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Evaluation of computed tomography in patients with atypical angina or chest pain clinically referred for invasive coronary angiography: randomised controlled trial
BMJ 2016; 355 doi: http://dx.doi.org/10.1136/bmj.i5441 (Published 24 October 2016)Cite this as: BMJ 2016;355:i5441
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Marc Dewey, Heisenberg professor of radiology1,
Matthias Rief, senior radiology registrar1,
Peter Martus, professor of biostatistics2,
Benjamin Kendziora, final year medical student1,
Sarah Feger, junior clinician scientist1,
Henryk Dreger, senior catheterisation laboratory physician1,
Sascha Priem, medical student1,
Fabian Knebel, senior echocardiography registrar1,
Marko Böhm, senior cardiology registrar1,
Peter Schlattmann, professor of statistics3,
Bernd Hamm, professor of radiology1,
Eva Schönenberger, internal medicine registrar1,
Michael Laule, physician coordinator of catheterisation laboratory1,
Elke Zimmermann, radiology registrar1
Correspondence to: M Dewey dewey@charite.de
Accepted 29 September 2016
Abstract
Objective To evaluate whether invasive coronary angiography or computed tomography (CT) should be performed in patients clinically referred for coronary angiography with an intermediate probability of coronary artery disease.
Design Prospective randomised single centre trial.
Setting University hospital in Germany.
Participants 340 patients with suspected coronary artery disease and a clinical indication for coronary angiography on the basis of atypical angina or chest pain.
Interventions 168 patients were randomised to CT and 172 to coronary angiography. After randomisation one patient declined CT and 10 patients declined coronary angiography, leaving 167 patients (88 women) and 162 patients (78 women) for analysis. Allocation could not be blinded, but blinded independent investigators assessed outcomes.
Main outcome measure The primary outcome measure was major procedural complications within 48 hours of the last procedure related to CT or angiography.
Results Cardiac CT reduced the need for coronary angiography from 100% to 14% (95% confidence interval 9% to 20%, P<0.001) and was associated with a significantly greater diagnostic yield from coronary angiography: 75% (53% to 90%) v 15% (10% to 22%), P<0.001. Major procedural complications were uncommon (0.3%) and similar across groups. Minor procedural complications were less common in the CT group than in the coronary angiography group: 3.6% (1% to 8%) v 10.5% (6% to 16%), P=0.014. CT shortened the median length of stay in the angiography group from 52.9 hours (interquartile range 49.5-76.4 hours) to 30.0 hours (3.5-77.3 hours, P<0.001). Overall median exposure to radiation was similar between the CT and angiography groups: 5.0 mSv (interquartile range 4.2-8.7 mSv) v 6.4 mSv (3.4-10.7 mSv), P=0.45. After a median follow-up of 3.3 years, major adverse cardiovascular events had occurred in seven of 167 patients in the CT group (4.2%) and six of 162 (3.7%) in the coronary angiography group (adjusted hazard ratio 0.90, 95% confidence interval 0.30 to 2.69, P=0.86). 79% of patients stated that they would prefer CT for subsequent testing. The study was conducted at a University hospital in Germany and thus the performance of CT may be different in routine clinical practice. The prevalence was lower than expected, resulting in an underpowered study for the predefined primary outcome.
Conclusions CT increased the diagnostic yield and was a safe gatekeeper for coronary angiography with no increase in long term events. The length of stay was shortened by 22.9 hours with CT, and patients preferred non-invasive testing.
Trial registration ClinicalTrials.gov NCT00844220.
Footnotes
We thank all the participants; radiographic staff; referring physicians; Gert Baumann (retired chair, Department of Cardiology); Lars Brillat, Mark Beling, Jürgen Frille, Angelika Frille, Fabian Stenzel, Lisa Hartmann, Robert Haase, Daniel Preuß, Paolo Ibes, Andrea Marek, Wasiem Sanad, Thomas Frank, and Ralf Offermann, for their collaboration; Jürgen Scholze, Karl Stangl, Verena Stangl, and Yvonne Dörffel for the management of the patients; Bettina Herwig for initial copy editing; Maria Bosserdt, Hans Tepe, and Laura Elzenbeck for data management; and Wolfgang Rutsch (retired chair of our catheterisation laboratory) for his vision and support.
The data safety and monitoring board: Albert de Roos (radiologist, Leiden University, Netherlands), Thomas Meinertz (cardiologist, Hamburg, Germany), and Andreas Faldum (statistician, Münster, Germany) independently reviewed all potential anonymised major and minor procedural complications and major adverse cardiovascular events blinded to the study group.
Contributors: MD had the idea for the study. MD, PM, ML, and EZ designed the study. MR and PS helped in the design of the study. MD drafted the manuscript and all other authors suggested revisions of important intellectual content. MD, MR, PM, BK, SF, HD, SP, PS, MB, BH, ES, ML, and EZ analysed and interpreted the data, and revised the manuscript for important intellectual content. EZ and MD had equal contributions. MD is the guarantor.
Funding: This study was funded by a grant of the Heisenberg programme of the German Research Foundation to Marc Dewey. All researchers are independent of the funding bodies. The funding bodies had no role in the study design; in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the manuscript for publication.
Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi-disclosure.pdf (available on request from the corresponding author) and declare that (1) MD has support from the Heisenberg programme of the German Research Foundation for the submitted work; (2) MD has relationships with Bayer, Bracco, Cardiac MR Academy, European Commission, European Regional Development Fund, German Foundation of Heart Research, German Federal Ministry of Education and Research, GE Healthcare, Guerbet, Springer, and Toshiba; BH has relationships with Bayer, Bracco, GE, Guerbet, Philips, Siemens, and Toshiba; (3) their spouses, partners, or children have no financial relationships that may be relevant to the submitted work; and (4) have no non-financial interests that may be relevant to the submitted work. Institutional master research agreements exist with Siemens Medical Solutions, Philips Medical Systems, and Toshiba Medical Systems. The terms of these arrangements are managed by the legal department of Charité–Universitätsmedizin Berlin.
Ethical approval: This study was approved by the local research ethics committee of Charité (EA-1-080-08) and the German Federal Office for Radiation Protection (Z5-22462/2-2008-048). All patients gave written informed consent before randomisation.
Data sharing: Requests for patient level data will be considered by the CAD-Man trial group.
Transparency: The lead author (MD) affirms that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.
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