Is the presence of coronary artery disease, as indicated by coronary artery calcium (CAC), associated with the development of clinical coronary heart disease before age 60 years?
In the Coronary Artery Risk Development in Young Adults Study, black and white Americans of both sexes aged 32 to 46 years who had any CAC (Agatston score >0) as seen on computed tomographic scan had an elevated risk of clinical coronary heart disease during 12.5 years of follow-up. Individuals with a CAC score of 100 or more had an incidence density of 22.4 deaths per 100 people observed for 12.5 years.
Any CAC in early adult life, even in those with very low scores, indicates significant risk of having and possibly dying of a myocardial infarction during the next decade beyond standard risk factors and identifies an individual at particularly elevated risk for coronary heart disease for whom aggressive prevention is likely warranted.
Coronary artery calcium (CAC) is associated with coronary heart disease (CHD) and cardiovascular disease (CVD); however, prognostic data on CAC are limited in younger adults.
To determine if CAC in adults aged 32 to 46 years is associated with incident clinical CHD, CVD, and all-cause mortality during 12.5 years of follow-up.
Design, Setting, and Participants
The Coronary Artery Risk Development in Young Adults (CARDIA) Study is a prospective community-based study that recruited 5115 black and white participants aged 18 to 30 years from March 25, 1985, to June 7, 1986. The cohort has been under surveillance for 30 years, with CAC measured 15 (n = 3043), 20 (n = 3141), and 25 (n = 3189) years after recruitment. The mean follow-up period for incident events was 12.5 years, from the year 15 computed tomographic scan through August 31, 2014.
Main Outcomes and Measures
Incident CHD included fatal or nonfatal myocardial infarction, acute coronary syndrome without myocardial infarction, coronary revascularization, or CHD death. Incident CVD included CHD, stroke, heart failure, and peripheral arterial disease. Death included all causes. The probability of developing CAC by age 32 to 56 years was estimated using clinical risk factors measured 7 years apart between ages 18 and 38 years.
At year 15 of the study among 3043 participants (mean [SD] age, 40.3 [3.6] years; 1383 men and 1660 women), 309 individuals (10.2%) had CAC, with a geometric mean Agatston score of 21.6 (interquartile range, 17.3-26.8). Participants were followed up for 12.5 years, with 57 incident CHD events and 108 incident CVD events observed. After adjusting for demographics, risk factors, and treatments, those with any CAC experienced a 5-fold increase in CHD events (hazard ratio [HR], 5.0; 95% CI, 2.8-8.7) and 3-fold increase in CVD events (HR, 3.0; 95% CI, 1.9-4.7). Within CAC score strata of 1-19, 20-99, and 100 or more, the HRs for CHD were 2.6 (95% CI, 1.0-5.7), 5.8 (95% CI, 2.6-12.1), and 9.8 (95% CI, 4.5-20.5), respectively. A CAC score of 100 or more had an incidence of 22.4 deaths per 100 participants (HR, 3.7; 95% CI, 1.5-10.0); of the 13 deaths in participants with a CAC score of 100 or more, 10 were adjudicated as CHD events. Risk factors for CVD in early adult life identified those above the median risk for developing CAC and, if applied, in a selective CAC screening strategy could reduce the number of people screened for CAC by 50% and the number imaged needed to find 1 person with CAC from 3.5 to 2.2.
Conclusions and Relevance
The presence of CAC among individuals aged between 32 and 46 years was associated with increased risk of fatal and nonfatal CHD during 12.5 years of follow-up. A CAC score of 100 or more was associated with early death. Adults younger than 50 years with any CAC, even with very low scores, identified on a computed tomographic scan are at elevated risk of clinical CHD, CVD, and death. Selective use of screening for CAC might be considered in individuals with risk factors in early adulthood to inform discussions about primary prevention.
Carr JJ, Jacobs DR, Terry JG, Shay CM, Sidney S, Liu K, Schreiner PJ, Lewis CE, Shikany JM, Reis JP, Goff DC. Association of Coronary Artery Calcium in Adults Aged 32 to 46 Years With Incident Coronary Heart Disease and Death. JAMA Cardiol. 2017;2(4):391-399. doi:10.1001/jamacardio.2016.5493