Potential Clinical Impact of Abdominal Aortic Calcification on Bone Density Lateral Spine Images

Abdominal aortic calcification (AAC) predicts incident atherosclerotic cardiovascular disease (ASCVD) events and can be accurately identified on densitometric lateral spine images obtained at the time of bone densitometry. Our objective was to estimate the proportion of patients referred for bone densitometry who have a high level of AAC and are not already known to have ASCVD or to be at high risk for ASCVD. AAC was scored on densitometric lateral spine images of 2168 individuals blinded to clinical diagnoses or risk factors using the 24-point Framingham scale. We ascertained preexisting ASCVD diagnoses and risk factors using electronic health record data. We used the risk calculator of the American Heart Association (AHA) and the American College of Cardiology (ACC) to estimate the 10-yr risk of hard ASCVD outcomes (myocardial infarction, death caused by coronary heart disease, or nonfatal or fatal stroke). A high level of AAC (AAC score ≥5) was present in 41 (6.1%, 95% confidence interval [CI]: 4.4%-8.2%) of those aged less than 65 yr, in 253 (23.1%, 95% CI: 20.7%-25.7%) of those aged 65-74 yr, and in 153 (37.8%, 95% CI: 33.0%-42.7%) of those aged 75-80 yr. Among those aged 65-74 yr, 16.9% (95% CI: 14.7%-19.3%) had a high level of AAC and no prior clinical diagnosis of ASCVD, but only 2.4% had a high level of AAC and a predicted 10-yr risk of hard ASCVD outcomes <7.5%. AAC is common among those aged 65 yr and older who were referred for bone densitometry and had no known ASCVD, although these individuals can also be recognized as being at intermediate to high risk using the AHA-ACC ASCVD risk calculator. Further studies regarding the impact of identification of AAC on provider and patient cardiovascular disease risk management choices are warranted.