Apparent Treatment Resistant Hypertension Among Stroke Survivors in Ghana

A Systematic Review of the Burden of Stroke in Ghana

Background: Stroke is considered a significant public health concern in sub-Saharan Africa and Ghana due to its impact on quality of life. However, there is a lack of comprehensive pooled data on the prevalence and incidence rates of stroke in Ghana. Updating this information would help inform decision-making bodies on measures to reduce the burden of stroke in Ghana. This systematic review is aimed at critically appraising evidence gathered from studies done in Ghana on the prevalence and incidence rates of stroke among the Ghanaian population. Method: Four databases (CINAHL via EBSCOhost, Web of Science, MEDLINE via PubMed, and PsycINFO via EBSCOhost) were searched, for articles published between May 2000 and May 2020 on stroke burden. The search was constrained to studies conducted in Ghana and published in English that have been peer reviewed. Cochrane risk of bias tool was used to assess the quality of evidence. Meta-analysis was conducted to estimate the pooled stroke prevalence and incidence in the country. Results: A total of three studies that documented 12,974 stroke cases in 1,197,498 participants based on the inclusion criteria were reviewed. The meta-analysis revealed that the overall national prevalence and incidence rate of stroke for the country were 7.96% and 1.17%, respectively, calculated at 95% confidence intervals. Conclusion: According to the review findings, the incidence and prevalence rates of stroke are high in Ghana or among the Ghanaian population, and they are increasing.

Stroke occurrence by hypertension treatment status in Ghana and Nigeria: A case-control study

BACKGROUND

Hypertension is preeminent among the vascular risk factors for stroke occurrence. The wide gaps in awareness, detection, treatment, and control rates of hypertension are fueling an epidemic of stroke in sub-Saharan Africa.

PURPOSE

To quantify the contribution of untreated, treated but uncontrolled, and controlled hypertension to stroke occurrence in Ghana and Nigeria.

METHODS

The Stroke Investigative Research and Educational Network (SIREN) is a case-control study across 16 study sites in Ghana and Nigeria. Cases were acute stroke (n = 3684) with age- and sex-matched stroke-free controls (n = 3684). We evaluated the associations of untreated hypertension, treated but uncontrolled hypertension, and controlled hypertension at BP of <140/90 mmHg with risk of stroke occurrence. We assessed the adjusted odds ratio and population-attributable risk of hypertension treatment control status associated with stroke occurrence.

RESULTS

The frequencies of no hypertension, untreated hypertension, treated but uncontrolled hypertension and controlled hypertension among stroke cases were 4.0%, 47.7%, 37.1%, and 9.2% vs 40.7%, 34.9%, 15.9%, and 7.7% respectively among stroke-free controls, p < 0.0001. The aOR and PAR (95% CI) for untreated hypertension were 6.58 (5.15-8.41) and 35.4% (33.4-37.4); treated but uncontrolled hypertension was 9.95 (7.60-13.02) and 35.9% (34.2-37.5); and controlled hypertension 5.37 (3.90-7.41) and 8.5% (7.6-9.5) respectively. Untreated hypertension contributed a PAR of 47.5% to the occurrence of intracerebral hemorrhage vs 29.5% for ischemic stroke. The aOR of untreated hypertension for stroke occurrence was 13.31 (7.64-23.19) for <50 years; 7.14 (4.51-11.31) for 50-64 years; and 3.48 (2.28-5.30) for 65 years or more.

CONCLUSION

The contribution of untreated hypertension and treated but uncontrolled hypertension to stroke occurrence among indigenous Africans is substantial. Implementing targeted interventions that address gaps in hypertension prevention and treatment, involving the local population, healthcare providers, and policymakers, can potentially substantially reduce the escalating burden of strokes in Africa.

Determinants of visit-to-visit systolic blood pressure variability among Ghanaians with hypertension and diabetes mellitus

Objective

To identify the determinants of systolic blood pressure variability (SBPV) among Ghanaians.

Design

We undertook a secondary analysis of data collected in a prospective study.

Setting

The study involved patients with hypertension and or diabetes receiving care in five hospitals in Ghana.

Main outcome measures

We assessed determinants of SBPV among 2,785 Ghanaian patients. We calculated the standard deviation (SD) of systolic BP recordings of 3 to 10 visits per patient over 18 months as a measure of SBPV. A multivariate linear regression analysis was fitted to identify factors independently associated with risk visit-to-visit SBP standard deviation.

