Efficacy of newer versus older antihypertensive drugs in black patients living in sub-Saharan Africa

Blood pressure and the hypertension care cascade in The Gambia: Findings from a nationwide survey

Community treatment of hypertension in sub-Saharan Africa is hampered by gaps at several stages of the care cascade. We compared blood pressure (BP) levels (systolic, diastolic and pulse pressures) in four groups of participants by hypertension and treatment status. We conducted a nationally representative survey of adults 35 years and older using a multistage sampling strategy based on the 2013 Gambia Population and Housing Census. The BP measurements were taken in triplicate 5 min apart, and the average of the last two measurements was used for analysis. Systolic and diastolic BP levels and pulse pressure were compared by hypertension status using mean and 95% confidence intervals (CI). 53.1% of the sample were normotensive with mean systolic BP (SBP) of 119.2 mmHg (95% CI, 118.7-119.6) and diastolic BP (DBP) of 78.1 mmHg (77.8-78.3). Among individuals with hypertension, mean SBP was 148.7 mmHg (147.7-149.7) among those unaware of their hypertension, 152.2 mmHg (151.0-153.5) among treated individuals and was highest in untreated individuals at 159.3 mmHg (157.3-161.2). The findings were similar for DBP levels, being 93.9 mmHg (93.4-94.4) among the unaware, 95.1 mmHg (94.4-95.8) among the treated and highest at 99.1 mmHg (98.1-100.2) in untreated participants. SBP and DBP were higher in men, and SBP was as expected higher in those aged ≥55 years. BP level was similar in urban and rural areas. Our data shows high BP levels among participants with hypertension including those receiving treatment. Efforts to reduce the health burden of hypertension will require inputs at all levels of the care cascade.

Fixed-dose combination therapy-based protocol compared with free pill combination protocol: Results of a cluster randomized trial

Fixed-dose combination (FDC) therapy is recommended for hypertension management in Nigeria based on randomized trials at the individual level. This cluster-randomized trial evaluates effectiveness and safety of a treatment protocol that used two-drug FDC therapy as the second and third steps for hypertension control compared with a protocol that used free pill combinations. From January 2021 to June 2021, 60 primary healthcare centers in the Federal Capital Territory of Nigeria were randomized to a protocol using FDC therapy as second and third steps compared with a protocol that used the same medications in free pill combination therapy for these steps. Eligible patients were adults (≥18 years) with hypertension. The primary outcome was the odds of a patient being controlled at their last visit between baseline to 6-month follow-up in the FDC group compared to the free pill group. 4427 patients (mean [SD] age: 49.0 [12.4] years, 70.5% female) were registered with mean (SD) baseline systolic/diastolic blood pressure 155 (20.6)/96 (13.1) mm Hg. Baseline characteristics of groups were similar. After 6-months, hypertension control rate improved in the two treatment protocols, but there were no differences between the groups after adjustment (FDC = 53.9% versus free pill combination = 47.9%, cluster-adjusted p = .29). Adverse events were similarly low (<1%) in both groups. Both protocols improved hypertension control rates at 6-months in comparison to baseline, though no differences were observed between groups. Further work is needed to determine if upfront FDC therapy is more effective and efficient to improve hypertension control rates.

Initial combination therapy for hypertension in patients of African ancestry: a systematic review and meta-analysis

We systematically reviewed randomized controlled trials (RCTs) that consider the effect of initial dual antihypertensive combination treatment on blood pressure (BP), morbidity, or mortality in hypertensive African ancestry adults, using the methodology of the Cochrane Collaboration. Main outcomes were difference in means (continuous data) and risk ratio (dichotomous data).We retrieved 1728 reports yielding 13 RCTs of 4 weeks to 3 years duration (median 8 weeks) in 3843 patients. Systolic BP was significantly higher on β-adrenergic blocker vs. other combinations, 3.80 [0.82;6.78] mmHg, but comparable for other combinations. Hypokalemia and hyperglycemia occurred with calcium channel blocker (CCB) + diuretics > diuretics + angiotensin converting enzyme inhibitor (ACEI)/angiotensin-II-type-1-receptor antagonist (ARB) > CCB + ACEI/ARB. An RCT including high-risk patients reported combined morbidity/mortality for hydrochlorothiazide (mg) 25 + benazepril 40 vs. amlodipine 10 + benazepril 40 of respectively 8.9% vs. 6.6% (n = 1414, risk ratio 1.35 [0.94;1.94]; all patients, N = 11 506, 1.23 [1.11;1.37]).We conclude that limited evidence supports CCB + ACEI rather than HCT + ACEI as first-line initial combination therapy in African ancestry patients with hypertension.

