CCTA matches IVUS for PCI guidance: Imaging expert Carlos Collet breaks down the data
Many interventional cardiologists who were early adopters of coronary CT angiography (CCTA) for planning and guiding percutaneous coronary intervention (PCI) procedures felt it helped them make better treatment decisions and improved workflows. The clinical evidence, however, was still lacking.
That all changed at TCT 2026 in San Diego, however, as late-breaking data from the P4 Trial confirmed that CCTA can match intravascular ultrasound (IVUS)-guided therapy in addition to cutting contrast, radiation dose and treatment times.
The study randomized 1,105 patients across 23 centers in eight countries, including the United States, Europe and Japan. Patients were randomized to undergo CCTA-guided PCI or IVUS-guided PCI. At one year, the rates of target-vessel failure were 4.1% for the CT-guided group and 4.6% in the IVUS-guided group. Researchers said this confirmed the non-inferiority of a CT-based strategy.
"Patients who had their procedure planned with CCTA, the physician knew exactly what they were going to do, were 17 minutes faster on average, had 20 ml less contrast during the procedure and had numerically lower radiation in the CT arm compared to the IVUS arm. So there is a benefit in terms of workflow with similar clinical outcomes compared to IVUS," Carlos Collet, MD, PhD, director of cardiovascular imaging, physiology and translational therapeutics at the Cardiovascular Research Foundation (CRF), told Cardiovascular Business. He presented the study's findings at TCT 2026 in front of a packed crowd.
Diving deeper into the data, operators using CT planning more than doubled the use of advanced calcium modification (9.2% vs. 3.8%) compared to those relying on IVUS. And, as Collet mentioned, procedure times in the CT group were reduced by 27%, from an average time of 63 minutes down to 46 minutes.
Collet said these findings demonstrate the value of knowing the anatomy and complexity of coronary disease before entering the cath lab. The CT-guided strategy involved the comprehensive analysis of the coronary anatomy, including lumen assessment, plaque characterization, myocardial mass and fractional flow reserve derived from CT (FFR-CT). Investigators also used virtual PCI planning software to simulate the effects of different stent strategies on coronary blood flow before the procedure.
Collet compared the approach to structural heart interventions, where CT-based procedural planning has been routine since transcatheter aortic valve replacement (TAVR) was first approved in 2012. Coronary interventionists are now learning that some of the benefits of CT-guided TAVR apply to CT-guided PCI.
P4 also provides evidence that CT can potentially replace some of the information traditionally obtained through preprocedural IVUS. Investigators found that vessel dimensions, lesion length and plaque characteristics could all be accurately assessed from CT images.
However, CT cannot evaluate stent expansion after implantation. To address this limitation, the trial mandated post-PCI IVUS in both groups, along with angiographic stent enhancement tools in the CT arm, to help ensure adequate stent expansion and avoid leaving under-expanded stents.
The trial's findings could have significant implications for cath lab efficiency and economics. Collet noted that a busy laboratory performing eight to 12 cases daily could potentially free up several hours of capacity by reducing procedure times by 17 minutes per case. Reduced radiation exposure also benefits both patients and cath lab staff.
The study primarily used conventional CT scanners, but higher resolution photon-counting CT systems were used in about 5% of patients. Collet said the findings therefore demonstrate the potential of CT-guided PCI using technology already widely available, rather than waiting for the newest generation of scanner technology.
He believes the results could help accelerate the adoption of CT-based procedural planning, particularly as software companies develop tools to make plaque analysis and virtual PCI planning easier to integrate into clinical workflows.
Collet also anticipates that the growing evidence base could eventually influence professional society guidelines.
"I think that most likely we'll be looking at recommendation in the next five to 10 years," he said. "CT should be utilized to plan the PCIs because that leads to all the benefit that we have seen in the trial."
While P4 excluded patients with severe kidney disease, Collet suggested that pre-procedural planning could be particularly useful in patients where minimizing iodine contrast use during PCI is important.
The full P4 study was simultaneously published in The New England Journal of Medicine.[1]
Dave Fornell has covered healthcare for more than 17 years, with a focus in cardiology and radiology. Fornell is a 5-time winner of a Jesse H. Neal Award, the most prestigious editorial honors in the field of specialized journalism. The wins included best technical content, best use of social media and best COVID-19 coverage. Fornell was also a three-time Neal finalist for best range of work by a single author. He produces more than 100 editorial videos each year, most of them interviews with key opinion leaders in medicine. He also writes technical articles, covers key trends, conducts video hospital site visits, and is very involved with social media. E-mail: [email protected]