Autopsy Findings Suggest End of Decline in CHD

Feb 16, 2008
Autopsies of individuals in one Minnesota County suggest
that the decades-long decline in the rate of coronary
artery disease may have ended and possibly reversed after
2000, according to a report in the February 11 issue of
Archives of Internal Medicine, one of the JAMA/Archiveer
been high and continues to decline, with a
national average of only 8.3 percent in 2003.

Olmsted County, Minnesota, has traditionally had high
autopsy rates across all age groups. Rates are especially
high for non-elderly individuals who died of unnatural
causes (such as accidents, homicides or suicides). Cynthia
Leibson, Ph.D., and colleagues from Mayo Clinic, Rochester,
Minn., and the University of British Columbia, Vancouver,
Canada, used data from death certificates and pathology
reports to assess trends in coronary artery disease among
Olmsted County residents age 16 through 64 who died of
unnatural causes between 1981 and 2004.

A total of 3,237 Olmsted County residents in this age group
died in those years, 515 of unnatural causes. Among those
515, 96 percent were autopsied and 82 percent (425) had
grades assigned based on the amount of blockage in several
coronary arteries, with grades ranging from zero (no
blockage) to five (100 percent blocked).

“Over the full period (1981 to 2004), 8.2 percent of the
425 individuals had high-grade disease, and 83 percent had
evidence of any disease,” the authors write. High-grade
disease was defined as a grade of three or higher in the
left main artery or a grade four or higher in any other
single artery. Analyses adjusted to consider the
individuals’ age and sex revealed declines over the entire
period for high-grade disease, any disease and the average
grade of disease. However, “declines in the grade of
coronary disease ended after 1995 and possibly reversed
after 2000.”

“Ourssigned based on the amount of blockage in several
coronary arteries, with grades ranging from zero (no
blockage) to five (100 percent blocked).

“Over the full period (1981 to 2004), 8.2 percent of the
425 individuals had high-grade disease, and 83 percent had
evidence of any disease,” the authors write. High-grade
disease was defined as a grade of three or higher in the
left main artery or a grade four or higher in any other
single artery. Analyses adjusted to consider the
individuals’ age and sex revealed declines over the entire
period for high-grade disease, any disease and the average
grade of disease. However, “declines in the grade of
coronary disease ended after 1995 and possibly reversed
after 2000.”

“Our finding that temporal declines in the grade of
coronary artery disease at autopsy have ended, together
with suggestive evidence that declines have recently
reversed, provides some of the first data to support
increasing concerns that declines in heart disease
mortality may not continue,” the authors conclude. “The
extent to which recent trends are attributable to the
epidemics of obesity and diabetes mellitus awaits further
investigation.”

In the context of other recent studies about increasing
rates of childhood obesity, “the study by Nemetz et al
underscores the importance of focusing prevention efforts
on lifestyle factors among younger generations, including
continued efforts to decrease smoking and encouraging
healthy diets and moderate physical activity, before
clinical symptoms of coronary artery disease have an
opportunity to be expressed,” write S. Jay Olshansky,
Ph.D., and Victoria Persky, M.D., of the University of
Illinois at Chicago, in an accompanying editorial.2

“This limited examination of the autopsies of Olmsted
County residents may be representative only of this unique
segment of the American population, but the results are
alarming enough to alert public health officials to begin
monitoring younger cohorts for early signs of coronary
artery disease with much greater vigilance,” they conclude.

References:

1. Arch Intern Med. 2008; 168[3]:264-270.
2. Arch Intern Med. 2008; 168[3]:261.