Alain Menanga

Prevalence, awareness, treatment and control of hypertension in a self-selected sub-Saharan African urban population: a cross-sectional study

Objectives Hypertension has been established as a major public health problem in Africa, but its specific contributions to disease burden are still incompletely understood. We report the prevalence and determinants of hypertension, detection, treatment and control rates among adults in major cities in Cameroon. Design Cross-sectional study. Settings Community-based multicentre study in major cities in Cameroon. Participants Participants were self-selected urban dwellers from the Center, Littoral, North-West and West Regions, who attended on 17 May 2011 a screening campaign advertised through mass media. Primary and secondary outcomes measures Hypertension defined as systolic (and/or diastolic) blood pressure (BP)≥ 140 (90) mm Hg, or ongoing BP-lowering medications. Results In all, 2120 participants (1003 women) were included. Among them, 1007 (prevalence rate 47.5%) had hypertension, including 319 (awareness rate 31.7%) who were aware of their status. The prevalence of hypertension increased with age overall and by sex and region. Among aware hypertensive participants, 191 (treatment rate 59.9%) were on regular BP-lowering medication, and among those treated, 47 (controlled rate 24.6%) were at target BP levels (ie, systolic (and diastolic) BP<140 (90) mm Hg). In multivariable logistic regression analysis, male gender, advanced age, parental history of hypertension, diabetes mellitus, elevated waist and elevated body mass index (BMI) were the significant predictors of hypertension. Likewise, male gender, high BMI and physical inactivity were associated with poor control. Conclusions High prevalence of hypertension with low awareness, treatment and control were found in this urban population; these findings are significant and alarming with consideration to the various improvements in the access to healthcare and the continuing efforts to educate communities over the last few decades.

Chronic heart failure, selected risk factors and co-morbidities among adults treated for hypertension in a cardiac referral hospital in Cameroon

Information on clinical characteristics of heart failure (HF) among Africans with hypertension is needed to help define the burden of hypertension in this population, but currently there is little data available.

Efficiency of an intervention package for arterial hypertension comprising telemanagement in a Cameroonian rural setting: The TELEMED-CAM study.

Introduction Sub-Saharan Africa has a disproportionate burden of disease and an extreme shortage of health workforce. Therefore, adequate care for emerging chronic diseases can be very challenging. We implemented and evaluated the effectiveness of an intervention package comprising telecare as a mean for improving the outcomes of care for hypertension in Rural Sub-Saharan Africa. Methods The study involved a telemedicine center based at the Yaounde General Hospital (5 cardiologists) in the Capital city of Cameroon, and 30 remote rural health centers within the vicinity of Yaoundé (20 centers (103 patients) in the usual care group, and 10 centers (165 patients) in the intervention groups). The total duration of the intervention was 24 weeks. Results Participants in the intervention group had higher baseline systolic (SBP) and diastolic (DBP) blood pressure, and included fewer individuals with diabetes than those in the usual care group (all p < 0.01). Otherwise, the baseline profile was mostly similar between the two groups. During follow-up, more participants in the intervention groups achieved optimal BP control, driven primarily by greater improvement of BP control among High risk participants (hypertension stage III) in the intervention group. Conclusion An intervention package comprising tele-support to general practitioners and nurses is effective in improving the management and outcome of care for hypertension in rural underserved populations. This can potentially help in addressing the shortage of trained health workforce for chronic disease management in some settings. However context-specific approaches and cost-effectiveness data are needed to improve the application of telemedicine for chronic disease management in resource-limited settings.

