Multilingual Validation of the Questionnaire for Verifying Stroke-Free Status in West Africa

Non-cigarette Tobacco Use and Stroke Among West Africans: Evidence From the SIREN Study

INTRODUCTION

Non-cigarette tobacco (NCT) represents a form of tobacco use with a misperceived significance in chronic disease events. Whether NCT use is sufficient to promote stroke events, especially among Africans, is yet to be understood. This study assessed the relationship between NCT use and stroke among indigenous Africans.

METHODS

A total of 7617 respondents (NCT users: 41 vs. non-NCT: 7576) from the Stroke Investigative Research and Educational Network (SIREN) study were included in the current analysis. NCT use was defined as self-reported use of smoked (cigars or piper) or smokeless (snuff or chewed) tobacco in the past year preceding stroke events. Stroke was defined based on clinical presentation and confirmed with a cranial computed tomography/magnetic resonance imaging. Multivariable-adjusted logistic regression was applied to estimate the odds ratio (OR) and 95% confidence interval (CI) for the relationship of NCT with stroke at a two-sided p < .05.

RESULTS

Out of the 41 (0.54%) who reported NCT use, 27 (65.9%) reported using smokeless NCT. NCT users were older than non-NCT users (62.8 ± 15.7 vs. 57.7 ± 14.8 years). Overall, NCT use was associated with first-ever stroke (OR: 2.08; 95% CI: 1.02, 4.23) in the entire sample. Notably, smokeless NCT use was independently associated with higher odds of stroke (OR: 2.74; 95% CI: 1.15, 6.54), but smoked NCT use (OR: 0.16; 95% CI: 0.02, 1.63) presented a statistically insignificant association after adjusting for hypertension and other covariates.

CONCLUSIONS

NCT use was associated with higher odds of stroke, and public health interventions targeting NCT use might be promising in reducing the burden of stroke among indigenous Africans.

IMPLICATIONS

A detailed understanding of the relationship between NCT use and stroke will likely inform well-articulated policy guidance and evidence-based recommendations for public health prevention and management of stroke on the African continent.

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.

Novel functional insights into ischemic stroke biology provided by the first genome-wide association study of stroke in indigenous Africans

BACKGROUND

African ancestry populations have the highest burden of stroke worldwide, yet the genetic basis of stroke in these populations is obscure. The Stroke Investigative Research and Educational Network (SIREN) is a multicenter study involving 16 sites in West Africa. We conducted the first-ever genome-wide association study (GWAS) of stroke in indigenous Africans.

METHODS

Cases were consecutively recruited consenting adults (aged > 18 years) with neuroimaging-confirmed ischemic stroke. Stroke-free controls were ascertained using a locally validated Questionnaire for Verifying Stroke-Free Status. DNA genotyping with the H3Africa array was performed, and following initial quality control, GWAS datasets were imputed into the NIH Trans-Omics for Precision Medicine (TOPMed) release2 from BioData Catalyst. Furthermore, we performed fine-mapping, trans-ethnic meta-analysis, and in silico functional characterization to identify likely causal variants with a functional interpretation.

RESULTS

We observed genome-wide significant (P-value < 5.0E-8) SNPs associations near AADACL2 and miRNA (MIR5186) genes in chromosome 3 after adjusting for hypertension, diabetes, dyslipidemia, and cardiac status in the base model as covariates. SNPs near the miRNA (MIR4458) gene in chromosome 5 were also associated with stroke (P-value < 1.0E-6). The putative genes near AADACL2, MIR5186, and MIR4458 genes were protective and novel. SNPs associations with stroke in chromosome 2 were more than 77 kb from the closest gene LINC01854 and SNPs in chromosome 7 were more than 116 kb to the closest gene LINC01446 (P-value < 1.0E-6). In addition, we observed SNPs in genes STXBP5-AS1 (chromosome 6), GALTN9 (chromosome 12), FANCA (chromosome 16), and DLGAP1 (chromosome 18) (P-value < 1.0E-6). Both genomic regions near genes AADACL2 and MIR4458 remained significant following fine mapping.

CONCLUSIONS

Our findings identify potential roles of regulatory miRNA, intergenic non-coding DNA, and intronic non-coding RNA in the biology of ischemic stroke. These findings reveal new molecular targets that promise to help close the current gaps in accurate African ancestry-based genetic stroke's risk prediction and development of new targeted interventions to prevent or treat stroke.

Risk Assessment Score and Chi-Square Automatic Interaction Detection Algorithm for Hypertension Among Africans: Models From the SIREN Study

BACKGROUND

This study aimed to develop a risk-scoring model for hypertension among Africans.

METHODS

In this study, 4413 stroke-free controls were used to develop the risk-scoring model for hypertension. Logistic regression models were applied to 13 risk factors. We randomly split the dataset into training and testing data at a ratio of 80:20. Constant and standardized weights were assigned to factors significantly associated with hypertension in the regression model to develop a probability risk score on a scale of 0 to 1 using a logistic regression model. The model accuracy was assessed to estimate the cutoff score for discriminating hypertensives.

RESULTS

Mean age was 59.9±13.3 years, 56.0% were hypertensives, and 8 factors, including diabetes, age ≥65 years, higher waist circumference, (BMI) ≥30 kg/m2, lack of formal education, living in urban residence, family history of cardiovascular diseases, and dyslipidemia use were associated with hypertension. Cohen κ was maximal at ≥0.28, and a total probability risk score of ≥0.60 was adopted for both statistical weighting for risk quantification of hypertension in both datasets. The probability risk score presented a good performance-receiver operating characteristic: 64% (95% CI, 61.0-68.0), a sensitivity of 55.1%, specificity of 71.5%, positive predicted value of 70.9%, and negative predicted value of 55.8%, in the test dataset. Similarly, decision tree had a predictive accuracy of 67.7% (95% CI, 66.1-69.3) for the training set and 64.6% (95% CI, 61.0-68.0) for the testing dataset.

CONCLUSIONS

The novel risk-scoring model discriminated hypertensives with good accuracy and will be helpful in the early identification of community-based Africans vulnerable to hypertension for its primary prevention.

Knowledge and perspectives of community members on risk assessment for stroke prevention using mobile health approaches in Nigeria

OBJECTIVES

To assess the knowledge of community dwelling adults on stroke risk and their willingness to use mobile health (mHealth) technology in assessing their stroke risk.

MATERIALS AND METHODS

A cross-sectional study was conducted among adults (≥18 years old) using survey questionnaires designed by neurologists and health promotion experts and administered by trained study staff. Logistic regression models were used to assess factors associated with receptivity toward knowing individual stroke risk score and willingness to use a mobile application (App) to assess stroke risk.

RESULTS

The survey was administered to 486 participants in Nigeria, with a mean age of 47.4 ± 15.5 years, comprising 53.5% females. Up to 84% of participants wanted to know their risk for developing stroke but only 29.6% of respondents had ever previously had their stroke risk assessed. Factors associated with willingness to know stroke risk were age [aOR (95% CI): 0.97 (0.95 - 0.99)], and Hausa tribe [16.68 (2.16 - 128.92)]. Up to 66% of participants wanted to know their immediate risk of stroke, compared with 6.6% and 2.1% who wanted to know their 5-year or 10-year future stroke risks respectively. Regarding locations, participants preferred stroke risk assessment to be performed at a health facility, at home by health professional, on their own using mHealth (stroke risk calculator application), or at communal gatherings (decreasing order). About 70% specifically wished to learn about their stroke risk via an mHealth application.

CONCLUSIONS

Community dwelling Nigerians wanted to know their immediate risk of stroke using digital platforms, such as a mobile phone stroke risk calculator application. Clinical trials are needed to assess the effectiveness of such a strategy for primary prevention of stroke in sub-Saharan African communities.

Prevalence and predictors of low folate levels among stroke survivors in a country without mandatory folate food fortification: Analysis of a Ghanaian sample

BACKGROUND

While additional folic acid (FA) treatment has a neutral effect on lowering overall vascular risk in countries that mandate FA fortification of food, meta-analytic data suggest that folate supplementation reduces stroke risk in certain patient subgroups, and among people living in countries without mandatory folate food fortification. However, the burden of folate deficiency among adults with stroke in the world's poorest continent is unknown.

