Diagnostic Accuracy of 64-Slice Spiral Computed Tomography Compared with Conventional Angiography
Date First Published:
May 8, 2006
Last Updated:
May 8, 2006
Report by:
Jeremiah Johns, Emergency Medicine Resident (Grand Rapids Medical Education and Research Center)
Search checked by:
Jeff Jones, Grand Rapids Medical Education and Research Center
Three-Part Question:
In [patients with suspected coronary artery disease] is [64-slice CT] accurate enough to [rule out clinically significant disease]?
Clinical Scenario:
A 60 year old male presents to the emergency department with substernal chest pain. He is a smoker, has hypertension and has never been diagnosed with coronary artery disease. EKG does not show an acute myocardial infarction and initial cardiac enzymes are negative. Aspirin and sublingual nitroglycerin have relieved his pain.
Search Strategy:
Medline 1996 – April 4, 2006 using the OVID interface, Cochrane Library Clinical Queries
Search Details:
[(exp Coronary Angiography/ or Coronary Angiography.mp) AND (exp Tomography, X-Ray Computed OR exp Tomography, Spiral Computed) AND (64-slice.mp)]. LIMIT to human AND English.
Outcome:
12 papers found, of which 5 were relevant.
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Quantification of obstructive and nonobstructive coronary lesions by 64-slice computed tomography: a comparative study with quantitative coronary angiography and intravascular ultrasound. Leber AW et. al. 2005 Germany | 59 patients scheduled for coronary angiography due to stable angina. | Prospective, blinded. Level 2b | Detection of stenosis < 50%, > 50%, and > 75%. All vessels included regardless of size. | Sensitivity 94% (17/18) for detecting patients with lesions requiring angioplasty or bypass. | 4 patients dropped from analysis due to poor image quality. High incidence of disease in study population. |
| Accuracy of MSCT coronary angiography with 64-slice technology: first experience. Leschka, S. et al. 2005 Switzerland | 67 consecutive patients referred for suspected CAD or prior to bypass surgery. | Prospective, Blinded. Level 2b | Vessels > 1.5mm evaluated and compared with conventional angiography. | Sensitivity 94%, Specificity 97%, PPV 87%, NPV 99%. | High incidence of disease in study population. 64% of patients were referred to study prior to bypass surgery. |
| Diagnostic accuracy of noninvasive coronary angiography using 64-slice spiral computed tomography. Raff, G. et al. 2005 USA | 70 consecutive patients with suspected CAD scheduled for invasive angiography. | Prospective, blinded. Level 2b | All vessels analyzed including < 1.5mm diameter, and compared to conventional angiography. Significant stenosis defined as > 50%. | For detection of significant stenosis, per-patient Sensitivity 95%, Specificity 90%, Positive Predictive Value and Negative Predictive Value both 93%. Sub-group analysis shows decreased sensitivity for heart rate > 70 and body mass index > 30. | Excluded patients suspected of acute coronary syndromes High incidence of disease in study population |
| High-resolution spiral computed tomography coronary angiography in patients referred for diagnostic conventional coronary angiography. Mollet, N. et. al. 2005 Netherlands | 52 patients enrolled after exclusion criteria. Patients included with atypical chest pain, stable or unstable angina or Non-ST-segment elevation myocardial infarction. | Prospective, blinded. Level 2b | All vessels included regardless of size. Significant stenosis defined as > 50%. | For detection of significant stenosis, Sensitivity 99% (94-99), Specificity 95%(93-96), PPV 76% (67-89), NPV 99% (99-100). | High prevalence of disease in study population. |
| Comparison of accuracy of 64-slice cardiovascular computed tomography with coronary angiography in patients with suspected coronary artery disease. Fine, J. et. al. 2006 USA | 66 sequential patients referred for conventional coronary angiography by their doctor. | Prospective, blinded, level 2b | Vessels > 1.5mm evaluated and compared with conventional angiography. | For detection of significant stenosis, Sensitivity 95%, Specificity 96%, PPV 97%, NPV 92%. | Patient inclusion and exclusion criteria not clearly defined. 4 subjects had poor quality scans which precluded diagnosis and it is unclear whether or not these patients were excluded from the final sensitivity and specificity calculations. |
Author Commentary:
All five studies found similar results and they have similar study design and patient population. The importance of CT coronary angiography for emergency department uses is to rule out clinically significant CAD. Leber and Mollet report a patient based analysis for the detection of clinically significant stenosis of 94% and 100%, respectively. Taken together this would be 55 of 56 patients for an excellent total sensitivity of 98%. Leschka also reports a patient based sensitivity of 100%, but does not give the total number of patients in the calculation, making further meta-analysis impossible. It is also clear from these studies that fast (>70 bpm) or irregular heart rates, stents, calcified arteries, and a body mass index > 30 impair accuracy. Furthermore, these studies were all done in a population of patients with a high prevalence of disease, which does not necessarily reflect an ED population.
Bottom Line:
64-slice CT coronary angiography shows promise regarding the ability to rule out clinically significant coronary artery disease. A large, multi-center study is needed to prove its accuracy in an emergency department setting with a carefully defined patient population geared to increase sensitivity before it can be used in clinical practice.
References:
- Leber AW et. al.. Quantification of obstructive and nonobstructive coronary lesions by 64-slice computed tomography: a comparative study with quantitative coronary angiography and intravascular ultrasound.
- Leschka, S. et al.. Accuracy of MSCT coronary angiography with 64-slice technology: first experience.
- Raff, G. et al.. Diagnostic accuracy of noninvasive coronary angiography using 64-slice spiral computed tomography.
- Mollet, N. et. al.. High-resolution spiral computed tomography coronary angiography in patients referred for diagnostic conventional coronary angiography.
- Fine, J. et. al.. Comparison of accuracy of 64-slice cardiovascular computed tomography with coronary angiography in patients with suspected coronary artery disease.