Okechukwu S Ogah

Global and regional effects of potentially modifiable risk factors associated with acute stroke in 32 countries (INTERSTROKE): a case-control study

BACKGROUND Stroke is a leading cause of death and disability, especially in low-income and middle-income countries. We sought to quantify the importance of potentially modifiable risk factors for stroke in different regions of the world, and in key populations and primary pathological subtypes of stroke. METHODS We completed a standardised international case-control study in 32 countries in Asia, America, Europe, Australia, the Middle East, and Africa. Cases were patients with acute first stroke (within 5 days of symptom onset and 72 h of hospital admission). Controls were hospital-based or community-based individuals with no history of stroke, and were matched with cases, recruited in a 1:1 ratio, for age and sex. All participants completed a clinical assessment and were requested to provide blood and urine samples. Odds ratios (OR) and their population attributable risks (PARs) were calculated, with 99% confidence intervals. FINDINGS Between Jan 11, 2007, and Aug 8, 2015, 26 919 participants were recruited from 32 countries (13 447 cases [10 388 with ischaemic stroke and 3059 intracerebral haemorrhage] and 13 472 controls). Previous history of hypertension or blood pressure of 140/90 mm Hg or higher (OR 2·98, 99% CI 2·72-3·28; PAR 47·9%, 99% CI 45·1-50·6), regular physical activity (0·60, 0·52-0·70; 35·8%, 27·7-44·7), apolipoprotein (Apo)B/ApoA1 ratio (1·84, 1·65-2·06 for highest vs lowest tertile; 26·8%, 22·2-31·9 for top two tertiles vs lowest tertile), diet (0·60, 0·53-0·67 for highest vs lowest tertile of modified Alternative Healthy Eating Index [mAHEI]; 23·2%, 18·2-28·9 for lowest two tertiles vs highest tertile of mAHEI), waist-to-hip ratio (1·44, 1·27-1·64 for highest vs lowest tertile; 18·6%, 13·3-25·3 for top two tertiles vs lowest), psychosocial factors (2·20, 1·78-2·72; 17·4%, 13·1-22·6), current smoking (1·67, 1·49-1·87; 12·4%, 10·2-14·9), cardiac causes (3·17, 2·68-3·75; 9·1%, 8·0-10·2), alcohol consumption (2·09, 1·64-2·67 for high or heavy episodic intake vs never or former drinker; 5·8%, 3·4-9·7 for current alcohol drinker vs never or former drinker), and diabetes mellitus (1·16, 1·05-1·30; 3·9%, 1·9-7·6) were associated with all stroke. Collectively, these risk factors accounted for 90·7% of the PAR for all stroke worldwide (91·5% for ischaemic stroke, 87·1% for intracerebral haemorrhage), and were consistent across regions (ranging from 82·7% in Africa to 97·4% in southeast Asia), sex (90·6% in men and in women), and age groups (92·2% in patients aged ≤55 years, 90·0% in patients aged >55 years). We observed regional variations in the importance of individual risk factors, which were related to variations in the magnitude of ORs (rather than direction, which we observed for diet) and differences in prevalence of risk factors among regions. Hypertension was more associated with intracerebral haemorrhage than with ischaemic stroke, whereas current smoking, diabetes, apolipoproteins, and cardiac causes were more associated with ischaemic stroke (p<0·0001). INTERPRETATION Ten potentially modifiable risk factors are collectively associated with about 90% of the PAR of stroke in each major region of the world, among ethnic groups, in men and women, and in all ages. However, we found important regional variations in the relative importance of most individual risk factors for stroke, which could contribute to worldwide variations in frequency and case-mix of stroke. Our findings support developing both global and region-specific programmes to prevent stroke. FUNDING Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, Canadian Stroke Network, Health Research Board Ireland, Swedish Research Council, Swedish Heart and Lung Foundation, The Health & Medical Care Committee of the Regional Executive Board, Region Västra Götaland (Sweden), AstraZeneca, Boehringer Ingelheim (Canada), Pfizer (Canada), MSD, Chest, Heart and Stroke Scotland, and The Stroke Association, with support from The UK Stroke Research Network.

