Coronary CT angiogram: what it shows.

A coronary CT angiogram (CTCA) is a non-invasive CT scan that images the coronary arteries directly, showing both calcified and soft (non-calcified) plaque, the plaque a calcium score alone can miss. It is one of the most informative tests available for assessing coronary artery disease before symptoms occur.

Why CTCA matters

A CT calcium score measures only hardened, calcified plaque. Younger people and those with early disease often have soft plaque that carries risk but shows no calcium. CTCA visualises the artery walls directly, detecting soft plaque, quantifying narrowing, and giving a far more complete picture of coronary risk.

What it helps assess: coronary artery disease, plaque burden, arterial narrowing (stenosis).

What the clinical evidence shows

• SCOT-HEART (NEJM 2018): adding CTCA to standard care significantly reduced the rate of fatal and non-fatal myocardial infarction over five years, largely by better targeting preventative therapy.
• PROMISE (NEJM 2015): in stable chest pain, an anatomical CTCA-first strategy was at least as effective as functional testing for guiding care.
• CAD-RADS 2.0 (JACC Cardiovascular Imaging 2022): established the standardised reporting scale used to grade coronary disease and direct management.

Evidence-based reference ranges

CTCA findings are reported using the standardised CAD-RADS scale, which grades the maximum coronary narrowing:

Clinical interpretation

• CTCA detects soft plaque that a calcium score cannot, making it valuable in younger or intermediate-risk people.
• Higher CAD-RADS grades indicate greater narrowing and generally warrant more intensive risk-factor management.
• A CTCA is a specialist imaging test involving contrast and radiation. It is arranged and interpreted by qualified radiologists and cardiologists, not ordered casually.

How this works at HodieLabs

CTCA is available as a doctor-referred add-on to any HodieLabs membership, arranged with accredited imaging partners and interpreted alongside your blood biomarkers and CT calcium score at our Melbourne Preventative Health & Longevity Clinic.

References

1. Newby DE, et al. (SCOT-HEART). Coronary CT angiography and 5-year risk of myocardial infarction. N Engl J Med. 2018;379:924–933.
2. Douglas PS, et al. (PROMISE). Outcomes of anatomical versus functional testing for coronary artery disease. N Engl J Med. 2015;372:1291–1300.
3. Cury RC, et al. CAD-RADS 2.0. JACC Cardiovasc Imaging. 2022;15:1974–2001.

This page is general information from the HodieLabs Evidence-Based Clinical Library, not medical advice. Speak with your GP about what testing and care is appropriate for you.