Anaemia and iron deficiency in heart failure: epidemiological gaps, diagnostic challenges and therapeutic barriers in sub-Saharan Africa.

Anaemia and iron deficiency (ID) are common and of prognostic importance in heart failure (HF). In both conditions the epidemiology, diagnosis and therapies have been extensively studied in high-income countries but are still largely unexplored in sub-Saharan Africa (SSA). The lack of adequate and robust epidemiological data in SSA makes it difficult to recognise the significance of anaemia and ID in HF. From a clinical perspective, less attention is paid by clinicians to screening for anaemia in HF, and as far as interventions are concerned, there are no clinical trials in SSA that provide guidance on the appropriate interventional approach. Therefore studies are needed to provide more insight into the burden and peculiarities of and intervention for anaemia and ID in HF in SSA, where the pathophysiology might be different from that in high-income countries. There is increasing appreciation that targeting ID may serve as a useful additional treatment strategy for patients with chronic HF in high-income countries. However, there is limited information on the diagnosis of and therapy for ID in HF in SSA, where infections and malnutrition are more likely to influence the situation. This article reviews the present epidemiological gap in knowledge about anaemia and ID in HF, as well as the diagnostic and therapeutic challenges in SSA.

Rates and risk factors of hypertension in adolescents and adults with sickle cell anaemia in Tanzania: 10 years' experience.

Data on the magnitude and risk factors for hypertension in sickle cell anaemia (SCA) are limited. A retrospective analysis of individuals with SCA aged ≥15 years enrolled from 2004-2014 at Muhimbili National Hospital, Tanzania was conducted to determine the prevalence, incidence and risk factors for hypertension. A total of 1013 individuals with SCA were analysed, of whom 571(56%) were females. The median age [interquartile range] was 17 [15-22] years. Four hundred and forty-one (44%) of the patients had relative hypertension [systolic blood pressure (SBP) 120-139 mmHg or diastolic blood pressure (DBP) 70-89 mmHg], and 79 (8%) had hypertension (SBP ≥ 140 mmHg or DBP ≥ 90 mmHg). The incidence of hypertension was 64/1000 person years of observation and the 5-year survival rate was 0·71 [95% confidence interval (CI): 0·67-0·75]. In multivariate analysis, age>18 years, Hazard ratio (HR) 1·50 (95% CI: 1·03-2·18); pulse pressure, HR 0·64 (95% CI: 0·42 to 0·98); pulse rate, 1·02 (95% CI: 1·01-1·03); body mass index (BMI), HR 1·08 (95% CI: 1·03-1·13); blood transfusion, HR 2·50 (95% CI: 1·01-6·21) and haemoglobin, HR 1·12 (95% CI: 1·05-1·33) were independently associated with hypertension. In conclusion, despite the younger age, hypertension in this population was higher than that reported in others studies. Age, BMI, pulse pressure and haemoglobin were independently associated with hypertension in SCA.

Heart failure in Tanzania and Sweden: Comparative characterization and prognosis in the Tanzania Heart Failure (TaHeF) study and the Swedish Heart Failure Registry (SwedeHF).

BACKGROUND: Heart failure (HF) in developing countries is poorly described. We compare characteristics and prognosis of HF in Tanzania vs. Sweden. METHODS: A prospective cohort study was conducted from the Tanzania HF study (TaHeF) and the Swedish HF Registry (SwedeHF). Patients were compared overall (n 427 vs. 51,060) and after matching 1:3 by gender and age±5years (n 411 vs. 1232). The association between cohort and all-cause mortality was assessed with multivariable Cox regression. RESULTS: In the unmatched cohorts, TaHeF (as compared to SwedeHF) patients were younger (median age [interquartile range] 55 [40-68] vs. 77 [64-84] years, p<0.001) and more commonly women (51% vs. 40%, p<0.001). The three-year survival was 61% in both cohorts. In the matched cohorts, TaHeF patients had more hypertension (47% vs. 37%, p<0.001), more anemia (57% vs. 9%), more preserved EF, more advanced HF, longer duration of HF, and less use of beta-blockers. Crude mortality was worse in TaHeF (HR 2.25 [95% CI 1.78-2.85], p<0.001), with three-year survival 61% vs. 83%. However, covariate-adjusted risk was similar (HR 1.07, 95% CI 0.69-1.66; p=0.760). In both cohorts, preserved EF was associated with higher mortality in crude but not adjusted analysis. CONCLUSIONS: Compared to in Sweden, HF patients in Tanzania were younger and more commonly female, and after age and gender matching, had more frequent hypertension and anemia, more severe HF despite higher EF, and worse crude but similar adjusted prognosis.

Prevalence and prognostic implications of anaemia and iron deficiency in Tanzanian patients with heart failure.

