Good News! Cases of Coronary Heart Disease in the US Dropping, According to New Study

Latest study shows the incidence rate of coronary heart disease among Americans has decreased by nearly 20 percent from 1983 to 2011, Science Daily reports.

Coronary disease, or coronary heart disease, is the failure of the coronary arteries to supply and circulate oxygen-rich blood to your heart muscles and surrounding tissue due to clogging caused by a wax-like material called plaque. It is the most common form of heart disease and is the leading causes of death in both men and women in the U.S.

Over the years, the main focus for coronary heart disease has been on the diagnosis and management of risk factors like blood pressure and blood lipids. The new research looked at how the said guidelines have affected or altered the incidence of coronary heart disease and its connection with modifiable risk factors on a population level.

According to Eureka Alert, Michael J. Pencina, Ph.D., of the Duke University Medical Center, Durham, N.C. and his colleagues collated individual patient-level data from five observational cohort studies acquired from the National Heart, Lung, and Blood Institute Biologic Specimen and Data Repository Information Coordinating Center, and created two analytic data sets: 1 set with baseline data collected from 1983 through 1990 (early era) with follow-up from 1996 through 2001, and l set with baseline data collected from 1996 through 2002 (late era) with follow-up from 2007 through 2011.

Researchers included characteristics of 14,009 pairs of participants in the two groups. Participants ages 40 to 79 years old who had no prior diagnosis of cardiovascular disease were chosen from each era and matched on age, race, and sex. Each group was followed for up to 12 years for new-onset of CHD - including but not limited to heart attack, coronary death, angina, and coronary insufficiency, the Medical Xpress reports.

In the study, which is set to appear on the November 15 issue of the Journal of the American Medical Association (JAMA), the authors write:

"Examination of adults from 5 large observational cohort studies led to several findings. First, the incidence of CHD declined almost 20 percent over time. Second, although the prevalence of diabetes increased, the fraction of CHD attributable to diabetes decreased over time, due to attenuation of the association between diabetes and CHD.

"This may have resulted from changing definitions and awareness of diabetes, improvements in diabetes treatment and control, and/or better primary prevention. Third, there was no evidence that the strength of the association between smoking, systolic blood pressure, or dyslipidemia and CHD changed between eras, nor was there evidence that the proportion of CHD due to these factors changed. This underscores the importance of continued prevention efforts targeting these risk factors."