Impact of Hypertension on Left Ventricular Geometry and Diastolic Function in Africa: Results from the Population-Based TAnve Health (TAHES) Cohort Study.

High blood pressure leads to morphologic changes and functional alterations of the myocardial structure. Transthoracic echocardiography is of great clinical interest to evaluate these alterations, using reference values proposed by the American Society of Echocardiography/European Association of Cardiovascular Imaging, largely based on studies in Caucasian Whites. We aimed to assess the impact of hypertension on echocardiographic parameters in a sub-Saharan African community, using ethnic-specific reference values. This study is part of the TAnve HEalth Study, a population-based prospective cohort study initiated in 2015 in the district of Tanve, Republic of Benin. Hypertension was defined as systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg and/or currently taking antihypertensive medications. All participants had a transthoracic echocardiography. The patterns of diastolic dysfunction and left ventricular (LV) geometry were defined from 486 subjects in the cohort, free from cardiovascular disease, diabetes, and hypertension. Of all participants, 318 (65% women, median age 48 years) had hypertension. Systolic blood pressure correlated significantly (p <0.0001) with LV mass (r = 0.28), wall thickness (r = 0.25), isovolumic relaxation time (r = 0.27), E/A ratio (r = -0.35), lateral e' velocity (r= -0.41), and E/E' ratio (r = 0.39). Ventricular geometry was normal in only 22% of participants with hypertension when using the American Society of Echocardiography/European Association of Cardiovascular Imaging reference values, versus 69% with ethnic-specific reference ranges. The severity of hypertension was associated with ventricular geometry abnormalities. The prevalence of diastolic dysfunction was 14.5% (confidence interval 10.6% to 18.4%), including relaxation impairment (9%) and pseudonormal pattern (6%). Thus, correct assessment of the repercussions of hypertension on LV geometry in Black Africans requires ethnic-specific reference values.

Normal reference values of cardiac chamber sizes and functional parameters in a beninese community population: the TAHES study.

Reported ranges of normal values for echocardiographic measurements are mostly issued from studies performed in Caucasians. This study is a part of TAHES, a population-based prospective cohort study in Benin and aims to establish normal reference values for echocardiographic cardiac chambers dimensions and Doppler parameters in a Sub-Saharan African population. We included 486 healthy (non-diabetic, non-obese and normotensive) individuals (202 men and 284 women, age 37[30-47] years, BSA 1.58 (1.47-1.67) m2). End-diastolic interventricular septal wall thickness, left ventricular (LV) internal diameter, posterior wall thicknesses, and systolic LV internal diameter were respectively at 10[9-12], 45[43-49], 9[8-11], 29[26-34] mm for male and 9[7-10], 43[41-46], 8[7-], 29[27-32] mm for females. LV mass was significantly greater in males even after normalization for the body surface area (98[85-117] vs. 82[71-96] g/m2). Upper limits of BSA-indexed LV mass were 145 g/m2 for males and 124 g/m2 for females. The allometric exponent that described the LV mass-Height relationship were 2.5 in both sexes but 1.2 for males and 1.8 for females separately. E-wave velocity was 0.79 [0.65-0.90] cm/sec in males and 0.88 [0.78-0.99]cm/sec in females (p < 0.0001) but without significant gender differences in E/A ratio (limits: 0.75 and 2.1). The e'-wave velocity (lower limit = 8 cm/sec) decreased and E/e' ratio (Upper limit = 9) increased with aging. Upper limit of BSA-indexed left atrium volume was 38 mL/m2 for both sexes. In conclusion, normal values from a general population in West Africa differ from those established in Caucasian populations with greater LV mass and wall thicknesses.

Normal limits of electrocardiogram in Africans and their consequences on the prevalence of left ventricular hypertrophy in hypertensive individuals: Insights from the TAHES study.

AIMS: To determine normal limits for major ECG variables, and the electrocardiographic impact of hypertension, in a rural sub-Saharan African setting. METHODS: This cross-sectional study included adults aged ≥25 years from Tanvè Health Study (TAHES) cohort. ECG were recorded at rest at 25 mm/s using a standard 12­lead device. Wave amplitudes and durations were measured. Corrected QT interval (QTc) was calculated using Bazett's formula. Sokolow-Lyon, Cornell and Peguero-Lo Presti criteria were determined to assess left ventricular hypertrophy (LVH). RESULTS: ECG was recorded among 997 out of 1407 TAHES participants. After exclusion of subjects with hypertension or diabetes, normal limits, defined as the 2nd and 98th percentiles, were evaluated in 622 healthy participants (median: 37 years; 60.1% women). The following limits were established in men (women): heart rate: 50 to 100 (55 to 102) beats/min, P wave duration: 80 to 120 (80 to 120) ms, PR interval: 120 to 200 (120 to 200) ms, QTc: 315 to 470 (323 to 465) ms, QRS duration: 50 to 120 (50 to 110) ms. Upper limits (in millimeter) for the Sokolow-Lyon, Cornell and Peguero-Lo Presti for men (women) were 47 (38), 30 (22) and 39 (30), respectively, all above current reference limits. The prevalence of LVH in hypertensive subjects according to these criteria were lower than those estimated according to current LVH criteria. CONCLUSION: The normal limits of ECG variables determined in this African population differ from those in Caucasians, indicating that ethnicity must be considered in ECG interpretation.

