Screening for rheumatic heart disease: evaluation of a focused cardiac ultrasound approach

Abstract

Background: Rheumatic heart disease (RHD) remains a major public health problem worldwide. Although early diagnosis by echocardiography may potentially play a key role in developing active surveillance, systematic evaluation of simple approaches in resource poor settings are needed.

Methods and results: We prospectively compared focused cardiac ultrasound (FCU) to a reference approach for RHD screening in a school children population. FCU included (1) the use of a pocket-sized echocardiography machine, (2) nonexpert staff (2 nurses with specific training), and (3) a simplified set of echocardiographic criteria. The reference approach used standardized echocardiographic examination, reviewed by an expert cardiologist, according to 2012 World Heart Federation criteria. Among the 6 different echocardiographic criteria, first tested in a preliminary phase, mitral regurgitation jet length≥2 cm or any aortic regurgitation was considered best suited to be FCU criteria. Of the 1217 subjects enrolled (mean, 9.6±1 years; 49.6% male), 49 (4%) were diagnosed with RHD by the reference approach. The sensitivity of FCU for the detection of RHD was 83.7% (95% confidence interval, 73.3-94.0) for nurse A and 77.6% (95% confidence interval, 65.9-89.2) for nurse B. FCU yielded a specificity of 90.9% (95% confidence interval, 89.3-92.6) and 92.0% (95% confidence interval, 90.4-93.5) according to users. Percentage of agreement among nurses was 91.4%.

Conclusions: FCU by nonexperts using pocket devices seems feasible and yields acceptable sensitivity and specificity for RHD detection when compared with the state-of-the-art approach, thereby opening new perspectives for mass screening for RHD in low-resource settings.

Keywords: acute rheumatic fever; developing countries; epidemiology; heart valve diseases; rheumatic heart disease; ultrasound.