Characteristics, complications, and gaps in evidence-based interventions in rheumatic heart disease: the Global Rheumatic Heart Disease Registry (the REMEDY study)

AIMS Rheumatic heart disease (RHD) accounts for over a million premature deaths annually; however, there is little contemporary information on presentation, complications, and treatment. METHODS AND RESULTS This prospective registry enrolled 3343 patients (median age 28 years, 66.2% female) presenting with RHD at 25 hospitals in 12 African countries, India, and Yemen between January 2010 and November 2012. The majority (63.9%) had moderate-to-severe multivalvular disease complicated by congestive heart failure (33.4%), pulmonary hypertension (28.8%), atrial fibrillation (AF) (21.8%), stroke (7.1%), infective endocarditis (4%), and major bleeding (2.7%). One-quarter of adults and 5.3% of children had decreased left ventricular (LV) systolic function; 23% of adults and 14.1% of children had dilated LVs. Fifty-five percent (n = 1761) of patients were on secondary antibiotic prophylaxis. Oral anti-coagulants were prescribed in 69.5% (n = 946) of patients with mechanical valves (n = 501), AF (n = 397), and high-risk mitral stenosis in sinus rhythm (n = 48). However, only 28.3% (n = 269) had a therapeutic international normalized ratio. Among 1825 women of childbearing age (12-51 years), only 3.6% (n = 65) were on contraception. The utilization of valvuloplasty and valve surgery was higher in upper-middle compared with lower-income countries. CONCLUSION Rheumatic heart disease patients were young, predominantly female, and had high prevalence of major cardiovascular complications. There is suboptimal utilization of secondary antibiotic prophylaxis, oral anti-coagulation, and contraception, and variations in the use of percutaneous and surgical interventions by country income level.

Prednisolone and Mycobacterium indicus pranii in Tuberculous Pericarditis

BACKGROUND Tuberculous pericarditis is associated with high morbidity and mortality even if antituberculosis therapy is administered. We evaluated the effects of adjunctive glucocorticoid therapy and Mycobacterium indicus pranii immunotherapy in patients with tuberculous pericarditis. METHODS Using a 2-by-2 factorial design, we randomly assigned 1400 adults with definite or probable tuberculous pericarditis to either prednisolone or placebo for 6 weeks and to either M. indicus pranii or placebo, administered in five injections over the course of 3 months. Two thirds of the participants had concomitant human immunodeficiency virus (HIV) infection. The primary efficacy outcome was a composite of death, cardiac tamponade requiring pericardiocentesis, or constrictive pericarditis. RESULTS There was no significant difference in the primary outcome between patients who received prednisolone and those who received placebo (23.8% and 24.5%, respectively; hazard ratio, 0.95; 95% confidence interval [CI], 0.77 to 1.18; P=0.66) or between those who received M. indicus pranii immunotherapy and those who received placebo (25.0% and 24.3%, respectively; hazard ratio, 1.03; 95% CI, 0.82 to 1.29; P=0.81). Prednisolone therapy, as compared with placebo, was associated with significant reductions in the incidence of constrictive pericarditis (4.4% vs. 7.8%; hazard ratio, 0.56; 95% CI, 0.36 to 0.87; P=0.009) and hospitalization (20.7% vs. 25.2%; hazard ratio, 0.79; 95% CI, 0.63 to 0.99; P=0.04). Both prednisolone and M. indicus pranii, each as compared with placebo, were associated with a significant increase in the incidence of cancer (1.8% vs. 0.6%; hazard ratio, 3.27; 95% CI, 1.07 to 10.03; P=0.03, and 1.8% vs. 0.5%; hazard ratio, 3.69; 95% CI, 1.03 to 13.24; P=0.03, respectively), owing mainly to an increase in HIV-associated cancer. CONCLUSIONS In patients with tuberculous pericarditis, neither prednisolone nor M. indicus pranii had a significant effect on the composite of death, cardiac tamponade requiring pericardiocentesis, or constrictive pericarditis. (Funded by the Canadian Institutes of Health Research and others; IMPI ClinicalTrials.gov number, NCT00810849.).

