The aim of the study was to examine the prevalence of cardiovascular risk factors and causes of heart failure at the Korle-Bu Teaching Hospital, the national referral center serving the southern sector of Ghana.
The study found that hypertension was the most common risk factor for HF. This is consistent with several studies done in Ghana [13,14,17] and other African countries [18-20]. Hypertension was most prevalent in patients aged 40 years and above. This finding is similar to the finding of a previous study where systolic blood pressure markedly increased with age . A meta-analysis on several studies in Ghana has shown that hypertension detection, treatment and control rates are very poor . This is due to several factors including poverty, illiteracy, poor accessibility to health care services and traditional beliefs about medication. In addition, medication non-adherence rates among patients with hypertension have been shown to be very high in a recent study . This begs for urgent action to improve hypertension detection, treatment, and control rates in Ghana if the raging epidemic of HF is to be curtailed. The study found other risk factors including history of smoking, alcohol use, diabetes mellitus, previous heart failure, dyslipidaemia, and obesity, similar to the findings of previous studies [21,24]. Smoking and alcohol use were significantly higher in males whereas obesity (BMI of >30kg/m2) was significantly higher in females and those aged 40 years and above. This is consistent with the findings made in a previous study where the history of former or current smoking was frequent among male patients and female patients were more obese . The current study found that the prevalence of diabetes mellitus was significantly higher in patients aged 40 years and above. This is in line with what has been reported elsewhere where the prevalence of DM temporally high among middle-aged patients presenting with acute heart failure . Cardiovascular risk factors particularly dyslipidaemia, hypertension, diabetes mellitus and smoking are widespread in adults worldwide , which may possibly be due to urbanization, increase life expectancy and changes in lifestyles including unhealthy diets and lack of physical activity.
The study identified hypertensive heart disease and cardiomyopathies as the most common causes of HF in this study (30.7% and 29.3% respectively). Other common causes were ischaemic (13.6%) and valvular heart diseases (12.9%). This is similar to the findings of the studies by Owusu et al in Komfo Anokye Teaching Hospital in Kumasi [14,15], and Amoah et al  in the National Cardiothoracic Center in Accra. However, in this study fewer rheumatic heart diseases and more cardiomyopathies and ischaemic heart diseases were identified compared to the earlier studies. This probably reflects the changing lifestyle of Ghanaians, growing urbanization, and ageing population. Hypertensive heart disease results from chronic systemic arterial hypertension and has emerged as the commonest cause of HF in several studies in Africa [6,18,24]. The causes of hypertensive heart disease seem to be a likely gene-environment interaction whereby weight gain, high salt intake and psychosocial factors may facilitate the rapid development of hypertension and hypertensive heart disease in susceptible individuals . It is clear from this study that hypertension remains a major health challenge in Ghana and other studies have shown that it remains undiagnosed and poorly controlled in a majority of the population .
Dilated cardiomyopathy was the second most common aetiology of HF identified in this study. Dilated cardiomyopathy has indeed been shown to be a common cause of HF in sub-Saharan Africa from earlier studies [27,28]. Several important causes of dilated cardiomyopathy have been identified in sub-Saharan Africa including HIV cardiomyopathy, peripartum cardiomyopathy, myocarditis, alcohol induced cardiomyopathy and genetic/familial forms . Familial disease accounts for 30-50% of cases depending on the extent to which investigations are done to identify the underlying cause. The current study identified idiopathic dilated cardiomyopathy (65.1%) as the commonest cause of dilated cardiomyopathy comparable to the 50% identified by Felker et al  among 1230 patients evaluated with initially unexplained cardiomyopathy. The high proportion of idiopathic dilated cardiomyopathy observed in the current study could probably be because of incomplete investigations in this study. Echocardiography is not very sensitive in differentiating the underlying causes of dilated cardiomyopathy. Furthermore, cardiac MRI and coronary angiography were not performed so one is likely to misclassify some cases of ischaemic heart disease as dilated cardiomyopathy and vice versa. Similarly, viral screening and serological tests were not done in this study. In the study by Felker et al , the prognosis of patients with ischaemic cardiomyopathy, infiltrative cardiomyopathy and HIV-associated cardiomyopathy was poorer than those with idiopathic cardiomyopathy. It is therefore of utmost importance to fully evaluate HF patients with dilated cardiomyopathy for any probable underlying causes.
Furthermore, ischaemic heart disease was found as more common than primary valvular heart disease in the aetiology of HF. This finding is at variance with the findings in earlier studies in Ghana [13,15], the heart of Soweto  and the THESUS-HF studies . In Ghana, several studies have shown high prevalence of traditional cardiovascular risk factors for coronary artery disease, such as hypertension, obesity, diabetes mellitus, dyslipidaemia and sedentary lifestyle [17,22,30]. This could therefore account for ischaemic heart disease becoming common as observed in this current study.
Our current study found only 12.9% of the HF was due to primary valvular heart disease. Moreover, most of the valvular heart diseases were degenerative rather than rheumatic, reflecting the ageing population. A similar low prevalence of rheumatic heart disease as a cause of contemporary HF was found in Abeokuta, Nigeria in a recent registry in which only 2.4% of the 452 HF patients had rheumatic heart disease . Both studies were done in urban communities in Africa where living standards and environmental conditions are better, thus may not be a true reflection of the general population.
Congenital heart diseases were very few in this study, like that found in the Abeokuta HF registry where only 2 congenital heart disease cases were identified in the 452 adults with HF . This may be due to either patients still going to see their pediatric doctors because of long-term relationship or some of them not living long enough into adulthood as a result of lack of resources for corrective heart surgeries in most places in sub-Saharan Africa. However, congenital heart diseases have been identified as very common cause of heart failure in earlier study [13,14]. This is probably due to the differences in the age range of patients included in the studies. Whereas Amoah et al  included patients 4 months to 95 years, in our current study, only adults 18 years and above were recruited.
The study found that hypertensive heart disease, cardiomyopathies and ischaemic heart diseases were predominant in patients aged 40 years and above. This is consistent with the finding made in a similar study among heart failure patients in a tertiary hospital in Kumasi, Ghana . It has been stipulated that enhancements in public health have led to the high prevalence of chronic diseases among the ageing population .
A major limitation of this study is the inability to do natriuretic peptides on admission. This test was not routinely available in the facility during the time of the study. Diagnosis of ischaemic cardiomyopathy was based on echocardiography with no coronary angiography. Additionally, virological and serological tests were not done to investigate the underlying cause of dilated cardiomyopathies. Past history of heart failure was established mainly by clinical history and may suffer from recall bias. The definition of hypertensive heart disease used for this study might have missed out patients with end-stage hypertensive heart disease with thinned walls.