Outcomes of borderline rheumatic heart disease: A prospective cohort study.

CONTEXT AND AIMS: The advent of systematic screening for rheumatic heart disease (RHD) by echocardiography in endemic regions has led to a new entity: borderline RHD. The pathogenicity and natural history of borderline RHD needs to be addressed. The aim of this study was to assess the outcomes of children detected by echocardiography as having borderline RHD. METHODS: Schoolchildren in 4th grade (i.e., aged 9-10years) who were prospectively echo-screened for RHD (2012-2014) in Nouméa, New Caledonia, were asked to participate. Children with borderline RHD according to consistent independent review by two cardiologists were included and followed-up in 2015. RESULTS: Among the 8684 schoolchildren screened, 49 were diagnosed with borderline RHD according to the Cardiologist clinically involved in the child's management plan. After independent review by two cardiologists, 25 children were consistently diagnosed with borderline RHD and included in the follow-up study. Overall, inter-observer agreement was moderate with diagnostic kappa values of 0.63 (95% CI 0.45-0.78). After a median follow-up of 23months (IQR (20.5-33.0), 15 children (60.0%) had stability of valvular lesions, 8 (32.0%) had normal findings according to the WHF criteria. Two children (8.0%) had definite RHD on the follow-up echocardiogram, but no clinical events or audible pathological murmur during the study period. No factor could be identified as prognostic of either stability or progression. CONCLUSIONS: Borderline RHD diagnosed by systematic screening in high-risk populations remains mostly unchanged at 2years follow-up. Diagnosis of borderline RHD may require two reviewers for consistency.

An epidemiological study to assess the true incidence and prevalence of rheumatic heart disease and acute rheumatic fever in New Caledonian school children.

AIM: To provide in New Caledonian school children (i) the prevalence of rheumatic heart disease (RHD) detected by annual screening program using new World Heart Federation diagnostic criteria; (ii) the point prevalence of acute rheumatic fever (ARF); and (iii) to investigate socio-demographic risk factors associated with RHD. METHODS: This study linked data from national ARF/RHD programs by combining ARF incidence data from the register with RHD prevalence data from echocardiographic screening data for a single age year of the population for overall point prevalence ARF/RHD rates. For the analysis, cases of echocardiographic detection of RHD are presumed to be synonymous with undiagnosed ARF. All results were weighted to minimise the bias introduced from absent pupils of each annual screening program. Incidence and prevalence were age-standardised to the WHO World Standard Population. Each 2013 cumulative prevalence of definite and borderline RHD was studied using a multivariate logistic regression adjusted for socio-demographic factors. RESULTS: The overall age-standardised incidence of clinical and undiagnosed ARF (i.e. echocardiographic-detected RHD) was combined as point prevalence and estimated to be 99/10 000 cases in 2012 and 114/10 000 cases in 2013. This included 40/10 000 prevalent cases of asymptomatic RHD detected by screening each year. Being Melanesian, OR 23.2 (95% CI: 3.4-157.3), or Polynesian, OR 21.5 (95% CI: 2.9-157.7), was associated with a higher prevalence of having definite RHD compared with being Caucasian. Being a girl was associated with a higher risk of having borderline RHD, OR 1.9 (95% CI: 1.03-3.3). CONCLUSION: Without echocardiographic screening, ARF/RHD burden is substantially underestimated.