Abstract 3956: Rheumatic Heart Disease Screening by Echocardiography: The Inadequacy of WHO Criteria for Optimising the Diagnosis of Subclinical Disease
Background Early case detection is vital in rheumatic heart disease (RHD) in children, to minimize the risk of advanced valvular heart disease by preventive measures. The currently utilized WHO criteria for echocardiographic diagnosis of subclinical RHD emphasize the presence of pathological valve regurgitation, but do not include valves with morphologic features of RHD without pathological regurgitation. We hypothesised that adding morphological features to diagnostic criteria might have significant consequences in terms of case detection rates.
Methods and Results We screened 2,170 randomly selected school children aged 6 –17 years in Maputo, Mozambique, clinically and by a portable ultrasound system. Two different echocardiographic sets of criteria for rheumatic heart disease were assessed: “WHO” (exclusively Doppler-based) and “combined” (Doppler and morphology-based) criteria. Independent investigators reviewed all suspected RHD cases using a higher resolution, nonportable ultrasound system. On-site echocardiography identified 18 and 124 children with suspected RHD, according to “WHO” and “combined” criteria respectively. After consensus review, 17 were finally considered to have definite rheumatic heart disease using “WHO” criteria, while 66 had definite rheumatic heart disease using “combined” criteria, giving prevalence rates of 7.8 (95% CI, 4.6 –12.5) and 30.4 (95% CI, 23.6 –38.5) per 1,000 children, respectively (P<0.0001).
Conclusions Important consideration should be given to echocardio-graphic criteria for detecting subclinical RHD as the number of cases detected may differ importantly according to the diagnostic criteria utilized.