Prevalence and pattern of rheumatic heart disease in the Nigerian savannah: an echocardiographic study

BACKGROUND: Rheumatic heart disease (RHD) remains a major public health problem in developing countries. Whereas Africa has 10% of the world’s population, as many as half of the 2.4 million children affected by RHD globally live on the continent. RHD accounts for a major proportion of all cardiovascular disease in children and young adults in African countries. While acute rheumatic fever is on the decline even in the developing world, there are still a large number of chronic rheumatic heart disease cases, often complicated by chronic congestive heart failure and recurrent thrombo-embolic phenomena, both posing greater challenges for management. We report on the prevalence and pattern of valve involvement in RHD using echocardiography from our centre. METHODS: In this retrospective study, transthoracic echocardiography (TTE) data collected from two echocardiography laboratories in Kano over a period of 48 months (June 2002 to May 2006) were reviewed. Patients with a diagnosis of rheumatic heart disease were selected. Information obtained from the records included the age, gender, clinical diagnosis and echocardiographic diagnoses. RESULTS: A total of 1 499 echocardiographic examinations were done in the two centres over the four-year study period. One hundred and twenty-nine of the 1 312 patients (9.8%) with abnormal results had an echocardiographic diagnosis of RHD. There were 47 males and 82 females (ratio 1:1.7) and their ages ranged from five to 60 (mean 24.02 ± 12.75) years. Mitral regurgitation was the commonest echocardiographic diagnosis present in 49 patients (38.0%). Thirty-six (27.9%) patients had mixed mitral valve disease, 25 (19.5%) had mixed aortic and mitral valve disease, 10 (7.8%) had pure mitral stenosis and four (3.1) had pure aortic regurgitation. Complications of RHD observed included secondary pulmonary hypertension in 103 patients (72.1%), valvular cardiomyopathy in 41 (31.8%), and functional tricuspid regurgitation was seen in 39 (30.2%). CONCLUSION: Our data show that RHD is still an important cause of cardiac morbidity and a large proportion of the patients already had complications at diagnosis. There is an urgent need to implement the ASAP programme of the Drakensberg declaration to avert this scourge.