Pharmacotherapy for hypertension in Sub-Saharan Africa: a systematic review and network meta-analysis

Effectiveness of community-based interventions for prevention and control of hypertension in sub-Saharan Africa: A systematic review

Hypertension poses a significant public health challenge in sub-Saharan Africa due to various risk factors. Community-based intervention for prevention and control of hypertension is an effective strategy to minimize the negative health outcomes. However, comprehensive systematic review evidence to inform effective community-based interventions for prevention and control of hypertension in low resource settings is lacking. This study aimed to synthesize the effectiveness of community-based interventions on prevention and control of hypertension in sub-Saharan Africa. A comprehensive search for studies was carried out on PubMed, CINAHL, Web of Science Core Collection, Embase, Scopus, and Google scholar databases. The result of the review was reported according to PRISMA guidelines. Studies published in English language were included. Two independent reviewers conducted critical appraisal of included studies and extracted the data using predefined excel sheet. Experimental, quasi experimental, cohort and analytical cross-sectional studies conducted on adults who have received community-based interventions for prevention and controls of hypertension in sub-Saharan Africa were included. In this systematic review, a total of eight studies were included, comprising of two interventional studies, two quasi-experimental studies, three cohort studies, and one comparative cross-sectional study. The interventions included health education, health promotion, home-based screening and diagnosis, as well as referral and treatment of hypertensive patients. The sample sizes ranged from 236 to 13,412 in the intervention group and 346 to 6,398 in the control group. This systematic review shows the effect of community-based interventions on reduction of systolic and diastolic blood pressure. However, the existing evidence is inconsistence and not strong enough to synthesize the effect of community-based interventions for the prevention and control of hypertension in sub-Saharan Africa. Hence, further primary studies need on the effect of community-based interventions for the prevention and control of hypertension in sub-Saharan Africa. Systematic review registration number: PROSPERO CRD42022342823.

Genetic Variation in ABCB1, ADRB1, CYP3A4, CYP3A5, NEDD4L and NR3C2 Confers Differential Susceptibility to Resistant Hypertension among South Africans

Resistant hypertension (RHTN) prevalence ranges from 4 to 19% in Africa. There is a paucity of data on the role of genetic variation on RHTN among Africans. We set out to investigate the role of polymorphisms in ABCB1, ADRB1, CYP3A4, CYP3A5, NEDD4L, and NR3C2, on RHTN susceptibility among South Africans. Using a retrospective matched case-control study, 190 RHTN patients (cases: blood pressure (BP) ≥ 140/90 mmHg on ≥3 anti-hypertensives or BP < 140/90 mmHg on >3 anti-hypertensives) and 189 non-RHTN patients (controls: <3 anti-hypertensives, BP < 140/90 or ≥140/90 mmHg), 12 single nucleotide polymorphisms were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), quantitative PCR and Sanger sequencing. Genetic association analyses were conducted using the additive model and multivariable logistic regression. Homozygosity for CYP3A5 rs776746C/C genotype (p = 0.02; OR: 0.44; CI: 0.22-0.89) was associated with reduced risk for RHTN. Homozygous ADRB1 rs1801252G/G (p = 0.02; OR: 3.30; CI: 1.17-10.03) and NEDD4L rs4149601A/A genotypes (p = 0.001; OR: 3.82; CI: 1.67-9.07) were associated with increased risk for RHTN. Carriers of the of ADRB1 rs1801252-rs1801253 G-C haplotype had 2.83-fold odds of presenting with RHTN (p = 0.04; OR: 2.83; CI: 1.05-8.20). These variants that are associated with RHTN may have clinical utility in the selection of antihypertensive drugs in our population.

Update of the clinical guideline for hypertension diagnosis and treatment in Iran

BACKGROUND

This article introduces the updated version of the Iranian guideline for the diagnosis and treatment of hypertension in adults. The initial version of the national guideline was developed in 2011 and updated in 2014. Among the reasons necessitating the update of this guideline were the passage of time, the incompleteness of the scopes, the limitation of the target group, and more important is the request of the ministry of health in Iran.

