Using a Low-Risk Population to Estimate the Specificity of the World Heart Federation Criteria for the Diagnosis of Rheumatic Heart Disease

Background: The 2012 World Heart Federation (WHF) criteria set the minimum standards for echocardiographic diagnosis of rheumatic heart disease (RHD) in a high-risk population without history of acute rheumatic fever. The high sensitivity of the 2012 WHF criteria is well accepted, but the specificity cannot be directly assessed without a confirmatory test. The objective of this study was to estimate the false-positive rate of the WHF criteria through their application in a population at very low risk for RHD. Methods: The Children's National Health System echocardiography database was searched for patients (615 years of age) with an International Classification of Diseases, Ninth Revision, code for chest pain.'' Chart review was performed; children with congenital heart disease or systemic disease were excluded. Patients were classified according to WHF criteria as having normal, borderline, or definite RHD on the basis of mitral and aortic valve morphology and the presence of pathologic mitral and/or aortic regurgitation. Results: A total of 1,251 studies were identified, and 152 were excluded. Fifty studies were randomly chosen from each age, with equal gender distribution, for a total of 500 echocardiograms. No patients met the criteria for definite RHD and four (0.8%) for borderline RHD, both by pathologic mitral regurgitation. No patients met the criteria for borderline RHD on the basis of mitral valve morphology or pathologic aortic regurgitation. Conclusion: In a US pediatric population, no children had findings of definite RHD, and 0.8% had findings of borderline RHD, most likely representing false-positive results. Although there appears to be some overlap between the findings of borderline RHD and those in the normal pediatric population, our data suggest acceptable specificity for all RHD, with excellent specificity for definite RHD.