Blood pressure, prevalence of hypertension and hypertension related complications in Nigerian Africans : A review

To review studies on hypertension in Nigeria over the past five decades in terms of prevalence, awareness and treatment and complications. Following our search on Pubmed, African Journals Online and the World Health Organization Global cardiovascular infobase, 1060 related references were identified out of which 43 were found to be relevant for this review. The overall prevalence of hypertension in Nigeria ranges from 8%-46.4% depending on the study target population, type of measurement and cut-off value used for defining hypertension. The prevalence is similar in men and women (7.9%-50.2% vs 3.5%-68.8%, respectively) and in the urban (8.1%-42.0%) and rural setting (13.5%-46.4%).The pooled prevalence increased from 8.6% from the only study during the period from 1970-1979 to 22.5% (2000-2011). Awareness, treatment and control of hypertension were generally low with attendant high burden of hypertension related complications. In order to improve outcomes of cardiovascular disease in Africans, public health education to improve awareness of hypertension is required. Further epidemiological studies on hypertension are required to adequately understand and characterize the impact of hypertension in society.

Recent advances in hypertension in sub-Saharan Africa

Background Hypertension was once considered rare in sub-Saharan Africa (SSA), but currently it has become a widespread problem with immense socioeconomic importance. The purpose of this review is to summarise new information on hypertension in SSA that has been published since the last major review in 2008. Methods and results A literature search was performed in Pubmed, Embase, WHO Global Cardiovascular Infobase, African Journal On-Line, and African Index Medicus using the following search criteria: hypertension, high blood pressure, and Africa/SSA. Epidemiological surveys that used the WHO STEPS approach or similar methods were also included. The overall prevalence of hypertension in SSA was estimated at 16.2% (95% CI 14.2% to 20.3%) with an estimated number of hypertensive individuals to be 74.7 million. The prevalence of hypertension varies widely from country to country. It is projected that the number of affected individuals will increase by 68% (125.5 million) by 2025. Mass migration of rural Africans to urban areas and rapid changes in lifestyle and risk factors account for the rising prevalence of hypertension. Conclusions Proactive public health interventions at a population level need to be introduced to control the growing hypertension epidemic, and there needs to be a major improvement in access to hypertensive care for the individual. There is an important need for better epidemiological data and hypertension related outcome trials in SSA.

Asymmetric Dimethylarginine and Reduced Nitric Oxide Bioavailability in Young Black African Men

Black Africans have a higher incidence of cardiovascular disease than white Europeans. We explored potential mechanisms of this excess risk by assessing endothelium function, inflammatory status (C-reactive protein), oxidative stress (isoprostane-F2&agr;), and plasma asymmetrical dimethyl arginine (ADMA; an endogenous competitive inhibitor of NO synthase) in each ethnic group. Thirty healthy black Africans and 28 well-matched white European male subjects were studied (mean age±SE: 32.2±0.9 and 29.2±1.2 years, respectively; P=0.07). High-resolution ultrasound was used to assess vascular function in the brachial artery by measuring flow mediated dilatation ([percentage of change]; endothelium-dependent function) and glyceryltrinitrate dilatation ([percentage of change]; endothelium-independent function). Blood pressure, fasting lipids, glucose, and estimated glomerular filtration rate levels were similar in both groups. There was no difference in C-reactive protein (black Africans: 0.8±0.1 mg/L; white Europeans: 0.6±0.1 mg/L; P=0.22), isoprostane-F2&agr; (black Africans: 42.9±1.5 pg/mL; white Europeans: 39.2±1.5 pg/mL; P=0.23), and leptin (black Africans: 64.1±10.2 ng/mL; white Europeans: 47.8±9.8 ng/mL; P=0.37) levels between the 2 ethnic groups. However, compared with white Europeans, plasma ADMA levels were significantly higher in black Africans (0.34±0.02 &mgr;mol/L and 0.25±0.03 &mgr;mol/L; P=0.03). There was no difference in the percentage of glyceryltrinitrate dilatation (P=0.7), but the percentage of flow-mediated dilatation was significantly lower in black Africans (black Africans: 5.2±0.3; white Europeans: 6.3±0.4; P=0.02). In a stepwise multiple regression model, ADMA level was the only independent determinant of flow-mediated dilatation (P=0.02). In turn, race was the only independent determinant of ADMA levels (P=0.03). Our findings indicate that circulating ADMA levels are significantly higher in healthy black African males than in white European males. This may contribute to the lower NO bioavailability and higher incidence of cardiovascular disease seen in black Africans.

