Best Evidence Topics


N. Mollet, F. Cademartiri, C. vanMieghem, G. Runza, E. McFadden, T. Baks, P. Serruys, G. Krestin, P. deFeyter.
High-Resolution Spiral Computed Tomography Coronary Angiography in Patients Referred for Diagnostic Conventional Coronary Angiography
October 11, 2005 pg2318-2323
  • Submitted by:Jeremiah Johns - Resident
  • Institution:Grand Rapids Medical Education and Research Center
  • Date submitted:1st March 2006
Before CA, i rated this paper: 9/10
1 Objectives and hypotheses
1.1 Are the objectives of the study clearly stated?
  Yes - Evaluate the ability of 64 slice CT scanner to detect significant coronary artery stenosis.
2 Design
2.1 Is the study design suitable for the objectives
  Yes - Angiography results were compared with CT findings in a blinded fashion.
2.2 Who / what was studied?
  Patients scheduled for coronary angiography with atypical chest pain, stable or unstable angina, or non-ST-segment elevation myocardial infarction.
2.3 Was this the right sample to answer the objectives?
2.4 Is the study large enough to achieve its objectives? Have sample size estimates been performed?
  No - Sample size estimates were not given. Only 52 patients were studied.
2.5 Were all subjects accounted for?
2.6 Were all appropriate outcomes considered?
  Yes - Lesions with greater than or equal to 50% stenosis were considered significant.
2.7 Has ethical approval been obtained if appropriate?
2.8 Was an independent blinded gold standard test applied to all subjects?
  Yes - Coronary Angiography
3 Measurement and observation
3.1 Is it clear what was measured, how it was measured and what the outcomes were?
  Yes - CT scans were reviewed by 2 observers who were blinded to the angiography results.
3.2 Are the measurements valid?
3.3 Are the measurements reliable?
3.4 Are the measurements reproducible?
  Yes - This paper quotes earlier studies showing promise in older generation CT scanners.
4 Presentation of results
4.1 Are the basic data adequately described?
  Yes - Table 2
4.2 Are the results presented clearly, objectively and in sufficient detail to enable readers to make their own judgement?
4.3 Are the results internally consistent, i.e. do the numbers add up properly?
5 Analysis
5.1 Are the data suitable for analysis?
5.2 Are the methods appropriate to the data?
5.3 Are any statistics correctly performed and interpreted?
6 Discussion
6.1 Are the results discussed in relation to existing knowledge on the subject and study objectives?
6.2 Is the discussion biased?
7 Interpretation
7.1 Are the authors' conclusions justified by the data?
7.2 What level of evidence has this paper presented? (using CEBM levels )
7.3 Does this paper help me answer my problem?
After CA, i rated this paper: 9/10
8 Implementation
8.1 Can the test be implemented in practice?
  Not yet. Sample size is too small, although this may be an acceptable test for patients with a low pre-test probability of significant disease.
8.2 What aids to implementation exist?
  The speed and non-invasive nature of the CT scans are attractive features.
8.3 What barriers to implementation exist?
  1. A 64-slice CT scanner is needed.
2. Patient must be able to hold breath for 15 seconds.
3. Beta-blockers are often needed to slow the heart rate.
4. The presence of coronary stents prevents assessment of reocclusion.
5. Image resolution may be compromised in obese patients or patients with arrythmias.
8.4 Are my patients the same as the patients tested?
  Yes; however, most patients in this study were diagnosed as having stable angina. This may not be true for most patients presenting to the emergency department.
8.5 Will the test improve diagnosis in my patients?
  It has potential, especially with more testing in the emergency setting.