Screening for rheumatic heart disease: evaluation of a simplified echocardiography-based approach

Abstract

Aims: Portable echocardiography has emerged as a potential tool to detect rheumatic heart disease (RHD) early. Complex echocardiographic criteria used in recent epidemiological studies may be difficult to translate into daily practice in areas where the burden of RHD is greatest and skilled practitioners are lacking. The aim of this study was to evaluate a simplified echo approach for RHD screening among children in low-income countries.

Methods and results: Retrospective analysis of data from a cross-sectional echocardiography-based study carried out in 2005 through the examination of 2170 school children in Maputo, Mozambique. We aimed to evaluate the value of a reference set of criteria (defined as a combination of Doppler and morphological rheumatic features of the aortic and/or mitral valves) compared with an easy-to-use single mitral regurgitation jet-length criterion (simplified set of criteria). All suspected lesions (according to reference or simplified criteria) detected in the field by a portable echo machine were reassessed by non-portable echocardiography and then read by three independent experts. Definite RHD cases in both groups were finally ascertained according to the reference criteria. Portable echocardiography detected valve regurgitation in 208 children. According to the reference criteria, 18 children were detected with suspected RHD on site. Of these, 15 children (83%) were considered to have definite RHD, giving a prevalence of 6.9 per 1000 (95% CI: 3.9-11.4). The simplified mitral regurgitation jet-length criteria detected 12 children at school, 11 of whom were subsequently confirmed to have definite RHD, giving an estimated prevalence of 5.1 per 1000 (95% CI: 2.5-9.1) (P = 0.12, exact McNemar test). When compared with the reference criteria, the simplified approach yields a maximum sensitivity of 73% for case detection, with a positive predictive value of 92%.

Conclusion: Simplified echocardiography-based screening for RHD appears feasible, allowing rapid and appropriate detection of a significant number of RHD cases on site.