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.
From the *University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, †Clinical Research Imaging Centre, University of Edinburgh; and ‡Royal Infirmary of Edinburgh, Edinburgh, United Kingdom.
Received for publication August 23, 2013; accepted October 24, 2013.
Reprints: Michelle Claire Williams, MBChB, BSc, University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, Chancellor’s Bldg SU305, 49 Little France Crescent, EH16SU4, United Kingdom (e-mail: firstname.lastname@example.org).
M. C. W. is supported by a British Heart Foundation Clinical Research and Training Fellowship (FS/11/14/28692). The Clinical Research Imaging Centre is supported by NHS Research Scotland through NHS Lothian. M. C. W., D. E. N., and E. J. R. V. B. have spoken at meetings sponsored by Toshiba Medical Systems. D. E. N. holds the British Heart Foundation John Wheatley Chair of Cardiology. The Centre for Cardiovascular Science is the recipient of a British Heart Foundation Centre of Research Excellence Award (RE/08/001).
The other authors report no conflicts of interest.