Accuracy of low-dose computed tomography coronary angiography using prospective electrocardiogram-triggering: first clinical experience

To evaluate the accuracy of low-dose computed tomography coronary angiography (CTCA) using prospective ECG-triggering for the assessment of coronary artery disease (CAD). A total of 30 patients (19 males, 11 females, mean age 58.8 +/- 9.9 years) underwent low-dose CTCA and invasive coronary angiography (CA) [median 2 days (0, 41)]. Before CT scanning, intravenous beta-blocker was administered in 18 of 30 patients as heart rate (HR) was > 65 b.p.m., achieving a mean HR of 55.7 +/- 7.9 b.p.m. CAD was defined as coronary artery narrowing >= 50%, using CA as standard of reference. The estimated mean effective radiation dose was 2.1 +/- 0.7 mSv (range: 1.0-3.3), yielding 96.0% (383/399) of evaluable segments. On an intention-to-diagnose-base, all non-evaluative segments were included in the analysis. Vessels with a non-evaluative segment and no further finding were censored as false positive. Patient-based analysis revealed sensitivity, specificity, positive predictive value, and negative predictive value of 100, 83.3, 90.0, and 100%, respectively. The respective values per vessel were 100, 88.9, 85.7, and 100%, respectively. Prospective ECG-triggering allows low-dose CTCA and provides high diagnostic accuracy in the assessment of CAD in patients with stable sinus rhythm and a low heart rate.