PROSPERO

CRD42021238529.

Urinary proteomics combined with home blood pressure telemonitoring for health care reform trial: rational and protocol

BACKGROUND

Hypertension and diabetes cause chronic kidney disease (CKD) and diastolic left ventricular dysfunction (DVD) as forerunners of disability and death. Home blood pressure telemonitoring (HTM) and urinary peptidomic profiling (UPP) are technologies enabling prevention.

METHODS

UPRIGHT-HTM (Urinary Proteomics Combined with Home Blood Pressure Telemonitoring for Health Care Reform [NCT04299529]) is an investigator-initiated 5-year clinical trial with patient-centred design, which will randomise 1148 patients to be recruited in Europe, sub-Saharan Africa and South America. During the whole study, HTM data will be collected and freely accessible for patients and caregivers. The UPP, measured at enrolment only, will be communicated early during follow-up to 50% of patients and their caregivers (intervention), but only at trial closure in 50% (control). The hypothesis is that early knowledge of the UPP risk profile will lead to more rigorous risk factor management and result in benefit. Eligible patients, aged 55-75 years old, are asymptomatic, but have ≥5 CKD- or DVD-related risk factors, preferably including hypertension, type-2 diabetes, or both. The primary endpoint is a composite of new-onset intermediate and hard cardiovascular and renal outcomes. Demonstrating that combining UPP with HTM is feasible in a multicultural context and defining the molecular signatures of early CKD and DVD are secondary endpoints.

EXPECTED OUTCOMES

The expected outcome is that application of UPP on top of HTM will be superior to HTM alone in the prevention of CKD and DVD and associated complications and that UPP allows shifting emphasis from treating to preventing disease, thereby empowering patients.

The coArtHA trial-identifying the most effective treatment strategies to control arterial hypertension in sub-Saharan Africa: study protocol for a randomized controlled trial

BACKGROUND

Arterial hypertension is the most prevalent risk factor for cardiovascular disease in sub-Saharan Africa. Only a few and mostly small randomized trials have studied antihypertensive treatments in people of African descent living in sub-Saharan Africa.

METHODS

In this open-label, three-arm, parallel randomized controlled trial conducted at two rural hospitals in Lesotho and Tanzania, we compare the efficacy and cost-effectiveness of three antihypertensive treatment strategies among participants aged ≥ 18 years. The study includes patients with untreated uncomplicated arterial hypertension diagnosed by a standardized office blood pressure ≥ 140/90 mmHg. The trial encompasses a superiority comparison between a triple low-dose antihypertensive drug combination versus the current standard of care (monotherapy followed by dual treatment), as well as a non-inferiority comparison for a dual drug combination versus standard of care with optional dose titration after 4 and 8 weeks for participants not reaching the target blood pressure. The sample size is 1268 participants with parallel allocation and a randomization ratio of 2:1:2 for the dual, triple and control arms, respectively. The primary endpoint is the proportion of participants reaching a target blood pressure at 12 weeks of ≤ 130/80 mmHg and ≤ 140/90 mmHg among those aged < 65 years and ≥ 65 years, respectively. Clinical manifestations of end-organ damage and cost-effectiveness at 6 months are secondary endpoints.

DISCUSSION

This trial will help to identify the most effective and cost-effective treatment strategies for uncomplicated arterial hypertension among people of African descent living in rural sub-Saharan Africa and inform future clinical guidelines on antihypertensive management in the region.

TRIAL REGISTRATION

Clinicaltrials.gov NCT04129840 . Registered on 17 October 2019 ( https://www.clinicaltrials.gov/ ).

