Lack of association between age and Coronary artery calcification (CAC): A cross-sectional study

Minhas, Sheharyar

Background:
366,000 people died from coronary artery disease (CAD) in 2015. Coronary artery calcification (CAC) can be used as a direct measure of CAD. CAC is a robust and independent predictor of cardiovascular events and all-cause mortality. The standard methodology for scoring the amount of CAC from computed tomography (CT) scans is the Agatston method. Despite CAC reflecting underlying coronary atherosclerosis, there is some conflicting data regarding the independent effect of age on CAC. We utilized a tertiary care center data warehouse to assess the relationship between age and CAC.

Methods:
We obtained a sample of 3241 patient from Emory University Hospital data warehouse between years 2011-2016 who had a coronary artery score obtained through computerized tomographic imaging of chest (CT chest). Patients without calcification (CAC score <8) were removed. CAC score and age of subjects with calcification was log transformed and then a simple linear regression model was used to assess the association between age and CAC score. Multivariable linear regression utilizing age, diabetes type II, CAD, stroke, and end stage renal disease (ESRD) was also used.

Results:
The mean age for our group was 71.8 years. The average CAC among our cohort was 70. Using general linear regression model to evaluate the independent effect of age on CAC, we found that there is no statistically significant association between age and CAC (P = 0.84).

Conclusions:
Our results indicate that there is no statistically significant relationship between age and CAC independent of atherosclerotic coronary artery disease. Adjusting for cardiovascular risk factors, age was not associated with the severity of CAC. In this study, patients were only from Emory data warehouse, predominately Caucasian, and had to have presented with symptoms or medical history that warranted a chest CT. Further research is warranted with a larger sample size and more variation in demographic factors.