Current status and future perspective of coronary artery calcium score in asymptomatic individuals.

Atherosclerotic cardiovascular disease remains a major cause of death, and it is important to accurately estimate the cardiovascular events risk stratification even in asymptomatic patients. The coronary artery calcium score (CACS), which is quantitatively evaluated by electrocardiogram (ECG)-gated non-contrast chest computed tomography (CT) imaging, has been reported to be useful for cardiovascular event risk stratification in large studies. In the USA and Europe, guidelines recommend the use of the CACS in borderline or intermediate-risk asymptomatic individuals based on a high level of evidence. In Japan, however, the use of CACS in clinical practice is currently limited. Although it has been reported that the prevalence and distribution of coronary artery calcification (CAC) may differ by race and ethnicity, there are few data on its usefulness in stratifying the risk of cardiovascular events in asymptomatic Japanese individuals. While it is important to establish evidence for the usefulness of CACS in the Japanese population, for widespread clinical dissemination it would be beneficial to evaluate CAC and to perform accurate cardiovascular event risk stratification from non-ECG-gated non-contrast chest CT imaging performed during medical check-up and routine clinical practice. There have been reports on the usefulness of CAC assessed by non-ECG-gated chest CT imaging and on the relationship of CAC between ECG-gated and non-ECG-gated chest CT imaging. In recent years, a more accurate method of evaluating CACS from non-ECG-gated chest CT imaging has been developed using artificial intelligence, and further development is expected in the future.