Prevalence of overweight and obesity in adult Nigerians - a systematic review.

Background Obesity is a major health problem, and there is an increasing trend of overweight and obese individuals in developing countries. Being overweight or obese is known to contribute significantly to morbidity and mortality rates in various countries around the world. We therefore aimed to identify and discuss current epidemiological data on the prevalence of obesity in Nigeria. Method A systematic review of papers published on the prevalence of obesity among adults in the country was carried out. We covered work published in MEDLINE, PubMed, Google, and African Journals Online using the terms “prevalence of overweight and obesity in Nigeria” or “overweight and obesity in Nigeria.” In addition, personal inquiries were made. The search limits were articles published from January 2001 to September 2012. Only studies that used the body mass index to assess for overweight and obesity were included. Results Four studies met the inclusion criteria out of the 75 studies reviewed. In Nigeria, the prevalence of overweight individuals ranged from 20.3%–35.1%, while the prevalence of obesity ranged from 8.1%–22.2%. Conclusion The prevalence of overweight and obese individuals in Nigeria is of epidemic proportions. There is a need to pay closer attention to combating these health disorders.

Clinical Outcomes in 3343 Children and Adults with Rheumatic Heart Disease from 14 Low and Middle Income Countries: 2-Year Follow-up of the Global Rheumatic Heart Disease Registry (the REMEDY study)

Background: There are few contemporary data on the mortality and morbidity associated with rheumatic heart disease or information on their predictors. We report the 2-year follow-up of individuals with rheumatic heart disease from 14 low- and middle-income countries in Africa and Asia. Methods: Between January 2010 and November 2012, we enrolled 3343 patients from 25 centers in 14 countries and followed them for 2 years to assess mortality, congestive heart failure, stroke or transient ischemic attack, recurrent acute rheumatic fever, and infective endocarditis. Results: Vital status at 24 months was known for 2960 (88.5%) patients. Two-thirds were female. Although patients were young (median age, 28 years; interquartile range, 18–40), the 2-year case fatality rate was high (500 deaths, 16.9%). Mortality rate was 116.3/1000 patient-years in the first year and 65.4/1000 patient-years in the second year. Median age at death was 28.7 years. Independent predictors of death were severe valve disease (hazard ratio [HR], 2.36; 95% confidence interval [CI], 1.80–3.11), congestive heart failure (HR, 2.16; 95% CI, 1.70–2.72), New York Heart Association functional class III/IV (HR, 1.67; 95% CI, 1.32–2.10), atrial fibrillation (HR, 1.40; 95% CI, 1.10–1.78), and older age (HR, 1.02; 95% CI, 1.01–1.02 per year increase) at enrollment. Postprimary education (HR, 0.67; 95% CI, 0.54–0.85) and female sex (HR, 0.65; 95% CI, 0.52–0.80) were associated with lower risk of death. Two hundred and four (6.9%) patients had new congestive heart failure (incidence, 38.42/1000 patient-years), 46 (1.6%) had a stroke or transient ischemic attack (8.45/1000 patient-years), 19 (0.6%) had recurrent acute rheumatic fever (3.49/1000 patient-years), and 20 (0.7%) had infective endocarditis (3.65/1000 patient-years). Previous stroke and older age were independent predictors of stroke/transient ischemic attack or systemic embolism. Patients from low- and lower-middle–income countries had significantly higher age- and sex-adjusted mortality than patients from upper-middle–income countries. Valve surgery was significantly more common in upper-middle–income than in lower-middle– or low-income countries. Conclusions: Patients with clinical rheumatic heart disease have high mortality and morbidity despite being young; those from low- and lower-middle–income countries had a poorer prognosis associated with advanced disease and low education. Programs focused on early detection and the treatment of clinical rheumatic heart disease are required to improve outcomes.

