Characterisation of heart failure with normal ejection fraction in a tertiary hospital in Nigeria

Delivering effective, comprehensive, multi-exercise component cardiac rehabilitation (CR) for chronic heart failure patients in low resource settings in sub-Saharan Africa: Queen Elizabeth Central Hospital-(QECH-CR) randomised CR study, Malawi

BACKGROUND

The delivery of Cardiac Rehabilitation (CR) and attaining evidence-based treatment goals are challenging in developing countries, such as Malawi. The aims of this study were to (i) assess the effects of exercise training/ CR programme on cardiorespiratory and functional capacity of patients with chronic heart failure (CHF), and (ii) examine the effectiveness of a novel, hybrid CR delivery using integrated supervised hospital- and home-based caregiver approaches.

METHODS

A pre-registered (UMIN000045380), randomised controlled trial of CR exercise therapy in patients with CHF was conducted between September 2021 and May 2022. Sixty CHF participants were randomly assigned into a parallel design-exercise therapy (ET) (n = 30) or standard of care (n = 30) groups. Resting hemodynamics, oxygen saturation, distance walked in six-minutes (6MWD) and estimated peak oxygen consumption (VO2 peak) constituted the outcome measures. The exercise group received supervised, group, circuit-based ET once weekly within the hospital setting and prescribed home-based exercise twice weekly for 12 weeks. Participants in both arms received a group-based, health behaviour change targeted education (usual care) at baseline, 8-, 12- and 16-weeks.

RESULTS

Most of the participants were female (57%) with a mean age of 51.9 ±15.7 years. Sixty-five percent (65%) were in New York Heart Association class III, mostly with preserved left ventricular ejection fraction (HFpEF) (mean Left Ventricular Ejection Fraction 52.9 ±10.6%). The 12-weeks ET led to significant reductions in resting haemodynamic measures (all P <0.05). The ET showed significantly higher improvements in the 6MWD (103.6 versus 13.9 m, p<0.001) and VO2 peak (3.0 versus 0.4 ml·kg-1·min-1, p <0.001). Significant improvements in 6MWD and VO2 peak (both p<0.001), in favour of ET, were also observed across all follow-up timepoints.

CONCLUSION

This novel, randomised, hybrid ET-based CR, delivered to mainly HFpEF patients using an integrated hospital- and home-based approach effectively improved exercise tolerance, cardiorespiratory fitness capacities and reduced perceived exertion in a resource-limited setting.

Risk factors of heart failure among patients with hypertension attending a tertiary hospital in Ibadan, Nigeria: The RISK-HHF case-control study

Aim

Hypertension is the leading cause of heart failure (HF) in sub-Saharan Africa. Preventive public health approach to reduce the scourge of HF must seek to understand the risk factors of HF in at-risk populations. The aim of this study was to characterize the risk factors of HF among patients with hypertension attending a cardiology clinic.

Methods and results

One hundred and one (101) case-control age- and sex-matched pairs were recruited. The study population were adults with a clinical diagnosis of hypertensive HF (cases) and individuals with systemic hypertension without HF. They were interviewed and evaluated for cardiovascular risk factors. Associations between variables were tested with chi square test, Fisher’s exact test and independent sample t test as appropriate. Logistic regression modelling was used to determine the independent risk factors of hypertensive HF (HHF) in the study population while ‘punafcc’ package in stata12 was used to calculate the population attributable fraction (PAF) of the risk factors. Suboptimal medication adherence was the strongest adverse risk factor of HHF (medium adherence aOR: 3.53, 95%CI: 1.35–9.25; low adherence aOR: 9.44, 95%CI: 3.41–26.10) with a PAF of 67% followed by dipstick proteinuria (aOR: 4.22, 95%CI: 1.62–11.02; PAF: 34%) and alcohol consumption/day per 10grams (aOR: 1.23, 95%CI: 1.02–1.49; PAF: 22%). The protective risk factors of HHF were use of calcium channel blockers (aOR 0.25, 95%CI: 0.11–0.59; PAF: 59%), then daily fruits and vegetable consumption (aOR 0.41, 95%CI: 0.17–1.01; PAF: 46%), and eGFR (aOR 0.98, 95%CI: 0.96–0.99; PAF: 5.3%).

Conclusions

The risk factors of HHF are amenable to lifestyle and dietary changes. Public health interventions and preventive cardiovascular care to improve medication adherence, promote fruit and vegetable consumption and reduce alcohol consumption among patients with hypertension are recommended. Renoprotection has utility in the prevention of HF among hypertensives.

Development and Validation of a Electrocardiographic Diagnostic Score of Heart Failure Among Patients with Hypertension Attending a Tertiary Hospital in Ibadan, Nigeria: The RISK-HHF Case-Control Study

Objectives

Hypertension is the leading cause of HF in sub-Saharan Africa. Electrocardiography (ECG) is a cheap and easily available stratification tool for the diagnosis and prognostication of individuals with hypertension. The aim of this study was to develop an ECG-based HF diagnostic score among patients with hypertension attending a specialist cardiology clinic.

Methods

One hundred and one (101) case-control age- and sex-matched pairs were recruited. The study population were adults with a clinical diagnosis of hypertensive HF failure (cases) and systemic hypertension without HF (controls). Participants underwent clinical assessment and ECG. Associations between ECG variables and HF risk were tested with chi square test. Logistic regression modelling (age- and sex adjusted) was trained on a random subset of participants and tested on the remaining participants to determine the ECG abnormalities that are diagnostic of HF and develop a HF diagnostic score. The HF diagnostic score was then validated in an independent dataset of the ECG-Hypertension Audit. Goodness of fit and c-statistics of the HF summed diagnostic score in the training, testing and validation datasets are presented. A two-sided p value of <0.05 was considered statistically significant.

