Coronary CT Angiography may detect 'silent' atherosclerosis: Study

Early detection of coronary atherosclerosis using coronary computed tomography angiography (CCTA), in addition to coronary artery calcification (CAC) scoring, may help inform prevention strategies.

A group of researchers from Sweden conducted a study to determine the prevalence, severity, and characteristics of coronary atherosclerosis and its association with CAC scores in a general population.

The researchers recruited 30 154 randomly invited individuals age 50 to 64 years to SCAPIS (the Swedish Cardiopulmonary Bioimage Study). The study includes individuals without known coronary heart disease (i.e., no previous myocardial infarctions or cardiac procedures) and with high-quality results from CCTA and CAC imaging performed using dedicated dual-source CT scanners. Non-contrast images were scored for CAC. CCTA images were visually read and scored for coronary atherosclerosis per segment.

The external validity of prevalence estimates was evaluated using an inverse probability for participation weighting and Swedish register data.

The results of the study are as follows:

· In total, 25 182 individuals without known coronary heart disease were included.

· Any CCTA-detected atherosclerosis was found in 42.1%; any significant stenosis in 5.2%; left main, proximal left anterior descending artery, or 3-vessel disease in 1.9%; and any noncalcified plaques in 8.3% of this population.

· Onset of atherosclerosis was delayed on average by 10 years in women.

· Atherosclerosis was more prevalent in older individuals and predominantly found in the proximal left anterior descending artery.

· Prevalence of CCTA-detected atherosclerosis increased with increasing CAC scores. Among those with a CAC score >400, all had atherosclerosis and 45.7% had significant stenosis.

· In those with 0 CAC, 5.5% had atherosclerosis and 0.4% had significant stenosis.

· In participants with 0 CAC and intermediate 10-year risk of atherosclerotic cardiovascular disease according to the pooled cohort equation, 9.2% had CCTA-verified atherosclerosis.

· Prevalence estimates had excellent external validity and changed marginally when adjusted to the age-matched Swedish background population.

Thus, the researchers concluded that using CCTA in a large, random sample of the general population without established disease, showed that silent coronary atherosclerosis is common in this population. High CAC scores convey a significant probability of substantial stenosis, and 0 CAC does not exclude atherosclerosis, particularly in those at higher baseline risk.

Reference:

Prevalence of Subclinical Coronary Artery Atherosclerosis in the General Population by Bergström G et. al published in the Circulation.

https://doi.org/10.1161/CIRCULATIONAHA.121.055340