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

Abstract

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.

Fig. 1.

Age and gender distribution of patients with rheumatic heart disease.

Fig. 2.

Valvular affectation in rheumatic heart disease in Kano, Nigeria. MR, mitral regurgitation; MS, mitral stenosis; AR, aortic regurgitation; AS, aortic stenosis; MV, mixed mitral valve disease; AV, mixed aortic valve disease.