Prevalence of rheumatic heart disease in young adults from New Caledonia

Abstract

Rheumatic heart disease (RHD) is an important public health issue, particularly in the Pacific region, but its true burden is unknown. To evaluate the prevalence of rheumatic heart disease (RHD) in young adults from New Caledonia, based on echocardiography, and to evaluate the accuracy of dynamic criteria, focusing on mitral valve (MV) leaflet motion. Blind analysis of echocardiography by three cardiologists; diagnosis of RHD required at least one dynamic criterion (exaggerated or restricted MV leaflet motion); subjects with morphological criteria (MV leaflet thickening), but without dynamic criteria, were considered as borderline. There were 834 subjects from three socioeconomic groups, aged 18-22 years: 699 had normal echocardiography; 93 (11.5%) had physiological regurgitation; nine (0.9%) had borderline RHD; and five (0.59%) had RHD. The prevalence of RHD in New Caledonia was thus estimated at 5.9 per 1000 (95% confidence interval 2.6-12.2). The RHD cases were of Pacific ethnicity. Physiological regurgitation was more frequent in Pacific subjects (13.7%) than in non-Pacific subjects (6.9%; P<0.0001). RHD was more prevalent in the lowest socioeconomic group. No disagreement occurred between the three reviewers concerning analysis of dynamic criteria; all disagreements were related to morphological criteria. The prevalence of echocardiographically diagnosed RHD in adults in New Caledonia is estimated at 5.9 per 1000; it occurs most frequently in Pacific subjects and those with low incomes. Dynamic criteria were more accurate and reproducible than standard morphological criteria.