Background: The 2012 World Heart Federation Criteria are the current gold standard for the diagnosis of latent rheumatic heart disease (RHD). Because data and experience using these criteria have grown, there is opportunity to simplify and develop outcome prediction tools. We aimed to develop a simple echocardiographic score applicable for RHD screening with potential to predict disease progression.
Methods: This study included 3 cohorts used for score derivation (n=9501), score validation (n=7312), and assessment of outcomes prediction (n=227). In the derivation cohort, variables independently associated with definite RHD were assigned point values proportional to their regression coefficients. The sum of these values was stratified into low (0-6), intermediate (7-9), and high (≥10) risk.
Results: Five components were selected for score development, including mitral valve anterior leaflet thickening, excessive leaflet tip motion, and regurgitation jet length ≥2 cm, and aortic valve focal thickening and any regurgitation. The score showed optimal discrimination and calibration for RHD diagnosis in the derivation and validation cohorts (C statistic, 0.998 and 0.994, respectively), with good discrimination for predicting disease progression (C statistic, 0.811). Progression-free survival rate in the low-risk children at 1-, 2-, and 3-year follow-up was 100%, 100%, and 93%, respectively, compared with 90%, 60%, and 47% in high-risk group. The point-based score was strongly associated with disease progression (hazard ratio, 1.270; 95% CI, 1.188-1.358; P<0.001).
Conclusions: This simplified score, based on components of the World Heart Federation criteria, is highly accurate to recognize definite RHD and provides the first tool for risk stratification, assigning children with latent RHD to low, intermediate, or high risk based on echocardiographic features at diagnosis.
Keywords: child; diagnostic screening programs; echocardiography; humans; mitral valve; patient outcome assessment; rheumatic heart disease.