Prevalence, clinical characteristics and outcomes of valvular atrial fibrillation in a cohort of African patients with acute heart failure: insights from the THESUS-HF registry

Heart failure with reduced ejection fraction and atrial fibrillation: a Sub-Saharan African perspective

Cardiovascular diseases are a well-established cause of death in high-income countries. In the last 20 years, Sub-Saharan Africa (SSA) has seen one of the sharpest increases in cardiovascular disease-related mortality, superseding that of infectious diseases, including HIV/AIDS, in South Africa. This increase is evidenced by a growing burden of heart failure and atrial fibrillation (AF) risk factors. AF is a common comorbidity of heart failure with reduced ejection fraction (HFrEF), which predisposes to an increased risk of stroke, rehospitalizations, and mortality compared with patients in sinus rhythm. AF had the largest relative increase in cardiovascular disease burden between 1990 and 2010 in SSA and the second highest (106.4%) increase in disability-adjusted life-years (DALY) between 1990 and 2017. Over the last decade, significant advancements in the management of both HFrEF and AF have emerged. However, managing HFrEF/AF remains a clinical challenge for physicians, compounded by the suboptimal efficacy of guideline-mandated pharmacotherapy in this group of patients. There may be an essential role for racial differences and genetic influence on therapeutic outcomes of HFrEF/AF patients, further complicating our overall understanding of the disease and its pathophysiology. In SSA, the lack of accurate and up-to-date epidemiological data on this subgroup of patients presents a challenge in our quest to prevent and reduce adverse outcomes. This narrative review provides a contemporary overview of the epidemiology of HFrEF/AF in SSA. We highlight important differences in the demographic and aetiological profile and the management of this subpopulation, emphasizing what is currently known and, more importantly, what is still unknown about HFrEF/AF in SSA.

Atrial Fibrillation in Heart Failure: Epidemiology, Quality of Life and Clinical Characteristics in the Iron Deficiency and ANaemia in Heart Failure (IDAN-HF) Study in Ogbomoso, Nigeria

Background

The cluster of atrial fibrillation (AF) with heart failure (HF) may be associated with a poorer prognosis. Its epidemiology and impact on clinical outcomes and quality of life among HF subjects in Africa have not yet been fully described. This study aimed at describing the epidemiology of AF among HF subjects, its impact on quality of life, clinical characteristics, and associations.

Methods

140 HF subjects were recruited by stratified random sampling method, and 12-lead electrocardiography was done to diagnose AF. Statistical analysis was done with SPSS 21.0. Informed consent was obtained from all participants.

Results

The frequency occurrence of AF was 28 (20.0%) of the HF subjects and were similar in age, systolic blood pressure, diastolic blood pressure, right ventricular internal dimension, packed cell volume, and gender distribution with those in sinus rhythm. The mean (S.D) six minutes walk test distance was significantly lower among HF subjects with AF compared to those without AF (171.1± 88.9 vs. 225.8 ± 102.1m respectively, p <0.05). Pulmonary hypertension, intracardiac clots, and kidney dysfunction were more frequent among HF subjects with AF than among those without AF. HF subjects with AF had a higher frequency of clusters of comorbidities than those without AF. AF was most prevalent and left atrial dimension was highest among subjects who had HF with reduced ejection fraction, compared to other HF phenotypes.

Conclusion

AF is common in HF among Nigerians and is associated with poor quality of life and poorer functional status compared to those with sinus rhythm.

Burden of atrial fibrillation among adults with heart failure in sub-Saharan Africa: a systematic review and meta-analysis

OBJECTIVES

This study aimed to estimate the prevalence of atrial fibrillation (AF) in adults with heart failure (HF) and summarise the all-cause mortality ratio among adult patients with coexisting HF and AF in sub-Saharan Africa (SSA).

SETTING

This was a systematic review and meta-analysis of cross-sectional and cohort studies with primary data on the prevalence and incidence of AF among patients with HF and the all-cause mortality ratio among patients with HF and AF in SSA. We combined text words and MeSH terms to search MEDLINE, PubMed and Global Health Library through Ovid SP, African Journals Online and African Index Medicus from database inception to 10 November 2021. Random-effects meta-analysis was used to estimate pooled prevalence.

PRIMARY OUTCOME MEASURES

The prevalence and incidence of AF among patients with HF, and the all-cause mortality ratio among patients with HF and AF.

RESULTS

Twenty-seven of the 1902 records retrieved from database searches were included in the review, totalling 9987 patients with HF. The pooled prevalence of AF among patients with HF was 15.6% (95% CI 12.0% to 19.6%). At six months, the all-cause mortality was 18.4% (95% CI 13.1% to 23.6%) in a multinational registry and 67.7% (95% CI 51.1% to 74.3%) in one study in Tanzania. The one-year mortality was 48.6% (95% CI 32.5% to 64.7%) in a study in the Democratic Republic of Congo. We did not find any study reporting the incidence of AF in HF.

CONCLUSION

AF is common among patients with HF in SSA, and patients with AF and HF have poor survival. There is an urgent need for large-scale population-based prospective data to reliably estimate the prevalence, incidence and risk of mortality of AF among HF patients in SSA to better understand the burden of AF in patients with HF in the region.

