During a follow-up period of 12.5 years, adults between 32 and 46 years old who had coronary artery calcium (CAC) had an increased risk of coronary heart disease (both fatal and nonfatal), according to a prospective, community-based study.

After the researchers adjusted for demographics, risk factors and treatments, they found that adults with CAC had a five-fold increase in coronary heart disease events and a three-fold increase in cardiovascular disease events.

Lead researcher John Jeffrey Carr, MD, MSc, of Vanderbilt University Medical Center in Nashville, Tennessee, and colleagues published their results online in JAMA Cardiology on Feb. 8.

This study, known as CARDIA (Coronary Artery Risk Development in Young Adults), enrolled 5,115 black and white participants who were 18 to 30 years old from March 25, 1985 to June 7, 1986. The participants were from Birmingham, Alabama, Chicago, Illinois, Minneapolis, Minnesota and Oakland, California.

The researchers performed CT imaging for the presence of CAC during 2000-01 (year 15), 2005-06 (year 20) and 2010-11 (year 25). They asked participants to fast for 12 hours and avoid smoking and strenuous physical activity for two hours before each examination. The participants self-reported their age, race/ethnicity, sex, years of education attained and smoking habits.

At year 15, the researchers had information on 3,043 of the participants. The mean age was 40.3 years old, and 54.6 percent of the participants were female and 10.2 percent had CAC with a geometric mean Agatston score of 21.6.

During 12.5 years of follow-up, the researchers observed 57 incident coronary heart disease events and 108 incident cardiovascular disease events. The presence of CAC was associated with 108 fatal or nonfatal cardiovascular disease events, but it was not associated with cardiovascular disease events that did not involve coronary heart disease

The unadjusted incidence density of coronary heart disease in participants with CAC was 8.9 events per 100 individuals, including 4.8 events per 100 persons at a CAC score of 1 to 19; 10.6 events per 100 persons at a CAC score of 20 to 99; and 26.1 events per 100 persons at a CAC score of 100 or more. The researchers noted that CAC scores between one and 19 increased the risk of coronary heart disease events by 2.6-fold compared with participants who did not have CAC.

Participants with CAC had an incidence density of 8.1 all-cause deaths per 100 people in the researchers’ fully adjusted model, which increased to 22.4 deaths per 100 people in participants with a CAC score of 100 or more. Of the 13 deaths among participants with a CAC score of 100 or more, 10 were adjudicated as coronary heart disease events.

The study had a few limitations, according to the researchers, including the relatively small number of coronary heart disease events. They also noted the findings might not be generalizable to people who are not black and white and living in the U.S. In addition, they mentioned that none of the risk assessment tools they used have been evaluated in a randomized clinical trial.

“The presence of any CAC on conventional chest CT examinations in individuals 56 years of age or younger should be recognized as a biomarker of elevated [coronary heart disease] risk and trigger a review of the individual’s cardiovascular health status and intensified prevention efforts personalized to the patient,” the researchers wrote. “Whether any kind of general screening for CAC is warranted needs further study, although we suggest that a strategy in which all individuals aged 32 to 46 years are screened is not indicated. Rather, a more targeted approach based on measuring risk factors in early adult life to predict individuals at high risk for developing CAC in whom the CT scan would have the greatest value can be considered. The finding that CAC present by ages 32 to 46 years is associated with increased risk of premature [coronary heart disease] and death emphasizes the need for reduction of risk factors and primordial prevention beginning in early life.”