing burden of cardiovascular diseases in Africa

This manuscript was handled by Deputy Editor Charalambos Antoniades

1. Introduction

Cardiovascular diseases (CVDs), including stroke and hypertension, have become the leading cause of death in Africa since 2019, despite Africa being the youngest continent in the world with a median age of 19.7 years.¹ Tackling this burden requires a detailed understanding and characterization of the interplay among the socioeconomic, behavioural, genetic, and environmental risk and protective factors driving the surge of the scourge. This involves longitudinal multidimensional data and biospecimen collection, analysis of these factors, and subsequent translation of knowledge gained to pragmatic solutions to reduce its burden. The cardiovascular cascade begins in patients with no standard modifiable cardiovascular risk factors or only one cardiovascular risk factor.² It progresses to include more risk factors, and intermediate phenotypes (atherosclerosis) and culminates in cardiovascular events such as stroke, heart attack, heart failure, and kidney disease.

2. The burden of CVDs in Africa: evidence gaps

Currently, the dominant CVDs in Africa include hypertension, stroke, obesity, dyslipidaemia, and diabetes mellitus. Hypertension affects one out of every two adults (older than 24 years of age) at the 140/90 mmHg threshold with a prevalence of 46%, at a 7% control rate in Africa.³ This by far exceeds overall worldwide prevalence and makes hypertension the predominant leading preventable cause of death, hugely contributing to the huge burden of stroke, myocardial infarction, heart failure, and kidney disease in Africa. The prevalence of metabolic syndrome in Africa in those aged ≥16 years ranges from 16.0% to 23.9% in a meta-analysis across 14 countries.⁴ The burden of each of the component diseases is however poorly characterized across Africa. The available studies mostly originate in urban centres of a few African countries, not reflecting a true disease burden. Therefore, there is a need for multicentre population-based representative studies to quantify the real burden of CVD in Africa.

3. Risk factors for CVDs in Africa: evidence base and knowledge gaps

While the epidemiology of CVD is better defined in high-income countries, this is not the case in Africa. Continuous assessment of temporal trends of disease and risk factor prevalence is urgently needed to enable targeted interventions. Unique genetic and environmental risk factors need to be characterized. For example, some neglected tropical diseases are associated with endomyocardial fibrosis.⁵ Moreover, some vascular risk factors including hypertension and urbanization with unhealthy diet and sedentary lifestyle portend higher population-attributable risks in Africa. Malnutrition, low birth weight, and prematurity which abound in the poorest countries of Africa have also been linked to obesity and higher risk of hypertension, insulin resistance, type 2 diabetes mellitus, stroke, ischaemic heart disease, and chronic kidney disease. Therefore, strategies to control CVD in Africa should incorporate political will to address poverty, promote a healthy lifestyle and tackle commercial and social risk factors. This will empower society with the resources and knowledge for primordial, primary, and secondary prevention of CVD.

4. Interventions for CVDs in Africa

All interventions should be tailored along the four pillars of the cardiovascular quadrangle.⁶Surveillance should include monitoring of the burden and determinants of CVDs in Africa. This will also enable monitoring of the impact of targeted interventions. Examples include the African Rigorous Innovative Stroke Epidemiological Surveillance, and Health and Demographic Surveillance Systems in several low- and middle-income countries in Africa and Asia. Prevention should be population-wide, community-based, holistic, primordial, and primary and not just secondary. It should incorporate strategies to promote healthy lifestyle, risk factor detection, treatment, and control using a range of approaches such as task-sharing, and mobile technology across the lifespan. Examples include the WHO HEARTS program and the Afrocentric riskometer app for stroke prevention.

Treatment: It is pertinent to implement pragmatic solutions for the treatment of risk factors and acute events to reduce mortality. Rehabilitation: through interdisciplinary care, will reduce disability-adjusted life years, improve quality of life, and prolong life among the survivors of disabling complications of CVDs.

