The myth and truth about cardiac CT

I think I am jumping the gun talking about cardiac CT before talking about coronary heart disease in general. The reason being there are a lot of us simply request for cardiac CT for no obvious reason. (cardiac CT=multislice CT=CTA coronary).

Advantage of multislice CT coronary
1. Avoidance for arterial puncture and coronary catheter manipulation, in which deemed fairly safe.
2. Cheaper than conventional coronary angiogram
3. Outpatient setting
4. Highly sensitive for proximal lesions

Disadvantages of multislice CT coronary
1. Excessive radiation exposure – 3x standard coronary angiogram
2. Excessive contrast use – 3x standard coronary angiogram, hence higher risk for kidney complication
3. Image quality dependent upon patient heart rate
4. Distal segments may be poorly visualized in some patient
5. Presence of calcium may cause underestimation of coronary artery narrowing

In my opinion, multisclice CT coronary is appropriate for
1. "Intermediate risk" chest pain that has an equivocal/non interpretable stress test.
2. Atypical chest pain in patients who can’t adequately perform treadmill stress test.
3. Unusual coronary anatomy.
4. New onset heart failure
(based on Appropriateness Criteria for Cardiac Computed Tomography and Cardiac Magnetic Resonance Imaging (JACC Vol 48, No 7, 2006, 1475-97)

Mulitslice CT coronary is not suitable for
1. Known coronary heart disease
2. High probability coronary heart disease based upon clinical assessment