Multi-Detector Coronary CT Imaging for the Identification of Coronary Artery Stenoses in a "Real-World" Population

Abstract

Background: Multi-detector computed tomography (CT) has emerged as a modality for the non-invasive assessment of coronary artery disease (CAD). Prior studies have selected patients for evaluation and have excluded many of the "real-world" patients commonly encountered in daily practice. We compared 64-detector-CT (64-CT) to conventional coronary angiography (CA) to investigate the accuracy of 64-CT in determining significant coronary stenoses in a "real-world" clinical population.

Methods: A total of 1,818 consecutive patients referred for 64-CT were evaluated. CT angiography was performed using the GE LightSpeed VCT (GE(®) Healthcare). Forty-one patients in whom 64-CT results prompted CA investigation were further evaluated, and results of the two diagnostic modalities were compared.

Results: A total of 164 coronary arteries and 410 coronary segments were evaluated in 41 patients (30 men, 11 women, age 39-85 years) who were identified by 64-CT to have significant coronary stenoses and who thereafter underwent CA. The overall per-vessel sensitivity, specificity, positive predictive value, negative predictive value, and accuracy at the 50% stenosis level were 86%, 84%, 65%, 95%, and 85%, respectively, and 77%, 93%, 61%, 97%, and 91%, respectively, in the per-segment analysis at the 50% stenosis level.

Conclusion: 64-CT is an accurate imaging tool that allows a non-invasive assessment of significant CAD with a high diagnostic accuracy in a "real-world" population of patients. The sensitivity and specificity that we noted are not as high as those in prior reports, but we evaluated a population of patients that is typically encountered in clinical practice and therefore see more "real-world" results.

Keywords: 64-detector coronary computed tomography; coronary angiography; coronary artery disease.

Figure 1

(A) Three-dimensional reconstruction (“volume rendered”) revealing the presence of proximal left anterior descending artery high grade long segment stenosis (arrow). (B) Curved multiplanar reconstruction in the same patient reveals the high grade stenosis consisting of predominantly fatty plaque (arrow). (C) Invasive CA confirms the stenosis (arrow).

Figure 2

(A) Curved multiplanar reconstruction of proximal left anterior descending artery in a patient with a prior history of angioplasty reveals a mixed (fatty and calcified) plaque with an area of significant stenosis (arrow) just distal to a septal perforator (asterisk). (B) Invasive CA confirms the stenosis (arrow) just distal to the septal perforator (asterisk), however, provides no information about the mixed nature of the plaque.

Figure 3

(A) Oblique tomographic view of the left circumflex coronary artery of a patient with a calcium score of 1377 agatston units reveals a severely calcified vessel generally precluding assessment for stenosis. Despite this, there is an area of narrowing noted by the arrow, which was found on invasive CA (B) to reveal a significant stenosis (arrow) just before the marginal branch.