OBJECTIVE: To determine the prevalence, correlates and prognostic implications of anaemia and iron deficiency (ID) in patients with heart failure (HF) in Tanzania. METHOD: This was a cross-sectional and prospective observational study conducted at Muhimbili National Hospital in Dar es Salaam, Tanzania. Patients were ≥ 18 years of age, with HF defined according to the Framingham criteria. The primary outcome was anaemia and the secondary outcome was a composite of hospitalisation for HF or all-cause mortality. RESULTS: A total of 401 HF patients (median age 56 years, IQR 41-67 years; women 51%) were included. The prevalence of anaemia was 57%. The overall prevalence of ID was 49% distributed as 69% versus 21% in subjects with and without anaemia (p < 0.001). Normocytic anaemia was seen in 18% of the patients while none had macrocytic anaemia. The risk of having anaemia was positively associated with residency outside Dar es Salaam (OR 1.72 (95% CI 1.02 to 2.89); p = 0.038), atrial fibrillation (4.12 (1.60 to 10.61); p=0.003), LVEF < 45% (2.70 (1.57 to 4.67); p < 0.001) and negatively (ORs per unit decrease) with creatinine clearance (0.98 (0.97 to 0.99); p = 0.012) and total cholesterol (0.78 (0.63 to 0.98); p = 0.029). One-year survival free from a composite endpoint was 70%. The presence of ID anaemia increased the likelihood for an event (HR 2.67; 95% CI 1.39 to 5.07; p = 0.003), while anaemia without ID did not influence the risk. CONCLUSIONS: ID anaemia was common in Tanzanian patients with HF and was independently associated with the risk for hospitalisation or death.

Contemporary aetiology, clinical characteristics and prognosis of adults with heart failure observed in a tertiary hospital in Tanzania: the prospective Tanzania Heart Failure (TaHeF) study.

OBJECTIVE: This study aimed to describe the contemporary aetiology, clinical characteristics and mortality and its predictors in heart failure (HF) in Tanzania. METHODS: Design; Prospective observational study. Setting; Cardiovascular Center of the Muhimbili National Hospital in Dar es Salaam, Tanzania. Patients ≥18 years of age with HF defined by the Framingham criteria. MAIN OUTCOME MEASURE: All-cause mortality. RESULTS: Among 427 included patients, 217 (51%) were females and the mean (SD) age was 55 (17) years. HF aetiologies included hypertension (45%), cardiomyopathy (28%), rheumatic heart disease (RHD) (12%) and ischaemic heart disease (9%). Concurrent atrial fibrillation (AF), clinically significant anaemia, diabetes, tuberculosis and HIV were found in 16%, 12%, 12%, 3% and 2%, respectively, while warfarin was used in 3% of the patients. The mortality rate, 22.4 per 100 person-years over a median follow-up of 7 months, was independently associated with AF, HR 3.4 (95% CI 1.6 to 7.0); in-patient 3.2 (1.5 to 6.8); anaemia 2.3 (1.2 to 4.5); pulmonary hypertension 2.1 (1.1 to 4.2) creatinine clearance 0.98 (0.97 to 1.00) and lack of education 2.3 (1.3 to 4.2). CONCLUSIONS: In HF in Tanzania, patients are younger than in the developed world, but aetiologies are becoming more similar, with hypertension becoming more and RHD less important. Predictors of mortality possible to intervene against are anaemia, AF and lack of education.

Prevalence and covariates of abnormal left ventricular geometry in never-treated hypertensive patients in Tanzania.

AIM. To assess prevalence, type and covariates of abnormal left ventricular (LV) geometry in untreated native Tanzanian patients with hypertension in relation to normotensive controls. METHODS. Echocardiography was performed in 161 untreated hypertensive outpatients and 80 normotensive controls at a tertiary hospital in Tanzania. Hypertensive heart disease was defined as presence of increased LV mass or relative wall thickness (RWT). RESULTS. The prevalence of hypertensive heart disease increased with the severity of hypertension and was on average 62.1% among patients and 12.5% in controls. In multivariate analyses, higher LV mass index was associated with higher systolic blood pressure (ß = 0.28), body mass index (ß = 0.20), peak early transmitral to medial mitral annulus velocity ratio (ß = 0.16), and with lower stress-corrected midwall shortening (scMWS) (ß = - 0.44) and estimated glomerular filtration rate (ß = - 0.16), all p < 0.05. Higher RWT was associated with higher systolic blood pressure (ß = 0.16), longer E-wave deceleration time (ß = 0.23) and lower scMWS (ß = - 0.66), irrespective of LV mass (all p < 0.05). CONCLUSION. Subclinical hypertensive heart disease is highly prevalent in untreated native hypertensive Tanzanians and associated with both systolic and diastolic LV dysfunction. Management of hypertension in Africans should include high focus on subclinical hypertensive heart disease.

Left atrial volume index as a marker of left ventricular diastolic dysfunction in asymptomatic Tanzanian diabetic patients.