Results

The mean SD of individual patient visit-to-visit SBP overall was 14.8± 6.3 mm Hg. Those with hypertension and diabetes had the highest SD of 15.4 ±6.2 mm Hg followed by 15.2 ±6.5 mm Hg among those with hypertension only and then 12.0 ± 5.2 mm Hg among those with diabetes only, p<0.0001. Factors independently associated with SBPV with adjusted β coefficients (95% CI) included age: 0.06 (0.03 - 0.08) for each year rise in age, eGFR -0.03 (-0.05 - -0.02) for each ml/min rise, low monthly income of <210 Ghana cedis 1.45 (0.43-2.46), and secondary level of education -1.10 (-1.69, -0.50). Antihypertensive classes were associated with SBPV, the strongest associations being hydralazine 2.35 (0.03 - 4.68) and Methyldopa 3.08 (2.39 - 3.77).

Conclusion

Several socio-demographic and clinical factors are associated with SBPV. Future studies should assess the contribution of SBPV to CVD outcomes among indigenous Africans and identify actionable targets.

Funding

Funding for this study was provided by MSD, Novartis, Pfizer, Sanofi (each a Participant Company) and the Bill and Melinda Gates Foundation (collectively, the Funders) through the New Venture Fund (NVF). FSS and BO are also supported by funding from the National Heart, Lung, and Blood Institute (R01HL152188).

Promise of Physiological Profiling to Prevent Stroke in People of African Ancestry: Prototyping Ghana

PURPOSE OF REVIEW

Worldwide, compared to other racial/ethnic groups, individuals of African ancestry have an excessively higher burden of hypertension-related morbidities, especially stroke. Identifying modifiable biological targets that contribute to these disparities could improve global stroke outcomes. In this scoping review, we discuss how pathological perturbations in the renin-angiotensin-aldosterone pathways could be harnessed via physiological profiling for the purposes of improving blood pressure control for stroke prevention among people of African ancestry.

RECENT FINDINGS

Transcontinental comparative data from the USA and Ghana show that the prevalence of treatment-resistant hypertension among stroke survivors is 42.7% among indigenous Africans, 16.1% among African Americans, and 6.9% among non-Hispanic Whites, p < 0.0001. A multicenter clinical trial of patients without stroke in 3 African countries (Nigeria, Kenya, and South Africa) demonstrated that physiological profiling using plasma renin activity and aldosterone to individualize selection of antihypertensive medications compared with usual care resulted in better blood pressure control with fewer medications over 12 months. Among Ghanaian ischemic stroke survivors treated without renin-aldosterone profiling data, an analysis revealed that those with low renin phenotypes did not achieve any meaningful reduction in blood pressure over 12 months on 3-4 antihypertensive medications despite excellent adherence. For a polygenic condition such as hypertension, individualized therapy based on plasma renin-aldosterone-guided selection of therapy for uncontrolled BP following precision medicine principles may be a viable strategy for primary and secondary stroke prevention with the potential to reduce disparities in the poor outcomes of stroke disproportionately shared by individuals of African ancestry. A dedicated clinical trial to test this hypothesis is warranted.

Apparent Treatment-Resistant Hypertension Among Stroke Survivors: A Transcontinental Study Assessing Impact of Race and Geography

BACKGROUND

Race and geographic differences in the prevalence and predictors of hypertension in stroke survivors have been reported, but apparent treatment-resistant hypertension (aTRH) among stroke survivors by race (African ancestry vs. non-Hispanic Caucasians) and by geography (continental Africa vs. the United States) are under studied.

METHODS

This is a cross-sectional study using ethically approved stroke registries from the University of Florida and the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. Univariate and multivariate regression was used to evaluate for differences in prevalence of aTRH and associations with clinical covariates.

RESULTS

Harmonized data were available for 3,365 stroke survivors of which 943 (28.0%) were indigenous Africans, 558 (16.6%) African Americans, and 1,864 (55.4%) non-Hispanic Caucasians with median ages (interquartile range) of 59 (49-68), 61 (55-72), and 70 (62-78) years, P < 0.0001. The overall frequency of aTRH was 18.5% (95% confidence interval [CI]: 17.2%-19.8%) with 42.7% (95% CI: 39.6%-46.0%) among indigenous Africans, 16.1% (95% CI: 13.2%-19.5%) among African Americans, and 6.9% (95% CI: 5.8%-8.2%) among non-Hispanic Caucasians, P < 0.0001. Five factors associated with aTRH: age, adjusted odds ratio (95% CI) of 0.99 (0.98-0.99), female sex 0.70 (0.56-0.87), cigarette smoking 1.98 (1.36-2.90), intracerebral hemorrhage 1.98 (1.57-2.48), and Black race namely indigenous Africans 4.42 (3.41-5.73) and African Americans 2.44 (1.81-3.29).

