​                         Professor Francisco Leyva-León

How to book a CT coronary angiogram

As with any test, it is essential that an experienced clinician assesses the appropriateness of a CT coronary angiogram (CTCA), the risks and benefits and most importantly, what to do with the results. If you have not been assessed by a doctor, you will need a consultation with Professor F Leyva-Leon or another doctor before proceeding to a CTCA.

 

To book, please send your request to the following double-encryted email address, attaching a clinic letter or referral letter from a doctor:

 

                               cardiacCT@proton.me

 

We will let you know whether a prior consultation is required or whether you can have the CTCA on the basis of the consultation you may have had. If you have not been assessed by a doctor, please note that a consultation (face-to-face, video or telephone) with Professor Leyva-Leon will be required. CT scans can be undertaken at Spire Hospital Little Aston in Sutton Coldfield and The Harborne Hospital in central Birmingham.

 

​What is a CT coronary angiogram ?

Computed tomography coronary angiography (CTCA) uses X-rays to provide images of the coronary arteries and the heart muscle. Combined with an intravenous contrast material, CTCA provides high-resolution, three-dimensional images of the heart and the coronary arteries. These images show whether there is furring or blockage of the coronary arteries (arteriosclerosis).

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What is a calcium score ?​

Calcium is deposited during the process of furring of the arteries. A high calcium score carries a higher risk of developing heart attacks than a low score.  A calcium score is computed for each of the coronary arteries based upon the volume and density of the calcium deposits. A score of zero indicates that there is no calcified plaque.  A score greater than zero indicates at least some coronary artery disease.  As the score increases, so does the likelihood of a significant coronary narrowing and the likelihood of a coronary event in the future, compared to people with lower scores (see figure below).​​

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​What does the CT coronary angiogram add?​

The calcium score, by itself, is a crude measure of coronary artery risk. The interpertation of a calcium scoring scan and the CT angiogram needs to take into account the patient's history (symptoms), the family history, ethnic origin, lipid levels, diabetic status and most importantly, the site of the coronary artery narrowings. In this regard, a narrowing in a main vessel, such as the left main stem or the LAD needs to be taken more seriously than a narrowing is small branches (see figure below).​​​​​​​​​​​

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Why have a CTCA ?​

​A CTCA may be considered in the following circumstances:

               • Screening for coronary artery disease in patiens with risk factors and no                            symptoms

               • Chest pain with features that suggest a cardiac cause.
               • Inconclusive stress test (treadmill, stress echocardiogram).
               • A negative stress test but continuing chest pain.
               • Unexplained breathlessness during physical exertion.
               • Suspicion of an underlying coronary artery anomaly
               • Investigation of coronary artery disease before cardiac surgery.



​What does a CTCA involve ?

A CTCA takes less than 10 minutes to perform. You lie down on a special couch which takes you into the bore of the scanner. A small canula is inserted into a vein in your arm so that we can give the contrast substance that highlights the coronary arteries.  Sometimes, we may need to give a beta-blocker intravenously to slow down the heart rate. You may be asked to lie still and to hold your breath at intervals. After contrast injection, some patients experience a metallic taste in the mouth or they may fell flushed. These effects are, however, short-lived. The scan will need to be analysed in in detail by the cardiologist. It is essential that the results are discussed with you afterwards.

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​Should I be worried about radiation exposure ?

You should not be worried, as the radiation involved has not been shown to have any effects on human health.

 

Radiation exposure can be measured in milliSieverts (mSv). A CT calcium scan involves an exposure of 1 mSv and a CTCA involves 2 to 6 mSv. Note that we all receive about 3 millisieverts (3 mSv) of background radiation per year from natural sources. The following chart puts this into prespective:

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​Calcium score and CTCA references:​

Greenland P et al. ACCF/AHA 2007 clinical expert consensus document on coronary artery calcium scoring. J Am Coll Cardiol 2007;49:378-402
 

Hendel RC et al. ACCF/ACR/SCCT/SCMR/ASNC/NASCI/SCAI/SIR 2006 appropriateness criteria for cardiac computed tomography. J Am Coll Cardiol 2006;48:1475-97.



Carr JJ, et. al., Evaluation of Subsecond Gated Helical CT for Quantification of Coronary Artery Calcium and Comparison with Electron Beam CT.; AJR 2000; 174: 915-921