Utilization of implantable defibrillators in Africa

Factors Associated With Non-Uptake of Implantable Cardioverter-Defibrillator (ICD) Among Eligible Patients at a Tertiary Hospital in Kenya

Background

Efficacy of Implantable Cardioverter-Defibrillator (ICD) implantation in both primary and secondary prevention of Sudden Cardiac Death (SCD) in at-risk population is well established. ICD implantation rates remain low particularly in Africa with a paucity of data regarding factors associated with non-uptake.

Objectives

The primary study objective was to determine the factors associated with non-uptake of ICD among heart failure (HF) patients with reduced ejection fraction (EF<35%). Reasons for ICD refusal among eligible patients were reviewed as a secondary objective.

Methods

This was a retrospective study among HF patients eligible for ICD implantation evaluated between 2018 to 2020. Comparison between ICD recipient and non-recipient categories was made to establish determinants of non-uptake.

Results

Of 206 eligible patients, only 69 (33.5%) had an ICD. Factors independently associated with non-uptake were lack of private insurance (42.3% vs 63.8%; p = 0.005), non-cardiology physician (16.1% vs 5.8%; p = 0.045) and non-ischemic cardiomyopathy (54.7% vs 36.4% p = 0.014). The most common (75%) reason for ICD refusal was inability to pay for the device.

Conclusion

ICDs are underutilized among eligible HF with reduced EF patients in Kenya. The majority of patients without ICD had no private insurance, had non-ischemic cardiomyopathy and non-cardiology primary physician. Early referral of HF with reduced EF patients to HF specialists to optimize guideline-directed medical therapy and make ICD recommendation is needed.

Clinical Profile and Health Disparities in a Multiethnic Cohort of Patients With Hypertrophic Cardiomyopathy

BACKGROUND

Clinical studies of hypertrophic cardiomyopathy are over-represented by individuals of European ethnicity, with less known about other ethnic groups. We investigated differences between patients in a multiethnic Australian hypertrophic cardiomyopathy population.

METHODS

We performed a retrospective cohort study of 836 unrelated hypertrophic cardiomyopathy probands attending a specialized clinic between 2002 and 2020. Major ethnic groups were European (n=611), East Asian (n=75), South Asian (n=58), and Middle Eastern and North African (n=68). The minor ethnicity groups were Oceanian (n=9), People of the Americas (n=7), and African (n=8). One-way ANOVA with Dunnett post hoc test and Bonferroni adjustment were performed.

RESULTS

Mean age of the major ethnic groups was 54.9±16.9 years, and 527 (65%) were male. Using the European group as the control, East Asian patients had a lower body mass index (29 versus 25 kg/m², P<0.0001). South Asians had a lower prevalence of atrial fibrillation (10% versus 31%, P=0.024). East Asians were more likely to have apical hypertrophy (23% versus 6%, P<0.0001) and Middle Eastern and North African patients more likely to present with left ventricular outflow tract obstruction (46% versus 34%, P=0.0003). East Asians were less likely to undergo genetic testing (55% versus 85%, P<0.0001) or have an implantable cardioverter-defibrillator implanted (19% versus 36%, P=0.037). East Asians were more likely to have a causative variant in a gene other than MYBPC3 or MYH7, whereas Middle Eastern and North African and South Asians had the highest rates of variants of uncertain significance (27% and 21%, P<0.0001).

CONCLUSIONS

There are few clinical differences based on ethnicity, but importantly, we identify health disparities relating to access to genetic testing and implantable cardioverter-defibrillator use. Unless addressed, these gaps will likely widen as we move towards precision-medicine-based care of individuals with hypertrophic cardiomyopathy.

Statistics on the use of cardiac electronic devices and interventional electrophysiological procedures in Africa from 2011 to 2016: report of the Pan African Society of Cardiology (PASCAR) Cardiac Arrhythmias and Pacing Task Forces

Aims

To provide comprehensive information on the access and use of cardiac implantable electronic devices (CIED) and catheter ablation procedures in Africa.

Methods and results

The Pan-African Society of Cardiology (PASCAR) collected data on invasive management of cardiac arrhythmias from 2011 to 2016 from 31 African countries. A specific template was completed by physicians, and additional information obtained from industry. Information on health care systems, demographics, economics, procedure rates, and specific training programs was collected. Considerable heterogeneity in the access to arrhythmia care was observed across Africa. Eight of the 31 countries surveyed (26%) did not perform pacemaker implantations. The median pacemaker implantation rate was 2.66 per million population per country (range: 0.14–233 per million population). Implantable cardioverter-defibrillator and cardiac resynchronization therapy were performed in 12/31 (39%) and 15/31 (48%) countries respectively, mostly by visiting teams. Electrophysiological studies, including complex catheter ablations were performed in all countries from Maghreb, but only one sub-Saharan African country (South Africa). Marked variation in cost (up to 1000-fold) was observed across countries with an inverse correlation between implant rates and the procedure fees standardized to the gross domestic product per capita. Lack of economic resources and facilities, high cost of procedures, deficiency of trained physicians, and non-existent fellowship programs were the main drivers of under-utilization of interventional cardiac arrhythmia care.