PURPOSE

To assess the prevalence and predictors of folate deficiency among recent ischemic stroke survivors.

METHODS

We analyzed data among consecutively encountered ischemic stroke patients aged ≥18 years at a tertiary medical center in Kumasi, Ghana between 10/2020 - 08/2021. We identified a modest sample of stroke free adults to serve as a comparator group. Fasting serum folate was measured using a radioimmunoassay and a cut-off of 4ng/mL used to define folate deficiency. Factors associated with serum folate concentration were assessed using a multilinear regression model.

RESULTS

Comparing stroke cases (n = 116) with stroke-free comparators (n = 20), mean folate concentration was lower among stroke cases (7 ng/ml vs. 10.2 ng/ml, p = 0.004). Frequency of folate deficiency was higher among stroke cases vs. stroke-free controls (31% vs 5%, p = 0.02). Male sex (beta coefficient of -2.6 (95% CI: -4.2, -0.9) and LDL (β: -0.76; -1.4, -0.07) were significantly associated with serum folate concentration.

CONCLUSION

Almost one in three ischemic stroke survivors have folate deficiency potentially accentuating their risk for further adverse atherosclerotic events in a setting without folate fortification. A clinical trial of folate supplementation among stroke survivors is warranted.

Effect of an Educational Intervention for Primary Stroke Risk Reduction in Ghana and Nigeria: Pilot Randomized Controlled Trial

BACKGROUND

Using tailored mobile health interventions to improve global vascular risk awareness and control is yet to be investigated for primary stroke prevention in Africa.

METHODS

This 2-arm pilot randomized controlled trial involved 100 stroke-free adults with at least 2 vascular risk factors for stroke. Eligible participants were assigned randomly to a control arm offering 1-time counseling (n=50) or a 2-month educational intervention arm (n=50) comprising a stroke video and riskometer app aimed at improving stroke risk factor awareness and health-seeking behavioral modification to control total vascular risk. Reduction in total stroke risk score was the primary outcome while feasibility and process measures were secondary outcomes.

RESULTS

All enrolled participants completed the 2-month follow-up (retention rate=100%). The mean (SD) age of participants was 59.5 (±12.5) years, 38% were males. The mean change in stroke risk score at 2 months was -11.9% (±14.2) in the intervention arm versus -1.2% (±9.1) in the control arm, P=0.0001. Stroke risk awareness improved by 16.1% (±24.7) in the intervention arm versus 8.9% (±24.7) in the control arm, P=0.08. The intervention arm had 11.1 mm Hg reduction in systolic blood pressure compared with 4.8 mm Hg reduction in the control arm.

CONCLUSIONS

The intervention demonstrated a positive signal of effect over a 2-month period. A definitive clinical trial with a longer duration of follow-up is warranted on the premise of these promising findings from this pilot randomized clinical trial.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT05619406.

Dietary patterns associated with stroke among West Africans: A case-control study

BACKGROUND

The relationship of diet with stroke risk among Africans is not well understood.

AIM

The aim of this study was to investigate the association between dietary patterns and stroke risk among West Africans.

METHODS

In this multi-center case-control study, 3684 stroke patients matched (for age and sex) with 3684 healthy controls were recruited from Nigeria and Ghana. Food consumption was assessed using a food frequency questionnaire, and dietary patterns were summarized using principal component analysis. Stroke was defined using predefined criteria primarily on clinical evaluation following standard guidelines. Conditional logistic regression was applied to compute odds ratio (OR) and 95% confidence interval (CI) for stroke risk by tertiles of dietary patterns adjusting for relevant confounders.

RESULTS

Overall, mean age was 59.0 ± 13.9 years, and 3992 (54.2%) were males. Seven dietary patterns were identified. Multivariable-adjusted OR (95% CI) for risk of stroke by second and third tertiles (using the lowest and first tertile as reference) of dietary patterns was 1.65 (1.43, 1.90) and 1.74 (1.51, 2.02), for "poultry product and organ meat"; 1.69 (1.47, 1.96) and 1.51 (1.31, 1.75) for "red meat"; 1.07 (0.92, 1.23) and 1.21 (1.04, 1.40) for "fried foods and sweetened drinks"; 0.69 (0.60, 0.80) and 0.45 (0.39, 0.53) for "vegetables"; 0.84 (0.72, 0.97) and 0.81 (0.70, 0.93) for "whole-grain and fruit drinks"; and 0.97 (0.84, 1.12) and 0.85 (0.73, 0.98) for "fruits" respectively (p < 0.05).

CONCLUSION

These data suggest that plant-based diets are associated with a lower risk of stroke and might be a beneficial dietary recommendation for the primary prevention of stroke among Africans.

Secondhand smoke exposure is independently associated with stroke among non-smoking adults in West Africa

BACKGROUND

Stroke is a leading cause of disability and mortality worldwide, but little is known about the contribution of secondhand smoke exposure (SHSE) to stroke epidemiology among indigenous Africans.

OBJECTIVE

To evaluate the association of SHSE with stroke among indigenous Africans.

METHODS

We analyzed the relationship of SHSE with stroke among 2990 case-control pairs of adults who had never smoked (identified in the SIREN study) using conditional logistic regression at a two-sided P < 0.05.

RESULTS

Multivariable-adjusted odds ratio and 95% confidence interval; 1.25 (1.04, 1.50; P = 0.02) revealed SHSE was positively associated with stroke independent of stroke subtypes.

CONCLUSION

Culturally relevant primary prevention strategies targeted at SHSE might be promising in preventing stroke among Africans.

Assessing the variability and the role of inflammatory cytokines and monocyte chemoattractant protein-1 (MCP-1) in predicting stroke among hypertensives: A case-control study

Background

Atherosclerosis is a complex lipid-driven inflammatory disease in which numerous cell types and inflammatory mediators are involved in the progression of hypertension to stroke. Mediators' markers that could predict the progression of hypertension to stroke are of research importance. We assessed the predictive value of individual and combined cytokines and monocyte chemoattractant protein-1 (MCP-1) among hypertensives with or without stroke.

Methods

In a case-control study, we enrolled 63 cases with stroke and hypertension (HPT-S), 59 stroke-free hypertensives (HPT), and 53 stroke free normotensives as controls (CS). Sociodemographic data and blood samples were collected for the estimation of Interleukin-10 (IL-10), IL-6, IL-8, IL-1β and monocyte chemoattractant protein-1 (MCP-1) using commercially available ELISA kits from Biobase Biotech, Shanghai, China. The Receiver Operator Characteristics (ROC) analysis was used to calculate diagnostic accuracy for cytokines in predicting stroke among hypertensives. A combined bioscore model of IL-10 and MCP-1 was generated to predict stroke among hypertensives. The multiple logistic regression analysis was used to assess the chances of IL-10 and MCP-1 in predicting stroke among hypertensives. Statistical analyses were performed using R-language.

Results

The HPT-S group had significantly higher levels of MCP-1 and IL-10 compared to the HPT and CS groups (p < 0.05). There was no significant difference in IL-1β, IL-8 and IL-6 amongst the three study groups. MCP-1 and IL-10 were predictive of stroke occurrence among hypertensives and were used to develop a bioscore model. An elevated MCP-1 and IL-10 with a bioscore 2 had a predictive accuracy of 0.81, a sensitivity of 0.77 and specificity of 0.84. At a bioscore of 1, the sensitivity and specificity for predicting stroke among hypertensives was 97.0% and 61.0% respectively. In a binary logistic regression, having a bioscore of 1 [aOR = 20.43, 95% CI (2.17-192.62), p = 0.008] or 2 [aOR = 26.00, 95% CI (2.92-231.31), p = 0.003] were significantly associated with stroke occurrence among hypertensives.

Conclusion

Higher levels of IL-10 with a concomitant level of MCP-1 could serve as a good predictor of stroke among hypertensives. Subsequently, MCP-1 may prove useful as a therapeutic target for atherosclerosis in hypertensives. Combined bioscore of MCP-1 and IL-10 could serve as a good predictor of stroke among hypertensives.

Differential associations between pre-diabetes, diabetes and stroke occurrence among West Africans

BACKGROUND

There are limited data from Africa on the burden and associations between pre-diabetes (pre-DM), diabetes mellitus (DM) and stroke occurrence in a region experiencing a profound rise in stroke burden.