Patterns of cardiovascular disease in a group of HIV-infected adults in Yaoundé, Cameroon

BACKGROUND Cardiovascular disease is an increasingly important issue in human immunodeficiency viral (HIV)-infected individuals. There is dearth of information on the patterns of cardiovascular disease especially in sub-Saharan Africa (SSA) patients. This study reports on the clinical, biological, electrocardiographic and echocardiographic characteristics of a group of HIV-infected patients presenting with symptoms of heart disease in Yaoundé, Cameroon. METHODS This was a cross-sectional study conducted at the Yaoundé Central Hospital and Jamot Hospital. Consenting HIV-infected adults aged ≥18 years with symptoms suggestive of heart disease were consecutively recruited between February and July 2014. All participants underwent a complete clinical examination; biological analyses including CD4 cell counts, fasting blood glucose, and serum lipids, resting electrocardiography and cardiac ultrasound, and a venous ultrasound where necessary. RESULTS Forty four subjects (21 men) were included. Their mean age was 48 (SD 13) years. Thirty patients (68.2%) were in WHO clinical stages 3 and 4 of HIV infection, 27 (61.4%) had a CD4 cell count <200/mm(3), and 31 (70.5%) were on antiretroviral therapy (ART). Hypertension (43.2%, n=19) was the most frequent cardiovascular risk factor; and dyslipidemia which was found in 17 subjects (38.6%) was significantly associated with ART (48.4% vs. 15.4%, P=0.04). Only men where smokers (23% vs. 0%, P=0.019). Exertional dyspnea (86.4%, n=38) and cough (59.1%, n=26) were the most frequent symptoms, and the clinical presentation was dominated by heart failure (75%, n=33). The most frequent echocardiographic abnormalities were pericardial effusion (45.5%, n=20) and dilated cardiomyopathy (22.7%, n=10). Dilated cardiomyopathy was significantly associated with CD4 cell counts <200/mm(3) (100%, P=0.003). Primary pulmonary hypertension (PH) rate was 11.4% (n=5) and all cases occurred at CD4 cell counts ≥200/mm(3) (P=0.005). The most frequent electrocardiographic abnormalities were abnormal repolarization (59%, n=26) and sinus tachycardia (56.8%, n=25). CONCLUSIONS Cardiovascular risk factors such as hypertension and dyslipidemia are common in HIV-infected adults with heart disease in our milieu. Advanced HIV infection in adults is associated with a high rate of symptomatic heart disease, mostly effusive pericarditis and dilated cardiomyopathy. Primary PH occurred in less advanced HIV disease.

Spectrum of heart diseases in children: an echocardiographic study of 1,666 subjects in a pediatric hospital, Yaounde, Cameroon

BACKGROUND Childrens health programs in Sub-Saharan Africa have always been oriented primarily to infectious diseases and malnutrition. We are witnessing in the early 21(st) century an epidemiological transition marked by the decline of old diseases and the identification of new diseases including heart disease. Therefore, it is necessary to describe the spectrum of these diseases in order to better prepare health workers to these new challenges. METHODS We conducted a cross-sectional study focused on heart disease diagnosed by echocardiography in children seen from January 2006 to December 2014 in a pediatric hospital of Yaounde. We collected socio-demographic data and the types of heart disease from registers, patients files as well as the electronic database of echocardiographic records. RESULTS A total of 2,235 patients underwent echocardiographic examination during the study period including 1,666 subjects with heart disease. Congenital cardiopathies were found in 1,230 (73.8%) patients and acquired abnormalities in 429 (25.8%). Seven children (0.4%) had a combination of both types. Congenital heart defects (CHD) were dominated by ventricular septal defect (VSD). Acquired heart disease was mostly rheumatic valvulopathies. Dyspnea on exertion was the most frequent presenting complaint (87.6%). Discovery of a heart murmur was the principal clinical finding on physical examination (81.4%). The median age was 9 months for congenital heart disease and 132 months for acquired heart disease. CONCLUSIONS As infectious diseases recede and the diagnostic facilities are improving, pediatric heart diseases occupy a more important position in the spectrum of pediatric diseases in our context. However, the ability to evoke the diagnosis remains unsatisfactory by the majority of health personnel and therefore needs to be improved. Apart from congenital heart diseases, the impact of acquired heart diseases, rheumatic valvulopathy being the highest ranking, is remarkable in pediatrics. Awareness of health personnel for better management of child tonsillitis is more than ever a necessity. This preventive attitude of rheumatic heart disease is the main attitude available in our disadvantaged economic environment.

