Application of the New 2023 World Heart Federation Criteria to Rheumatic Heart Disease in the Setting of First Episode of Acute Rheumatic Fever: Predictors for Resolution.

Rheumatic heart disease (RHD) is a chronic complication of acute rhematic fever (ARF). Echocardiography is used to assess valve disease in ARF. Acute valvulitis in ARF may normalise once inflammation has subsided. In the Top End of the Northern Territory (NT), a diagnosis of RHD is regularly made in conjunction with ARF diagnosis. We aimed to determine if baseline echocardiogram features could predict resolution of RHD when diagnosed during ARF. This retrospective cohort study includes children and young Australians diagnosed concurrently with first ARF and RHD between January 2012 and December 2021. Echocardiograms were reclassified based on the 2023 World Heart Federation guidelines for diagnosis of RHD. Primary outcome was echocardiographic resolution of RHD. The NT register recorded 311 individuals with concurrent diagnoses of ARF and RHD with 165 eligible for inclusion. Median age was 10 years (IQR 8-13 years), and 51.5% were female. Early RHD was diagnosed in 64% (106/165) of cases. Median follow-up time was 34 months. Resolution of RHD occurred in 19% (32/165) and 97% (31/32) of those had Early RHD at diagnosis. Absence of mitral valve leaflet thickening, restriction, and excessive leaflet motion were all associated with RHD resolution with univariate analysis. Multivariate Cox proportional modelling found that Early RHD at baseline independently predicted RHD resolution with HR of 16.6 (95% CI 2.25-122.74, p = 0.006). No difference was found between Stage A or Stage B RHD, (p = 0.461). The morphological features of valve disease were not as important as the severity in predicting resolution of RHD.