Unmet needs in the management of arrhythmias among heart failure patients in Africa

Several studies suggest that the burden of heart failure (HF) in Africa is on the increase with patients presenting late to hospitals.1 Such a high burden is fuelled by an increase in the prevalence of cardiovascular risk factors, sub-optimal management of these risk factors, and an ageing population. Despite this increase, there is a paucity of data on the burden and management strategies for HF, its arrhythmic, and other complications in Africa. Contemporary studies demonstrate that HF in Africa is mainly due to hypertensive heart disease (HHD), non-ischaemic cardiomyopathies (NICMD), rheumatic heart disease (RHD), and ischaemic heart disease (IHD) with pericardial and congenital heart diseases being other causes. The THESUS-HF study1 revealed that African HF patients are two decades younger than their counterparts from high-income countries.2 This may relate to differences in aetiologies, with common causes of HF in Africa presenting at a younger age. Heart failure in African countries carries a significantly higher morbidity and mortality than in other countries.3 Hypertension is the leading cause of HF and remains a disease of public health importance with a high prevalence in Africa. This burden is exaggerated by low rates of awareness, treatment, and poor blood pressure control. This means patients present late with left ventricular hypertrophy (LVH) which can lead to HF, arrhythmias, and sudden cardiac death (SCD). In the RELY-AF registry, the prevalence of hypertension in patients with atrial fibrillation/flutter (AF/AFL) in Africa was significantly high. Although this prevalence was lower compared with worldwide, patients from Africa had more LVH probably due to poor blood control.4 A systematic review that included an autopsy study reported that hypertension was present in more than two-thirds of all SCD in Africa.5 To the best of our knowledge, there are no studies reporting on the prevalence and incidence of arrhythmias in patients with HHD in Africa. There is a need to emphasize on education and early detection followed by the provision of adequate management that can halt the progression of HHD and thereby the occurrence of arrhythmias. In Africa, cardiomyopathies are the second most common cause of HF contributing to about a quarter of all HF cases with dilated cardiomyopathy being the most common.3 Geographically, ischaemic cardiomyopathy is more common in Northern Africa than in sub-Saharan Africa (SSA) where NICMD such as idiopathic, peripartum, hypertrophic, and human immunodeficiency virus-associated cardiomyopathies are commoner causes.1 Idiopathic cardiomyopathy is a debatable term in Africa given the lack of diagnostic tools to rule out many causes of cardiomyopathies. Because of the limited diagnostic capacity in resource-poor settings, the so-called NICMD may be under-reported. Poor access to diagnosis and treatment leads to advanced disease presentation including arrhythmias. To the best of our knowledge, the prevalence and incidence of SCD and AF/AFL in cardiomyopathies have not been reported in Africa. The ongoing prospective African Cardiomyopathy and Myocarditis Registry Program (IMHOTEP) and Kenyan HF and AF/AFL registries will provide information to narrow this knowledge gap.6 Rheumatic heart disease continues to be the most common cause of cardiac morbidity and mortality among children and young adults in Africa. Overall, RHD is the third most common cause of HF after HHD and NICMD. This preventable and treatable disease presents at a younger age, among people in the lower end of the socio-economic ladder. Many patients have limited access to healthcare and present late with advanced HF and associated complications such as AF/AFL, pulmonary hypertension, and stroke. These complications are not uncommonly discovered during pregnancy and delivery. Atrial fibrillation/flutter is the most important arrhythmia complicating RHD, reported in up to a third of patients and associated with recurrent hospital admission and mortality.1,4,7 Among African patients presenting to the emergency room with AF/AFL in the RELY-AF registry, RHD was present in a quarter of the patients.4 The high prevalence of AF/AFL is compounded by difficulties with oral anticoagulation, with wide variability in its use and inadequate time in the therapeutic range.7 The ongoing INVestIgation of rheumatiC AF Treatment (INVICTUS) trial (NCT02832544) will address the safety and efficacy of rivaroxaban compared with warfarin for stroke prevention in a rheumatic AF population. Compared