Rheumatic heart disease in Uganda: predictors of morbidity and mortality one year after presentation

Emmy Okello,Peter Lwabi,Andrea Beaton,Moses R Kamya,Chris T Longenecker

doi:10.1186/s12872-016-0451-8

Abstract

BackgroundRheumatic heart disease (RHD), the long-term consequence of rheumatic fever, accounts for most cardiovascular morbidity and mortality among young adults in developing countries. However, data on contemporary outcomes from resource constrained areas are limited.MethodsA prospective cohort study of participants aged 5–60 years with established RHD was conducted in Kampala, Uganda, in which clinical exam, echocardiography, electrocardiography (ECG), and laboratory evaluation were done every 3 months and every 4-week benzathine penicillin prophylaxis was prescribed. Participants were followed up for 12 months and outcomes and predictors of morbidity and mortality were assessed using Kaplan Meier curves and Cox proportional hazards models.ResultsOf 449 subjects, 66.8% (300/449) were females, median age was 30 (interquartile range 20). 73.7% (331/449) had atleast one follow up visit. Among these, 35% (116/331) developed decompensated heart failure and, 63.7% (211/331) developed atrial fibrillation. Heart failure was associated with poor penicillin adherence (OR = 3.3, CI 2–5.4, p = 0.001), and left ventricular end diastolic diameter greater than 55 mm (OR = 3.16, CI 1.73–5.76, p = 0.001). Atrial fibrillation was associated with left atrial diameter >40 mm (OR = 7.5, CI 2.4–9.8, p = 0.001).There were 59 deaths with a 1-year mortality rate of 17.8%. Most deaths occurred within the first three months of presentation. Subjects whose average adherence to benzathine penicillin was <80% had significantly greater mortality (31% vs. 9%, log rank p < 0.001). In multivariate analysis, the risk of death among those with poor penicillin adherence was 3.81 times higher than those with better adherence (HR = 3.81, CI 1.92–7.63, p = 0.001). Other predictors of 1 year mortality included heart failure (HR 8.36, CI 3.28–21.31, p = 0.001) and left ventricular end diastolic diameter greater than 55 mm (HR = 1.93, CI 1.07–3.49, p = 0.02).ConclusionIn this study of RHD in Uganda, morbidity and mortality within 1 year of presentation were higher than in recently published from other low and middle income countries. Suboptimal adherence to benzathine penicillin injections was associated with incident heart failure and mortality over 1 year. Future studies should test interventions to improve adherence among patients with advanced disease who are at the highest risk of mortality.

Highlights

Rheumatic heart disease (RHD), the long-term consequence of rheumatic fever, accounts for most cardiovascular morbidity and mortality among young adults in developing countries
At the univariate level (Table 2), male sex, heart failure at study entry, severe mitral regurgitation, left ventricular end diastolic dimension >55 mm, left ventricular end systolic dimension >40 mm, atrial fibrillation, infective endocarditis, elevated C reactive protein (CRP), and benzathine penicillin adherence less than 80%, were significantly associated with increased mortality
Left ventricular diastolic diameter >55 mm and heart failure were not collinear in our model. Results of this first follow up study on outcomes of RHD in Uganda show a remarkably high mortality within 1-year of initial diagnosis of RHD, indicating that patients present for care at a very late stage of disease

Summary

Introduction

Rheumatic heart disease (RHD), the long-term consequence of rheumatic fever, accounts for most cardiovascular morbidity and mortality among young adults in developing countries. Rheumatic heart disease (RHD) remains a leading cause of morbidity and mortality among young adults in the developing world, accounting for at least 345,000 deaths annually [1, 2]. In Uganda, RHD is the most common cause of heart disease in young adults [6]. As is true in many underserved areas, Ugandan patients tend to present late in the disease course, and almost half present with a complication [7]. Longitudinal studies of acute rheumatic fever (ARF) and RHD suggest that adherence to penicillin prophylaxis can significantly decrease disease progression and mortality [5, 8, 9]

Methods

Results

Discussion

Conclusion