Author + information
- Received August 21, 2007
- Revision received November 15, 2007
- Accepted November 19, 2007
- Published online March 1, 2008.
- Stephan Achenbach, MD⁎,⁎ (, )
- Ulrike Ropers, MD⁎,
- Axel Kuettner, MD†,
- Katharina Anders, MD†,
- Tobias Pflederer, MD⁎,
- Sei Komatsu, MD⁎,
- Werner Bautz, MD†,
- Werner G. Daniel, MD⁎ and
- Dieter Ropers, MD⁎
Reprint requests and correspondence:
Dr. Stephan Achenbach, University of Erlangen, Ulmenweg 18, 91054 Erlangen, Germany.
Objectives The purpose of this study was to analyze the influence of a systematic approach to lower heart rate for coronary computed tomography (CT) angiography on diagnostic accuracy of 64-slice single- and dual-source CT.
Background Coronary CT angiography is often impaired by motion artifacts, so that routine lowering of heart rate is usually recommended. This is often conceived as a major limitation of the technique. It is expected that higher temporal resolution, such as with dual-source 64-slice CT, would allow diagnostic imaging even without systematic pre-treatment for lowering the heart rate.
Methods Two hundred patients with suspected coronary artery disease were first randomized to either 64-slice single-source CT (n = 100) or dual-source CT (n = 100) for contrast-enhanced coronary artery evaluation. In each group, patients were further randomized to either receive systematic heart rate control (oral and intravenous beta-blockade for a target heart rate ≤60 beats/min) or receive no premedication. Evaluability of datasets and diagnostic accuracy were compared between groups against the results obtained from invasive angiography.
Results Systematic pre-treatment lowered heart rate during CT coronary angiography by 10 beats/min. Heart rate control significantly improved evaluability in single-source CT (93% vs. 69% on a per-patient basis, p = 0.005), whereas it did not in dual-source CT (96% vs. 98%). In evaluable patients, sensitivity to detect the presence of at least 1 coronary stenosis by single-source CT was 86% and 79%, respectively, with and without heart rate control (p = NS). For dual-source CT, it was 100% and 95%, respectively (p = NS). The rate of correctly classified patients, defined as evaluable and correct classification as to the presence or absence of at least 1 coronary artery stenosis, was significantly improved by heart rate control in single-source CT (78% vs. 57%, p = 0.04), whereas there was no such influence in dual-source CT (87% vs. 93%).
Conclusions Systematic heart rate control significantly improves image quality for coronary visualization by 64-slice single-source CT, whereas image quality and diagnostic accuracy remain unaffected in dual-source CT angiography. Improved temporal resolution obviates the need for heart rate control.
This study was partly supported by a grant from Budesministerium für Bildung und Forschung (BMBF), Germany. Robert Bonow, MD, served as Guest Editor for this paper.
- Received August 21, 2007.
- Revision received November 15, 2007.
- Accepted November 19, 2007.
- American College of Cardiology Foundation