The importance of big databases in understanding valvular heart disease

This editorial refers to ‘Normative values of the aortic valve area and Doppler measurements using two-dimensional transthoracic echocardiography: results from the Multicenter World Alliance of Societies of Echocardiography Study’, by J.I. Cotella et al. https://doi.org/10.1093/ehjci/jeac220. Aortic valve (AV) disease is related to high morbidity and mortality worldwide, and its prevalence is still rising with the ageing population.1 Cotella et al.2 propose normal values for AV area (AVA) and Doppler measurements using 2D transthoracic echocardiography, on the basis of a large data set from the ‘Multicenter World Alliance of Societies of Echocardiography’ study. Currently, reference values and cut-off values [published by the European Association of Cardiovascular Imaging (EACVI) and the American Society of Echocardiography (ASE)3,4] are based on parameters derived from several well-designed cross-sectional population-based studies. However, these data have been derived predominantly from North-American observational registries with limited sample size.4 Moreover, the epidemiology of AV disease varies significantly around the world, with a predominance of rheumatic heart disease in developing countries, whereas in developed countries, the greatest burden of valvular heart disease is due to calcific AV disease.1 Therefore, these reference values may not be extrapolated to the worldwide population. Additionally, sex-related differences for several AV parameters have been reported, and significant variation is observed between racial and ethnic groups.5,6 This underscores the need for subgroup-specific echocardiographic reference values.