Elsevier

The Lancet

Volume 368, Issue 9540, 16–22 September 2006, Pages 1005-1011
The Lancet

Articles
Burden of valvular heart diseases: a population-based study

https://doi.org/10.1016/S0140-6736(06)69208-8Get rights and content

Summary

Background

Valvular heart diseases are not usually regarded as a major public-health problem. Our aim was to assess their prevalence and effect on overall survival in the general population.

Methods

We pooled population-based studies to obtain data for 11 911 randomly selected adults from the general population who had been assessed prospectively with echocardiography. We also analysed data from a community study of 16 501 adults who had been assessed by clinically indicated echocardiography.

Findings

In the general population group, moderate or severe valve disease was identified in 615 adults. There was no difference in the frequency of such diseases between men and women (p=0·90). Prevalence increased with age, from 0·7% (95% CI 0·5–1·0) in 18–44 year olds to 13·3% (11·7–15·0) in the 75 years and older group (p<0·0001). The national prevalence of valve disease, corrected for age and sex distribution from the US 2000 population, is 2·5% (2·2–2·7). In the community group, valve disease was diagnosed in 1505 (1·8% adjusted) adults and frequency increased considerably with age, from 0·3% (0·2–0·3) of the 18–44 year olds to 11·7% (11·0–12·5) of those aged 75 years and older, but was diagnosed less often in women than in men (odds ratio 0·90, 0·81–1·01; p=0·07). The adjusted mortality risk ratio associated with valve disease was 1·36 (1·15–1·62; p=0·0005) in the population and 1·75 (1·61–1·90; p<0·0001) in the community.

Interpretation

Moderate or severe valvular diseases are notably common in this population and increase with age. In the community, women are less often diagnosed than are men, which could indicate an important imbalance in view of the associated lower survival. Valve diseases thus represent an important public-health problem.

Introduction

In the past, valvular heart diseases were typically caused by rheumatic heart disease, which remains a major burden in developing countries.1 However, in industrialised countries, rheumatic disease has fallen substantially,1, 2 and residual valvular diseases are now mostly degenerative3, 4, 5, 6, 7, 8 and are not regarded as a major public-health problem. The low number of valve replacements, by comparison with coronary bypass surgery,9 and the low mortality attributed to valve diseases in the USA lend support to this view.10

However, several facts suggest that the role of valve disease as a public-health problem should be reconsidered. Valve diseases are poorly represented in the international classification of diseases, and their contribution to mortality and morbidity might have been ignored without echocardiography. Also, the results of the EuroHeart Survey11 suggest that a substantial burden of such disease exists, at least in Europe, a situation that is lent support by the link between degenerative valve disease, older age,3, 4, 5, 6, 7, 8 and increasing life expectancy.12

Nevertheless, the burden of valve diseases is unknown because previous studies have focused mostly on hospital patients11 and because assessment of valve diseases is clinically imprecise13 and requires large samples with echocardiography. Seminal echocardiographic studies reported some data for valve disease prevalence.6, 14, 15, 16 Although these and observational17 studies suggest a link to ageing, the absolute prevalence in specific age groups and comprehensive burden of valve diseases are unknown. Furthermore, in the community—a population that can inform us about diseases that are of potential concern—the rates of diagnosed valve diseases are unknown.

We postulated that valvular diseases are highly prevalent and are a public-health problem. Thus, our aim was to assess the prevalence, distribution patterns, and consequences of noteworthy (moderate or severe) left-sided valve disease in the general population and in the community.

Section snippets

Study population

The National Heart, Lung, and Blood Institute (NHLBI) organises the gathering of data from large epidemiological studies with well-characterised population samples. From this database, we selected studies with prospectively defined echocardiographic valvular analysis. Echocardiography with comprehensive, specific valvular analysis was done prospectively in three large national population-based epidemiological studies—the Coronary Artery Risk Development in Young Adults (CARDIA) Study,18 the

Results

There were 11 911 echocardiographs in the pooled population-based studies. The number of adult residents of Olmsted County alive in January, 2000, with available echocardiographs was 16 501, which represents 18·6% of the adult population of Olmsted County.

In the population-based studies, valvular heart disease was present in 615 (5·2%, 95% CI 4·8–5·6) participants. The national prevalence of valve diseases, taking into account the oversampling of the elderly population, and after adjustment for

Discussion

Our study has shown that the population burden of clinically noteworthy valvular heart diseases is considerable in the US population. This burden is also notable for clinically diagnosed valve disease in the community. The difference between the prevalence of such diseases in the population and the percentage of people diagnosed with valvular heart diseases in the community (2·5% vs 1·8%) is probably due to undiagnosed valve diseases.

Valve diseases detected in the general population and

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