Thèse soutenue de Julien MAGNE

The epidemiology of valvular heart disease (VHD) is difficult to clarify since patients remain asymptomatic for long1. In addition, grading the severity of VHD remains challenging and based on holistic approach requiring multi-parametric assessment, which may further limit implementation in large-scale population-based study. Cardiac murmurs at auscultation are associated with low sensitivity and specificity2 and evaluation of an accurate prevalence of VHD requires echocardiography in a representative population. Consequently, the worldwide epidemiology of VHD is poorly described and studied. The known western countries prevalence of VHD in western countries simply relies on a population-based study performed in US during 80’s and 90’s3. These data show that prevalence of moderate or severe VHD could be estimated at 2.5% (95%CI: 2.2-2.7%), without gender difference. This prevalence increases with age, because of development of degenerative process, and could result of >13% of VHD in subject older than 75 years old. Nevertheless, these data are now old, mainly driven by rheumatic heart disease and do not report the potential heterogeneity within western countries, and global data are even more sparse.

<p style="text-align: justify"In addition, the progressive decrease of rheumatic VHD trade by the dramatic increase in degenerative VHD, related to aging and development of cardio-metabolic disorders and pro-inflammatory, pro-thrombotic and pro-atherosclerotic burden, may markedly change the current prevalence of VHD. In France and in Europe, an approximation of the prevalence of severe VHD may be derived from EuroHeart Survey I and II but only focused on patients requiring intervention. In low- or middle-income countries (LMIC), only small series are available and may help clarifying the prevalence of VHD. Consequently, since the management of VHD is profoundly modified by new therapeutic and interventional option, there is an obvious need to describe the current worldwide epidemiology of VHD.

General objective: To describe the prevalence of VHD in 2000’s

Proposed methods: We proposed 4 main work leads with specific objectives.
1- To produce a consensus document on the definition, relevant grading methods and appropriateness criteria useful to assess the epidemiology of VHD worldwide. Active members of working group on VHD of the French Society of Cardiology will be contacted and involve in the process.
2- A systematic review and if possible meta-analysis (including stratified analysis according to geographic areas and incomes) to determine the prevalence of VHD worldwide with population-based studies published after 2000.
3- A specific analysis of echocardiographic exams performed in TAHES cohort to describe left-sided VHD in general population in Benin.
4- A specific analysis of Système National des Données de Santé (SNDS) and Système National Inter-Régimes d’Assurance Maladie (SNIIRAM) databases to describe the prevalence, presentation and management of VHD in France (including sub-analysis in tropical areas).

Perspective: These data would allow a better evaluation of the future health and economic burden related to VHD. The clarification of VHD prevalence worldwide will improve knowledge on these diseases and could help to identify countries or geographic area with lack of contemporary or accurate data and in whom new population-based studies may be required. In addition, these studies may be helpful to estimate the prevalence of VHD in countries lacking appropriate data.

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Mots clés : epidemiology, Valvular Heart Disease