with Northern Africa, IHD is less prevalent in SSA. With the increase in the prevalence of cardiovascular risk factors, the prevalence of IHD in SSA is on the rise. Ischaemic heart disease may indeed be under-reported, partly due to population unawareness, the lack of diagnostic work-up, scarcity of trained personnel, and poor uptake of post-mortems. Many studies reporting on HF aetiology have relied on resting 12-lead electrocardiograms (ECGs) and echocardiography without complimentary ischaemia (stress, perfusion imaging) or anatomical (angiography) testing. In North Africa (Tunisia), autopsies revealed that IHD was more prevalent among SCD cases.5 A lack of diagnostic tools used to classify HF, assess arrhythmias, and other HF complications, and determine indications for device therapy, remains an important obstacle to optimal treatment outcomes.5,7–9 The availability of diagnostic tools in Africa in a recent survey was as follows: ECG were available in all of the surveyed countries while 24 h ECG monitors, stress testing, signal-average ECGs only in South Africa, head-up tilt testing, echocardiography, cardiac computerized tomography, and magnetic resonance imaging are less commonly available.7 Moreover, access within each country is restricted to urban areas leaving large areas underserved. The limited availability and high costs of older (beta-blockers, aldosterone antagonists, and angiotensin-converting enzyme inhibitors), and contemporary (Sacubitril-Valsartan and SGLT-2 inhibitors) HF drugs,8 remain major determinants of poor outcomes in societies with low health insurance coverage, poor access to healthcare facilities, and shortage of healthcare personnel.3 Two surveys conducted in the last 4 years revealed that about one-fifth of countries of SSA did not have even one registered cardiologist.8,9 For these reasons, studies document low utilization of evidence-based medication and devices for HF in Africa. Beta-blocker use is lower compared with Europe as reported in the EHFS-II study.2 Aldosterone antagonists are also under-utilized. As mentioned before, anticoagulation use among HF patients with AF/AFL is sub-optimal.7 Even the non-Vitamin K oral anticoagulants remain less accessible.4,7 In a continent with only half of countries having access to electrical cardioversion,7 device and catheter ablation therapies are available to a select few. Availability of device therapy including cardiac resynchronization therapy (CRT) and/or implantable cardioverter defibrillators is hindered by shortage of clinicians, arrhythmia specialists, and lack of hardware, e.g. catheterization laboratories and apathy among manufacturers to make devices readily available. Recent interest from industry should be complemented by capacity-building initiatives at the governmental level that aim to address this shortage. The Pan-African Society of Cardiology (PASCAR) reports in 20188,9 revealed a low median density of CRT centres, operators, and implantation rate per million population (0.14, 0.10, and 2.26, respectively).9 The report revealed gaps in the management of HF and related arrhythmias including electrophysiological studies and ablation techniques.8 A recent (2020) survey of centres implanting cardiac electronic devices by the African Heart Rhythm Association (AFHRA) highlights the low operator density with a median of 0.14 operators per million inhabitants and a median population density of CRT centres of 0.02, compared with the European median density of CRT centres of 1.4.10 The survey also highlights cost as an important factor, with significant cost variation in different countries and a much higher uptake of CRT-P than of CRT-D for the same reason (cost difference as wide as 800USD vs. 18 000USD). Even among centres that participated in the AFHRA survey, one-fifth do not offer CRT. This lack of CRT is not surprising since around one-fifth of African countries do not provide basic pacing to their populations.9 There is an unmet need in the management of arrhythmias among HF patients in Africa. Cardiac resynchronization therapy services and invasive cardiac arrhythmias management are scanty. Factors causing the need-access gap include high medications/procedural costs, lack of adequate data for planning and policy development, and few trained doctors/technologists, among others. In our view, these gaps need to be addressed in a multidisciplinary approach involving governments, medical organizations, and industry (Figure 1). The unmet needs in the management of arrhythmias among heart failure patients in Africa. Conflict of interest: none declared.