CT Scan Guidance Matches Ultrasound in Heart Artery Procedure, Trial Finds

The findings come from the P4 trial, presented at TCT 2026 — one of the world’s leading interventional cardiology conferences. The trial tested whether detailed CT coronary angiography (CCTA), a type of X-ray scan that produces detailed images of the heart’s arteries, could guide doctors through a procedure called percutaneous coronary intervention (PCI), which involves inserting a small mesh tube called a stent to open a blocked or narrowed artery.

Doctors currently rely on intravascular ultrasound (IVUS) — a tiny ultrasound probe threaded inside the artery — to guide stent placement in real time. The P4 trial asked whether structured planning using CT images taken before the procedure, combined with guidance during it, could match that standard.

It can.

According to the New England Journal of Medicine, which published the full results, the CT-guided approach was non-inferior to ultrasound guidance when measuring target-vessel failure — meaning repeat procedures, heart attacks linked to the treated artery, or death from cardiac causes — at 12 months. Non-inferiority in clinical trial terms means the newer method was not meaningfully worse than the established one.

The trial was randomised, meaning patients were allocated to one approach or the other by chance, which is considered the most reliable way to compare two treatments. The New England Journal of Medicine is one of the most widely read and peer-reviewed medical journals in the world.

CT coronary angiography is already widely used before PCI to assess blockages. If these results are confirmed in broader practice, the approach could allow more structured pre-operative planning without requiring the ultrasound probe during the procedure itself — though decisions about clinical practice would rest with individual hospitals and specialist teams.

Anyone with concerns about heart health should contact their GP or call NHS 111.