“If this is borne out by future analyses, it will be the first change in the trend since the decline in heart disease death rates began in the mid-1960s,” says Cynthia Leibson, Ph.D., Mayo Clinic epidemiologist and senior author of the study. In their article, the researchers recognize the corresponding rise in national obesity and diabetes rates in roughly the same period but say that further research would be needed to establish any connection.

Researchers from Mayo Clinic and from the University of British Columbia used death certificate data to identify all Olmsted County, Minn., residents who died between 1981 and 2004. Olmsted County, long the focus of detailed medical record reporting by Mayo Clinic and the Rochester Epidemiology Project, has been a reliable snapshot of national disease trends. The study was limited to persons who died at ages 16 through 64 from nonnatural causes, a subset for which the autopsy rate is exceptionally high.

Review of the pathology reports for these 515 individuals revealed that 425 (82 percent) had a degree of coronary artery atherosclerosis assessed at autopsy. Of that group, 83 percent showed signs of coronary artery disease and just over 8 percent had a high level of the disease. The analysis over the entire 23-year period revealed declines for three distinct categories: high level, any level, and average degree of coronary artery disease. However, the declines in the degree of disease stopped after 1995 and may have actually headed upward -- after the year 2000.

Source: Mayo Clinic