PURPOSE

To characterize the associations between stroke and dysglycemic status among West Africans.

METHODS

The Stroke Investigative Research and Educational Network (SIREN) is a multicenter, case-control study involving 15 sites in Ghana and Nigeria. Cases include adults aged ≥18 years with clinical and radiological evidence of an acute stroke. Controls were age-and-gender matched stroke-free adults. Detailed evaluations for vascular factors were performed. Pre-diabetes was defined as HBA1c of 5.7%-6.4% or Fasting blood glucose (FBG) 5.6-7.0 mmol/L and DM as HBA1c >6.5% or FBG>7.0 mmol/L. We used conditional logistic regression to estimate adjusted odds ratios (aOR) with 95% Confidence Interval.

RESULTS

Among 2,935 stroke cases the mean age was 60.0 ± 14.2 years with 55.2% being males. By glycemic status, 931 (31.7%) were euglycemic, 633 (21.6%) had Pre-diabetes and 1371 (46.7%) had DM. Of the age- and sex-matched stroke-free controls 69.2% were euglycemic, 13.3% had pre-DM and 17.5% had DM. Pre-DM [aOR (95% CI): 3.68(2.61-5.21)] and DM [4.29 (3.19-5.74)] were independently associated with stroke. The aOR of Pre-DM for ischemic stroke 3.06 (2.01-4.64)] was lower than 4.82 (3.37-6.89) for DM. However, the aOR of Pre-DM for hemorrhagic stroke 6.81 (95% CI: 3.29 - 14.08)] was higher than 3.36 (1.94-5.86) for DM. Furthermore, the aOR of pre-DM for ischemic stroke subtypes were 9.64 (1.30-71.57) for cardio-embolic stroke, 3.64 (1.80-7.34) for small-vessel occlusive disease and 4.63 (0.80-26.65) for large-vessel disease.

CONCLUSION

Pre-DM is strongly and independently associated with stroke in Africans. Improving glycemic control through screening, healthy lifestyle and pharmacotherapy at a population level may be strategic in reducing the rising burden of stroke in Africa.

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.

Risk Factor Characterization of Ischemic Stroke Subtypes Among West Africans

BACKGROUND AND PURPOSE

To identify the qualitative and quantitative contributions of conventional risk factors for occurrence of ischemic stroke and its key pathophysiologic subtypes among West Africans.

METHODS

The SIREN (Stroke Investigative Research and Educational Network) is a multicenter, case-control study involving 15 sites in Ghana and Nigeria. Cases include adults aged ≥18 years with ischemic stroke who were etiologically subtyped using the A-S-C-O-D classification into atherosclerosis, small-vessel occlusion, cardiac pathology, other causes, and dissection. Controls were age- and gender-matched stroke-free adults. Detailed evaluations for vascular, lifestyle, and psychosocial factors were performed. We used conditional logistic regression to estimate adjusted odds ratios with 95% CI.

RESULTS

There were 2431 ischemic stroke case and stroke-free control pairs with respective mean ages of 62.2±14.0 versus 60.9±13.7 years. There were 1024 (42.1%) small vessel occlusions, 427 (17.6%) large-artery atherosclerosis, 258 (10.6%) cardio-embolic, 3 (0.1%) carotid dissections, and 719 (29.6%) undetermined/other causes. The adjusted odds ratio (95% CI) for the 8 dominant risk factors for ischemic stroke were hypertension, 10.34 (6.91-15.45); dyslipidemia, 5.16 (3.78-7.03); diabetes, 3.44 (2.60-4.56); low green vegetable consumption, 1.89 (1.45-2.46); red meat consumption, 1.89 (1.45-2.46); cardiac disease, 1.88 (1.22-2.90); monthly income $100 or more, 1.72 (1.24-2.39); and psychosocial stress, 1.62 (1.18-2.21). Hypertension, dyslipidemia, diabetes were confluent factors shared by small-vessel, large-vessel and cardio-embolic subtypes. Stroke cases and stroke-free controls had a mean of 5.3±1.5 versus 3.2±1.0 adverse cardio-metabolic risk factors respectively (P<0.0001).

CONCLUSIONS

Traditional vascular risk factors demonstrate important differential effect sizes with pathophysiologic, clinical and preventative implications on the occurrence of ischemic stroke among indigenous West Africans.

African Rigorous Innovative Stroke Epidemiological Surveillance: Protocol for a Community-Based Mobile-Health Study

Despite projections of stroke being a leading cause of mortality in Africa, reliable estimates of stroke burden on the continent using rigorous methods are not available. We aimed to implement a mobile-Health community-based interactive Stroke Information and Surveillance System to sustainably measure stroke burden and improve stroke health literacy and outcomes in urban and rural sites in Nigeria. African Rigorous Innovative Stroke Epidemiological Surveillance (ARISES) is an observational cohort study, which will be conducted in urban (Ibadan North LGA Ward 3) and rural (Ibarapa Central LGA) sites with a combined base population of over 80,000 people. The study will use a consultative approach to establish an mHealth-based Stroke Information and Surveillance System comprising a Stroke Alert System and a Stroke Finding System. These systems will enable the community to report stroke events and the research team/health workers find stroke cases using phone calls, short message service, and Voice Over Internet Protocols (VoIP). We will update community household data and geo-locate all households. Over the 5 years of the study, the system will collect information on stroke events and educate the community about this disease. Reported stroke cases will be clinically adjudicated at home and in prespecified health facilities. Baseline and endline community surveys will be conducted to assess stroke occurrence and other important study variables. The proportion of strokes alerted and found will be determined over the study period. Focus group discussions and key informant interviews will be conducted to understand community stroke literacy and perspectives. The study will also assess any impact of these efforts on time from stroke onset to referral, community uptake of orthodox health services for stroke patients. ARISES is anticipated to establish proof of concept about using mHealth for stroke surveillance in Africa. The potential impact of the SISS on improving patient outcomes will also be determined.

A Novel Afrocentric Stroke Risk Assessment Score: Models from the Siren Study

BACKGROUND

Stroke risk can be quantified using risk factors whose effect sizes vary by geography and race. No stroke risk assessment tool exists to estimate aggregate stroke risk for indigenous African.

OBJECTIVES

To develop Afrocentric risk-scoring models for stroke occurrence.

MATERIALS AND METHODS

We evaluated 3533 radiologically confirmed West African stroke cases paired 1:1 with age-, and sex-matched stroke-free controls in the SIREN study. The 7,066 subjects were randomly split into a training and testing set at the ratio of 85:15. Conditional logistic regression models were constructed by including 17 putative factors linked to stroke occurrence using the training set. Significant risk factors were assigned constant and standardized statistical weights based on regression coefficients (β) to develop an additive risk scoring system on a scale of 0-100%. Using the testing set, Receiver Operating Characteristics (ROC) curves were constructed to obtain a total score to serve as cut-off to discriminate between cases and controls. We calculated sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) at this cut-off.

RESULTS

For stroke occurrence, we identified 15 traditional vascular factors. Cohen's kappa for validity was maximal at a total risk score of 56% using both statistical weighting approaches to risk quantification and in both datasets. The risk score had a predictive accuracy of 76% (95%CI: 74-79%), sensitivity of 80.3%, specificity of 63.0%, PPV of 68.5% and NPV of 76.2% in the test dataset. For ischemic strokes, 12 risk factors had predictive accuracy of 78% (95%CI: 74-81%). For hemorrhagic strokes, 7 factors had a predictive accuracy of 79% (95%CI: 73-84%).

CONCLUSIONS

The SIREN models quantify aggregate stroke risk in indigenous West Africans with good accuracy. Prospective studies are needed to validate this instrument for stroke prevention.

Phone-Based Intervention under Nurse Guidance after Stroke (PINGS II) Study: Protocol for a Phase III Randomized Clinical Trial

OBJECTIVES

The Sub-Saharan African (SSA) region now has the highest estimated effect size of hypertension for stroke causation worldwide. An urgent priority for countries in SSA is to develop and test self-management interventions to control hypertension among those at highest risk of adverse outcomes. Thus the overall objective of the Phone-based Intervention under Nurse Guidance after Stroke II study (PINGS-2) is to deploy a hybrid study design to assess the efficacy of a theoretical-model-based, mHealth technology-centered, nurse-led, multi-level integrated approach to improve longer term blood pressure (BP) control among stroke survivors.

