Abstract 14701: Agreement Between Handheld and Standard Echocardiography for Diagnosis of Latent Rheumatic Heart Disease in Brazilian Schoolchildren From High-Prevalence Settings

Abstract

Background: Handheld echocardiography (echo) is the tool of choice for Rheumatic Heart Disease (RHD) screening, based on the 2012 World Heart Federation (WHF) Criteria. We aimed to assess the agreement between screening and standard echo for diagnosis of latent RHD in schoolchildren from an endemic setting. Methods: Over 14 months, 3 non-physicians used handheld machines (GE, VSCAN) and the 2012 WHF Criteria to determine RHD prevalence in low-income public schools in Minas Gerais, Southeast Brazil. Consented children were eligible for participation. Studies were interpreted remotely using a telemedicine cloud-server by 2 experts in Brazil and the US. RHD-positive children (borderline and definite) and those with congenital heart disease (CHD) were referred for standard echo with portable devices (GE, Vivid IQ), with acquisition and interpretation by an expert cardiologist. Agreement between screening and standard echo, by category and according to the WHD criteria, was assessed, and the kappa statistic was applied. Results: A total of 1,390 students were screened in 6 schools and, among these, 110 (7.9%, 95% CI 6.5 - 9.5) were screen-positive and referred for standard echo, with mean age of 14±2 years, 80 (72%) women. Among the 16 cases initially diagnosed as definite RHD, 11 (69%) were confirmed, 4 (25%) reclassified to borderline and 1 to normal. Among the 79 cases flagged as borderline RHD, 19 (24%) were confirmed, 50 (63%) reclassified to normal, 8 (10%) to definite RHD and 2 had mild CHD. Among 11 children with CHD in screening, 4 were confirmed, 5 were reclassified to normal and 2 to RHD. Considering the 4 diagnostic categories, kappa was 0.18. In patients with borderline RHD reclassified to non-RHD, the most frequent WHF criteria was B (isolated mitral regurgitation): 64%, followed by A (2 morphological features of the mitral valve): 31%. In the only patient with definite RHD reclassified to normal, WHF criteria was D (borderline RHD in aortic and mitral valves). After standard echo, RHD prevalence was 3.2% (95% CI 2.3 - 4.2). Conclusions: Although practical, RHD screening with handheld devices tend to overestimate prevalence. Even in endemic settings, continuous education for detection, and application of risk stratification for management are crucial.