METHOD

The members of the guideline updating group, after reviewing the original version and the new evidence, prepared 10 clinical questions regarding hypertension, and based on the evidence found from the latest scientific documents, provided recommendations or suggestions to answer these questions.

RESULT

According to the updated guideline, the threshold for office prehypertension diagnosis should be considered the systolic blood pressure (SBP) of 130-139 mmHg and/or the diastolic blood pressure (DBP) of 80-89 mmHg, and in adults under 75 years of age without comorbidities, the threshold for office hypertension diagnosis should be SBP ≥ 140 mmHg and or DBP ≥ 90 mmHg. The goal of treatment in adults who lack comorbidities and risk factors is SBP < 140 mmHg and DBP < 90 mmHg. The first-line treatment recommended in people with prehypertension is lifestyle modification, while for those with hypertension, pharmacotherapy along with lifestyle modification. The threshold to start drug therapy is determined at SBP ≥ 140 mmHg and or DBP ≥ 90 mmHg, and the first-line treatment is considered a drug or a combined pill of antihypertensive drugs, including ACEIs, ARBs, thiazide and thiazide-like agents, or CCBs. At the beginning of the pharmacotherapy, the Guideline Updating Group members suggested studying serum electrolytes, creatinine, lipid profile, fasting sugar, urinalysis, and an electrocardiogram. Regarding the visit intervals, monthly visits are suggested at the beginning of the treatment or in case of any change in the type or dosage of the drug until achieving the treatment goal, followed by every 3-to-6-month visits. Moreover, to reduce further complications, it was suggested that healthcare unit employees use telehealth strategies.

CONCLUSIONS

In this guideline, specific recommendations and suggestions have been presented for adults and subgroups like older people or those with cardiovascular disease, diabetes mellitus, chronic kidney disease, and COVID-19.

Examining the referral of patients with elevated blood pressure to health resources in an under-resourced community in South Africa

BACKGROUND

Low-and-middle income countries face a disproportionate burden of non-communicable diseases (NCDs) that threaten to overwhelm under-resourced health systems. Community health workers (CHWs) can promote NCD prevention, reach patients, and connect them to local community health resources; however, little has been done to examine how referrals to these resources are utilized by community members. The purpose of this study is to examine the use of referrals to community-based health resources and investigate the factors influencing patient utilization of referrals connecting them to appropriate health resources for elevated blood pressure (BP).

METHODS

CHWs conducted home visits, which included BP screening and brief counseling, with community members in Soweto, South Africa. Participants with elevated (systolic BP: 121-139/ diastolic BP: 81-89 mmHg) or high (≥ 140/90 mmHg) BP were referred to either a local, community-based physical activity (PA) program managed by a non-governmental organization or local health clinics. The number of participants that received and utilized their referrals was tracked. Follow-up interviews were conducted with individuals given a referral who: (1) went to the PA program, (2) did not go to the PA program, (3) went to a clinic, and (4) did not go to a clinic. Interviews were transcribed and analyzed to identify common themes and differences between groups regarding their decisions to utilize the referrals.

RESULTS

CHWs visited 1056 homes, with 1001 community members consenting to the screening; 29.2% (n = 292) of adults were classified as having optimal BP (≤120/80 mmHg), 35.8% (n = 359) had elevated BP, and 35.0% (n = 350) had high BP. One hundred and seventy-three participants accepted a referral to the PA program with 46 (26.6%) enrolling. Five themes emerged from the interviews: (1) prior knowledge and thoughts on BP, (2) psychosocial factors associated with BP control, (3) perception about receiving the referral, (4) contextual factors influencing referral utilization, and (5) perceived benefits of utilizing the referral.

CONCLUSION

CHWs can successfully increase community members' access to health resources by providing appropriate referrals. However, greater attention needs to address community members' barriers and hesitancy to utilize health resources.