MATERIALS AND METHODS

A phase III randomized controlled trial involving 500 recent stroke survivors to be enrolled across 10 Ghanaian hospitals. Using a computer-generated sequence, patients will be randomly assigned 1:1 into the intervention or usual care arms. The intervention comprises of (i) home BP monitoring at least once weekly with nurse navigation for high domiciliary BP readings; (2) medication reminders using mobile phone alerts and (3) education on hypertension and stroke delivered once weekly via audio messages in preferred local dialects. The intervention will last for 12 months. The control group will receive usual care as determined by local guidelines. The primary outcome is the proportion of patients with systolic BP <140 mm Hg at 12 months. Secondary outcomes will include medication adherence, self-management of hypertension, major adverse cardiovascular events, health related quality of life and implementation outcomes.

CONCLUSION

An effective PINGS intervention can potentially be scaled up and disseminated across healthcare systems in low-and-middle income countries challenged with resource constraints to reduce poor outcomes among stroke survivors.

Factors associated with incidence of stroke and heart failure among people living with HIV in Ghana: Evaluating Vascular Event Risk while on Long-Term Antiretroviral Suppressive Therapy (EVERLAST) Study

People living with HIV (PLWH) have a two‐fold higher risk of cardiovascular diseases (CVDs) compared with HIV‐negative populations. Although 70% of the global HIV population reside in Africa, data on CVD outcomes among PLWH are scarce. We seek to evaluate factors associated with incidence of stroke and heart failure in a prospective cohort of Ghanaian PLWH. We followed up a cohort of PLWH on antiretroviral therapy for 12 months to assess rates of clinically adjudicated stroke, and heart failure. We calculated incidence rates of events/1000 person‐years and fitted Cox proportional hazards regression models to identify factors associated with incident stroke and heart failure as a combined outcome measure and as separate outcome measures. Among 255 participants, the mean age was 46 years and 211 (82.7%) were female. The participants contributed 245 years of follow‐up data with mean follow‐up duration of 11.5 months. There were three incident strokes giving an incidence rate of 12.24 per 1000 person‐years (95% CI: 3.13–33.33) and two heart failure events with an incidence rate of 8.16 (95%CI: 1.37–26.97) per 1000 py. The combined event rate was 20.41 (95% CI: 7.48–45.24) per 1000 py. Being hypertensive was associated with aHR of 8.61 (1.32–56.04) of the combined outcome while each 100 cells/mm³ rise in CD4 count was associated with aHR of 0.56 (0.35–0.88). Carotid bulb intimal media thickness was independently associated with stroke occurrence with aHR of 12.23 (1.28–117.07). People living with HIV on long‐term cART in this Ghanaian sample have high rates of clinically adjudicated cardiovascular diseases driven by uncontrolled hypertension and persisting immunosuppression. Integration of CVD care into routine HIV management may help alleviate this untoward confluence of rising CVDs among PLWH.

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.

Antecedent febrile illness and occurrence of stroke in West Africa: The SIREN study

BACKGROUND

Acute infections have been posited as potential precipitants or triggers of the occurrence of stroke among adults with traditional vascular risk factors. We evaluated associations between stroke occurrence and reported febrile illness within 4 weeks (potential antecedent infections) among West Africans.

METHODS

The Stroke Investigative Research and Educational Network (SIREN) is a multicenter, case-control study involving 15 sites in Ghana and Nigeria. Cases include adults aged ≥18 years with radiologically confirmed strokes. Controls were stroke-free adults matched with cased by age, gender and ethnicity. Detailed evaluations for vascular, lifestyle and psychosocial factors were performed. Participants were asked for evidence of any febrile illness within the past 4 weeks. We used conditional logistic regression to estimate adjusted odds ratios (aOR) with 95% Confidence Interval.

RESULTS

Among 3588 stroke cases recruited in Ghana and Nigeria between August 2014 and July 2018, 363 cases (10.1%) reported having a febrile illness within the 4 weeks prior to stroke occurrence. Having an antecedent infection was associated with stroke occurrence with an unadjusted OR of 1.19 (1.00-1.51) but aOR of 0.83 (0.59-1.17) upon adjusting for traditional vascular risk factors. Stress, aOR of 4.69 (2.59-8.50) and consumption of green vegetables 2.27 (1.35-2.85) were associated with antecedent febrile illness.

CONCLUSION

1 in 10 stroke cases reported antecedent history of febrile illness prior to occurrence of stroke but no independent association was observed in this study. Infectious exposures may be important triggers of cardiovascular events requiring further exploratory studies to better understand the role of this emerging risk factor.

Prevalence and predictors of post-stroke epilepsy among Ghanaian stroke survivors

BACKGROUND

Post-stroke epilepsy (PSE) is associated with poorer quality of life, higher mortality, and greater health expenditures. We are unaware of any published reports on the frequency of and factors associated with PSE in Africa.

PURPOSE

To assess the frequency and factors associated with PSE among Ghanaian stroke survivors.

METHODS

We conducted a cross-sectional study of consecutive stroke survivors seen at an out-patient Neurology clinic enrolled into a stroke registry at a tertiary medical center in Ghana between January 2018 and March 2020. We collected baseline demographic and clinical details including diagnosis of post-stroke epilepsy, anti-epileptic medications, presence, treatment and control of vascular risk factors. Multivariate logistic regression models were constructed to identify factors associated with PSE.

RESULTS

Of 1101 stroke patients encountered, 126 had PSE (frequency of 11.4%; 95% CI of 9.6-13.5%). Mean (± SD) age among PSE vs. non-PSE patients was 57.7 (± 15.2) vs. 58.7 (± 13.9) years. Factors independently associated with PSE were being male (aOR 1.94; 95% CI: 1.32-2.86), cortical ischemic strokes (1.79; 1.12-2.87), blood pressure > 130/80 mmHg (OR 2.26; 1.06-4.79), use of antihypertensive treatment (OR 0.43; 0.23-0.79). There was an inverted J-shaped curve association between number of classes of antihypertensive drugs prescribed and occurrence of PSE, with the lowest inflection point at 3 classes (OR 0.34; 0.17-0.68).

CONCLUSION

In this convenience sample of ambulatory Ghanaian stroke survivors, one in ten had PSE. Further investigations to confirm and clarify the associations between the identified demographic and clinical characteristics are warranted.

Low blood pressure levels & incident stroke risk among elderly Ghanaians with hypertension

BACKGROUND

Clinical trial data indicate that more intensive blood pressure (BP) lowering below standard cut-off targets is associated with lower risks of strokes in the elderly. There is a relative paucity of real-world practice data on this issue, especially among Africans.

OBJECTIVE

To assess BP control rates, its determinants, and whether a lower BP < 120/80 mmHg is associated with a lower incident stroke risk among elderly Ghanaians with hypertension.

METHODS

We retrospectively evaluated data, which were prospectively collected as part of a cohort study involving adults with hypertension and/or diabetes in 5 Ghanaian hospitals. BP control was defined using the JNC-8 guideline of <150/90 mmHg for elderly with hypertension aged >60 years or 140/90 mmHg for those with diabetes mellitus. Risk factors for poor BP control were assessed using multivariable logistic regression models. We calculated incident stroke risk over an 18-month follow-up at 3 BP cut-off's of <120/80, 120-159/80-99, and > 160/100 mmHg.

RESULTS

Of the 1365 elderly participants with hypertension, 38.2% had diabetes mellitus and 45.8% had uncontrolled BP overall. Factors associated with uncontrolled BP were higher number of antihypertensive medications prescribed adjusted odds ratio of 1.45 (95% CI: 1.27-1.66), and having diabetes 2.56 (1.99-3.28). Among the elderly, there were 0 stroke events/100py for BP < 120/80 mmHg, 1.98 (95%CI: 1.26-2.98) for BP between 120 and 159/80-99 mmHg and 2.46 events/100py (95% CI: 1.20-4.52 at BP > 160/100 mmHg.

CONCLUSION

A lower BP target <120/80 mmHg among elderly Ghanaians with hypertension is associated with a signal of lower incident stroke risk. Pragmatic trials are needed to evaluate lower BP targets on stroke incidence in Africa.

