Validation and Prognosis of Coronary Artery Calcium Scoring in Nontriggered Thoracic Computed Tomography

Abstract

Compared with electrocardiography-triggered CT, nontriggered CT is extensively used. In 2007, 13.6 million nontriggered thoracic CT examinations were performed in the United States, in contrast to 0.7 million electrocardiography-triggered CT examinations for calcium scoring. 7 Recent trial results have increased the interest in lung cancer screening by thoracic CT.8 Thus, the number of nontriggered examinations will likely further increase. Age and smoking, the current selection criteria for lung cancer screening, are also correlated with coronary calcification and coronary heart disease.9 In lung cancer screening, coronary calcification is a frequent finding.10 If nontriggered CT can be used for calcium scoring, to stratify individuals in categories of cardiovascular risk and to identify Background-Coronary calcium score (CS), traditionally based on electrocardiography-triggered computed tomography (CT), predicts cardiovascular risk. Currently, nontriggered thoracic CT is extensively used, such as in lung cancer screening. The purpose of the study was to determine the correlation in CS between nontriggered and electrocardiographytriggered CT, and to evaluate the prognostic performance of the CS derived from nontriggered CT.

2016 SCCT/STR guidelines for coronary artery calcium scoring of noncontrast noncardiac chest CT scans: A report of the Society of Cardiovascular Computed Tomography and Society of Thoracic Radiology

“…There were 8.8% false negative NCCT for CAC noted on the gated scans, and 19.1% underestimation of high CAC scores. 63 Most recently, 4544 subjects underwent both 3mm gated CAC scans and 6 mm standard nongated chest CT scans by electron beam computed tomography, with a 6 year follow up for all cause mortality. 64 There were 157 deaths, matched 1:3 to 494 survivor controls.…”

Coronary artery calcification in clinical practice: what we have learned and why should it routinely be reported on chest CT?

“…It is estimated that 7 million Americans would be eligible for such a screening (10), a number that of course does not include the millions of additional adults who undergo a chest CT for other reasons. The strong association between smoking and CV risk, explains the high prevalence of CAC >0 that was over 50% in many of the studies (49), and the proportion of individuals with the highest category of CAC (similar to an Agatston score >400) that was approximately 20%.…”

“…In a systematic review and meta-analysis by Xie et al (49), found a strong agreement in CAC scores categorization between non-triggered CT and electrocardiographytriggered CT. Based on five studies (49-53) that authors concluded that compared with electrocardiographytriggered CT, a high calcium score category in nontriggered CT is a fairly reliable finding. However they found that nontriggered CT yielded false-negative score in 8.8% of individuals, and underestimated high score in 19.1%.…”

Clinical Implications of the Coronary Artery Calcium Score in Japanese Patients

“…In addition, previous cohort studies by Itani et al 23) and Ikeda et al 42) evaluated whether the presence of CAC is associated with cardiac mortality or cerebral atherosclerosis using conventional spiral CT. Although this method does not replace dedicated ECG-triggered CT scanning, calcium scoring in the setting of non-triggered CT has the potential to be used to evaluate evidence for diagnostic and prognostic purposes 41) .…”