Bilateral pulmonary embolism in a patient with pulmonary tuberculosis: a rare association in Yaoundé, Cameroon

Pulmonary embolism is a complication of pulmonary tuberculosis that has received little emphasis in the literature. We describe a 52 year old male, with no risk factors for thromboembolic disease referred to our service for an in depth clinical review for cardiomegaly and dyspnea on exertion. Echocardiography and CT scans revealed dilated heart cavities and bilateral proximal pulmonary emboli respectively and a cavitation in the apical lobe of the right lung. Bronchial aspirate and culture revealed the presence of mycobacterium tuberculosis. There was no evidence of malignancy. Elsewhere, a clinical review and a lower limb ultrasound showed no evidence of deep venous thrombosis. Clinical course on anti - tuberculosis and anti - coagulant therapies was remarkably favorable. Clinicians need to be conscious of the risk of developing thromboembolic disease in patients treated for tuberculosis, in especially high prevalence settings like ours.

Pattern and correlates of cardiac lesions in a group of sub-Saharan African patients on maintenance hemodialysis

Introduction Cardiovascular disease is the leading cause of morbidity and mortality in patients on maintenance hemodialysis. We investigated the pattern and correlates of cardiac lesions in a group of Cameroonians on chronic hemodialysis. Methods This was a cross-sectional study conducted at the Yaoundé General Hospitals hemodialysis unit, involving 45 patients (29 men, 64%) on maintenance hemodialysis for at least three months using a native arterio-venous fistula. Cardiovascular risk factors, biological, electrocardiographic and echocardiographic data were collected. Results Hypertension (29%), chronic glomerulonephritis (24%) and diabetes mellitus (24%) were the main etiological factors of chronic kidney disease. Blood pressure was controlled in 14 (31%) patients. Nineteen (42%) patients had anemia and 5 (14%) had a calcium-phosphorus product >55 mg2/dl2. All patients had at least one cardiovascular risk factors with hypertension (95%), anemia (42%) and highcalcium-phosphorus product (42%) being the most frequent. Thirty-eight (84%) patients had at least one cardiac lesion and 11 (29%) had three or more lesions. The cardiac lesions were left ventricular hypertrophy (60%), valvular calcifications (38%), heart failure (36%), conduction disorders (33%), pericardial effusion (13%), valvular diseases (11%) and ischemic heart diseases (2%). Left ventricular hypertrophy was significantly associated with a longer duration on dialysis and low hemoglobin level (both p < 0.047) while cardiac failure and valvular calcifications were associated with advanced age and high interdialytic weight gain (both p <0.05). Conclusion Cardiac lesions and cardiovascular risk factors are frequent in these patients receiving sub-optimal dose maintenance hemodialysis despite their younger age, suggesting an increased susceptibility to cardiovascular complications.

An assessment of discriminatory power of office blood pressure measurements in predicting optimal ambulatory blood pressure control in people with type 2 diabetes.

Introduction Ambulatory blood pressure (BP) measurements (ABPM) predict health outcomes better than office BP, and are recommended for assessing BP control, particularly in high-risk patients. We assessed the performance of office BP in predicting optimal ambulatory BP control in sub-Saharan Africans with type 2 diabetes (T2DM). Methods Participants were a random sample of 51 T2DM patients (25 men) drug-treated for hypertension, receiving care in a referral diabetes clinic in Yaounde, Cameroon. A quality control group included 46 non-diabetic individuals with hypertension. Targets for BP control were systolic (and diastolic) BP. Results Mean age of diabetic participants was 60 years (standard deviation: 10) and median duration of diabetes was 6 years (min-max: 0-29). Correlation coefficients between each office-based variable and the 24-h ABPM equivalent (diabetic vs. non-diabetic participants) were 0.571 and 0.601 for systolic (SBP), 0.520 and 0.539 for diastolic (DBP), 0.631 and 0.549 for pulse pressure (PP), and 0.522 and 0.583 for mean arterial pressure (MAP). The c-statistic for the prediction of optimal ambulatory control from office-BP in diabetic participants was 0.717 for SBP, 0.494 for DBP, 0.712 for PP, 0.582 for MAP, and 0.721 for either SBP + DBP or PP + MAP. Equivalents in diabetes-free participants were 0.805, 0.763, 0.695, 0.801 and 0.813. Conclusion Office DBP was ineffective in discriminating optimal ambulatory BP control in diabetic patients, and did not improve predictions based on office SBP alone. Targeting ABPM to those T2DM patients who are already at optimal office-based SBP would likely be more cost effective in this setting.

