Valvular heart disease: the oncoming tsunami

This editorial refers to ‘Prevalence of asymptomatic valvular heart disease in the elderly population: a community-based echocardiographic study’, by V. Tsampasian et al., https://doi.org/10.1093/ehjci/jeae127. Despite the decline of rheumatic heart disease in the western world, the global burden of valvular heart disease (VHD) is expected to steadily increase.1 The associated health cost is tremendous, because VHD is associated with major cardiovascular events such as heart failure, arrhythmia, and early mortality. The limitations of many of the published studies on the prevalence of VHD included retrospective design and selected patient populations such as those referred for echocardiography.1 The study by Tsampasian et al.2 was a prospective community-based echocardiographic study on the prevalence of VHD in the UK. The authors screened 10 000 patients from medical practices in three areas of the country and includes patients over 60 years of age with no known VHD. They found VHD, mostly mild tricuspid or mitral regurgitation, in 28.2%. Significant dysfunction (moderate or severe) in 2.4% of the population was associated with age. These findings are consistent with other epidemiologic studies underscoring the burgeoning burden of VHD in the older population and the need for public health strategies in dealing with this increasingly important health issue.3–5 The 2014 ACC/AHA guideline on the management of VHD has laid out the conceptual framework that VHD is a progressive disease going from mild structural alteration in valve leaflet morphology to increasing severity of anatomic abnormalities with associated dysfunction and culminating in severe anatomic and functional changes leading to development of symptoms. The corresponding clinical stages are the early stage in patients at risk for valve dysfunction to a later stage where patients have progressive dysfunction and finally to a stage with symptomatic severe valve dysfunction.6 Indeed, identification of the early stage of VHD was performed in the OxVALVE study that was a prospective study of patients over 65 years of age from five medical practices in the UK, showing that VHD was present in 50.8%.4 Not surprisingly VHD was mostly mild with the most common condition being aortic sclerosis accounting for 34%. In the present study, aortic sclerosis was not included as VHD, which likely accounted for the lower prevalence of VHD of 28.2% in their population, although again the majority had mild disease with significant disease in only 2.4%.2 The significance of detecting early VHD, namely aortic sclerosis, was addressed in the Atherosclerosis Risk in Community study that was a prospective community-based study with long-term follow-up that included 6118 participants with a mean age of 76 ± 5 years.7 Subclinical VHD was common present in 57% of the participants, and early stage VHD such as aortic sclerosis was present in 39%. There was a graded association, independent of traditional risk factors, between the stages of VHD and the risk of cardiovascular events including all-cause mortality and heart failure. Over a follow-up of six years, the prevalence of severe VHD increased from 1% to 7%.7 Thus, in epidemiologic studies on VHD particularly in older adults, it is vital to include the identification of early disease that has been shown to be common, increases in frequency with age, progresses in severity over time, and is associated with an increased risk of cardiovascular events.2–5,7 Mitral annular calcification (MAC) has been recognized as a cause for mitral valve dysfunction. In an echocardiographic database study, we included 11 605 patients with mean age 73 ± 10 years and showed that MAC was common and frequently progressed resulting in mitral valve dysfunction in 10% in 10 years.8 The present study reported MAC as a cause of mitral regurgitation in seven patients and mitral stenosis in one patient.2 However, they did not provide the prevalence and severity of MAC in their population. We believe that MAC represents an early stage of VHD and should have been included in studies on prevalence of VHD. Bicuspid aortic valve (BAV) with an estimated prevalence of 0.5–2% is a common predisposing condition for aortic valve dysfunction including stenosis and regurgitation. Yet, BAV patients can have normal functioning or minimally dysfunctional aortic valve, and they can have excellent life expectancy.9 It is plausible that asymptomatic BAV individuals may not come to medical attention even late in life. BAV was identified in eight participants in the OxVALVE study and none in the current study.2,4 Although aortic valve dysfunction due to BAV generally becomes evident by the time they are in the age groups as in the abovementioned studies, the suspicion remains that BAV may have been under-detected due to the difficulty in assessing aortic valve morphology in the older adults. Tsampasian et al.2 reported newly diagnosed tricuspid regurgitation in 13.8% and pulmonic regurgitation in 6%. Regurgitation severity was mild in most patients with moderate tricuspid regurgitation in 0.5% and moderate pulmonic regurgitation in <0.1%. No severe regurgitation was observed, and no cases of tricuspid stenosis or pulmonic stenosis were found. In the OxVALVE study, only moderate or severe tricuspid or pulmonic regurgitation was considered VHD with a prevalence of 2.7% and 0.3%, respectively.4 The higher prevalences of moderate or severe tricuspid and pulmonic regurgitation probably were due to the inclusion of patients with atrial fibrillation (AF) in the OxVALVE study and not in the study by Tsampasian et al. The OxVALVE study demonstrated an association of AF with VHD, but the association of AF with individual valve dysfunction was not presented.4 The significance of right-sided VHD in asymptomatic individuals without structural heart disease is uncertain, because trivial to mild tricuspid or pulmonic regurgitation appears ubiquitous in the general population.10 Prospective long-term follow-up studies are needed to understand the clinical significance of tricuspid or pulmonic regurgitation in this setting. In summary, Tsampasian et al. provided additional data on the prevalence of VHD in asymptomatic individuals in the community, clearly highlighting that VHD is common in older adults and the prevalence increases with age. With the aging population, VHD is a looming burden that our healthcare system cannot ignore. Strategies are urgently needed to mitigate the progression of VHD and to prepare our healthcare system for the oncoming tsunami. None. Data availability is not applicable for this editorial.