Improved accuracy of noninvasive electron beam coronary angiography.

Objectives: We investigated the effect of electrocardiographic (ECG) triggering on the accuracy of coronary electron-beam angiography (EBA) as compared with invasive angiography.

Methods: One hundred thirty-three patients with suspected coronary disease were studied with intravenous coronary EBA and conventional coronary angiography. Patients were divided into 2 groups based upon ECG triggering on the EBA study. Patients were divided into 2 groups based upon different ECG triggering used: 80% R-R interval trigger method (group 1, n = 53) and end-systolic triggering (group 2, n = 80). End-systolic ECG triggering, which started at the end of the T wave in each study, was based on baseline heart rate.

Results: Overall sensitivity to detect a > or = 50% luminal stenosis was 69% in group 1 and 91% in group 2 (P = 0.002); specificity was 82% and 94% in group 1 and group 2, respectively (P < 0.001). Using newer triggering techniques (group 2) with EBA, the sensitivity, specificity, and accuracy for patients with disease of the left main coronary artery or 3 vessel disease was 100%, 94%, and 98%, respectively. Nonassessability of coronary segments on 3D-EBA images was reduced from 35% in group 1 to 9% in group 2 patients (P < 0.001). The number of motion-free coronary images increased from 67% to 95% from group 1 to group 2 (P < 0.0001).

Conclusion: End-systolic ECG triggering improves accuracy, image quality, and assessability of segments of coronary EBA for the detection of angiographic coronary artery disease.