AIM: To determine the prevalence of left atrial (LA) enlargement and its relation to left ventricular (LV) diastolic dysfunction among asymptomatic diabetic outpatients attending Muhimbili National Hospital in Dar es Salaam, Tanzania. METHODS: Echocardiography was performed in 122 type 2 and 58 type 1 diabetic patients. Diastolic dysfunction was defined as peak transmitral blood velocity to medial mitral annulus velocity (E/E') ratio ≥ 15. LA volume indexed to body surface area (LAVI) was considered enlarged if ≥ 29 ml/m(2). RESULTS: Enlarged LAVI and LV diastolic dysfunction were more common in type 2 than in type 1 diabetic patients (44.3 vs 25.9% and 20.5 vs 3.5%, respectively, both p < 0.05). In multivariate linear regression analysis, larger LAVI was associated with LV diastolic dysfunction independent of significant associations with LV mass index and presence of mitral regurgitation in type 2 diabetic patients, while LV mass index, lower ejection fraction and longer duration of diabetes were the main covariates of larger LAVI in type 1 diabetic patients (all p < 0.05). CONCLUSION: Enlarged LA is common among asymptomatic Tanzanian diabetic patients, and particularly associated with LV diastolic dysfunction in type 2, and with cardiomyopathy and lower systolic function in type 1 diabetic patients.

Factors associated with, and echocardiographic findings of heart failure among HIV infected patients at a tertiary health care facility in Dar es Salaam, Tanzania.

Cardiovascular diseases, including heart failure are a known complication of Human Immunodeficiency Virus (HIV) infection globally. The objective of this study was to describe factors associated with, and echocardiographic findings of heart failure among HIV infected patients at a tertiary health care facility in Dar es Salaam, Tanzania. Clinical, laboratory and echocardiographic assessment was performed in all HIV-infected patients presenting with cardiac complaints at the medical department, Muhimbili National Hospital between September 2009 and April 2010. HF was diagnosed clinically and confirmed by echocardiography. Of the 102 HIV-infected patients with cardiac complaints 50 (49%) were in HF. Commonest causes of HF were hypertensive heart disease, pulmonary hypertension and dilated cardiomyopathy. In multivariate analysis male gender (OR 4.03), low education (OR 4.91), previous history of tuberculosis (OR 3.01), and low haemoglobin (OR 0.83), were independently associated with the diagnosis of HF (p<0.05 for all). In conclusion, heart failure is common in HIV-infected patients with cardiac complaints, and is associated with both modifiable and non-modifiable factors.

Increased relative wall thickness is a marker of subclinical cardiac target-organ damage in African diabetic patients.

OBJECTIVE: To assess the prevalence and covariates of abnormal left ventricular (LV) geometry in diabetic outpatients attending Muhimbili National Hospital in Dar es Salaam, Tanzania. METHODS: Echocardiography was performed in 61 type 1 and 123 type 2 diabetes patients. LV hypertrophy was taken as LV mass/height(2.7) > 49.2 g/m(2.7) in men and > 46.7 g/m(2.7) in women. Relative wall thickness (RWT) was calculated as the ratio of LV posterior wall thickness to end-diastolic radius and considered increased if ≥ 0.43. LV geometry was defined from LV mass index and RWT in combination. RESULTS: The most common abnormal LV geometries were concentric remodelling in type 1 (30%) and concentric hypertrophy in type 2 (36.7%) diabetes patients. Overall, increased RWT was present in 58% of the patients. In multivariate analyses, higher RWT was independently associated with hypertension, longer isovolumic relaxation time, lower stress-corrected midwall shortening and circumferential end-systolic stress, both in type 1 (multiple R(2) = 0.73) and type 2 diabetes patients (multiple R(2) = 0.66), both p < 0.001. These associations were independent of gender, LV hypertrophy or renal dysfunction. CONCLUSION: Increased RWT is common among diabetic sub-Saharan Africans and is associated with hypertension and LV dysfunction.

Echocardiographic diagnoses in HIV-infected patients presenting with cardiac symptoms at Muhimbili National Hospital in Dar es Salaam, Tanzania.

OBJECTIVE: To determine the pattern of echocardiographic diagnoses in HIV-infected patients presenting with cardiac symptoms at Muhimbili National Hospital in Dar es Salaam, Tanzania. METHODS: Patients known to be HIV positive and with cardiac complaints were prospectively recruited from the Hospital's care and treatment centre as well as from the medical wards. Clinical assessment, laboratory tests and echocardiography were performed. RESULTS: A total of 102 patients were recruited from September 2009 to April 2010. The patients' mean age was 42.4 years and 68.6% were women. The most common diagnosis was pericardial effusion present in 41.2% of the patients. The effusion was large in 5.9% and small in 35.3% of the patients. Hypertensive heart disease was diagnosed in 34.3%, while pulmonary hypertension and dilated cardiomyopathy were present in 12.7 and 9.8%, respectively. CONCLUSION: Cardiac abnormalities are common in HIV-infected patients, particularly when they present with symptoms.