Spectrum of heart diseases in a new cardiac service in Nigeria: An echocardiographic study of 1441 subjects in Abeokuta

BackgroundEchocardiography is a non-invasive, relatively cheap and useful imaging technique for the evaluation of cardiac diseases. The procedure has reliable levels of accuracy.Echocardiography commenced at the Federal medical centre Abeokuta on September 9, 2005.The aim of this study is to report our experience with the procedure, and to define the clinical cases seen in our setting.MethodsThis is a retrospective analysis of a prospectively collected data. Echocardiography was performed using Aloka SSD 1,100 echocardiograph equipped with 2.5–5.0 MHz transducerResultsDuring the period of 18 months under review (September 2005–February 2007), 1629 procedures were performed. The reports of 188 echocardiograms were excluded due to poor echo-window, repeated procedure or incomplete report. 1441 reports were reviewed for demographic parameter, indications for the procedure and the main echocardiographic diagnoses.The mean age of the 1441 individuals studied was 54 +/- 14.3 years (15–90). There were 744 men and 697 women. Eight hundred and seventeen subjects (56.7%) had hypertensive heart disease, 53 subjects (3.7%) had rheumatic heart disease while 44(3.0%) had dilated cardiomyopathy. Pericardial diseases, cor-pulmonale, ischaemic heart disease, congenital heart diseases, diabetic heart disease, thyroid heart disease, sickle cell cardiopathy were present in 26(1.8%), 23(1.6%), 9(0.6%), 6(0.4%), 6(0.4%), 6(0.4%), 1(0.1%), and 1(0.1%) respectively. Four hundred and forty nine (31.2%) subjects had normal study.ConclusionHypertensive heart disease was found to be the most prevalent cardiac condition in this study. The relatively frequent diagnoses of rheumatic heart disease, cardiomyopathies and pericardial diseases reflect the impact of infections and infestations on the cardiovascular health of adult Nigerians.We suggest that prevention and treatment of cardiac diseases in our setting should among other things focus on blood pressure control and early treatment of infections causing heart diseases.

Left ventricular geometric patterns in newly presenting nigerian hypertensives: An echocardiographic study

BackgroundHypertension is a global problem and it is prevalent in Nigeria. Left ventricular hypertrophy is a major complication of hypertension with risk of sudden death and arrhythmias among others. Abnormal left ventricular geometric patterns also increase the burden of morbidity and mortality. It is therefore important to know the different left ventricular geometric patterns in Nigerian hypertensives because of their prognostic significance.MethodsOne hundred (100) newly presenting hypertensives (53 males and 47 females) and 100 controls (53 males and 47 females) were recruited for the study. All were subjected to clinical evaluation and full echocardiographic examination was performed according to the ASE recommendation. The relative wall thickness and the presence or absence of echocardiographic left ventricular hypertrophy were used to determine the various geometric patternsResultsThe mean age of the hypertensive subjects was 56.06 (± 7.68) years while that of the control subjects was 56.10 (± 7.68) years. There was no significant difference in the mean ages of the two groups. In the hypertensive subjects 28% had normal geometry, 26% had concentric remodeling, 28% had concentric hypertrophy and 18% had eccentric hypertrophy. In the control group, 86% had normal geometry, 11% had concentric remodeling, 3% had eccentric hypertrophy and none had concentric hypertrophy. There was statistical significance when the geometric patterns of the hypertensive and controls were compared (χ2 = 74.30, p value < 0.0001).ConclusionThe study showed that only 28% of the hypertensive subjects had normal LV geometric pattern while 86% of the normal subjects had normal geometry. There is need for longitudinal studies in order to prognosticate the various geometric patterns.