Genetic mutations in African patients with atrial fibrillation: Rationale and design of the Study of Genetics of Atrial Fibrillation in an African Population (SIGNAL).

BACKGROUND: There is an urgent need to understand genetic associations with atrial fibrillation in ethnically diverse populations. There are no such data from sub-Saharan Africa, despite the fact that atrial fibrillation is one of the fastest growing diseases. Moreover, patients with valvular heart disease are underrepresented in studies of the genetics of atrial fibrillation. METHODS: We designed a case-control study of patients with and without a history of atrial fibrillation in Kenya. Cases with atrial fibrillation included those with and without valvular heart disease. Patients underwent clinical phenotyping and will have laboratory analysis and genetic testing of >240 candidate genes associated with cardiovascular diseases. A 12-month follow-up assessment will determine the groups' morbidity and mortality. The primary analyses will describe genetic and phenotypic associations with atrial fibrillation. RESULTS: We recruited 298 participants: 72 (24%) with nonvalvular atrial fibrillation, 78 (26%) with valvular atrial fibrillation, and 148 (50%) controls without atrial fibrillation. The mean age of cases and controls were 53 and 48 years, respectively. Most (69%) participants were female. Controls more often had hypertension (45%) than did those with valvular atrial fibrillation (27%). Diabetes and current tobacco smoking were uncommon. A history of stroke was present in 25% of cases and in 5% of controls. CONCLUSION: This is the first study determining genetic associations in valvular and nonvalvular atrial fibrillation in sub-Saharan Africa with a control population. The results advance knowledge about atrial fibrillation and will enhance international efforts to decrease atrial fibrillation-related morbidity.

Screening for diabetes and hypertension in a rural low income setting in western Kenya utilizing home-based and community-based strategies.

BACKGROUND: The burdens of hypertension and diabetes are increasing in low- and middle-income countries (LMICs). It is important to identify patients with these conditions early in the disease process. The goal of this study, therefore, is to compare community- versus home-based screening for hypertension and diabetes in Kenya. METHODS: This was a feasibility study conducted by the Academic Model Providing Access to Healthcare (AMPATH) program in Webuye, a town in western Kenya. Home-based (door-to-door) screening occurred in March 2010 and community-based screening in November 2011. HIV counselors were trained to screen for diabetes and hypertension in the home-based screening with local district hospital based staff conducting the community-based screening. Participants >18 years old qualified for screening in both groups. Counselors referred all participants with a systolic blood pressure (SBP) ≥ 160 mmHg and/or a random blood glucose ≥ 7 mmol/L (126 mg/dL) to a local clinic for follow-up. Differences in likelihood of screening positive between the two strategies were compared using Fischer's Exact Test. Logistic regression models were used to identify factors associated with the likelihood of following-up after a positive screening. RESULTS: There were 236 participants in home-based screening: 13 (6%) had a SBP ≥ 160 mmHg, and 54 (23%) had a random glucose ≥ 7 mmol/L. There were 346 participants in community-based screening: 35 (10%) had a SBP ≥ 160 mmHg, and 27 (8%) had a random glucose ≥ 7 mmol/L. Participants in community-based screening were twice as likely to screen positive for hypertension compared to home-based screening (OR=1.93, P=0.06). In contrast, participants were 3.5 times more likely to screen positive for a random blood glucose ≥ 7 mmol/L with home-based screening (OR=3.51, P<0.01). Rates for following-up at the clinic after a positive screen were low for both groups with 31% of patients with an elevated SBP returning for confirmation in both the community-based and home-based group (P=1.0). Follow-up after a random glucose was also low with 23% returning in the home-based group and 22% in the community-based group (P=1.0). CONCLUSION: Community- or home-based screening for diabetes and hypertension in LMICs is feasible. Due to low rates of follow-up, screening efforts in rural settings should focus on linking cases to care.

Clinical characteristics and 12-month outcomes of patients with valvular and non-valvular atrial fibrillation in Kenya.

BACKGROUND: Atrial fibrillation (AF) is a major contributor to the global cardiovascular disease burden. The clinical profile and outcomes of AF patients with valvular heart diseases in sub-Saharan Africa (SSA) have not been adequately described. We assessed clinical features and 12-month outcomes of patients with valvular AF (vAF) in comparison to AF patients without valvular heart disease (nvAF) in western Kenya. METHODS: We performed a cohort study with retrospective data gathering to characterize risk factors and prospective data collection to characterize their hospitalization, stroke and mortality rates. RESULTS: The AF patients included 77 with vAF and 69 with nvAF. The mean (SD) age of vAF and nvAF patients were 37.9(14.5) and 69.4(12.3) years, respectively. There were significant differences (p<0.001) between vAF and nvAF patients with respect to female sex (78% vs. 55%), rates of hypertension (29% vs. 73%) and heart failure (10% vs. 49%). vAF patients were more likely to be taking anticoagulation therapy compared to those with nvAF (97% vs. 76%; p<0.01). After 12-months of follow-up, the overall mortality, hospitalization and stroke rates for vAF patients were high, at 10%, 34% and 5% respectively, and were similar to the rates in the nvAF patients (15%, 36%, and 5%, respectively). CONCLUSION: Despite younger age and few comorbid conditions, patients with vAF in this developing country setting are at high risk for nonfatal and fatal outcomes, and are in need of interventions to improve short and long-term outcomes.