Real-World Effectiveness and Safety of Two-Drug Single Pill Combinations of Antihypertensive Medications for Blood Pressure Management: A Follow-Up on Daily Cardiology Practice in Douala, Cameroon

INTRODUCTION

Hypertension is the leading cause of morbidity and mortality in sub-Saharan Africa (SSA). Current guidelines recommend using two or more antihypertensive agents in single pill combinations (SPCs) to treat hypertension, but data from African patients that support these recommendations are lacking. We assessed the effectiveness and tolerance of three SPCs in lowering blood pressure (BP) amongst hypertensive patients in Douala.

METHOD

All patients included in the hypertension registry of the Douala General Hospital and the Douala Cardiovascular Center between January 2010 and May 2020, and receiving a two-drug SPCs (renin-angiotensin system inhibitors (RAASi) + diuretics (DIU), calcium channel blockers (CCB) + RAASi, or DIU + CCB) were tracked from baseline through 16 weeks. Our primary outcome was a decrease in systolic BP (SBP) from baseline up to 16 weeks after initiation of treatment. A mixed linear repeated model was used to evaluate the change of SBP from baseline to week 16, while controlling for age, gender, and baseline SBP. Statistical significance was set at p < 0.05.

RESULTS

Of 377 participants on two-drug SPCs, 123 were on CCB + DIU, 96 on RAASi + CCB, and 158 on RAASi + DIU. The mean age was 54.6 (± 11.2) years. At baseline, participants on RAASi + CCB presented with slightly higher SBP compared to the other two groups. Overall, the SBP decreased by 34.3 (± 14.2) mmHg from baseline values and this was comparable across the three groups of SPCs (p = 0.118). The control rate after 16 weeks of follow-up was 62.3% with no significant difference between groups. The occurrence of adverse events was 3.4% and was comparable among the three groups.

CONCLUSION

The three two-drug SPCs were highly effective in reducing and controlling BP with low and similar rates of adverse effects. Long-term data documenting safety and whether these agents exert a differential cardiovascular effect in addition to and independent of their BP-lowering effect are needed for SSA populations.

Blood pressure-lowering medication prescribing, its adherence to guidelines and relationship with blood pressure control at a family medicine department

Background

In many resource-constrained countries, control of blood pressure (BP) is low. Antihypertensive drug prescribing practices may influence BP control. However, adherence of prescribing to treatment guidelines may not be optimal in resource-constrained settings. The aim of this study was to evaluate the pattern of blood pressure-lowering medication prescribing, and how it adheres to treatment guidelines, and to identify the relationship between medication prescriptions and BP control.

Methods

It was a cross-sectional study of hypertensive outpatients at the Korle Bu Teaching Hospital (KBTH) Family Medicine department (FMD)/Polyclinic. Data was collected with a validated structured form. Adherence of "prescribing" to recommendations of the 2017 Standard Treatment Guidelines of Ghana and 2018 European Society of Cardiology guidelines was assessed using a composite measure. We analyzed data with SPSS.

Results

About 81% (247/304) of patients received two or more antihypertensive drugs. Most patients (41%; 267/651) received calcium channel blockers (CCB), and 21.8% (142/651), 15.7% (102/651) and 12.7% (83/651) were on diuretics, angiotensin-receptor blockers (ARBs) and angiotensin converting enzyme (ACE) inhibitors respectively. CCB plus RAS inhibitor (50%) was the most prescribed two-drug combination. Number of BP drugs per patient had a statistically significant inverse relationship with BP control (beta Coefficient = -0.402; 95% Cl: 1.252-2.470; p = 0.015). The composite adherence score was 0.73 (moderate adherence) but Single-pill combination (SPC) was poor (3.2%; n = 8).

Conclusion

Most patients received multiple-pill combination treatment, and overall adherence to guidelines was suboptimal, largely owing to complex drug therapy. Number of drugs predicted BP control. Our findings suggest a need to prioritize simplified treatment, and implement other strategies to improve hypertension guideline adherence. Further research on the influence of SPC on BP control may inform future hypertension guidelines in Ghana and elsewhere in Africa.