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

BACKGROUND

The highest burden of hypertension is found in Sub-Saharan Africa (SSA) with a threefold greater mortality from stroke and other associated diseases. Ethnicity is known to influence the response to antihypertensives, especially in black populations living in North America and Europe. We sought to outline the impact of all commonly used pharmacological agents on both blood pressure reduction and cardiovascular morbidity and mortality in SSA.

METHODS

We used similar criteria to previous large meta-analyses of blood pressure agents but restricted results to populations in SSA. Quality of evidence was assessed using a risk of bias tool. Network meta-analysis with random effects was used to compare the effects across interventions and meta-regression to explore participant heterogeneity.

RESULTS

Thirty-two studies of 2860 participants were identified. Most were small studies from single, urban centres. Compared with placebo, any pharmacotherapy lowered SBP/DBP by 8.51/8.04 mmHg, and calcium channel blockers (CCBs) were the most efficacious first-line agent with 18.46/11.6 mmHg reduction. Fewer studies assessing combination therapy were available, but there was a trend towards superiority for CCBs plus ACE inhibitors or diuretics compared to other combinations. No studies examined the effect of antihypertensive therapy on morbidity or mortality outcomes.

CONCLUSION

Evidence broadly supports current guidelines and provides a clear rationale for promoting CCBs as first-line agents and early initiation of combination therapy. However, there is a clear requirement for more evidence to provide a nuanced understanding of stroke and other cardiovascular disease prevention amongst diverse populations on the continent.

TRIAL REGISTRATION

PROSPERO, CRD42019122490. This review was registered in January 2019.

Office and Home Blood Pressures as Determinants of Electrocardiographic Left Ventricular Hypertrophy Among Black Nigerians Compared With White Flemish

BACKGROUND

The association of electrocardiographic left ventricular hypertrophy (ECG-LVH) with blood pressure (BP) in Blacks living in sub-Saharan Africa remains poorly documented.

METHODS

In 225 Black Nigerians and 729 White Flemish, we analyzed QRS voltages and voltage-duration products and 12 criteria diagnostic of ECG-LVH in relation to office BP (mean of 5 consecutive readings) and home BP (duplicate morning and evening readings averaged over 1 week).

RESULTS

In multivariable analyses, QRS voltage and voltage-duration indexes were generally higher in Blacks than Whites. By using any of 12 criteria, ECG-LVH was more prevalent among Black than White men (54.4% vs. 36.0%) with no ethnic difference among women (17.1%). Precordial voltages and voltage-duration products increased with office and home systolic BP (SBP), and increases were up to 3-fold steeper in Blacks. In Blacks vs. Whites, increases in the Sokolow–Lyon voltage associated with a 10-mm Hg higher SBP were 0.18 mV (95% confidence interval [CI], 0.09–0.26) vs. 0.06 mV (0.02–0.09) and 0.17 mV (0.07–0.28) vs. 0.11 mV (CI, 0.07–0.15) for office and home BP, respectively, with a significant ethnic gradient (P < 0.05). The risk of ECG-LVH increased more with office and home BP in Blacks than Whites.

CONCLUSIONS

Associations of ECG voltages and voltage-duration products and risk of ECG-LVH with BP are steeper in Black Nigerians compared with a White reference population. In resource-poor settings of sub-Saharan Africa, the ECG in combination with office and home BP is an essential instrument in risk stratification across the entire BP range.

Hypertension in Sub-Saharan Africa: A Contextual View of Patterns of Disease, Best Management, and Systems Issues

