American Journal of Medicine, internal medicine, medicine, health, healthy lifestyles, cancer, heart disease, drugs

Trends in Coronary Atherosclerosis: A Tale of Two Population Subgroups

Age- and sex-adjusted rate of deaths due to heart disease in the United States (1900-2011). Data were obtained from several sources.

Age- and sex-adjusted rate of deaths due to heart disease in the United States (1900-2011). Data were obtained from several sources.

Coronary artery disease presents an increasing burden on our public health system. It is important to emphasize prevention, while at the same time addressing the appropriate treatment of existing disease.

Background

We previously investigated trends in subclinical coronary artery disease and associated risk factors among autopsied non-elderly adults who died from nonnatural causes. Although grade of atherosclerosis declined from 1981 through 2009, the trend was nonlinear, ending in 1995, concurrent with increasing obesity/diabetes in this population. The previous study used linear regression and examined trends for all 4 major epicardial coronary arteries combined. The present investigation of coronary artery disease trends for the period 1995 through 2012 was prompted by a desire for more detailed examination of more recent coronary artery disease trends in light of reports that the epidemics of obesity and diabetes have slowed and are perhaps ending.

Methods

This population-based series of cross-sectional investigations identified all Olmsted County, Minnesota residents aged 16-64 years who died 1995 through 2012 (N = 2931). For decedents with nonnatural manner of death, pathology reports were reviewed for grade of atherosclerosis assigned each major epicardial coronary artery. Using logistic regression, we estimated calendar-year trends in grade (unadjusted and age- and sex-adjusted) for each artery, initially as an ordinal measure (range, 0-4); then, based on evidence of nonproportional odds, as a dichotomous variable (any atherosclerosis, yes/no) and as an ordinal measure for persons with atherosclerosis (range, 1-4).

Results

Of 474 nonnatural deaths, 453 (96%) were autopsied; 426 (90%) had coronary stenosis graded. In the ordinal-logistic model for trends in coronary artery disease grade (range, 0-4), the proportional odds assumption did not hold. In subsequent analysis as a dichotomous outcome (grades 0 vs 1-4), each artery exhibited a significant temporal decline in the proportion with any atherosclerosis. Conversely, for subjects with coronary artery disease grade 1-4, age- and sex-adjusted ordinal regression revealed no change over time in 2 arteries and statistically significant temporal increases in severity in 2 arteries.

Conclusions

Findings suggest that efforts to prevent coronary artery disease onset have been relatively successful. However, statistically significant increases in the grade of atherosclerosis in 2 arteries among persons with coronary artery disease may be indicative of a major public health challenge.

Heart disease mortality in the United States has fallen steadily since the 1970s. Declines have been attributed to both decreased incidence of clinically evident heart disease (eg, hospitalized myocardial infarction) and improved survival among persons with heart disease. Multiple factors have been implicated as contributing to declining incidence, including increased use of pharmaceuticals for hyperlipidemia/hypertension/type 2 diabetes mellitus, reductions in the prevalence of smoking, and other lifestyle improvements, including increased exercise among certain sectors of the population.

Although declining heart disease incidence and mortality are suggestive of a continuing amelioration of this major public health problem, duration of these trends is unclear. Although the overall rate of deaths due to heart disease in the United States continues to decline, a few investigations from the United States and Europe have observed a leveling off or increase in heart disease deaths among some age (sex) groups. It has been proposed that observations of an end to declines in mortality might have resulted from substantial increases in 2 major risk factors for coronary artery disease, namely diabetes mellitus and obesity.

 

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-Peter N. Nemetz, PhD, Carin Y. Smith, BS, Kent R. Bailey, PhD, Veronique L. Roger, MD, MPH, William D. Edwards, MD, Cynthia L. Leibson, PhD

This article originally appeared in the March 2016 issue of The American Journal of Medicine.

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