Abstract

Objective To prospectively investigate the diagnostic accuracy of dual-source 64-slice computed tomography coronary angiography (CTCA), calcium scoring (CS), and both methods combined for assessing significant coronary artery stenoses relative to conventional coronary angiography (CCA).

Design, Setting and Patients Prospective, single-center study conducted in a referral center enrolling 74 consecutive patients (24 women; mean age 62±12years) from August-October 2006. All study participants underwent CS, CTCA, and CCA. Diagnostic accuracy was calculated for CS, CTCA, and both methods combined relative to CCA. Not-evaluative segments at computed tomography were considered false-positive.

Results CCA identified 139 stenoses in 36 patients. Average heart rate during CTCA was 68±13bpm (range 35-102bpm), and 2% of segments (21/1001) in 11% of patients (8/74) were not-evaluative. Considering these as false-positives, per-patient sensitivity and specificity was 98% and 87%. When using CS cut-off values of 0 to exclude and (3)400 to predict stenosis, sensitivity and specificity of CS was 100% and 70%, respectively. Combining CS and CTCA in all patients correctly reclassified 5 patients, while 6 were falsely classified as stenotic, all of them correctly classified with CTCA alone. Using CS only in patients with not-evaluative segments correctly reclassified 5 patients while avoiding misclassifications (sensitivity 98%, specificity 100%).

Conclusion Dual-source CTCA allows the diagnosis of significant stenoses with a high diagnostic accuracy. Selectively combining CS with CTCA in patients with not-evaluative coronary segments improves specificity from 87% to 100% without decreasing the high sensitivity of 98%.