5. Current status of research in Africa; the unmet needs, research opportunities for basic science and challenges

Cardiovascular research in Africa is still at the rudimentary stage, mainly epidemiological, with few interventional, and genomic studies, only contributing to 3% of the global research output despite the huge burden of CVDs that could provide robust resources for data science to unravel health challenges and proffer adaptable control measures.⁷ The abundance of natural resources that could be harnessed to locally manufacture essential medicines is another opportunity, also, lost to dearth of well-trained and skilled researchers and poor research infrastructure including unstable power, and lack of access to library resources and laboratory equipment. Research grants and funding, as well as strategic partnerships are lacking on the continent compared to high-income countries. These, coupled with the poor socioeconomic situation, has led to ‘brain-drain’ and therefore choking the already constrained training and research environments.

6. Novel strategies and future directions to control CVD in Africa

Accelerating the control of CVDs in Africa requires novel revolutionary evidence-based pragmatic solutions. Such evidence should be co-created from needs-driven research shaped by the existing knowledge gaps, particularly the inability to sustain the implementable approaches and guidelines formulated to address the surge in CVDs and their associated complications (Figure 1). As such, a critical approach entails confronting the critical determinants of CVD. Achieving this requires a quadruple helix approach where academia (researchers), industry, government, and civil society (communities) converge to enhance innovation to co-design and co-implement novel solutions.⁸ This will foster knowledge translation, transfer, and utilization for sustainable impact (Figure 1). Examples of such ecosystems include:

Figure 1.

Controlling the increasing burden of cardiovascular diseases in Africa.

• Leveraging, adapting, and expanding the African Stroke Control Observatory Risk Reduction Ecosystem for other CVDs. This ecosystem is adapted from the ecosystem for control of neurological disorders and the WSO–Lancet Neurology Commission on Stroke, involving the policy-makers, patients, payers, providers, the populace, and implementation partners in their respective capacities to develop enduring and sustainable CVD control programs.

• Improved surveillance, prevention, and treatment for hypertension through the ‘African Control of Hypertension through Innovative Epidemiology and a Vibrant Ecosystem (ACHIEVE)’⁹ will ensure an accelerated reduction in the burden of CVDs in Africa. ACHIEVE is based on the principle of iterative implementation cycle and co-creation for the contextualization and implementation of the adapted HEARTS package.

Communication is critical for the success of ecosystems. Digital solutions and mobile health approaches for risk quantification can be deployed through social media to enhance literacy, self-efficacy, and behavioural change to accelerate the control of CVDs in Africa.¹⁰

7. Conclusions

Impactful research into CVDs in Africa must not only unravel intricate understanding of the interplay of risk factors and disease mechanisms but also foster effective dissemination and implementation of emergent evidence-based interventions. Rigorous needs-driven scientific investigation must be combined with equitable access to knowledge, resources, and healthcare. As urbanization, lifestyle changes, and global health trends continually reshape the CVD landscape, constant adaptation and reassessment of research strategies and interventions are imperative. This endeavour requires robust collaboration from stakeholders, including scientists, policy-makers, and healthcare providers. Poverty and the need for culturally sensitive and demographically diverse research approaches pose significant hurdles. Additionally, fostering health literacy is an essential enabler for broad societal impact. Overall, evidence-based co-created pragmatic solutions are urgently needed for population-wide implementation to accelerate the control of dominant CVDs in Africa.

