P4 Trial Compares CT-Guided PCI Using Medis’ QAngio CT Versus IVUS Guidance 

November 1, 2026—Medis Medical Imaging announced that results of the randomized P4 trial, which compared coronary CT angiography (CCTA)–guided percutaneous coronary intervention (PCI) with intravascular ultrasound (IVUS) guidance, were presented by Principal Investigator Carlos Collet, MD, at TCT 2026 and published simultaneously by Dr. Collet et al in The New England Journal of Medicine.

Separately, Medis announced the launch of QGuideCT at TCT 2026. The software provides interactive CT-derived lumen and plaque information to support treatment planning before PCI and guide decisions during the procedure. According to the company, QGuideCT received FDA 510(k) clearance in October 2026.

According to Medis, P4 (Precise Procedural and PCI Plan) was an investigator-initiated, international, randomized, open-label noninferiority trial involving 1,105 patients at 23 centers in Europe, the United States, and Japan. Eligible patients were aged 18 to 80 years and had chronic coronary syndrome or stabilized non–ST-segment elevation acute coronary syndrome, with at least one lesion showing > 70% diameter stenosis and CT-derived fractional flow reserve ≤ 0.80.

In the CT-guided arm, the company’s QAngio CT Research Edition was used to assess plaque composition, including calcium, and plan stent landing zones before the procedure. The software also displayed three-dimensional CT reconstructions synchronized with the C-arm angle to guide treatment in the catheterization lab, stated the press release.

Medis reported that at 12 months, target vessel failure (a composite of cardiac death, target vessel myocardial infarction, and ischemia-driven target vessel revascularization) occurred in 4.1% of patients in the CT-guided group and 4.6% in the IVUS-guided group (risk difference, −0.42 percentage points; 95% CI, −2.82 to 1.99). The upper confidence limit was below the prespecified noninferiority margin of 4.5 percentage points, meeting the criterion for noninferiority (P < .001); superiority could not be demonstrated.

Additionally, the company reported a 17-minute difference in median procedure duration favoring CT guidance (46 vs 63 minutes). Median contrast volume during the invasive procedure was also lower with CT guidance (150 vs 170 mL), while radiation exposure was similar between groups (difference in medians, −2.91 Gy·cm²; 95% CI, −9.03 to 3.80). Advanced calcium modification devices were used more frequently in the CT-guided group (9.2% vs 3.8%).

“P4 shows that, in appropriately selected patients, information we usually gather inside the artery during PCI can be obtained before catheterization, without an apparent loss of clinical efficacy,” commented Dr. Collet in the Medis press release. “That supports moving PCI planning from the cath lab to the CT scan and expands the role of CT from diagnosis to therapeutic guidance.”