Integrated multi-month dispensing of antihypertensive and antiretroviral therapy to sustain hypertension and HIV control

Multi-month dispensing (MMD) is a patient-centered approach in which stable patients receive medicine refills of three months or more. In this pre-post longitudinal study, we determined hypertension and HIV treatment outcomes in a cohort of hypertensive PLHIV at baseline and 12 months of receiving integrated MMD. At each clinical encounter, one healthcare provider attended to both hypertension and HIV needs of each patient in an HIV clinic. Among the 1,082 patients who received MMD, the mean age was 51 (SD = 9) years and 677 (63%) were female. At the start of MMD, 1,071(98.9%) patients had achieved HIV viral suppression, and 767 (73.5%) had achieved hypertension control. Mean blood pressure reduced from 135/87 (SD = 15.6/15.2) mmHg at the start of MMD to 132/86 (SD = 15.2/10.5) mmHg at 12 months (p < 0.0001). Hypertension control improved from 73.5% to 78.5% (p = 0.01) without a significant difference in the proportion of patients with HIV viral suppression at baseline and at 12 months, 98.9% vs 99.0% (p = 0.65). Patients who received MMD with elevated systolic blood pressure at baseline were less likely to have controlled blood pressure at 12 months (OR-0.9, 95% CI, 0.90,0.92). Overall, 1,043 (96.4%) patients were retained at 12 months. Integrated MMD for stable hypertensive PLHIV improved hypertension control and sustained optimal HIV viral suppression and retention of patients in care. Therefore, it is feasible to provide integrated MMD for both hypertension and HIV treatment and achieve dual control in the setting of sub-Saharan Africa.

In-hospital outcomes of patients with a hypertensive emergency at a medical center, Ethiopia: A prospective observational study

Background

Hypertensive emergency is associated with substantial complications and loss of life across the world. Early identification and treatment of hypertensive emergency complications are critical to prevent or avoid any consequences. Despite this, in Ethiopia, studies addressing mortality rate and its predictors as well as complications of hypertensive emergency are limited.

Aims

This study aim to evaluate in-hospital mortality of patients admitted with a hypertensive emergency at the emergency ward of Jimma Medical Center.

Methods

A consecutive sample of 140 adult (≥18 years of age) patients with a hypertensive emergency were recruited from September 1, 2020 to February 25, 2021 at Jimma Medical Center, Ethiopia and were followed up from admission to discharge/death. Patients who declined to participate and readmitted during the study period were excluded. To assess factors associated with in-hospital mortality, bivariate and multivariate Cox regression analyses were performed. A p value of less than 0.05 was used to declare the statistical significance.

Results

Over three-fourths of the study participants, that is, 108 (77.1%), were males with a mean (±standard deviation) age of 52.8 ± 13.6 years. Hemorrhagic stroke, 53 (38.0%), and acute kidney injury, 38 (27.1%), were the most common complications of hypertensive emergency. The average (±standard deviation) length of stay in the hospital was 8.53 ± 3.61 days. During in-hospital follow-up, 16 patients (11.4%, 95% confidence interval: 6.7-17.9) died. Multivariate Cox regression analysis showed that there was a significant relationship between patients not doing regular physical exercise before the current admission (adjusted hazard ratio = 4.629, 95% confidence interval: 1.171-18.294, p = 0.015) and in-hospital mortality.

Conclusion

More than one-tenth of patients with hypertensive emergency death was recorded at Jimma Medical Center. The frequent complications of hypertensive emergency were hemorrhagic stroke and acute renal injury. Not doing regular physical exercise before the current admission raises the likelihood of in-hospital death. Therefore, strengthening and encouraging patients to perform regular physical exercise is imperative.