Markers of Atherosclerosis, Clinical Characteristics, and Treatment Patterns in Heart Failure: A Case-Control Study of Middle-Aged Adult Heart Failure Patients in Rural Kenya.

BACKGROUND: Although risk factors for heart failure are increasingly common worldwide, the contribution of atherosclerosis to heart failure in sub-Saharan Africa is largely unknown. OBJECTIVE: This study assessed the association between atherosclerotic risk factors and heart failure in a developing country. METHODS: We performed a case-control study of heart failure in rural Kenya. We assessed the risk factors for heart failure by using international criteria based on electrocardiogram (ECG), echocardiogram, physical examination findings, and laboratory testing. Atherosclerotic risk factors were determined by ECG, echocardiogram, ankle-brachial index (ABI), and lipid testing. We described the relationship of wall motion abnormalities on echocardiogram, ABI <0.9, and ischemic pattern on ECG with the presence of heart failure with multivariable logistic regression adjusting for age and sex and using adjusted odds ratios (AORs) and 95% confidence intervals (CIs). RESULTS: There were 125 cases and 191 controls (n = 316); 49% were male. The mean age was 60 (SD = 13) years. Most patients had hypertension (53%), and 16% had human immunodeficiency virus infection. Lipids were in the normal range for all. Cases were older than controls (62 years vs. 58 years, respectively). The most common abnormality associated with heart failure was dilated cardiomyopathy. Ischemic heart failure was the second most common cause in men. Cases were more likely to have an ABI <0.9 (46% vs. 31%; AOR: 1.99; 95% CI: 1.19 to 3.32), ischemia or infarct on ECG (68% vs. 43%; AOR: 3.01; 95% CI: 1.43 to 6.34), and wall motion abnormalities on echocardiogram (54% vs. 15%; AOR: 7.00; 95% CI: 3.95 to 12.39). CONCLUSIONS: Ischemic heart failure is more common in Kenya than previously recognized. Noninvasive markers of atherosclerosis are routinely found among patients with heart failure. Treatment and prevention of heart failure in sub-Saharan Africa must consider many causes including those related to atherosclerosis.

Building Sustainable Capacity for Cardiovascular Care at a Public Hospital in Western Kenya.

Cardiovascular disease deaths are increasing in low- and middle-income countries and are exacerbated by health care systems that are ill-equipped to manage chronic diseases. Global health partnerships, which have stemmed the tide of infectious diseases in low- and middle-income countries, can be similarly applied to address cardiovascular diseases. In this review, we present the experiences of an academic partnership between North American and Kenyan medical centers to improve cardiovascular health in a national public referral hospital. We highlight our stepwise approach to developing sustainable cardiovascular services using the health system strengthening World Health Organization Framework for Action. The building blocks of this framework (leadership and governance, health workforce, health service delivery, health financing, access to essential medicines, and health information system) guided our comprehensive and sustainable approach to delivering subspecialty care in a resource-limited setting. Our experiences may guide the development of similar collaborations in other settings.

Optimizing linkage and retention to hypertension care in rural Kenya (LARK hypertension study): study protocol for a randomized controlled trial.

BACKGROUND: Hypertension is the leading global risk factor for mortality. Hypertension treatment and control rates are low worldwide, and delays in seeking care are associated with increased mortality. Thus, a critical component of hypertension management is to optimize linkage and retention to care. METHODS/DESIGN: This study investigates whether community health workers, equipped with a tailored behavioral communication strategy and smartphone technology, can increase linkage and retention of hypertensive individuals to a hypertension care program and significantly reduce blood pressure among them. The study will be conducted in the Kosirai and Turbo Divisions of western Kenya. An initial phase of qualitative inquiry will assess facilitators and barriers of linkage and retention to care using a modified Health Belief Model as a conceptual framework. Subsequently, we will conduct a cluster randomized controlled trial with three arms: 1) usual care (community health workers with the standard level of hypertension care training); 2) community health workers with an additional tailored behavioral communication strategy; and 3) community health workers with a tailored behavioral communication strategy who are also equipped with smartphone technology. The co-primary outcome measures are: 1) linkage to hypertension care, and 2) one-year change in systolic blood pressure among hypertensive individuals. Cost-effectiveness analysis will be conducted in terms of costs per unit decrease in blood pressure and costs per disability-adjusted life year gained. DISCUSSION: This study will provide evidence regarding the effectiveness and cost-effectiveness of strategies to optimize linkage and retention to hypertension care that can be applicable to non-communicable disease management in low- and middle-income countries. TRIAL REGISTRATION: This trial is registered with (NCT01844596) on 30 April 2013.