Urinary Protein Excretion Is Associated with Left Ventricular Hypertrophy in Treatment-Naïve Hypertensive Patients in an African Hospital Setting

Background: Left ventricular hypertrophy (LVH) is an independent predictor of fatal and non-fatal cardiovascular events in hypertensive patients. Current guidelines for the management of hypertension are based on cardiovascular risk stratification. This study evaluated the possibility that an inexpensive, simple random, single-void urinary protein-to-creatinine ratio (UPCR) would be associated to left ventricular (LV) mass in a black African setting, and therefore direct appropriate management of these patients. Methods: We measured echocardiographic LV mass and a random spot UPCR in 34 untreated newly diagnosed hypertensive patients attending the cardiology consultation unit at the Yaoundé General Hospital. LV mass was indexed to height (in m2.7) to obtain the LV mass index (LVMI). A regression model was used to verify the independent association between UPCR and LVMI. Results: The mean age of our patients was 52.65 years, and the mean systolic and diastolic blood pressures were 152.44 and 92.84 mm Hg, respectively. The prevalence of LVH was 41.2%. UPCR was higher in patients with LVH compared to those without (p = 0.043). There was a significant correlation between UPCR and LVMI (r = 0.581, p < 0.001). In the multiple linear regression model, UPCR was associated with LVMI independent of systolic blood pressure (p < 0.001). Conclusion: Random spot UPCR is associated with an increased LV mass and may be very useful in screening and guiding appropriate management of high-risk untreated hypertensive patients.

[PS 03-24] HYPERTENSION PREVALENCE, AWARENESS AND CONTROL IN CAMEROON: A SYSTEMATIC REVIEW WITH PROJECTIONS FOR 2025 AND 2035

Objective: The public health impact of hypertension in Cameroon is known. However, the exact future burden and the degree of awareness have not been quantified. We aimed to study the trend in the prevalence rates, awareness, treatment and associated risk factors of hypertension in Cameroon. Design and method: We systematically searched PubMed, Google Scholar and grey literature for large scale community surveys of hypertension and its related risk factors up to 2015. Studies considered were those on adults aged ≥ 15 years of both sexes, residing in both urban and rural settings, which used the cutoff “≥140/90 mmHg” to define hypertension. Regression models were used to estimate the prevalence rates of hypertension for the years 2025 and 2035. Results: Forty-four (44) surveys were identified, of which 16 (with pooled population of 65,500 participants) carried out between 1993 and 2013 were considered for analysis. The estimated crude prevalence rate of hypertension for 2025 is 35.5% (95% CI: 35.48 – 35.52, [≈6.3 million people]), and 37.3% (95% CI: 37.18 – 37.22, [≈8.7 million people]) for 2035. The age-adjusted prevalence rate of hypertension for 2025 is 31.9% (95% CI: 31.88 – 31.92, [≈5.6 million people]), and 33.5% (95% CI: 33.48 – 33.52, [≈7.8 million people]) for 2035. This represents a 40% increase by 2025 and a 95% increase by 2035 compared to the estimated 3.99 million hypertensive patients in 2015. This was coupled with a decreasing trend in the awareness rate, and an increased rate of associated risk factors such as diabetes, obesity, and tobacco use. Conclusions: Our findings suggest that the prevalence of hypertension is increasing in Cameroon at an alarming rate, and many hypertensive patients will be underdiagnosed, untreated or poorly treated. Further research efforts to investigate road blocks to hypertension control, and enhance specific interventions for improving blood pressure control are advocated.