Results

The independent ECG diagnostic markers of HF among hypertensive patients in this study in decreasing order of effect size were sinus tachycardia (aOR: 7.72, 95% CI: 2.31-25.85). arrhythmia (aOR: 7.14, 95% CI: 2.57-19.86), left ventricular hypertrophy (aOR: 4.47; 1.85-10.77) and conduction abnormality (aOR: 3.41, 95% CI: 1.21-9.65). The HF summed diagnostic score showed excellent calibration and discrimination in the training (Hosmer Lemeshow p = 0.90; c-statistic 0.82; 95% CI 0.76–0.89) and test samples (Hosmer Lemeshow p=0.31; c-statistic 0.73 95% CI 0.60 to 0.87) of the derivation cohort and an independent validation audit cohort (Hosmer Lemeshow p = 0.17; c-statistic 0.79 95% CI 0.74 to 0.84) respectively. The model showed high diagnostic accuracy in individuals with different intermediate pre-test probabilities of HF.

Conclusions

A ECG based HF score consisting of sinus tachycardia, arrhythmia, conduction abnormality and left ventricular hypertrophy is diagnostic of HF especially in those with intermediate pre-test probability of HF. This has clinical importance in the stratification of individuals with systemic hypertension.

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.

Explaining Heart Failure Hyper-mortality in Sub Saharan Africa: Global Genomic and Environmental Contribution Review

The annual heart failure (HF) mortality rate in Africa is 34% according to the INTERHF study. This is twice the world average of 16.5% and 3.7 times that of South America, 9%. We review evidence-based explanations for the Hyper-mortality of HF, by comparison of North American, Caribbean, Afro-Brazilian with Sub-Saharan African (SSA) nations profiles, and suggest amelioration. 1 year HF mortality rates in SSA ranged from 29% to 58%, and intra-hospital mortality rate from 8 to 26% (n = 8). A clustering of adverse genetic single nucleotide polymorphisms (SNP) predisposing to hypertension and/or left ventricular hypertrophy (LVH) in the black diaspora may contribute. A higher prevalence of HF with reduced Ejection Fraction (HF r EF) phenotype, which is associated with greater mortality is more common in SSA nations. Additionally, a worse co-morbidity burden, especially valvular regurgitations causing LV remodeling (LVR), chronic kidney disease (CKD), anemia, lung disease, infections, late presentation in NYHA III/IV, right ventricular disease (RVD) were also common in SSA. Geographic variation in SSA, HF risk factors and co-morbidity was observed. There was sub-optimal use of guideline directed medical therapy (GDMT) and intracardiac device (ICD) unavailability. Gross Domestic Product -per purchasing power parity (GDP-PPP), which is low in SSA, was inversely correlated both to higher intra-hospital mortality rate % (r = -0.73, r 2 = 0.54 p = 0.038) and higher 1 year HF mortality rate % (r = -0.62, r 2 = 0.38, = 0.098). Localized primary prevention, early detection and prompt treatment of hypertension, diabetes, rheumatic fever, early cardiac valve repair and use of cardiovascular polypill, optimal use of GDMT, national health insurance scheme are advocated to stem the dismal mortality and cost burden of HF.

Heart failure care in low- and middle-income countries: a systematic review and meta-analysis

BACKGROUND

Heart failure places a significant burden on patients and health systems in high-income countries. However, information about its burden in low- and middle-income countries (LMICs) is scant. We thus set out to review both published and unpublished information on the presentation, causes, management, and outcomes of heart failure in LMICs.

METHODS AND FINDINGS

Medline, Embase, Global Health Database, and World Health Organization regional databases were searched for studies from LMICs published between 1 January 1995 and 30 March 2014. Additional unpublished data were requested from investigators and international heart failure experts. We identified 42 studies that provided relevant information on acute hospital care (25 LMICs; 232,550 patients) and 11 studies on the management of chronic heart failure in primary care or outpatient settings (14 LMICs; 5,358 patients). The mean age of patients studied ranged from 42 y in Cameroon and Ghana to 75 y in Argentina, and mean age in studies largely correlated with the human development index of the country in which they were conducted (r = 0.71, p<0.001). Overall, ischaemic heart disease was the main reported cause of heart failure in all regions except Africa and the Americas, where hypertension was predominant. Taking both those managed acutely in hospital and those in non-acute outpatient or community settings together, 57% (95% confidence interval [CI]: 49%-64%) of patients were treated with angiotensin-converting enzyme inhibitors, 34% (95% CI: 28%-41%) with beta-blockers, and 32% (95% CI: 25%-39%) with mineralocorticoid receptor antagonists. Mean inpatient stay was 10 d, ranging from 3 d in India to 23 d in China. Acute heart failure accounted for 2.2% (range: 0.3%-7.7%) of total hospital admissions, and mean in-hospital mortality was 8% (95% CI: 6%-10%). There was substantial variation between studies (p<0.001 across all variables), and most data were from urban tertiary referral centres. Only one population-based study assessing incidence and/or prevalence of heart failure was identified.

CONCLUSIONS

The presentation, underlying causes, management, and outcomes of heart failure vary substantially across LMICs. On average, the use of evidence-based medications tends to be suboptimal. Better strategies for heart failure surveillance and management in LMICs are needed. Please see later in the article for the Editors' Summary.