Valve Disease Study Suggests New Public Health Concern

Research from Mayo Clinic estimates that about 5 million adult Americans have moderate or severe heart valve disease as a consequence of aging, according to a Mayo Clinic study published online in The Lancet.

While rheumatic fever was previously the main cause of valve diseases and was a major public health issue even in the middle of the 20th century, rheumatic fever is not a serious concern in this country today, thanks to antibiotic therapy and improved living standards.

"Valve diseases are a significant public health concern because the proportion of our elderly population is increasing," says Vuyisile Nkomo, M.D., cardiologist and lead author of the study. "This study shows that valve diseases increase significantly with aging. It is a major step in understanding the scope of the burden of valve diseases today and their contribution to declining health with aging."

Physicians have suspected the increase in valvular disease, but Mayo's research is the first comprehensive study to look at data from the general population and the community. Data from the general population reveals information on systematic samples of individuals to reveal trends; data from the community - in this case, Olmsted County, where Mayo Clinic is based - provides information on people who have already been offered clinical attention for an illness.

Researchers used data from echocardiograms from the general population of 11,911 participants in three National Heart, Lung and Blood Institute-funded population studies: the Coronary Artery Risk Development in Young Adults (CARDIA) Study, the Atherosclerosis Risk in Communities (ARIC) Study, and the Cardiovascular Health Study (CHS). Researchers also analyzed data from Olmsted County of adults who had been assessed by clinically indicated echocardiograms.

In the general population studies, the prevalence of adults diagnosed with moderate or severe valve disease increased with age, from 0.7 percent in 18- to 44-year-olds to 13.3 percent in those 75 and older. The projected national estimate of valve diseases based on the age and gender distribution of the 2000 U.S. population census is 2.5 percent of adults or approximately 5 million people.

In Olmsted County, 1.8 percent (adjusted to U.S. census figures) of the adults were diagnosed with valve disease and prevalence also increased with age, from 0.3 percent in the 18- to 44-year-olds to 11.7 percent of those 75 and older. Remarkably, the prevalence of valve disease was similar in the population but in the community, valve disease was diagnosed less in women, suggesting a possible gender bias and the need for further study, Dr. Nkomo says.

"The results of this study are not trivial. We predict - in view of the growth and aging of the population - that the number of U.S. patients with valve disease will double in the next 20 years," says co-author Maurice Enriquez-Sarano, M.D., also a Mayo Clinic cardiologist.