Two-year evolution of latent rheumatic heart disease in Malawi

In asymptomatic children, screening echocardiography has been used to attempt to diagnose rheumatic heart disease (RHD) at an early stage (latent RHD). World Heart Federation guidelines have standardized categorization of "definite," "borderline," or no RHD by echo findings. The progression of RHD diagnosed through echo screening is not known. In 2014, we screened 1450 schoolchildren in Malawi.

Our objective was to evaluate 2-year RHD evolution among those diagnosed through screening.

Two-year follow-up echocardiograms of those diagnosed with latent RHD were read by a primary, secondary, then third reader if there was disagreement. Progression or regression of both definite and borderline groups were tabulated. Penicillin adherence, age, gender, number in home, and household income were compared between those with definite RHD who regressed to borderline and those that stayed definite. We utilized the local system used to track HIV defaulters in order to bring participants back into care. Comparisons were made using Fisher's exact and Wilcoxon rank-sum tests.

Of the 39 with borderline RHD, 1 was lost to follow-up (2.6%), 1 progressed to definite (2.6%), 19 remained borderline (48.7%), 17 (43.6%) regressed to normal, and 1 was reclassified as mitral valve prolapse (2.6%). Of the 11 with definite RHD, 6 (54.5%) remained definite, 4 regressed to borderline (36.4%), and 1 regressed to normal (9.1%). Two of 11 with definite RHD had penicillin adherence above 80% for the 2-year follow-up period. There were no differences in adherence, gender, age, household income, or number in household between those with definite RHD that regressed to borderline and those who did not (P > .19).

Borderlines had a very low progression rate to definite RHD. A strength of our study was a high retention rate (98%). Longer follow-up is needed to determine expected disease evolution.