Analysis of the coronary artery calcium score for identifying coronary artery plaque in patients clinically referred for preventive screening with non-typical symptoms stratified by age and sex

AIMS: To evaluate the impact of age and sex on the diagnostic performance of the coronary artery calcium (CAC) score to detect any coronary plaque in individuals referred for preventive screening. METHODS AND RESULTS: We analyzed 1372 patients (56 ​% male, mean age 51 ​± ​9 years) referred for preventive coronary artery disease (CAD) screening due to a positive family history of premature CAD in a first degree family member that had non cardiac or atypical symptoms or an abnormal exercise tolerance test. All individuals underwent CAC scoring and coronary computed tomography angiography. The diagnostic performance of a CAC score >0 to detect any coronary plaque was assessed across 5-year age categories, stratified by sex. Coronary plaque was demonstrated by CCTA in 761 patients (55 ​%), including 156 individuals (20 ​%) with a CAC score of 0. The sensitivity of the CAC score increased with age, from 53 ​% (95%CI: 34-71 ​%) in individuals aged <40-93 ​% (95%CI: 84-98 ​%) in patients ≥65 years old. Consequently, a CAC score of 0 resulted in an absolute risk reduction for coronary plaque of 8 ​% in patients <40, whereas this was 50 ​% in individuals ≥65. The sensitivity of the calcium score in detecting coronary plaque was generally higher in males and patients on lipid lowering therapy across all age groups. CONCLUSIONS: The diagnostic accuracy of a CAC score of 0 improves with age. A CAC score of 0 does not reliably exclude coronary plaque in younger individuals, whereas its utility is greater in older adults.