Use of Perindopril Arginine/Indapamide/Amlodipine in the Management of Hypertension in Two Sub-Saharan African Island Countries of Madagascar and Mauritius

INTRODUCTION

Most patients with hypertension in sub-Saharan Africa require two or more drugs to control their blood pressure. Triple fixed-dose combination therapy of perindopril arginine/indapamide/amlodipine is more effective in lowering blood pressure, offers better target organ protection and has increased adherence compared to monotherapy and free combination therapy, and is safe to use. This observational study evaluates the effectiveness of perindopril arginine/indapamide/amlodipine in controlling blood pressure at least 1 month after treatment initiation and assesses patient- and physician- reported drug tolerance over a 3-month period in Madagascar and Mauritius.

METHODS

A total of 198 patients with hypertension in ambulatory care who had been on fixed-dose combination of perindopril arginine, indapamide, and amlodipine for at least 4 weeks were included. The main outcome measures were changes in systolic and diastolic blood pressure, attainment of blood pressure control under 140/90 mmHg and 130/80 mmHg, self-reported drug tolerance by the patient, and perceived drug tolerance by the treating physician. Data was collected at 1 month and 3 months.

RESULTS

Mean systolic blood pressure was significantly lower at the 1-month (- 3.4 mmHg, p = 0.002) and 3-month (- 8.5 mmHg, p < 0.0001) visits. Diastolic blood pressure also decreased significantly (- 2.4 mmHg at 1-month, p = 0.017 and - 5.4 mmHg at the 3-month visits, p < 0.0001). At 3 months, 80.4% of the patients attained blood pressure targets less than 140/90 mmHg and 42.7% attained targets less than 130/80 mmHg on the basis of their baseline blood pressure. Excellent drug tolerance was reported by more than 90% of patients and physicians at the 1-month visit and by more than 95% at the 3-month visit.

CONCLUSION

Triple fixed-dose therapy of perindopril arginine/indapamide/amlodipine continues to show additional blood pressure-lowering capacity even months after initiating the treatment in patients with hypertension in Madagascar and Mauritius. It is also well tolerated by patients with hypertension and assessed as safe to use by physicians.

Non-pharmacological interventions to achieve blood pressure control in African patients: a systematic review

OBJECTIVES

This systematic review aims to evaluate the evidence of non-pharmacological strategies to improve blood pressure (BP) control in patients with hypertension from African countries.

DESIGN

We performed a systematic review and searched Medline, Central, CINAHL and study registers until June 2020 for randomised studies on interventions to decrease BP of patients with hypertension in African countries. We assessed the study quality using the Cochrane risk of bias tool and narratively synthesised studies on non-pharmacological hypertension interventions.

SETTING

We included studies conducted in African countries.

PARTICIPANTS

Adult African patients with a hypertension diagnosis.

INTERVENTIONS

Studies on non-pharmacological interventions aiming to improve BP control and treatment adherence.

OUTCOMES

Main outcomes were BP and treatment adherence.

RESULTS

We identified 5564 references, included 23 with altogether 18 153 participants from six African countries. The studies investigated educational strategies to improve adherence (11 studies) and treatment by healthcare professionals (5 studies), individualised treatment strategies (2 studies), strategies on lifestyle including physical activity (4 studies) and modified nutrition (1 study). Nearly all studies on educational strategies stated improved adherence, but only three studies showed a clinically relevant improvement of BP control. All studies on individualised strategies and lifestyle changes resulted in clinically relevant effects on BP. Due to the type of interventions studied, risk of bias in domain blinding of staff/participants was frequent (83%). Though incomplete outcome data in 61% of the studies are critical, the general study quality was reasonable.

CONCLUSIONS

The identified studies offer diverse low-cost interventions including educative and task-shifting strategies, individualised treatment and lifestyle modifications to improve BP control. Especially trialled physical activity interventions show clinically relevant BP changes. All strategies were trialled in African countries and may be used for recommendations in evidence-based guidelines on hypertension in African settings.

PROSPERO REGISTRATION NUMBER

CRD42018075062.

Pathophysiologically based antihypertensive pharmacotherapeutics rationality, efficacy and safety in Sub Saharan African Nations – A review

Background

Hypertension (HT) prevalence, Uncontrolled Blood Pressure (UBP), morbidity and mortality are highest in Sub-Saharan Africa (SSA). Correlating pathophysiology of HT to pharmaco-therapy with antihypertensive drugs (AHD) may bring amelioration. Aims:To review peculiarities of HT in SSA, UBP causes, diagnostic modalities, AHD use, rationality and efficacy.

