Best Evidence Topics


MJ Gallagher, MA Ross, GL Raff, et al
The Diagnostic Accuracy of 64-Slice Computed Tomography Coronary Angiography Compared With Stress Nuclear Imaging in Emergency Department Low-Risk Chest Pain Patients
Annals of Emergency Medicine
February 2007; 125-136
  • Submitted by:Can Tamkoc - Resident Emergency Physician
  • Institution:Tampa General Hospital/University of South Florida
  • Date submitted:30th March 2007
Before CA, i rated this paper: 9/10
1 Objectives and hypotheses
1.1 Are the objectives of the study clearly stated?
  Yes, A comparison was evaluated between the diagnostic accuracy of multidetector CT vs. nuclear stress testing in detecting acute coronary syndrome in low-risk chest pain patients.
2 Design
2.1 Is the study design suitable for the objectives
  Yes. The diagnostic accuracy of Multidetector CT vs. Stress Nuclear Imaging was compared.
2.2 Who / what was studied?
  Low-risk chest pain patients without ischemic ECG changes or biomarker elevation were evaluated for acute coronary syndrome.
2.3 Was this the right sample to answer the objectives?
  Yes. Low-risk chest pain patients with non ischemic ECG and normal cardiac markers and the absence of known cardiac disease (CAD, Cardiomyopathy, CHF with EF less than or equal to 45%) were compared and evaluated.
2.4 Is the study large enough to achieve its objectives? Have sample size estimates been performed?
  The study size was small and a larger sample should be evaluated to appraise reproducability/accuracy. However, the sample utilized was adequate to introduce the suggestion of using multidetector CT as an effective method to risk stratisfy low-risk chest pain patients for ACS.
2.5 Were all subjects accounted for?
2.6 Were all appropriate outcomes considered?
2.7 Has ethical approval been obtained if appropriate?
2.8 Was an independent blinded gold standard test applied to all subjects?
  No. Not all patients recieved cardiac catheterization/invasive coronary angiography.
3 Measurement and observation
3.1 Is it clear what was measured, how it was measured and what the outcomes were?
  Yes. The sensitivity, specificity, NPV, PPV with confidence intervals were calculated and compared for multidetector CT and stress nuclear imaging.
3.2 Are the measurements valid?
3.3 Are the measurements reliable?
3.4 Are the measurements reproducible?
  Another trial would need to be performed to evaluate reproducibilty.
4 Presentation of results
4.1 Are the basic data adequately described?
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?
  No. The objective results were discussed including the limitations of the study.
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?
  Yes. This paper suggests that 64-slice CT coronary angiography has comparable accuracy to that of stress nuclear imaging for detecting acute coronary syndrome in low-risk chest pain patients.
After CA, i rated this paper: 9/10
8 Implementation
8.1 Can the test be implemented in practice?
  No. Another trial, preferably with a larger sample size should be evaluated for reproducibility prior to instituting 64-slice CT coronary angiography as a standard of care in detecting acute coronary syndrome in low-risk chest pain patients. Guidelines are needed when lesions are present, specifically the lesions considered not significant for PCI.
8.2 What aids to implementation exist?
  1. The technological advancement of multidetector CT.
2. A need to effectively and efficiently make disposition decisions in low-risk chest pain patients.
3. The ability to evaluate significant cardiac and non-cardiac etiology for chest pain. For example, "triple rule-out" protocol allowing evaluation for acute coronary syndrome, pulmonary embolus, aortic dissection, as well as other intrathoracic pathology.
8.3 What barriers to implementation exist?
  1. There is no protocol in place to make decisions on what is to be considered a significant coronary lesion requiring PCI and what to do with patients in whom lesions are not considered significant.
2. Legal implications.
3. If a significant lesion is found what is the delay in PCI secondary to the patient having recieved contrast for CT.
8.4 Are my patients the same as the patients tested?
  Yes. However, there was no mention on patients presenting with "cocaine chest pain" and how this factors into exclusion/inclusion.
8.5 Will the test improve diagnosis in my patients?
  According to the data, diagnosis was found to be at least equivicol in comparing 64-slice CT coronary angiography to stress nuclear imaging. The possibility of finding alternate pathology for chest pain, the ability to avoid hospitilization, and the associated savings in medical cost to the patient and society is definately an attractive concept.