Cardio-ct

Cardiac CT is a non-invasive technique for visualizing the morphology of the coronary arteries (Krakow 2005). Cardiac CT is therefore a CT-guided form of coronary angiography (Christ 2019).

A distinction is made in cardiac CT between:

- Electron beam tomography (rarely performed anymore)

- Multiline CT, also known as multidetector CT. This is a so-called standard method (Fink 2022).

According to Krakow (2005), cardiac CT is not yet a real alternative to invasive coronary angiography. The sensitivity with regard to CHD is between 63 - 90 %, the specificity between 71 - 90 %. The devices initially used only allowed the visualization of calcification. In the meantime, however, three-dimensional reconstruction of the proximal sections is possible in selected patients (Krakow 2005).

Since 2024, cardiac CT has also been offered to patients with statutory health insurance if there is a 15 - 50 % probability of CHD. If the probability is > 50 %, an invasive cardiac catheterization should be performed first (Einecke 2024).

A cardio CT scan can be used to:

• Calcium score can be checked. This is a marker for the extent of CHD.
• Coronary angiography to visualize the vessels, any collaterals and bypass vessels The sensitivity is approx. 90 %, the specificity approx. 80 % (Krakow 2005)

Indications:

• Assessment of any valve stenosis or insufficiency
• Assessment of the coronary vessels: good sensitivity and a negative predictive value of almost 100% (Herold 2023).
• Early detection of an asymptomatic bypass occlusion (Silber 2003)
• In case of unclear clinical symptoms
• Before percutaneous aortic valve replacement to measure the valve size and precisely analyze the anatomical conditions (Christ 2019)

Procedure

The examination is performed with a contrast agent application. The radiation exposure is low at 1 - 2 mSV (Christ 2019).

If the cardiac CT shows a high pretest probability of CHD, an invasive left heart catheterization should be performed immediately. As this is also performed with a contrast agent, coronary angiography should be performed immediately if there is a high pretest probability of CHD in order to avoid further contrast agents (Christ 2019).

Advantages of cardio CT:

• The examination is a non-invasive coronary angiography
• It can also be performed on patients with a pacemaker
• The examination times are short (Krakow 2005).

Disadvantages of cardio CT:

• There are weaknesses with tachycardic arrhythmias
• Severe calcifications of the coronary arteries are disturbing during coronary angiography
• The contrast medium consumption is 100 - 120 ml (Krakow 2005).

1. Christ J, Sagmeister V (2019) Fundamentals of cardiology. Elsevier Urban and Fischer Germany 26 - 27
2. Einecke, D (2024) Cardio-CT also for people with statutory health insurance. Cardiovascular (24) 9 https://doi.org/10.1007/s15027-024-3581-4
3. Fink B, Antwerpes F, Güler I (2022) Cardiac computed tomography. DocCheck Flexikon doi: https://flexikon.doccheck.com/en/Cardiac_Computed_Tomography
4. Herold G et al. (2022) Internal medicine. Herold Publishing 157, 243
5. Kasper DL, Fauci AS, Hauser SL, Longo DL, Jameson JL, Loscalzo J et al. (2015) Harrison's principles of internal medicine. Mc Graw Hill Education
6. Krakau I, Lapp H (2005) Das Herzkatheterbuch: Diagnostische und interventionelle Kathetertechniken. Georg Thieme Verlag Stuttgart / New York 34, 65 - 73
7. Silber S, Finsterer S, Krischke I, Lochow P, Mühling H (2003) Non-invasive angiography of coronary bypasses with cardio-CT in a cardiology practice. Heart 28 (2) 126 135