Conclusion

There is limited access to CIED and ablation procedures in Africa. A quarter of countries did not have pacemaker implantation services, and catheter ablations were only available in one country in sub-Saharan Africa.

The first cardioverter defibrillator implanted in Central Africa

Sudden cardiac deaths, which account for approximately 350 000 deaths each year, is a major health care problem. Antiarrhythmic drugs have not been reliable in preventing sudden cardiac death. Although β-blockers, angiotensin-converting enzyme inhibitors, and revascularization play a role in prevention of sudden cardiac death, the development and subsequent refinement of the implantable cardioverter-defibrillator has made the most important contribution to its management. We report the first documented implantation of a cardioverter defibrillator in central, eastern and western Africa.

Variations in Cause and Management of Atrial Fibrillation in a Prospective Registry of 15 400 Emergency Department Patients in 46 Countries

Background—

Atrial fibrillation (AF) is the most common sustained arrhythmia; however, little is known about patients in a primary care setting from high-, middle-, and low-income countries.

Methods and Results—

This prospective registry enrolled patients presenting to an emergency department with AF at 164 sites in 46 countries representing all inhabited continents. Patient characteristics were compared among 9 major geographic regions. Between September 2008 and April 2011, 15 400 patients were enrolled. The average age was 65.9, standard deviation 14.8 years, ranging from 57.2, standard deviation 18.8 years in Africa, to 70.1, standard deviation 13.4 years in North America, P <0.001. Hypertension was globally the most common risk factor for AF, ranging in prevalence from 41.6% in India to 80.7% in Eastern Europe, P <0.001. Rheumatic heart disease was present in only 2.2% of North American patients, in comparison with 21.5% in Africa and 31.5% in India, P <0.001. The use of oral anticoagulation among patients with a CHADS 2 score of ≥2 was greatest in North America (65.7%) but was only 11.2% in China, P <0.001. The mean time in the therapeutic range was 62.4% in Western Europe, 50.9% in North America, but only between 32% and 40% in India, China, Southeast Asia, and Africa, P <0.001.

Conclusions—

There is a large global variation in age, risk factors, concomitant diseases, and treatment of AF among regions. Improving outcomes globally requires an understanding of this variation and the conduct of research focused on AF associated with different underlying conditions and treatment of AF and predisposing conditions in different socioeconomic settings.

Epidemiology of heart failure in sub-Saharan Africa

Heart failure has emerged as a dominant form of cardiovascular disease in Africa, and has great social and economic relevance owing to its high prevalence, mortality and impact on young, economically active individuals. The causes of heart failure in Africans remain largely nonischemic. Hypertension, cardiomyopathy, rheumatic heart disease, chronic lung disease and pericardial disease are the main contributors to the etiology of cardiac failure in sub-Saharan Africa, accounting for over 90% of cases. Hypertensive heart disease complications occur more frequently in Africans and the majority of affected patients are younger. Endemic cardiomyopathies include dilated cardiomyopathy, peripartum cardiomyopathy and endomyocardial fibrosis. Nonendemic cardiomyopathies apparently occur with the same frequency as in other parts of the world, and include hypertrophic cardiomyopathy and arrhythmogenic right ventricular dysplasia/cardiomyopathy. Coronary artery disease and its complications remain uncommon in Africa, but the situation is changing due to modifications in lifestyle, risk-prone behavior, diet, cultural attitudes and other consequences of rapid urbanization. As the prevalence of heart failure is expected to rise substantially in sub-Saharan Africa, the authors call for population-based studies and registries of the epidemiology of heart failure in Africans and the urgent study of interventions that will decrease morbidity and mortality from the causes of heart failure, with a focus both on nonischemic and ischemic risk factors.

Epidemiology and Etiology of Cardiomyopathy in Africa

Background— Cardiomyopathy, an often irreversible form of heart muscle disease that is associated with a dismal outcome, is endemic in Africa. The primary objective of this review was to summarize the current state of knowledge on the epidemiology and etiology of cardiomyopathy in people living in Africa and to identify new avenues for research.

Methods and Results— We searched MEDLINE (January 1, 1966, through February 12, 2005) and reference lists of articles for relevant references. Unlike other parts of the world in which cardiomyopathy is rare, dilated cardiomyopathy is a major cause of heart failure throughout Africa. Similarly, peripartum cardiomyopathy is ubiquitous on the continent, with an incidence ranging from 1 in 100 to 1 in 1000 deliveries. There is an apparent marked regional variation in the pathogenesis of dilated cardiomyopathy and peripartum cardiomyopathy, underlining the heterogeneity of causative factors in these conditions. By contrast, endomyocardial fibrosis is restricted to the tropical regions of East, Central, and West Africa. Although the pathogenesis of endomyocardial fibrosis is not fully understood, it seems that the conditioning factors are geography and diet, the triggering factor may be an as yet unidentified infective agent, and the perpetuating factor is eosinophilia. Although epidemiological studies are lacking, hypertrophic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy seem to have characteristics similar to those of other populations elsewhere in the world.

Conclusions— There is a need for large-scale epidemiological studies of the incidence, prevalence, determinants, and outcome of cardiomyopathy in Africa to inform strategies for the treatment and prevention of heart muscle disease on the continent.