Carotid and Vertebral Atherosclerosis in West African Stroke Patients: Findings from the Stroke Investigative Research and Education Network.

Background: We evaluated the characteristics of carotid and vertebral atherosclerosis in indigenous West Africans with stroke. Methodology: Of the 3778stroke patients recruited between 01/2014 and 08/2017, 1070 (28.3%) received carotid and vertebral artery evaluation with B-mode Ultrasound. Carotid and vertebral intima-media thickness (IMT) using multiple site technique were measured bilaterally and plaque frequency was determined. Descriptive and comparative analyses between stroke types and vessels were carried out. Results: There were 809 (75.6%) patients with ischemic stroke. The prevalence of intima-media thickening in the study population was 84.0% (898/1070) [95% CI: 81.7-86.1], being higher in the ischemic stroke (688/809, 85.0%) [95% CI: 82.4-87.3] than in the hemorrhagic stroke group (211/261, 80.8%) [95% CI: 75.6-85.2]. Overall prevalence of plaques which was 26.1% [95% CI: 23.5-28.8], was found also to be higher in ischemic than hemorrhagic stroke (29.8%[95% CI: 26.7-33.0] vs. 14.6% [95% CI: 10.8-19.4], p < 0.05). The mean IMT (carotids: 2.01+1.33 mm; vertebrals: 0.96+0.54mm, p<0.001) and prevalence of plaques (carotids: 8.8%; vertebrals: 1.7%,p<0.001) were higher in carotid than vertebral arteries. Age, hypertension, level of formal education, history of smoking, average monthly income, and family histories of hypertension and stroke were associated with intima-media thickening in the carotids (all p< 0.05) in the ischemic stroke patients while family history of hypertension, diabetes mellitus, and level of formal education were independently associated with intima-media thickening in the carotids (all p< 0.05) in the hemorrhagic stroke patients. No CVRF showed an independent association with the presence of plaque in the carotid and vertebral arteries both stroke types. Conclusions: One off our stroke patients in our cohort had atherosclerotic plaques, with ischemic patients being twice as likely to have this burden compared to hemorrhagic patients, and carotid atherosclerosis being five times as frequent as vertebral atherosclerosis.

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.

Exploring Overlaps Between the Genomic and Environmental Determinants of LVH and Stroke: A Multicenter Study in West Africa.

BACKGROUND: Whether left ventricular hypertrophy (LVH) is determined by similar genomic and environmental risk factors with stroke, or is simply an intermediate stroke marker, is unknown. OBJECTIVES: We present a research plan and preliminary findings to explore the overlap in the genomic and environmental determinants of LVH and stroke among Africans participating in the SIREN (Stroke Investigative Research and Education Network) study. METHODS: SIREN is a transnational, multicenter study involving acute stroke patients and age-, ethnicity-, and sex-matched control subjects recruited from 9 sites in Ghana and Nigeria. Genomic and environmental risk factors and other relevant phenotypes for stroke and LVH are being collected and compared using standard techniques. RESULTS: This preliminary analysis included only 725 stroke patients (mean age 59.1 ± 13.2 years; 54.3% male). Fifty-five percent of the stroke subjects had LVH with greater proportion among women (51.6% vs. 48.4%; p < 0.001). Those with LVH were younger (57.9 ± 12.8 vs. 60.6 ± 13.4; p = 0.006) and had higher mean systolic and diastolic blood pressure (167.1/99.5 mm Hg vs 151.7/90.6 mm Hg; p < 0.001). Uncontrolled blood pressure at presentation was prevalent in subjects with LVH (76.2% vs. 57.7%; p < 0.001). Significant independent predictors of LVH were age <45 years (adjusted odds ratio [AOR]: 1.91; 95% confidence interval [CI]: 1.14 to 3.19), female sex (AOR: 2.01; 95% CI: 1.44 to 2.81), and diastolic blood pressure > 90 mm Hg (AOR: 2.10; 95% CI: 1.39 to 3.19; p < 0.001). CONCLUSIONS: The prevalence of LVH was high among stroke patients especially the younger ones, suggesting a genetic component to LVH. Hypertension was a major modifiable risk factor for stroke as well as LVH. It is envisaged that the SIREN project will elucidate polygenic overlap (if present) between LVH and stroke among Africans, thereby defining the role of LVH as a putative intermediate cardiovascular phenotype and therapeutic target to inform interventions to reduce stroke risk in populations of African ancestry.