Funding

M.O.O. is supported by The National Institutes of Health grants: SIREN (U54HG007479), SIBS Genomics (R01NS107900), SIBS Gen Gen (R01NS107900-02S1), ARISES (R01NS115944-01), H3Africa CVD Supplement (3U24HG009780-03S5), CaNVAS (1R01NS114045-01), Sub-Saharan Africa Conference on Stroke (SSACS) 1R13NS115395-01A1 and Training Africans to Lead and Execute Neurological Trials & Studies (TALENTS) D43TW012030 and Growing Data-science Research in Africa to Stimulate Progress (GRASP, 1UE5HL172183-01). P.M. is supported by the British Heart Foundation (BHF) (Grant Nos PG/19/84/34771, FS/19/56/34893A, PG/21/10541, PG/21/10634, PG/21/10557) and FRA 2020—Linea A, University of Naples Federico II/Compagnia di San Paolo. P.M. and M.O.O. are supported by the University of Glasgow Scottish Funding Council and the Global Challenges Research Fund, the Erasmus+International Credit Mobility (ICM) 2020-1- UK01-KA107-078782 and the Erasmus+2022-1-IT02-KA171-HED-000075494. T.J.G. is supported by the European Research Council (ERC and InflammaTENSION, ERC-CoG-726318); European Research Area—CVD (ERA-CVD) [BrainGutImmune (ERA-CVD/Gut-brain/8/2021 and ImmmuneHyperCog, NCBiR Poland)], British Heart Foundation grants (FS/14/49/30838 and FS/4yPhD/F/20/34127A), and as part of the British Heart Foundation Centre for Research Excellence at the University of Edinburgh (RE/18/5/34216).

Authors

Biography: Dr Paul Olowoyo is a consultant Neurologist at the Federal Teaching Hospital Ido-Ekiti, Ekiti State, Nigeria, and an Associate Professor of Medicine (Neurology), at Afe Babalola University, Ado-Ekiti, Nigeria. He is also a visiting consultant Neurologist at Ekiti State University Teaching Hospital, Ado-Ekiti, Nigeria. He is a graduate of the University of Ibadan and a fellow of the West African College of Physicians (neurology subspecialty) who has been involved in the mentoring and training of medical students and resident doctors in Neurology for the past 9 years. He is a public lecturer on cardiovascular and Neurological diseases on which he has authored and co-authored over 70 publications in reputable international journals. He is the Medical Director of St Philip's Neuromedical Clinic, Ado-Ekiti, Nigeria, which is the first and the only private neurological centre in Ekiti State, Nigeria. His areas of special interest are hypertension and other cardiovascular diseases, most especially vascular neurology and epilepsy.

Biography: Pasquale Maffia currently holds the position of Professor of Cardiovascular Immunology at the University of Glasgow in the UK, within the School of Infection & Immunity. Additionally, he serves as the International Lead of the School and co-leads the Africa-Europe CoRE in Non-Communicable Diseases & Multimorbidity, a project supported by the African Research Universities Alliance (ARUA) & The Guild of European Research-intensive Universities.Dr Maffia is an elected fellow of the Royal Society of Biology, the British Pharmacological Society, and the European Society of Cardiology. He plays key roles as the Vice-President and Chair of the Engagement Committee of the British Pharmacological Society (BPS), Chair of the International Union of Basic and Clinical Pharmacology (IUPHAR) Immunopharmacology Committee, and as a Nucleus Member of the European Society of Cardiology (ESC) Working Group on Atherosclerosis & Vascular Biology. Moreover, he serves on the Executive Committee of the British Atherosclerosis Society (BAS), the Fellowship Committee of the British Heart Foundation (BHF), and as Vice-Chair of the Heart Research UK (HRUK) Translational Research Medical Review Panel. In editorial capacities, Dr Maffia acts as Deputy Editor of Cardiovascular Research, Associate Editor of Pharmacological Research, and Editor in Chief of Frontiers for Young Minds (Human Health Section). Additionally, he serves as an Editorial Board Member for several journals, including ATVB and Scientific Reports. Dr Maffia's primary research focus lies in understanding the immune response in cardiovascular disease. His research endeavors involve studying, imaging, and targeting immune mechanisms implicated in the pathophysiology of atherosclerosis, hypertension, and heart failure. He has authored around 130 scientific papers to peer-reviewed journals, including Nature Genetics, Nature Reviews Immunology, Nature Reviews Cardiology, Immunity, European Heart Journal, Circulation, and Circulation Research.