Methods and results

14 published therapeutic audits in 4 SSA nations on Google Scholar or PUBMED, (total n = 6496 patients) were evaluated. Calcium Channel blockers (CCB) amlodipine, and thiazide diuretics (TD), hydrochlorothiazide (HCTZ) were the commonest AHD. Thiazide Like Diuretics (TLD) were underutilized. The % of patients on AHD were: 1 drug 5.4–55%; 2 drugs 37–82%; >/ = 3 drugs 6–50.3%. 2-drug combinations were: ACEI/ARB + TD (42%); CCB + TD (36.8%); ACEI + CCB (15.8%) of studies. Triple/quadruple therapy included Methyldopa (MTD) with ACEI + CCB or TD. The (%) attaining BP < 140/< 90 mmHg, ranged from 29 to 53.6%, median, 44%. The co-morbidities, range and median were: Diabetes Mellitus (DM): 9.8–64%, 19.2%; Chronic Kidney Disease (CKD): 5.7–7.5%, 6.9%, and Coronary artery Disease (CAD): 0.9–2.6%, 2.3%. ACEI + CCB ± TD were the preferred AHD for comorbidities.

Conclusions

Therapeutic inertia; Non-compliance; co-morbidities; refractory HT; ignorance; substandard AHD; contribute to UBP. Studies relating 24 hour ABPM to complications and mortality in SSA hypertensives; and impact of different AHD classes on ABPM, are needed. Study of ACEI + alpha-₁ blockers + TLD on 24 hour ABPM and personalized care, are required.

Preclinical Evaluation of the Antihypertensive Effect of an Aqueous Extract of Anogeissus leiocarpa (DC) Guill et Perr. Bark of Trunk in L-NAME-Induced Hypertensive Rat

BACKGROUND

The present study investigates the effect of an aqueous extract of Anogeissus leiocarpa (AEAL) on normotensive Wistar rats and its chronic antihypertensive effects in L-NAME-induced hypertensive rats by using a non-invasive tail-cuff model.

METHODS

The effects of AEAL (50mg/kg) and NaCl 0.9% on blood pressure were investigated by daily oral administration in normotensive Wistar rats over four weeks. L-NAME-induced hypertensive rats were produced by L-NAME (40mg/kg) daily oral administration for two weeks. For chronic antihypertensive effects, induced hypertensive rats have received L-NAME in combination with AEAL (10 or 50mg/kg/day) for two following weeks.

RESULTS

In normotensive rats, daily administration of AEAL (50mg/kg) has no significant effect on their blood pressure, which was similar to that of the control group. L-NAME's daily oral administration induces a progressive increase in systolic blood pressure (SBP) from 115.8 ± 7.9mmHg to 153.5 ± 4.6mmHg after two weeks, which was maintained to the end of the treatment. In L-NAME-induced hypertensive rats, AEAL (50mg/kg/day) significantly decreases the SPB from 160.0 ± 5.8 mmHg to 108.8 ± 2.7mmHg after only four days of administration. However, the lower dose of AEAL (10mg/kg) also normalized the SBP of L-NAME-induced hypertensive rats but only evident after seven days of administration. Moreover, AEAL does not effect on the serum biochemical parameters (ALAT, ASAT, CREAT, etc.) and any macroscopic adverse effect was detected on the sensible organs involved during hypertension. In the aorta rings from treated rats, AEAL (50mg/kg/day) alone or in combination with L-NAME has enhanced the vasodilation effect of acetylcholine. However, the vasodilation effect of AEAL alone or in association with L-NAME has enhanced the sodium nitroprusside effect in treated rat aorta rings after autopsy.

CONCLUSION

These findings suggest that AEAL affords significant antihypertensive effects against L-NAME-induced hypertensive rats without modification of serum parameters and deleterious effects.