Objective: We aimed to establish the feasibility of single-heartbeat 320-multidetector computed tomographic coronary angiography (CTCA) and assess variables affecting image quality.
Methods: Consecutive patients (n = 249, 38% male) underwent CTCA. Two observers assessed image quality using a 4-point scale (1, excellent; 4, poor).
Results: Mean heart rate was 60 beats per minute (95% confidence interval, 59–62); body mass index, 29 kg/m2 (28–30); and dose-length product, 283 mGy·cm (266–301). During scanning, 133 (51%) received sublingual glyceryl trinitrate (GTN), 9 (4%) had ectopics, and 12 (5%) had atrial fibrillation. Diagnostic image quality was obtained in 99% with mean image quality of 1.4 (1.3, 1.5). Age, sex, atrial fibrillation, ectopics, diabetes mellitus (12%), and obstructive disease were not related to image quality. A lower heart rate and GTN were associated with improved image quality (P ≤ 0.001).
Conclusions: Optimal image quality in single-heartbeat 320-multidetector CTCA is achievable in 99% of unselected patients. Image quality is improved by lower heart rate and GTN.