Contemporary aetiology of acute heart failure in a teaching hospital in Ghana.

BACKGROUND: Heart failure (HF) is recognized as a global public health disease associated with high morbidity and mortality. It is suggested that the main underlying causes of HF in developing countries differ from those identified in well-resourced countries. This study therefore presents the cardiovascular risk factors and the underlying aetiology of HF among admitted patients in a teaching Hospital in Ghana. METHOD: The study prospectively recruited 140 consecutive patients admitted for heart failure at the Medical department of the Korle-Bu Teaching Hospital from March to October, 2014. The study evaluated the cardiovascular risk factors and the aetiologies of heart failure, and compared the risk factors and aetiologies with patient's age and gender. RESULTS: The mean age of the study participants was 51.3 ± 16.8 years. The commonest cardiovascular risk factors observed were hypertension (46.5%), history of previous HF (40.7%), excessive alcohol use (38.6%), and family history of heart disease (29.3%); predominantly hypertension (68.3%). The major underlying aetiology of HF were dilated cardiomyopathy (38.6%), hypertensive heart disease (21.4%), ischaemic heart disease (13.6%) and valvular heart disease (12.9%). These underlying aetiology of HF were more common in patients aged 40 years and above (p = 0.004) and those presenting with multiple risk factors (p = 0.001). CONCLUSION: The major underlying aetiology of heart failure in adults were dilated cardiomyopathy, hypertensive heart disease, ischaemic heart disease and valvular heart disease, which were significantly high among patients aged 40 years and above and those presenting multiple risk factors. Hypertension, excessive alcohol use, family history of heart disease and personal history of previous heart failure diagnosis are noted as the main cardiovascular risk factors among heart failure patients.

Multilocus analysis of hypertension: a hierarchical approach.

While hypertension is a complex disease with a well-documented genetic component, genetic studies often fail to replicate findings. One possibility for such inconsistency is that the underlying genetics of hypertension is not based on single genes of major effect, but on interactions among genes. To test this hypothesis, we studied both single locus and multilocus effects, using a case-control design of subjects from Ghana. Thirteen polymorphisms in eight candidate genes were studied. Each candidate gene has been shown to play a physiological role in blood pressure regulation and affects one of four pathways that modulate blood pressure: vasoconstriction (angiotensinogen, angiotensin converting enzyme - ACE, angiotensin II receptor), nitric oxide (NO) dependent and NO independent vasodilation pathways and sodium balance (G protein-coupled receptor kinase, GRK4). We evaluated single site allelic and genotypic associations, multilocus genotype equilibrium and multilocus genotype associations, using multifactor dimensionality reduction (MDR). For MDR, we performed systematic reanalysis of the data to address the role of various physiological pathways. We found no significant single site associations, but the hypertensive class deviated significantly from genotype equilibrium in more than 25% of all multilocus comparisons (2,162 of 8,178), whereas the normotensive class rarely did (11 of 8,178). The MDR analysis identified a two-locus model including ACE and GRK4 that successfully predicted blood pressure phenotype 70.5% of the time. Thus, our data indicate epistatic interactions play a major role in hypertension susceptibility. Our data also support a model where multiple pathways need to be affected in order to predispose to hypertension.