CONCLUSIONS

Future studies are needed to investigate the contribution of socioeconomic disparities in the prevalence aTRH in those with African Ancestry to explore the long-term impact, and evaluate effective therapeutic interventions in this subpopulation.

Key determinants of long-term post-stroke mortality in Ghana

BACKGROUND

Stroke affects a predominantly young to middle-aged population in Africa and is associated with poor outcomes. There are limited data on patient-level determinants of long-term stroke survival on the continent.

PURPOSE

To assess factors associated with long-term, all-cause mortality among stroke survivors in a Ghanaian medical system.

METHODS

We analyzed the dataset of clinical trial involving hypertensive stroke survivors (n = 60) who enrolled in a 9-month study primarily assessing the effect of an m-health intervention on blood pressure control. This was a single tertiary center study conducted in a Ghanaian medical center. Participants or relatives were contacted by a phone call to assess vital status 4.5 years after stroke onset. Demographic, psycho-social and vascular risk factors data were collected during the study. Cox proportional hazards regression modeling was used to assess the factors associated with death.

RESULTS

Among the study participants, long term information was obtainable on 58 of 60 (97%). After a median follow-up of 52 months [IQR: 48 to 53 months], 16 participants had died, resulting in a mortality rate of 27.6% (95% CI of 16.6% - 40.9%). Upon adjustment for confounders, the two factors independently associated with long-term mortality were resistant hypertension (Hazard Ratio 3.99; 95% CI: 1.29-12.37] and depression (Hazard Ratio 1.18; 95% CI: 1.05-1.31; per unit rise on the Hamilton Depression Scale).

CONCLUSION

In this convenience sample of recent stroke patients in Ghana, over a quarter had died within 5 years of index stroke onset. Resistant hypertension and depression may be modifiable therapeutic targets to improve outcomes in these patients.

Influence of age on links between major modifiable risk factors and stroke occurrence in West Africa

Background The burden of stroke in Africa is high. Understanding how age associates with major modifiable stroke risk factors could inform tailored demographic stroke prevention strategies. Purpose To quantify the magnitude and direction of the effect sizes of key modifiable stroke risk factors according to three age groups: <50 years (young), 50-65 years (middle age) and > 65 years (elderly) in West Africa. Methods This was a case-control study involving 15 sites in Ghana and Nigeria. Cases included adults aged ≥18 years with CT/MRI scan-typed stroke. Controls were age-and gender-matched stroke-free adults. Detailed evaluations for vascular, lifestyle and psychosocial factors were performed. We estimated adjusted odds ratios (aOR) using conditional logistic regression and population attributable risk (PAR) with 95% Confidence Interval of vascular risk factors by age groups. Results Among 3553 stroke cases, 813 (22.9%) were young, 1441 (40.6%) were middle-aged and 1299 (36.6%) were elderly. Among the 5 co-shared risk factors, dyslipidemia with PAR and aOR (95%CI) of 62.20% (52.82-71.58) and 4.13 (2.64-6.46) was highest among the young age group; hypertension with PAR of 94.31% (91.82-96.80) and aOR of 28.93 (15.10-55.44) was highest among the middle-age group. Diabetes with PAR of 32.29%(27.52-37.05) and aOR of 3.49 (2.56-4.75); meat consumption with PAR of 42.34%(32.33-52.35) and aOR of 2.40 (1.76, 3.26); and non-consumption of green vegetables, PAR of 16.81%(12.02-21.60) and aOR of 2.23 (1.60-3.12) were highest among the elderly age group. However confidence intervals of risk estimates overlapped across age groups. Additionally, among the young age group cigarette smoking, psychosocial stress and cardiac disease were independently associated with stroke. Furthermore, education, stress, physical inactivity and salt intake were associated with stroke in the middle-age group while cardiac disease was associated with stroke in the elderly age group. Conclusion There is a differential influence of age on the associations of major risk factors with stroke in this West African cohort. Targeting modifiable factors predominant within an age group may be more effective as a stroke prevention strategy.

Prevalence and Predictors of Multivitamin Supplement Use After Stroke in Ghana

BACKGROUND

Multivitamins are commonly used supplements in high income countries, but their net benefit-risk, remains inconclusive. Little is known about the prevalence and predictors of multivitamin supplementation among individual with chronic illnesses in sub-Saharan Africa, especially stroke.

PURPOSE

To assess the frequency and factors associated with of use of multivitamin supplement among stroke survivors in Ghana.

