Diagnostic accuracy of coronary computed tomography angiography : a comparison between prospective and retrospective electrocardiogram triggering

Objectives: The aim of this study was to compare the diagnostic performance of multidetector computed tomography (MDCT) with prospective electrocardiogram (ECG) triggering versus retrospective ECG triggering. Background: MDCT allows the noninvasive visualization of the coronary arteries. However, radiation exposure is a reason for concern. Methods: One hundred eighty consecutive patients scheduled for invasive coronary angiography were enrolled in this study. Twenty patients were excluded due to contraindications to sustain MDCT. Of the 160 remaining patients, 80 were studied with MDCT with prospective ECG triggering (Group 1) and 80 with a retrospective ECG triggering (Group 2). The individual radiation dose exposure was estimated. Results: In nonstented segments, the evaluability of Groups 1 and 2 was 96% versus 97%, respectively (p = 0.05), the accuracy in segment-based model was 93% versus 96%, respectively (p < 0.05) including diagnostic segments and 91% versus 94%, respectively (p < 0.01) including all segments, whereas the accuracy in a patient-based model was 98% in both groups. In stented segments the evaluability in Groups 1 and 2 was 92% versus 94%, respectively, and the accuracy was 93% versus 92%, respectively, including diagnostic stented segments and 90% versus 89%, respectively, including all stented segments. Group 1 presented lower radiation dose compared with Group 2 (5.7 ± 1.5 mSv vs. 20.5 ± 4.3 mSv, p < 0.01). Conclusions: Prospective ECG-triggering computed tomography allows an accurate detection of coronary stenosis, despite a slight reduction of diagnostic performance, with a low radiation dose.