Frequency and factors linked to refractory hypertension among stroke survivors in Ghana

BACKGROUND

Refractory hypertension (RfH) is a rare, severe phenotype of resistant hypertension, linked to higher risk of adverse cardiovascular outcomes. Little is known about the association of RfH with stroke type and subtype.

OBJECTIVE

To determine the prevalence and predictors of RfH among stroke survivors in Ghana.

METHODS

We interrogated the dataset of a prospectively collected registry of hypertensive patients seen between July 2015 and June 2019, at five hospitals in Ghana. We compared stroke survivors to stroke-free controls. Clinic-based blood pressure was measured using a standardized protocol and antihypertensive medications were assessed via review of medical records and inspection of pills. Refractory hypertension was defined as office BP ≥140/90 mmHg on ≥5 classes of antihypertensive medications. Multivariate logistic regression models were constructed to assess factors associated with RfH.

RESULTS

Of 3927 hypertensive patients (1169 stroke survivors, 2758 controls), 86 had RfH for an overall prevalence of 2.2% (95% CI: 1.8-2.7%). Among patients with RfH, 5.8% (4.5-7.3%) were stroke survivors vs. 0.7% (0.4-1.0%) were stroke-free (p < .0001). Adjusted odds ratio (95% CI) for factors associated with RfH were being male (1.81, 1.15-2.85), age < 60 years (2.64, 1.59-4.40), chronic kidney disease (2.09, 1.21-3.60), and known stroke (7.53, 4.35-13.04). RfH was associated with intracerebral hemorrhage, (11.43, 5.65-23.14), ischemic stroke (9.76, 5.47-17.42), lacunar stroke (13.58, 6.45-28.61), and non-lacunar ischemic stroke (3.67, 1.04-13.02).

CONCLUSION

Presence of RfH is significantly accentuated among stroke survivors. Intensified efforts are warranted to identify and aggressively address barriers to control in these patients to avert subsequent vascular events.

Prevalence and predictors of statin utilization among patient populations at high vascular risk in Ghana

BACKGROUND

Inadequate implementation of evidence-based preventive measures for individuals at high risk of cardiovascular disease (CVD) will only worsen the current epidemic of CVDs in sub-Saharan Africa. We assessed rates and predictors of statin utilization among two high CVD risk patient populations, people with type 2 diabetes mellitus (T2DM) and those with stroke, encountered across five hospitals in Ghana.

METHODS

A cross-sectional study among 1427 patients with T2DM and 159 stroke survivors encountered at 5 hospitals (1 primary-level, 2 secondary level and 2 tertiary level) in Ghana between July 2015 and June 2018. We collected baseline demographic and clinical details including statin prescription from medical records. Factors associated with statin prescription among T2DM for primary prevention and stroke survivors for secondary prevention were evaluated using multivariate logistic regression analysis.

RESULTS

Among patients with T2DM without CVDs, 240 (16.8%) were on statins for primary prevention. Factors associated with statin use among diabetics expressed as aOR (95% CI) were being treated at a tertiary level hospital 5.86 (3.22-10.68), hypertension comorbidity 1.80 (1.25-2.60), and lower income 0.43 (0.26-0.70). Among 159 stroke survivors, 22 (14.0%) were on statins with the following associated factors: lower income 0.16 (0.03-0.77), secondary level vs. tertiary level education 0.21 (0.05-0.97) and having T2DM 4.69 (1.63-13.49).

CONCLUSION

Approximately 1 in 6 individuals with T2DM without CVD and 1 in 7 stroke survivors are prescribed statins in Ghana. Efforts to bridge this practice gap and improve access to life saving preventative medications for CVD risk reduction in low-and-middle income countries are urgently warranted.

Unraveling the risk factors for spontaneous intracerebral hemorrhage among West Africans

OBJECTIVE

To characterize risk factors for spontaneous intracerebral hemorrhage (sICH) occurrence and severity among West Africans.

METHODS

The Stroke Investigative Research and Educational Network (SIREN) study is a multicenter case-control study involving 15 sites in Ghana and Nigeria. Patients were adults ≥18 years old with CT-confirmed sICH with age-, sex-, and ethnicity-matched stroke-free community controls. Standard instruments were used to assess vascular, lifestyle, and psychosocial factors. Factors associated with sICH and its severity were assessed using conditional logistic regression to estimate odds ratios (ORs) and population-attributable risks (PARs) with 95% confidence intervals (CIs) for factors.

RESULTS

Of 2,944 adjudicated stroke cases, 854 were intracerebral hemorrhage (ICH). Mean age of patients with ICH was 54.7 ± 13.9 years, with a male preponderance (63.1%), and 77.3% were nonlobar. Etiologic subtypes of sICH included hypertension (80.9%), structural vascular anomalies (4.0%), cerebral amyloid angiopathy (0.7%), systemic illnesses (0.5%), medication-related (0.4%), and undetermined (13.7%). Eight factors independently associated with sICH occurrence by decreasing order of PAR with their adjusted OR (95% CI) were hypertension, 66.63 (20.78-213.72); dyslipidemia, 2.95 (1.84-4.74); meat consumption, 1.55 (1.01-2.38); family history of CVD, 2.22 (1.41-3.50); nonconsumption of green vegetables, 3.61 (2.07-6.31); diabetes mellitus, 2.11 (1.29-3.46); stress, 1.68 (1.03-2.77); and current tobacco use, 14.27 (2.09-97.47). Factors associated with severe sICH using an NIH Stroke Scale score >15 with adjusted OR (95% CI) were nonconsumption of leafy green vegetables, 2.03 (1.43-2.88); systolic blood pressure for each mm Hg rise, 1.01 (1.00-1.01); presence of midline shift, 1.54 (1.11-2.13); lobar ICH, 1.72 (1.16-2.55); and supratentorial bleeds, 2.17 (1.06-4.46).

CONCLUSIONS

Population-level control of the dominant factors will substantially mitigate the burden of sICH in West Africa.

Clinical outcomes after AF cardioversion in patients presenting left atrial sludge in trans-esophageal echocardiography

BACKGROUND

Direct-current cardioversion (DCC) for atrial fibrillation carries a risk of stroke, probably associated with the temporary atrial stunning following cardioversion. The presence of a cardiac thrombus, usually localized in the left atrial appendage (LAA), is recognized as a clear contra-indication to the cardioversion. However, the presence of atrial sludge without LAA thrombus in trans-esophageal echocardiography (TEE) remains, for many cardiologists, a relative contra-indication to the cardioversion. The aim of this study was to evaluate the safety of DCC in patients presenting atrial sludge without LAA thrombus.

METHODS

We prospectively included all consecutive patients demonstrating atrial sludge without LAA thrombus in TEE and undergoing DCC for persistent atrial fibrillation (AF). Safety of DCC was evaluated by the occurrence of clinical events at 1 month following cardioversion, i.e., up to the end of the atrial stunning period, as assessed by clinical examination and the standardized and validated Questionnaire for Verifying Stroke-Free Status (QVSFS).

RESULTS

Over a period of 2 years, 21 patients presenting atrial sludge without LAA thrombus underwent DCC for AF. During the follow-up period of 1 month after DCC, no clinical embolic event, cardiac event, or unscheduled consultations/hospitalizations occurred. At 1 month, 67% of the patients remained in sinus rhythm.

CONCLUSION

No clinical event occurred in patients demonstrating atrial sludge without thrombus and undergoing DCC for AF. These findings support current guidelines that only keep atrial thrombus as a contraindication to cardioversion, but warrant further investigation in large studies.

The Sub-Saharan Africa Conference on Stroke (SSACS): An idea whose time has come

Stroke is a leading cause of global morbidity and mortality. Sub-Saharan Africa (SSA), where an unprecedented rise in stroke burden is currently raging, has the highest age-standardized stroke incidence, stroke prevalence, and stroke mortality rates. This is in sharp contrast to the relative decline in stroke incidence in high-income countries over the past four decades through better awareness and control of vascular risk factors. Compared to other groups, Africans tend to have a higher risk of stroke, higher percentage of the hemorrhagic type and much poorer outcomes. Indeed, stroke levies a heavy toll on the developing SSA economy by affecting a relatively younger age group. In this commentary, we examine the disproportionately high burden of stroke in the setting of grossly inadequate resources and evidence-based interventions. We propose an annual pan-regional stroke conference (starting in 2020) to harness global resources and local talent with the goal of galvanizing action to tackle this escalating burden. We anticipate that a successful conference series could become a rallying point for the eventual establishment of an African Stroke Organization.