PROSPERO REGISTRATION NUMBER

CRD42018087564.

Epidemiological characteristics, management, and outcomes of atrial fibrillation in TUNISIA: Results from the National Tunisian Registry of Atrial Fibrillation (NATURE-AF)

BACKGROUND

Contemporary registries on atrial fibrillation (AF) are scare in North African countries.

HYPOTHESIS

In the context of the epidemiological transition, prevalence of valvular AF in Tunisia has decreased and the quality of management is still suboptimal.

METHODS

NATURE-AF is a prospective Tunisian registry, involving consecutive patients with AF from March 1, 2017 to May 31, 2017, with a one-year follow-up period. All the patients with an Electrocardiogram-documented AF, confirmed in the year prior to enrolment were eligible. The epidemiological characteristics and outcomes were described.

RESULTS

A total of 915 patients were included in this study, with a mean age of 64.3 ± 22 years and a male/female sex ratio of 0.93. Valvular AF was identified in 22.4% of the patients. The mean CHA₂ DS₂ VASC score in nonvalvular AF was 2.4 ± 1.6. Monotherapy with antiplatelet agents was prescribed for 13.8% of the patients. However, 21.7% of the subjects did not receive any antithrombotic agent. Oral anticoagulants were prescribed for half of the patients with a low embolic risk score. In 341 patients, the mean time in therapeutic range was 48.87 ± 28.69%. Amiodarone was the most common antiarrhythmic agent used (52.6%). During a 12-month follow-up period, 15 patients (1.64%) had thromboembolism, 53 patients (5.8%) had major hemorrhage, and 52 patients (5.7%) died.

CONCLUSIONS

NATURE-AF has provided systematic collection of contemporary data regarding the epidemiological and clinical characteristics as well as the management of AF by cardiologists in Tunisia. Valvular AF is still prevalent and the quality of anticoagulation was suboptimal.

A Systematic Review of the Spectrum of Cardiac Arrhythmias in Sub-Saharan Africa

Major structural cardiovascular diseases are associated with cardiac arrhythmias, but their full spectrum remains unknown in sub-Saharan Africa (SSA), which we addressed in this systematic review. Atrial fibrillation/atrial flutter (AF/AFL) prevalence is 16-22% in heart failure, 10-28% in rheumatic heart disease, 3-7% in cardiology admissions, but <1% in the general population. Use of oral anticoagulation is heterogenous (9-79%) across SSA. The epidemiology of sudden cardiac arrest/death is less characterized in SSA. Cardiopulmonary resuscitation is challenging, owing to low awareness and lack of equipment for life-support. About 18% of SSA countries have no cardiac implantable electronic devices services, leaving hundreds of millions of people without any access to treatment for advanced bradyarrhythmias, and implant rates are more than 200-fold lower than in the western world. Management of tachyarrhythmias is largely non-invasive (about 80% AF/AFL via rate-controlled strategy only), as electrophysiological study and catheter ablation centers are almost non-existent in most countries.

Highlights

- Atrial fibrillation/flutter prevalence is 16-22% in heart failure, 10-28% in rheumatic heart disease, 3-7% in cardiology admissions, and <1% in the general population in sub-Saharan Africa (SSA).- Rates of oral anticoagulation use for CHA2DS2VASC score ≥2 are very diverse (9-79%) across SSA countries.- Data on sudden cardiac arrest are scant in SSA with low cardiopulmonary resuscitation awareness.- Low rates of cardiac implantable electronic devices insertions and rarity of invasive arrhythmia treatment centers are seen in SSA, relative to the high-income countries.

A review of the epidemiology of atrial fibrillation in sub-Saharan Africa

This systematic review summarizes the data on the prevalence, risk factors, complications, and management of atrial fibrillation (AF) in sub-Saharan Africa (SSA). Bibliographic databases were searched from inception to 31 May 2019, to identify all published studies providing data on AF in populations living in SSA. A total of 72 studies were included. The community-based prevalence of AF was 4.3% and 0.7% in individuals aged ≥40 years and aged ≥70 years, respectively. The prevalence of AF ranged between 6.7% and 34.8% in patients with ischemic stroke, between 9.5% and 46.8% in those with rheumatic heart disease (RHD), between 5% and 31.5% in patients with dilated cardiomyopathy. The main risk factors for AF were hypertension, affecting at least one-third of patients with AF, and valvular heart disease (12.3%-44.4%) and cardiomyopathy (~20%). Complications of AF included heart failure in about two thirds and stroke in 10% to 15% of cases. The use of anticoagulation for stroke prevention was suboptimal. Rate control was the most frequent therapeutic strategy, used in approximately 65% to 95% of AF patients, with approximately 80% of them achieving rate control. The management of AF was associated with exorbitant cost. In conclusion, AF seems to have a higher prevalence in the general population than previously thought and is mostly associated with hypertension, cardiomyopathy, and RHD in SSA. It is associated with a high incidence of heart failure and stroke. The management of AF is suboptimal in SSA, especially with a low uptake of oral anticoagulation.