Sub-Saharan Africa (SSA) bears the highest burden of both communicable and noncommunicable disease and has the weakest health systems. Much attention is directed toward a rising burden of chronic disease in the setting of epidemiologic transition and urbanization. Indeed, the highest prevalence of hypertension globally is in the World Health Organization's African region at 46% of adults aged 25 and above. And while hypertension in SSA is common, its prevalence varies significantly between urban and rural settings. Although there is evidence for epidemiologic transition in urban areas, there is also evidence of static levels of hypertension within rural areas, which comprise more than 70% of the population of SSA. Furthermore, overall cardiovascular (CV) risk in rural areas remains low. The mean age of hypertensives in SSA is approximately 30s to 40s, burdening those at peak productivity. Complications of hypertension are frequent, given the poor levels of awareness and treatment (<10%) of hypertension on the continent. Such complications include primarily stroke and hypertensive heart disease, as ischemic heart disease is uncommon. Mortality associated with these complications is high, with in-hospital mortality from 2 different sites reported as around 20%. The overall burden of hypertension is likely to be more related to poor access and availability of health systems and is representative of a looming crisis in health care delivery. The best approaches to population-wide treatment are those that utilize CV risk prediction for those with stage 1 hypertension, whereas treatment is generally indicated for all those with stage 2 or greater hypertension, especially in light of the high burden of stroke in SSA. Current guidelines recommend first-line drug therapy with a diuretic or calcium channel blocker. Despite these recommendations, the major obstacles to hypertension treatment are systemic and include the availability and cost of medications, the adequacy of health facilities and systems, and the lack of health insurance to address affordability. New and innovative systems-oriented approaches are needed to address the burden of hypertension on a platform of global equity.

Nigerian Population Research on Environment, Gene and Health (NIPREGH) - objectives and protocol

Sub-Saharan Africa is currently undergoing an epidemiological transition from a disease burden largely attributable to communicable diseases to that resulting from a combination of both communicable and chronic non-communicable diseases. Data on chronic disease incidence, lifestyle, environmental and genetic risk factors are sparse in this region. This report aimed at providing relevant information in respect to risk factors that increase blood pressure and lead to development of intermediate cardiovascular phenotypes. We presented the rationale, objectives and key methodological features of the Nigerian Population Research on Environment, Gene and Health (NIPREGH) study. The challenges encountered in carrying out population study in this part of the world and the approaches at surmounting them were also presented. The preliminary data as at 20 November 2013 showed that out of the 205 individuals invited starting from early April 2013, 160 (72 women) consented and were enrolled; giving a response rate of 78%. Participants' age ranged from 18 to 80 years, with a mean (SD) of 39.8 (12.4) years and they were of 34 different ethnic groups spread over 24 states out of the 36 states that constitute Nigeria. The mean (SD) of office and home blood pressures were 113.0 (15.2) mm Hg systolic, 73.5 (12.5) mm Hg diastolic and 117.3 (15.0) mm Hg systolic, and 76.0 (9.6) mm Hg diastolic, respectively. Forty-three (26.8%) participants were hypertensive and 8 (5.0%) were diabetic. In addition to having the unique potential of recruiting a cohort that is a true representative of the entire Nigerian population, NIPREGH is feasible and the objectives realisable.

Heart rate variability on antihypertensive drugs in black patients living in sub-Saharan Africa

Background

Compared with Caucasians, African Americans have lower heart rate variability (HRV) in the high-frequency domain, but there are no studies in blacks born and living in Africa.

Methods

In the Newer versus Older Antihypertensive agents in African Hypertensive patients trial (NCT01030458), patients (30–69 years) with uncomplicated hypertension (140–179/90–109 mmHg) were randomized to single-pill combinations of bisoprolol/hydrochlorothiazide (R) or amlodipine/valsartan (E). 72 R and 84 E patients underwent 5-min ECG recordings at randomization and 8, 16 and 24 weeks. HRV was determined by fast Fourier transform and autoregressive modelling.

Results

Heart rate decreased by 9.5 beats/min in R patients with no change in E patients (− 2.2 beats/min). R patients had reduced total (− 0.13 ms²; p = 0.0038) and low-frequency power (− 3.6 nu; p = 0.057), higher high-frequency (+ 3.3 nu; p = 0.050) and a reduced low- to high-frequency ratio (− 0.08; p = 0.040). With adjustment for heart rate, these differences disappeared, except for the reduced low-frequency power in the R group (− 4.67 nu; p = 0.02). Analyses confined to 39 R and 47 E patients with HRV measurements at all visits or based on autoregressive modelling were confirmatory.

Conclusion

In native black African patients, antihypertensive drugs modulate HRV, an index of autonomous nervous tone. However, these effects were mediated by changes in heart rate except for low-frequency variability, which was reduced on beta blockade independent of heart rate.