Detection and characteristics of hypertension patients admitted in 37 cardiology departments from 17 Sub-Saharan African countries

Background

High blood pressure (BP) is a major risk factor for several common cardiovascular (CV) disease such as stroke, heart failure or chronic kidney disease. The Sub-Saharan Africa (SSA) should face the highest rate of hypertension worldwide with an overall prevalence estimation of 46%. Due to scarce resources and inadequate healthcare provision, SSA have scarce hard data on treatment and control of high BP.

Purpose

To assess the detection and characteristics of hypertension patients admitted in hospitalizations 17 SSA countries

Methods

We conducted a transversal and longitudinal study in CV department of 37 hospitals from 23 cities in 17 SSA countries (10 low income: Niger, Guinea, Benin, Mali, Democratic Republic of the Congo, Tchad, Burkina Faso, Togo, Burundi, Ethiopia and 7 middle income: Cote d'Ivoire, Senegal, Cameroon, Congo, Soudan, Mauritania, Gabon). The February study was designed by a multidisciplinary collaborative team of epidemiologists, pharmacists and cardiologists from Africa and France. This ongoing observatory included all inpatients in February from each year since 2016. Data including socio-demographic and clinical characteristics, causes of admission, clinical, biological, complementary examinations, treatments, length of stay and discharge diagnosis were collected by the investigating physicians. Hypertension and severity of hypertension were defined according to 2018 ESC/ESH guidelines and BP was measured twice using standardized method. All analyses were performed through scripts developed in the R software (4.0.3 (2020-10-10))

Results

The study involved 4360 patients. Hypertension was measured on 1906 (43.7%) patients at admission. Proportion of patients with high BP in hospital increased from 42.2% in 2016 to 52.2% in 2021 (p<0.05) and differed significantly across countries from 77.6% in Niger to 100% in Chad. Among hypertensive patients, men represented 59.6% of patients and mean of age was 59±15.1 years. Overall, 61.4% of patients were from low income countries. The mains causes of admission among hypertensive patients were heart failure (37.8%) and stroke (18.9%). Average of systolic BP was 159±29.3 mmHg and average of diastolic BP was 96.7±16mmHg. Overall, 760 (40.3%), 525 (27.8%) and 602 (31.9%) had grade 1, grade 2 and grade 3 hypertension respectively. History of CV disease was observed in 51.5% of patients. Thus, 70.4% of patients had at least one CV risk factor other than hypertension. Angiotensin converting enzyme inhibitors and diuretics was prescribed in 56.9% and 55.8% of patients respectively. The average amount of antihypertensive drugs prescribed in hospital was 2.09±1.18. Overall, 237 (12.4%), 295 (15.5%), 640 (33.6%) and 734 (38.5%) received respectively no drug, monotherapy, two-drug strategies and three and more drug strategies.

Conclusion

In patients admitted in cardiology departments, hypertension is a huge burden in SSA.

Funding Acknowledgement

Type of funding sources: None.

[Severe high blood pressure recently diagnosed in an urban milieu from Subsahelian Africa: Epidemiologic, clinical, therapeutic and evolutionary aspects]

OBJECTIVES

High Blood Pressure (HBP) is a worldwide public health problem. It can be particularly severe in the Black race. Recent studies in Cameroon, showed an alarming prevalence, leading us to want to study the epidemiological, clinical, therapeutic and evaluative aspects of severe, (BP op to 180/110mmHg), recently diagnosed HBP in Yaounde. Our objective was to determine its clinical presentation and evolution.

METHODS

We conducted nine months prospective cohort study, from January to September 2016. We recruited from the active population participants who voluntarily accepted blood pressure screening offered in various localities in Yaounde, and were aged from 18 years and above.

RESULTS

Of a total of 6519 people who participated in the screening, 1875 (28.8%.), presented a HBP and 363 (5.6%) had severe HBP. Our cohort comprised 153 (42.1%) of these individuals with sustained severe hypertension, not on medication, who accepted the invitation to participate in the study. The range of 45-54 years and 55-64 years were the most represented; the sex ratio was 0.9. The cardiovascular risk factors number range from 5 to 8 with a median of 6. Systolic BP ranged from 184 to 225mmHg with a median of 200mmHg; while the diastolic BP ranged between 111-132.5mmHg with a median of 119mmHg. Kidney injury (77.8%) was the main complications. We identified 3 clinical forms: hypertensive emergencies 121 (79.1%) cases and hypertensive crises 32 (20.9%) cases. In these two groups, 33 (21.6%) patients presented with "super HBP" (a blood pressure>250/150mmHg). The average rate of BP control over 6 month was 39%. The main cause of poor BP control was lack of therapeutic compliance. We registered one death at the 3rd month of follow up due to acute kidney injury.

CONCLUSION

Severe HBP prevalence in Yaounde is high in the active fraction of the population insidiously affected. Particularly, unsuspected renal impairment appears to be the major complication. The bad blood pressure control is linked to poor therapeutic observance and persistence.