Characteristics of heart failure with a preserved ejection fraction in black South African patients.

Background: Heart failure with a preserved ejection fraction (HFpEF) is common in the elderly (≥75 years) and associated with arterial stiffness. The mean age of HFpEF presentation is lower (40-55 years) in sub-Saharan Africa. No clinical study has been conducted on HFpEF in identifying and characterising this phenotype at a younger age, moreover in a South African black population where the risk of HFpEF is two times higher than in other ethnic groups. This study investigated the characteristics of HFpEF in a black South African population, the biochemical markers that predict HFpEF and cardiac structural changes in this HF phenotype. Methods: Sixty-six participants with HFpEF and 213 controls were enrolled. All participants gave informed consent and completed a standardised questionnaire. Echocardiographic, anthropometric, central haemodynamic measurements, pulse wave velocity (PWV) and biomarker analysis were done. Results: The mean age of HFpEF participants was 54.88 ± 13.51 years. Most of the participants (76 %) were between 20 and 64 years, while only 24 % were older. HFpEF participants were hypertensive, and more obese with increased incidence of alcohol consumption. PWV was increased in HFpEF (9.97 ± 2.78 m/s) when compared to participants without HFpEF (6.11 ± 2.18 m/s), p < 0.0001. There were no significant associations between central haemodynamic parameters, N-terminal pro B-type natriuretic peptide (NT-proBNP) (p = 0.9746), and galectin-3 (p = 0.2166). NT-proBNP, but not galectin-3, was associated with left ventricular hypertrophy (p = 0.0002) and left atrial diameter (p = 0.0005). Conclusion: HFpEF in South Africa is predominant in obese young to middle-age individuals with arterial stiffness and who consume alcohol regularly. NT-proBNP could be used to diagnose HFpEF, however, should be interpreted with caution in populations with a high prevalence of obesity.

The alpha 2C Del322-325 adrenergic receptor polymorphism is not associated with heart failure due to idiopathic dilated cardiomyopathy in black Africans.

BACKGROUND: A four-amino acid deletion was identified within the alpha 2C-adrenergic receptor (alpha 2C Del322-325) that, when homozygous, increases the risk of heart failure in African-Americans nearly six-fold. We hypothesised that homozygosity for the alpha 2C Del322-325 polymorphism may be a risk factor for heart failure due to idiopathic dilated cardiomyopathy (DCM) in black South Africans. METHODS: The alpha 2C Del322-325 polymorphism was genotyped in 37 patients with heart failure and 34 controls, all of black African ancestry. Genotyping was performed by a size-fractionation assay. RESULTS: The patients studied ranged in age from 21 to 79 years with a mean age of 50 years, and 62% were male. No significant difference was observed in homozygosity for the alpha 2C Del322-325 polymorphism or in allele and genotype frequencies between patients and controls. The frequency of the allele containing the deletion was 0.54 in cases and 0.53 in controls. The genotype frequencies in the patients were consistent with those of the controls (p = 0.56). CONCLUSIONS: Homozygosity for the alpha 2C Del322-325 polymorphism is not associated with an increased risk for heart failure due to idiopathic DCM in black South Africans.

Mortality in Patients Treated for Tuberculous Pericarditis in Sub-Saharan Africa

Objective: To determine the mortality rate and its predictors in patients with a presumptive diagnosis of tuberculous pericarditis in sub-Saharan Africa. Design: Between 1 March 2004 and 31 October 2004; we enrolled 185 consecutive patients with presumed tuberculous pericarditis from 15 referral hospitals in Cameroon; Nigeria; and South Africa; and observed them during the 6-month course of antituberculosis treatment for the major outcome of mortality. This was an observational study; with the diagnosis and management of each patient left at the discretion of the attending physician. Using Cox regression; we have assessed the effect of clinical and therapeutic characteristics (recorded at baseline) on mortality during follow-up. Results: We obtained the vital status of 174 (94) patients (median age 33; range 14-87 years). The overall mortality rate was 26. Mortality was higher in patients who had clinical features of HIV infection than in those who did not (40versus 17; P=0.001). Independent predictors of death during follow-up were: (1) a proven non-tuberculosis final diagnosis (hazard ratio [HR] 5.35; 95confidence interval 1.76 to 16.25); (2) the presence of clinical signs of HIV infection (HR 2.28; 1.14-4.56); (3) co-existent pulmonary tuberculosis (HR 2.33; 1.20-4.54); and (4) older age (HR 1.02; 1.01-1.05). There was also a trend towards an increase in death rate in patients with haemodynamic instability (HR 1.80; 0.90-3.58) and a decrease in those who underwent pericardiocentesis (HR 0.34; 0.10-1.19). Conclusion : A presumptive diagnosis of tuberculous pericarditis is associated with a high mortality in sub-Saharan Africans. Attention to rapid aetiological diagnosis of pericardial effusion and treatment of concomitant HIV infection may reduce the high mortality associated with the disease

Lone ventricular cardiomyopathy, 1993-1996.

OBJECTIVE: To identify subjects with univentricular idiopathic structural and/or functional myocardial disorders (as defined) and to describe the characteristic features. DESIGN: Over a period of 4 years, 1993-1996, all adult subjects were obtained consecutively from a centralised referral cardiological service. The subjects had to fulfil a set of formulated diagnostic criteria for each isolated type of univentricular disease-symptomatic or asymptomatic. The subjects were diagnosed on the basis of clinical features, supported by electrocardiographic, radiological and echocardiographic evidence of lone ventricular disease, with a further definition of abnormalities based on appropriately selected standard left and right heart assessments, inter alia: (i) cardiac catheterisation, including coronary arteriography and pulmonary angiography; (ii) radio-isotope studies-mibiscan; (iii) ventilation perfusion scan; and (iv) laboratory tests to identify likely cause(s) of diffuse myocardial damage as well as to recognise nonspecific effects of tissue damage and organ dysfunction. SETTING: A referral cardiological service of a tertiary academic hospital, which provides a consultative service for inpatients and ambulatory cases. All subjects were studied on admission to hospital. PARTICIPANTS: A set of criteria was formulated for each category of lone ventricular myopathy. A total of 30 patients were thus identified and included in the study-men and women ranging in age from 18 years to 84 years, with an average of 48 years. All were investigated after admission to hospital by means of a detailed set of investigations that rigorously excluded overt or occult causes of diffuse myocardial damage and any severe myocardial dysfunction secondary to haemodynamic conditions. Seven patients with significant coronary artery disease were excluded. Any subject with pulmonary or systemic hypertension was also excluded. MAIN OUTCOME MEASURES: Total number of patients, number of patients in each subgroup were analysed by age, sex, clinical features, and by special investigation. The mode of presentation and electrocardiographic features were analysed separately. RESULTS: Twenty-two left ventricular and 8 right ventricular cases of lone ventricular cardiomyopathy were diagnosed. All but 1 patient with right ventricular disease were symptomatic and 5 subjects with left ventricular myopathy were incidentally discovered. There were 17 men and 13 women in the series. Of the 8 patients with right ventricular disease, 6 were women, while of the 22 patients with left ventricular cardiomyopathy, 15 were men. CONCLUSION: The study supports the previously described existence of lone ventricular idiopathic cardiomyopathy. Further studies are, however, indicated in order to define its prevalence and nature more accurately, as well as to describe any relationship with univentricular cardiomyopathies, and define the characteristics of each category and the possible evolutionary patterns. Right ventricular cardiomyopathy is a new entity which may pose difficult diagnostic challenges, while left ventricular disease is generally accepted as a stage in the clinical spectrum of classic idiopathic dilated cardiomyopathy.