Biography: Prof. Guzik is the Chair of Cardiovascular Medicine at the University of Edinburgh and an Honorary Consultant Physician at NHS Lothian. He also holds a professorship at Jagiellonian University, Krakow, Poland. His research primarily investigates the intersection of inflammation and oxidation in vascular biology, with a focus on hypertension. Key achievements of his group include elucidating oxidative stress and vascular dysfunction mechanisms in humans and identifying new roles for inflammation and adaptive immunity in hypertension, leading to novel clinical trial-tested therapies. His main focus is on using translational approaches to understand disease pathology. From 2021-2023, he was recognized as a Highly Cited Scientist and received numerous awards, such as the Arthur Corcoran Hypertension Award (AHA, US) and the JJ Marshal Award in Cardiovascular Research (BSCR, UK). He leads the British Atherosclerosis Society and since 2018 has been a board member of the European Society of Cardiology, chairing its Publications Committee (2020-22) and recently Research and EU Grants Committee.

Biography: Prof. Mayowa Ojo Owolabi, MBBS, MSc, DrM, MD, DSc, FMCP, FWACP, FRCP, FANA, FAHA, FAAN, FAAS, FAS, FAMedS, is a renowned Professor of Neurology, and Director, Center for Genomic and Precision Medicine, University of Ibadan. He is an eminent scholar with a stroke phenotyping software patent (Reg.#: NG/PT/NC/2016/2007); >400 publications in peer-reviewed journals including The Lancet, and Nature, with >131,000 citations and a Google Scholar h-index of 87. Prof. Owolabi is a recognized global leader in medicine, neurology, cardiovascular diseases, neuro-rehabilitation, global health, brain health, community-based genomic epidemiology of stroke in Africa, clinical trials, and implementation science. He is an outstanding scientist with several inventions and innovations including ‘stroke quadrangle' and ‘brain quadrangle’, which are accepted globally as key ingredients driving the global interventions against stroke and for promoting brain health in Africa and beyond. He led the SIREN team as the first to discover the association between APOL 1 and small vessel disease stroke. He also led the discovery of genome-wide association of SNPs near AADACL2 and miRNA (MIR5186) genes and microRNA and stroke in Africans. He led the development of prediction models for stroke and hypertension. He is among the global top 2% scientists (2023) and the winner of the 2021 World Stroke Organization Global Award for Outstanding Contributions to Clinical Stroke Research. He is a foremost leader in the global fight against stroke and a frontline leader in the fight against hypertension, stroke, and non-communicable diseases in Africa. He is currently leading the implementation call for action against hypertension in Africa working with the World Hypertension League, World Health Organization and Resolve To Save Lives. He is associate editor of Stroke journal and several other top tier Neurology journals. He leads the largest stroke study in Africa as principal investigator of several grants and co-investigator in several (with >$80 million overall) including Stroke Investigative Research & Educational Network (SIREN) grant (with the largest neurobiobank in Africa >170,000 samples) from National Institutes of Health (NIH), USA; Systematic Investigation of Blacks with Stroke using Genomics (SIBS Genomics) R01NS107900. He is the pioneer Chair of the largest study of cardiovascular diseases in Africa (H3Africa-CVD WG with >55,000 subjects). He is the pioneer Regional Vice-President, World Federation of Neurorehabilitation (Africa); member Board of Directors, World Stroke Organization; African Regional Director, World Hypertension League; Lead Co-Chair, WSO- Lancet Commission on stroke. He is foundation co-chair of the steering committee of African Stroke Organization; and Member/Rapporteur of the WHO Technical Action Group on NCD (Research and Innovation). He is co-Lead of the African Research Universities Alliance- The Guild Universities Cluster of Excellence for non-communicable diseases. He is a Fellow of the American Academy of Neurology, American Heart Association, Royal College of Physicians, Academy of Medical Specialties, Nigerian Academy of Science, African Academy of Science, and Atria Academy of Science and Medicine (USA).