Knowledge, attitudes and practices of West Africans on genetic studies of stroke: Evidence from the SIREN Study

BACKGROUND

It is crucial to assess genomic literacy related to stroke among Africans in preparation for the ethical, legal and societal implications of the genetic revolution which has begun in Africa.

OBJECTIVE

To assess the knowledge, attitudes and practices (KAP) of West Africans about stroke genetic studies.

METHODS

A comparative cross-sectional study was conducted among stroke patients and stroke-free controls recruited across 15 sites in Ghana and Nigeria. Participants' knowledge of heritability of stroke, willingness to undergo genetic testing and perception of the potential benefits of stroke genetic research were assessed using interviewer-administered questionnaire. Descriptive, frequency distribution and multiple regression analyses were performed.

RESULTS

Only 49% of 2029 stroke patients and 57% of 2603 stroke-free individuals knew that stroke was a heritable disorder. Among those who knew, 90% were willing to undergo genetic testing. Knowledge of stroke heritability was associated with having at least post-secondary education (OR 1.51, 1.25-1.81) and a family history of stroke (OR 1.20, 1.03-1.39) while Islamic religion (OR=0.82, CI: 0.72-0.94), being currently unmarried (OR = 0.81, CI: 0.70-0.92), and alcohol use (OR = 0.78, CI: 0.67-0.91) were associated with lower odds of awareness of stroke as a heritable disorder. Willingness to undergo genetic testing for stroke was associated with having a family history of stroke (OR 1.34, 1.03-1.74) but inversely associated with a medical history of high blood pressure (OR = 0.79, 0.65-0.96).

CONCLUSION

To further improve knowledge of stroke heritability and willingness to embrace genetic testing for stroke, individuals with less formal education, history of high blood pressure and no family history of stroke require targeted interventions.

Estimated glomerular filtration rate predicts incident stroke among Ghanaians with diabetes and hypertension

Background

Sub-Saharan Africa is currently experiencing a high burden of both chronic kidney disease (CKD) and stroke as a result of a rapid rise in shared common vascular risk factors such as hypertension and diabetes mellitus. However, no previous study has prospectively explored independent associations between CKD and incident stroke occurrence among indigenous Africans. This study sought to fill this knowledge gap.

Methods

A prospective cohort study involving Ghanaians adults with hypertension or type II diabetes mellitus from 5 public hospitals. Patients were followed every 2 months in clinic for 18 months and assessed clinically for first ever stroke by physicians. Serum creatinine derived estimated glomerular filtration rates (eGFR) were determined at baseline for 2631 (81.7%) out of 3296 participants. We assessed associations between eGFR and incident stroke using a multivariate Cox Proportional Hazards regression model.

Results

Stroke incidence rates (95% CI) increased with decreasing eGFR categories of 89, 60–88, 30–59 and <29 ml/min corresponding to incidence rates of 7.58 (3.58–13.51), 14.45 (9.07–21.92), 29.43 (15.95–50.04) and 66.23 (16.85–180.20)/1000 person-years respectively. Adjusted hazard ratios (95%CI) for stroke occurrence according to eGFR were 1.42 (0.63–3.21) for eGFR of 60-89 ml/min, 1.88 (1.17–3.02) for 30-59 ml/min and 1.52 (0.93–2.43) for <30 ml/min compared with eGFR of >89 ml/min. Adjusted HR for stroke occurrence among patients with hypertension with eGFR<60 ml/min was 3.69 (1.49–9.13), p = .0047 and among those with diabetes was 1.50 (0.56–3.98), p = .42.

Conclusion

CKD is dose-dependently associated with occurrence of incident strokes among Ghanaians with hypertension and diabetes mellitus. Further studies are warranted to explore interventions that could attenuate the risk of stroke attributable to renal disease among patients with hypertension in SSA.

•

We assessed association between incident stroke and estimated glomerular filtration rate.

•

2631 participants stroke-free Ghanaian adults with hypertension or diabetes were followed for 14 months.

•

There were 45 incident strokes.

•

Incident stroke risk independently increased with declining eGFR.

Risk factors for stroke occurrence in a low HIV endemic West African country: A case-control study

BACKGROUND

HIV infection is an emerging vascular risk factor associated with stroke occurrence. The weight of evidence from sub-Saharan Africa in support of this has accrued from countries with high HIV prevalence. Our objective was to assess the contribution of HIV sero-positivity to the occurrence and outcomes of stroke in a West African country with low HIV prevalence.

METHODS

A case-control study design conducted at a tertiary medical center in Ghana involved in the Stroke Investigative Research & Educational Networks (SIREN) epidemiological study. Stroke cases were adults (aged ≥18 years) with CT or MRI confirmed stroke and stroke-free controls were age-matched and recruited from communities in the catchment areas of cases. Standard instruments were used to assess vascular and lifestyle factors and serological screening for HIV antibodies was conducted for all study participants. Stroke patients were followed for in-patient mortality outcomes. Associations between HIV, demographic and vascular risk factors and stroke occurrence and outcomes were assessed using logistic regression analysis.

RESULTS

We enrolled 540 stroke cases and 540 control subjects with a mean (± SD) age of 60.8 ± 15.5 years (cases) and 60.0 ± 15.5 (controls). Among stroke cases, the frequency of HIV was 12/540 (2.2%, 95% CI: 1.3% - 3.6%) versus 15/540 (2.8%, 95% CI: 1.7% - 4.6%) among stroke-free controls, p = .70. However, the median (IQR) age of Persons Living with HIV (PLWH) with stroke was significantly lower at 46.5 (40-65.3) years versus 61.0 (50-74) years, p = .03 among HIV- stroke patients. Stroke among PLWHA was predominantly hemorrhagic in 7 out of 12 cases and ischemic in 5 of 12 with notable clustering of established factors such as hypertension, (100%), dyslipidemia, 83.3%, central obesity, 50.0%, diabetes mellitus, 33.3%, cardiac diseases, 8.3% in this group. None of the PLWH with stroke were receiving antiretroviral therapy.

CONCLUSION

We found no associations between HIV infection and stroke occurrence among Ghanaians. However a clustering of cardio-metabolic factors in the context of HIV may promote stroke occurrence in younger individuals.

Incident stroke among Ghanaians with hypertension and diabetes: A multicenter, prospective cohort study

Background

The burden of stroke among hypertensive and diabetic population in sub-Saharan Africa remains high. We sought to identify the risk factors associated with stroke occurrence in these high-risk population groups.

Methods

A prospective cohort study involving adults with hypertension and or type II diabetes mellitus at 5 public hospitals in Ghana who were stroke-free at enrollment. Patients were followed every 2 months at clinic for 18 months and assessed clinically for first ever stroke by physicians. We calculated crude incidence rates for stroke and assessed the factors associated with stroke occurrence using a multivariate Cox Proportional Hazards regression models.

Results

Of 3220 eligible participants with 3805 person-years of follow-up, there were 54 clinically confirmed new strokes. Incidence rate of stroke was 14.19 events per 1000 person-years [95% CI: 10.77–18.38], with rates among diabetics with hypertension being 16.64 [10.58–25.00], hypertension of 13.77 [9.33–19.64] and diabetes was 9.81 [3.59–21.74]. Two factors independently associated with stroke occurrence were previous cigarette smoking with adjusted HR (95% CI) of 2.59 (1.18–5.67) and physical inactivity, 1.81 (1.06–3.10). In secondary analysis, stage II hypertension compared with optimal BP was associated with aHR of 3.04 (1.00–9.27), p = .05 for stroke occurrence.

Conclusion

Incident stroke among Ghanaians with hypertension and diabetes is quite high. Stricter control of blood pressure and engaging in regular physical activities are strongly recommended to reduce the risk of strokes.

