JACC: Prospective ECG-triggering detects coronary stenosis with less radiation
Prospective ECG-triggering CT allows an accurate detection of coronary stenosis with a low radiation dose, despite a slight reduction of diagnostic performance, according to a single-center study in the July 21 issue of the Journal of the American College of Cardiology.

Gianluca Pontone, MD, and colleagues from the Centro Cardiologico Monzino and the department of cardiovascular sciences at the University of Milan in Italy, evaluated the diagnostic performance of multidetector CT (MDCT) with prospective ECG-triggering compared with retrospective ECG-triggering. The authors noted that the benefits of visualization with MDCT are often overshadowed by the concern over radiation exposure.

The researchers enrolled 180 consecutive patients scheduled for invasive coronary angiography in the study. They excluded 20 patients 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.

In nonstented segments, the investigators found that the evaluability of Groups 1 and 2 was 96 vs. 97 percent, respectively, the accuracy in segment-based model was 93 vs. 96 percent, respectively, including diagnostic segments, and 91 vs. 94 percent, respectively, including all segments, whereas the accuracy in a patient-based model was 98 percent in both groups.

In stented segments, Pontone and his collagues found that the evaluability in Groups 1 and 2 was 92 versus 94 percent, respectively, and the accuracy was 93 vs. 92 percent, respectively, including diagnostic stented segments, and 90 vs. 89 percent, respectively, including all stented segments.

Overall, they found that Group 1 had a significantly lower radiation dose compared with Group 2 (5.7 mSv vs. 20.5 mSv).

The authors noted that in a patient-based model, which is "more useful from the clinical standpoint, the accuracy was very high and exactly the same in the 2 groups (98 percent), regardless of the ECG-triggering technique used and the inclusion of only diagnostic segments or all segments. Therefore, the technique using prospective ECG-triggering showed a high diagnostic performance for the assessment of CAD [coronary artery disease] including all coronary segments and coronary stents."

These findings are of clinical importance, because MDCT is increasingly used for the evaluation of stent patency and assessment of the presence of CAD, Pontone and colleagues concluded.