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

Abstract

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. 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 Stroke Investigative Research and Education Network (SIREN) study. Methods SIREN is a transnational, multi-centre study involving acute stroke patients and age, ethnicity and sex-matched controls 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% males). 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 BP (167.1/99.5 mmHg vs 151.7/90.6 mmHg, p <0.001). Uncontrolled blood pressure (BP) 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 (AOR =1.91, 95% CI: 1.14 to 3.19), female gender (AOR = 2.01; 95% CI:1.44 to 2.81), and diastolic BP > 90mmHg (AOR = 2.10; 95% CI:1.39 to 3.19, p <0.001). Conclusion 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 left ventricular hypertrophy 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.

Left Ventricular Hypertrophy in Young Africans With First Ever Stroke in Tanzania: A Prospective Cohort Study&nbsp;

“…This study aimed to investigate the burden and early outcomes of LVH among young adults with rst ever stroke admitted at a tertiary hospital in Tanzania. We found that three-quarters of young stroke participants had LVH as diagnosed by TTE, which is higher than that described in a West African study by Adeoye et al, were 55% of the blacks (mean age of 59.1±13.2 years) with rst stroke had LVH (12). The authors also found that younger age ≤45 years was independently associated with LVH, suggesting an underlying genetic factor in the pathogenesis which merits further investigation.…”

“…Independent predictors for LVH were: younger age (<45 years), female gender and uncontrolled hypertension (12).…”

“…A study in West Africa revealed that more than half of the stroke patients were found to have LVH by electrocardiogram. Independent predictors for LVH were: younger age (<45 years), female gender and uncontrolled hypertension (12).…”

The burden, correlates and outcomes of left ventricular hypertrophy among young Africans with first ever stroke in Tanzania

“…Compared to whites, Africans with or without stroke are more likely to have LVH across all age groups. Adeoye et al in West Africa found that in a cohort of stroke participants above 18 years, younger age (≤ 45 years), female gender and uncontrolled hypertension was independently associated with LVH [ 11 ].…”

“…In SSA, there is a high burden of LVH (up to 50%) particularly among untreated hypertensive patients [ 10 ]. A study in West Africa revealed that more than half of the stroke patients were found to have LVH by electrocardiogram: independent predictors for LVH included younger age (< 45 years), female gender and uncontrolled hypertension [ 11 ]. Transthoracic echocardiography (TTE) is a noninvasive modality of choice to assess cardiac structure and function (including the detection of LVH) [ 12 ].…”