•

The first prospective cohort study to assess factors associated with incident strokes among Ghanaians

•

3220 participants stroke free adults with hypertension or diabetes were followed for an average of 14 months

•

There were 54 strokes with incidence rate of 14.19 events per 1000 person-years

•

Patients with both diabetes with hypertension had highest stroke rates

•

Previous cigarette smoking and physical inactivity were independently associated with incident strokes

Stroke Among Young West Africans: Evidence From the SIREN (Stroke Investigative Research and Educational Network) Large Multisite Case-Control Study

BACKGROUND AND PURPOSE

Stroke in lower and middle-income countries affects a young and productive age group. Data on factors associated with stroke in the young are sorely lacking from lower and middle-income countries. Our objective is to characterize the nature of stroke and its risk factors among young West Africans aged <50 years old.

METHODS

The SIREN (Stroke Investigative Research and Educational Network) is a multicenter, case-control study involving 15 sites in Nigeria and Ghana. Cases included adults aged ≥18 years with computed tomography/magnetic resonance imaging-confirmed stroke. Controls were age-and gender-matched stroke-free adults recruited from the communities in catchment areas of cases. Comprehensive evaluation for vascular, lifestyle, and psychosocial factors was performed. We used conditional logistic regression to estimate odds ratios and population attributable risks with 95% confidence intervals.

RESULTS

Five hundred fifteen (24.3%) out of 2118 cases enrolled were <50 years old. Among subjects <50 years old, hemorrhagic stroke proportion was 270 (52.5%) versus 245 (47.5%) for ischemic strokes. Etiologic subtypes of ischemic strokes included large artery atherosclerosis (40.0%), small vessel disease (28.6%), cardioembolism (11.0%), and undetermined (20.4%). Hypertension (91.7%), structural lesions (3.4%), and others (4.9%) were causally associated with hemorrhagic stroke. Six topmost modifiable factors associated with stroke in descending order of population attributable risk (95% confidence interval) were hypertension: 88.7% (82.5%-94.8%), dyslipidemia: 48.2% (30.6%-65.9%), diabetes mellitus: 22.6% (18.7%-26.5%), low green vegetable consumption: 18.2% (-6.8%-43.2%), stress: 14.5% (4.9%-24.1%), and cardiac disease: 8.4% (5.8%-11.1%).

CONCLUSIONS

The high and rising burden of stroke among young Africans should be curtailed via aggressive, population-wide vascular risk factor control.

Dominant modifiable risk factors for stroke in Ghana and Nigeria (SIREN): a case-control study

BACKGROUND

Sub-Saharan Africa has the highest incidence, prevalence, and fatality from stroke globally. Yet, only little information about context-specific risk factors for prioritising interventions to reduce the stroke burden in sub-Saharan Africa is available. We aimed to identify and characterise the effect of the top modifiable risk factors for stroke in sub-Saharan Africa.

METHODS

The Stroke Investigative Research and Educational Network (SIREN) study is a multicentre, case-control study done at 15 sites in Nigeria and Ghana. Cases were adults (aged ≥18 years) with stroke confirmed by CT or MRI. Controls were age-matched and gender-matched stroke-free adults (aged ≥18 years) recruited from the communities in catchment areas of cases. Comprehensive assessment for vascular, lifestyle, and psychosocial factors was done using standard instruments. We used conditional logistic regression to estimate odds ratios (ORs) and population-attributable risks (PARs) with 95% CIs.

FINDINGS

Between Aug 28, 2014, and June 15, 2017, we enrolled 2118 case-control pairs (1192 [56%] men) with mean ages of 59·0 years (SD 13·8) for cases and 57·8 years (13·7) for controls. 1430 (68%) had ischaemic stoke, 682 (32%) had haemorrhagic stroke, and six (<1%) had discrete ischaemic and haemorrhagic lesions. 98·2% (95% CI 97·2-99·0) of adjusted PAR of stroke was associated with 11 potentially modifiable risk factors with ORs and PARs in descending order of PAR of 19·36 (95% CI 12·11-30·93) and 90·8% (95% CI 87·9-93·7) for hypertension, 1·85 (1·44-2·38) and 35·8% (25·3-46·2) for dyslipidaemia, 1·59 (1·19-2·13) and 31·1% (13·3-48·9) for regular meat consumption, 1·48 (1·13-1·94) and 26·5% (12·9-40·2) for elevated waist-to-hip ratio, 2·58 (1·98-3·37) and 22·1% (17·8-26·4) for diabetes, 2·43 (1·81-3·26) and 18·2% (14·1-22·3) for low green leafy vegetable consumption, 1·89 (1·40-2·54) and 11·6% (6·6-16·7) for stress, 2·14 (1·34-3·43) and 5·3% (3·3-7·3) for added salt at the table, 1·65 (1·09-2·49) and 4·3% (0·6-7·9) for cardiac disease, 2·13 (1·12-4·05) and 2·4% (0·7-4·1) for physical inactivity, and 4·42 (1·75-11·16) and 2·3% (1·5-3·1) for current cigarette smoking. Ten of these factors were associated with ischaemic stroke and six with haemorrhagic stroke occurrence.

INTERPRETATION

Implementation of interventions targeting these leading risk factors at the population level should substantially curtail the burden of stroke among Africans.

FUNDING

National Institutes of Health.

APOL1, CDKN2A/CDKN2B, and HDAC9 polymorphisms and small vessel ischemic stroke

OBJECTIVE

Worldwide, the highest frequencies of APOL1-associated kidney variants are found in indigenous West Africans among whom small vessel disease (SVD) ischemic stroke is the most common stroke phenotype. The objective of this study was to investigate the association and effect sizes of 23 selected SNPs in 14 genes of relevance, including the APOL1 G1 variants, with the occurrence of SVD ischemic stroke among indigenous West African participants in the Stroke Investigative Research and Education Network (SIREN) Study.

MATERIALS AND METHODS

Cases were consecutively recruited consenting adults (aged 18 years or older) with neuroimaging-confirmed first clinical stroke. Stroke-free controls were ascertained using a locally validated version of the Questionnaire for Verifying Stroke-Free Status (QVSFS). Logistic regression models adjusting for known vascular risk factors were fitted to assess the associations of the 23 SNPs in rigorously phenotyped cases (N = 154) of SVD ischemic stroke and stroke-free (N = 483) controls.

RESULTS

Apolipoprotein L1 (APOL1) rs73885319 (OR = 1.52; CI: 1.09-2.13, P-value = .013), rs2383207 in CDKN2A/CDKN2B (OR = 3.08; CI: 1.15-8.26, P -value = .026) and rs2107595 (OR = 1.70; CI: 1.12-2.60, P-value = .014) and rs28688791 (OR = 1.52; CI: 1.03-2.26, P-value = .036) in HDAC9 gene were associated with SVD stroke at 0.05 significance level. Polymorphisms in other genes did not show significant associations.

CONCLUSION

This is the first report of a specific association of APOL1 with a stroke subtype. Further research is needed to confirm these initial findings and deepen understanding of the genetics of stroke in people of African ancestry with possible implications for other ancestries as all humans originated from Africa.

Plasma Glial Fibrillary Acidic Protein, Copeptin, and Matrix Metalloproteinase-9 Concentrations among West African Stroke Subjects Compared with Stroke-Free Controls

BACKGROUND

Measurement of plasma molecular markers among stroke patients has been proposed as an avenue for improving the accuracy of stroke diagnosis. There is paucity of data on the potential role of these markers in resource-limited settings, where the burden of stroke is greatest.

OBJECTIVE

To assess the potential diagnostic and prognostic performance of 3 proposed biomarkers for stroke in a resource-constrained setting.

METHODS

Consecutive stroke subjects presenting at a tertiary medical center in Kumasi, Ghana, with radiologically confirmed diagnosis and etiologic subtype information available were recruited along with age- and gender-matched controls in a 2:1 ratio. Plasma concentrations of glial fibrillary acidic protein (GFAP), copeptin, and matrix metalloproteinase-9 (MMP-9) among stroke patients and stroke-free controls were measured in duplicates using enzyme linked immunoassays. Diagnostic and prognostic correlates were assessed using area-under-the-curve (AUC) measures of receiver operator curves and logistic regression analysis, respectively.

