Background: Computed tomographic coronary angiography (CTA) is a non-invasive alternative to conventional coronary angiography (CCA) in detecting chronic coronary artery disease (CAD). However, the value of CTA in estimating acute myocardial infarction (AMI) has not been evaluated.
Methods: CTA and CCA were performed on 10 patients with non-ST-elevated AMI and 17 patients with stable angina pectoris. The plaque components and stenosis severity were assessed by both modalities to clarify the diagnostic values of CTA in AMI and stable angina pectoris.
Results: A high total coronary artery calcium (CAC) score was significantly correlated with the presence of CAD and the target lesion CAC score (p < 0.01). The AMI group tended to have a lower target CAC score (p = 0.10) and target plaque burden (p = 0.27), compared to the stable angina pectoris group. To estimate the coronary artery stenotic severity, CTA and CCA had concordant correlations in all segments, except in the proximal left anterior descending (LAD) artery. The calcium score and calcification fraction percentage in the proximal LAD artery were significantly higher than those of other segments (p < 0.01). Compared to CCA, CTA overestimated the severity of stenosis in the proximal LAD arterial segment in the stable angina pectoris group (p = 0.028), but not in the AMI group.
Conclusions: CTA has diagnostic values similar to those of CCA in detecting coronary lesions in patients with AMI or stable angina pectoris. However, a high level of plaque CAC in the stable angina pectoris group may lead to an overestimation of the severity of coronary stenosis, especially in the proximal LAD arterial segment. Although less remarkable, the impact of CAC on the diagnostic value of CTA was still substantial in patients with AMI.