CTCA & FFR-CT: Assessing Cardiac Artery Blockages Without a Catheter

18 February 2026 3 min read

Until now, the most accurate test for detecting blockages in the heart arteries was coronary angiography using a catheter in a cath lab. However, technological advances now allow non-invasive assessment of the heart vessels through CT Coronary Angiography (CTCA) and FFR-CT. These two tests help doctors see not only the form of narrowing of the blood vessels but also its impact on blood flow to the heart muscle.

Understanding CT Coronary Angiography (CTCA)

CTCA is a specialized CT scan of the heart that uses contrast dye through the veins to visualize the coronary arteries. This exam can show the location of narrowing, the amount of plaque, and the degree of blockage in the blood vessel walls.

What is FFR-CT?

FFR-CT is an advanced analysis of CTCA data using computer modeling to assess blood flow in the heart vessels. This exam helps determine whether visible narrowing actually impedes blood flow to the heart muscle or simply appears narrow visually. With this information, doctors can determine whether a patient is adequately treated with medication and lifestyle changes, or whether invasive evaluation such as coronary angiography and stent placement is necessary.

Limitations and Things to Note

Using Contrast & Radiation
• Contrast can affect the kidneys in some patients, so it should be assessed first.
• Radiation exposure is kept as low as possible, but it is still present.
Not always suitable for all patients
• In patients with very severe vessel calcification, images can be difficult to assess.
If results show severe blockage, angiography is still necessary.
• CTCA + FFR-CT is excellent for assessing who can avoid unnecessary catheters.
• However, if results show anatomically or functionally significant narrowing, doctors often still consider coronary angiography for confirmation and treatment.
Availability & Cost
• Not all hospitals have access to FFR-CT.
• Costs and insurance coverage may vary.

Therefore, the decision to use CTCA/FFR-CT or direct angiography should be made in collaboration with a doctor, based on the clinical condition, risks, and available facilities.

Steps After the Examination

CTCA and FFR-CT results will form the basis for the doctor's treatment plan. If no significant blockages are found, the primary focus will be on controlling risk factors such as cholesterol, blood pressure, blood sugar, and lifestyle. If significant narrowing is found, the doctor will discuss the most appropriate further therapy options for the patient.

CTCA and FFR-CT represent important innovations in the detection of coronary heart disease. With increasingly accurate, non-invasive approaches, patients can undergo a more comfortable, safe, and targeted cardiac evaluation before deciding on further action with their doctor.

FAQ

Is FFR-CT the same as FFR in a cath lab?
The concept is similar (assessing the impact of narrowing on blood flow), but FFR-CT is calculated from CT data and computer modeling, without a catheter. Invasive FFR in a cath lab uses sensors directly inside the blood vessels.

Does CTCA hurt?
A CTCA is performed with you lying on a CT machine. You will be injected with contrast into your arm (like an IV), then asked to hold your breath for a few seconds. There is no catheter in the heart; the procedure is usually painless.

When should you proceed directly to angiography instead of CTCA?
In cases of acute heart attack, very typical chest pain with high risk, or severe symptoms with clear EKG/cardiac enzymes, doctors usually don't delay with CTCA and proceed directly to angiography.