RESULTS

There were 156 stroke subjects with a mean age of 61.3 years of which 47.4% were females and 74 age- and gender-matched stroke-free controls. Median (interquartile range) time from symptom onset to hospital presentation for care was 7 days (5-11). Diagnostic accuracy of a single measurement of the 3 biomarkers for stroke using AUC (95% confidence interval) plots were as follows: .84 (.77-0.91), P < .0001, for GFAP; .85 (.79-0.92), P < .0001, for copeptin; and .65 (.56-0.73), P = .0003, for MMP-9. None of the biomarkers was associated with stroke severity or mortality.

CONCLUSION

Plasma concentrations of GFAP and copeptin demonstrated stronger associations with stroke occurrence in this West African cohort compared with controls.

Advancing stroke genomic research in the age of Trans-Omics big data science: Emerging priorities and opportunities

BACKGROUND

We systematically reviewed the genetic variants associated with stroke in genome-wide association studies (GWAS) and examined the emerging priorities and opportunities for rapidly advancing stroke research in the era of Trans-Omics science.

METHODS

Using the PRISMA guideline, we searched PubMed and NHGRI- EBI GWAS catalog for stroke studies from 2007 till May 2017.

RESULTS

We included 31 studies. The major challenge is that the few validated variants could not account for the full genetic risk of stroke and have not been translated for clinical use. None of the studies included continental Africans. Genomic study of stroke among Africans presents a unique opportunity for the discovery, validation, functional annotation, Trans-Omics study and translation of genomic determinants of stroke with implications for global populations. This is because all humans originated from Africa, a continent with a unique genomic architecture and a distinctive epidemiology of stroke; as well as substantially higher heritability and resolution of fine mapping of stroke genes.

CONCLUSION

Understanding the genomic determinants of stroke and the corresponding molecular mechanisms will revolutionize the development of a new set of precise biomarkers for stroke prediction, diagnosis and prognostic estimates as well as personalized interventions for reducing the global burden of stroke.

Burden and Predictors of Poststroke Cognitive Impairment in a Sample of Ghanaian Stroke Survivors

BACKGROUND AND OBJECTIVE

There are limited data on vascular cognitive impairment (VCI) from low- and middle-income countries where the stroke burden is burgeoning. The aim of this study was to characterize the burden, determinants, and effects of VCI on health-related quality of life in sub-Saharan Africa (SSA).

METHODS

From January 2015 to February 2016, we collected information on 147 consecutive stroke survivors (>45 years) seen at a tertiary hospital in Ghana and 49 demographically matched stroke-free controls. Data collected included demographics, clinical factors, health-related quality of life, and presence of depression. Cognitive status was evaluated using a standard Vascular Neuropsychological Battery that assessed memory, executive function and mental speed, language, and visuospatial-visuoconstructive functioning. Expert VCI guideline and Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition criteria were used to classify stroke patients into no VCI, VCI but no dementia, and vascular dementia (VD).

RESULTS

The mean age ± standard deviation of the stroke survivors was 59.9 ± 13.7 years, of which 47.6% were women. Among the cohort, 77 out of 147 (52.3%) had no VCI, 50 of the 147 (34.0%) had VCI without dementia, and 20 of the 147 (13.6%) had VD. Three factors remained significantly associated with VCI: increasing age for each successive 10-year rise (odds ratio [OR] 1.44, 95% confidence interval [CI]: 1.03-2.02), lack of formal education (OR 5.26, 95% CI: 1.01-27.52), and worse functional disability on the modified Rankin scale (OR 2.46, 95% CI: 1.61-3.75). Patients with VD had the poorest health-related quality of life.

CONCLUSIONS

Half of the Ghanaian stroke survivors encountered in this cross-sectional study had evidence of cognitive dysfunction. Future studies in SSA will need to identify strategies to address this immense burden.

Interleukin-6 (IL-6) rs1800796 and cyclin dependent kinase inhibitor (CDKN2A/CDKN2B) rs2383207 are associated with ischemic stroke in indigenous West African Men

BACKGROUND

Inherited genetic variations offer a possible explanation for the observed peculiarities of stroke in sub - Saharan African populations. Interleukin-6 polymorphisms have been previously associated with ischemic stroke in some non-African populations.

AIM

Herein we investigated, for the first time, the association of genetic polymorphisms of IL-6, CDKN2A- CDKN2B and other genes with ischemic stroke among indigenous West African participants in the Stroke Investigative Research and Education Network (SIREN) Study.

METHODS

Twenty-three previously identified single nucleotide polymorphisms (SNPs) in 14 genes of relevance to the neurobiology of ischemic stroke were investigated. Logistic regression models adjusting for known cardiovascular disease risk factors were constructed to assess the associations of the 23 SNPs in rigorously phenotyped cases (N=429) of ischemic stroke (Men=198; Women=231) and stroke- free (N=483) controls (Men=236; Women=247).

RESULTS

Interleukin-6 (IL6) rs1800796 (C minor allele; frequency: West Africans=8.6%) was significantly associated with ischemic stroke in men (OR=2.006, 95% CI=[1.065, 3.777], p=0.031) with hypertension in the model but not in women. In addition, rs2383207 in CDKN2A/CDKN2B (minor allele A with frequency: West Africans=1.7%) was also associated with ischemic stroke in men (OR=2.550, 95% CI=[1.027, 6.331], p=0.044) with primary covariates in the model, but not in women. Polymorphisms in other genes did not show significant association with ischemic stroke.

CONCLUSION

Polymorphisms rs1800796 in IL6 gene and rs2383207 in CDKN2A/CDKN2B gene have significant associations with ischemic stroke in indigenous West African men. CDKN2A/CDKN2B SNP rs2383207 is independently associated with ischemic stroke in indigenous West African men. Further research should focus on the contributions of inflammatory genes and other genetic polymorphisms, as well as the influence of sex on the neurobiology of stroke in people of African ancestry.

Administration of a pictorial questionnaire to screen for stroke among patients with hypertension or diabetes in rural Ghana

BACKGROUND

Stroke prevention is an important public health goal in low-and-middle income countries (LMIC) due to its high mortality and morbidity in these settings. Epidemiological data from high-income countries have demonstrated a potent predictive association between self-reported stroke symptoms and risks of future strokes, incident cognitive impairment and all-cause mortality.

OBJECTIVE

To utilize a pictographic version of the 8-item Questionnaire for Verifying Stroke Free Status (QVSFS) to screen for stroke symptoms and determine its predictors among hypertensive and diabetic patients in a rural hospital within a LMIC.

METHODS

Between July and October 2016, 500 consecutive patients with hypertension and/or diabetes mellitus encountered in clinic at the Agogo Presbyterian Hospital, a district level health institution in Ghana were enrolled. A validated pictographic version of the QVSFS was administered by trained research assistants to all study participants and demographic and clinical information on hypertension and diabetes control were collected. The neurologist/specialist physician examined all patients neurologically using a structured questionnaire and reviewed medical charts for objective documentary evidence of stroke. Predictors of stroke symptoms were assessed using a multivariate logistic regression model.

RESULTS

Among the cohort, median (IQR) age was 58 (51-66) years, 399 (79.8%) were women, 388 (77.6%) had hypertension, 92 (18.4%) had diabetes and hypertension, and 20 (4.0%) had just diabetes. 30 (6.0%) patients had confirmed stroke/TIA after physician evaluation, 151 (30.6%) had at least one symptom of stroke (SS) without prior diagnosis of stroke/TIA and 319 (63.8%) reported no stroke symptoms. Independent predictors of reporting stroke symptoms were increasing age - aOR: 1.38 (1.16-1.64) for each 10years older and HBA1C-OR: 1.74 (1.16-2.61) for each 2% increase. Subjects with previous stroke/TIA diagnosis had significantly higher mean±SD systolic blood pressure (148.0±21.2mmHg vs. 136.0±17.3mmHg vs. 138.3±19.7mmHg, p=0.009) and median (IQR) HBA1C (8.8% (6.7-10.2) vs. 8.2 (6.4-10.6) vs. 7.2 (6.3-8.0), p=0.05) compared with SS and asymptomatic groups.

CONCLUSION

One in three patients with hypertension and/diabetes in rural Ghana report stroke-like symptoms. Routine use of the pictographic version of the QVSFS could assist in identifying patients with or at high risk for stroke who may benefit from appropriate prevention treatments.