May Measurement Month 2018: an analysis of blood pressure screening results from Benin.

Hypertension is the strongest cardiovascular risk factor worldwide. May Measurement Month (MMM) is an international campaign for blood pressure (BP) screening initiated by the International Society of Hypertension. This work aims to estimate the proportion and the levels of awareness, treatment, and control of hypertension in participants of the MMM survey in Benin in 2018. A cross-sectional survey focused on people aged ≥18 years was conducted in May 2018 in nine rural and urban areas in Benin. A sampling of volunteers was done. BP was measured following the MMM protocol. Hypertension was defined as a systolic BP ≥140 mm Hg and/or a diastolic BP ≥90 mm Hg (mean of the second and third readings) and/or taking antihypertensive medication. Linear regression was used to identify BP associations. A total of 2035 people were screened, including 55.9% women. The mean age was 44.2 ± 15.9 years. The percentage with hypertension was 35.4%. Of 721 participants with hypertension, 56.2% were aware of their diagnosis, 39.7% were on antihypertensive medication, and 13.6% were controlled (<140/90 mmHg). The results confirm the significant proportion of hypertension in Benin. Education programs on risk factors, early detection, and better management strategies should be developed.

Normal values of proximal aorta diameters in healthy Sub Saharan Africans: The TAHES study.

OBJECTIVES: Reported ranges of normal values are mostly issued from studies performed with Caucasians. This study is a part of TAHES, a population-based prospective cohort study in Benin and aims to establish normal reference values for echocardiographic diameters of the proximal aorta in Africans. METHODS: Transthoracic echocardiography (TTE) examinations were performed by four cardiologists following pre-defined protocols, and analyzed off-line by a single observer. Aortic root diameters were measured during diastole for sinuses of Vasalva (SV), sinotubular junction (STJ) and proximal ascending aorta (AA), and during systole for annulus. Upper limits were defined as the 95th percentiles. RESULTS: We included 513 normotensive, non-diabetic, and cardiovascular disease-free individuals (206 men, 307 women, age 40 ± 14 years). The diameters of the proximal aorta were significantly greater in men. The inner-edge-to-inner-edge non-indexed upper values for the annulus, SV, STJ and AA were respectively 25, 34, 28.5, 32 mm in men and 22, 30, 26, 30 mm in women. The leading-edge-to-leading-edge upper values were respectively 38, 35, 36 for men and 34, 33, 32 mm for women. No significant differences between sexes were recorded for body surface area (BSA)-indexed diameters of the annulus, STJ and AA. BSA-indexed SV dimension was greater in men than women were. SV, STJ, AA indexed-diameters correlated with age in both sexes but not for annulus indexed-diameter. CONCLUSION: Normal values from a general population in West Africa could to differ from those established in Caucasian populations. Ethnic-specific reference diameters are here proposed for appropriate diagnosis of proximal aortic diseases in sub-Saharan Africa.

Epidemiology of lower extremity artery disease in a rural setting in Benin, West Africa: The TAHES study.

BACKGROUND: Data on epidemiology of lower extremity artery disease (LEAD) in general population in Sub-Saharan Africa are sparse. This study aims to estimate the prevalence of LEAD among participants of Tanve Health Study (TAHES), a cohort about cardiovascular diseases (CVD) in a rural setting in Benin. METHODS: The cohort was launched since 2015 among adults aged over 25 years in Tanve, a village in Benin. Ankle-brachial index (ABI) was measured for the first time during the third annual visit of the cohort in 2017. Risk factors data were collected using the WHO STEPS adapted questionnaire in a systematic door-to-door survey. The LEAD was defined as ABI ≤ 0.90. RESULTS: We recorded ABI among 1003 out of 1407 TAHES' participants. A predominance of females (61.4%) was observed. The mean age was 44.4 ±â€¯15.7 years and 49.9% were under 40 years. Regarding CVD risk factors, prevalences were estimated for sedentary behavior (68.2%), harmful use of alcohol (3.9%), fruit and vegetable low intake (96.0%), tobacco smoking (5.2%), Overweight or obesity (Body mass index > 25) (27.7%), raised blood pressure (36.8%) and raised blood glucose (5.4%). Prevalence of LEAD was 5.5% (95%CI: 4.2%­7.1%) in the sample, 7.0% (95%CI: 5.1%­9.4%) in women and 3.1% (95%CI: 1.7%­5.5%) in men. Five individuals (0.5%; 95%CI: 0.2%­1.2%) had incompressible arteries (ABI ≥ 1.40), including four men. In multivariate analysis, LEAD was significantly associated with age ≥ 55 years (OR: 2.17; 95%CI: 1.20­3.92; p = 0.009) and female gender (OR: 2.27; 95%CI: 1.17­4.40; p = 0.014). CONCLUSION: Prevalence of LEAD is high in rural Benin and predominates among women and people over 55 years old.