METHODS

We analyzed prospectively collected data on consecutively encountered stroke survivors seen at an out-patient clinic in Ghana between January 2018 and March 2020. We collected baseline demographic and clinical details, and use of multivitamins among other secondary prevention medications prescribed. We assessed factors associated with multivitamin supplementation using a multivariable logistic regression analysis.

RESULTS

Among 1,101 stroke survivors, 324 (29.4%) were on multivitamin supplements. Factors independently associated with multivitamin use were being divorced (OR 2.88; 95% CI: 1.52-5.47), time since diagnosis of index per each month increase (OR 0.99; 95% CI: 0.99-1.00), and number of prescribed classes of antihypertensive medications (OR 0.81; 95% CI: 0.72-0.92).

CONCLUSION

Nearly a third of stroke survivors in this Ghanaian sample were on multivitamin supplementation, with select socio-clinical factors being linked to this practice. Future studies should examine how/if this practice is interfering with optimal stroke outcomes.

Atherosclerotic event risk and risk reduction therapies among Ghanaian hemorrhagic stroke survivors

BACKGROUND

Intracerebral hemorrhage (ICH) stroke constitute up to 40% of incident strokes in Africa. While ICH patients are at high risk for atherosclerotic events, the risk-benefit of anti-atherosclerotic therapies in this patient population is uncertain.

PURPOSE

To assess whether utility of statins and/or antithrombotic agents after surviving an ICH correlates with atherosclerotic risk of an observational cohort.

METHODS

We analyzed data in a stroke registry prospectively collected on consecutively encountered stroke survivors seen at an out-patient clinic in Ghana between January 2018 and March 2020. We collected baseline demographic and clinical details, including diagnosis of ICH, co-morbidities, and key atherosclerotic risk reduction therapies (statins and anti-platelet drugs). We computed ischemic vascular risk using the Framingham Risk Score (FRS) to classify patients into low, intermediate and high vascular risk.

RESULTS

Of 1101 stroke survivors seen during the period, 244 (22.2%) had ICH. Vascular risk profiles were low (n = 86; 35.2%), intermediate (n = 71; 29.1%) and high (n = 87; 35.7%). Utility of statin use was 76.7% (low risk), 84.5% (intermediate risk), and 87.4% (high risk), p = 0.16 while antiplatelet use trended with atherosclerotic risk being 9.3% (low risk), 25.4% (intermediate risk), and high risk (34.5%), p = 0.0004. Independent factors associated with statin use were hypertension (OR 8.80; 95% CI: 2.34-33.11) and cigarette smoking (OR 0.29; 95% CI: 0.09-0.89) while antiplatelet drug use was associated with age (OR 1.43; 95% CI: 1.06-1.92) and time from index stroke (OR: 1.02; 95% CI: 1.01-1.02).

CONCLUSION

Approximately two-thirds of ICH survivors in this African sample had intermediate to high risk of future atherosclerotic events. Clinical trials on the timing, safety, and efficacy of statins and antiplatelet drugs among ICH survivors could help better guide risk mitigation in this population.

Factors Linked to Chronic Kidney Disease Among Stroke Survivors in Ghana

BACKGROUND

Chronic kidney disease (CKD) is associated with poor outcomes among stroke survivors. In Africa, where both stroke and CKD incidence rates are escalating, little, if anything, is known about the burden of CKD among stroke survivors.

OBJECTIVE

To assess the frequency and factors associated with CKD among stroke survivors by primary stroke types.

METHODS

Stroke registry data were prospectively collected on consecutively encountered stroke survivors seen at an out-patient clinic in Ghana between January 2018 and March 2020. We calculated estimated glomerular filtration rate (eGFR) using the CKD-EPI formula and defined CKD as eGFR <60ml/min. Factors associated with CKD were assessed using multiple logistic regression modelling.

RESULTS

Among 759 stroke survivors, 159 had CKD giving a prevalence of 21.0% (95%CI: 18.1% - 23.8%). The mean age of those with CKD was 61.6 ± 14.2 years compared with 57.5 ± 13.6 years, p=0.0007 among those without CKD. Five factors remained significantly associated with CKD with the following adjusted odds ratio (aOR and 95% CI). Age per decile rise 1.30 (1.13-1.50), male sex 1.99 (1.36-2.93), rural dwelling residence 1.95 (1.06-3.59), prior use of antihypertensive meds before index stroke onset 1.63 (1.08-2.47), and number of antihypertensive medication classes 1.25 (1.06-1.45).

CONCLUSION

1 in 5 stroke survivors have evidence of chronic kidney disease in this Ghanaian study. Targeted interventions focusing on optimizing blood pressure control and rural dwellers may mitigate their risk for adverse outcomes.