San Diego, California – November 3, 2026 – Medis Medical Imaging today shared its perspective on the final results of the PIONEER IV randomized trial, presented by Prof. Patrick W. Serruys at TCT 2026. PIONEER IV compared percutaneous coronary intervention (PCI) guided by angiography-derived physiology (ADP), including Medis QFR® version 2.1, with contemporary usual care in 2,130 all-comer patients from 27 centers in six European countries. 

In the prespecified per-protocol analysis of patients treated according to the assigned strategy and stent, patient-oriented composite endpoint (POCE) occurred in 6.1% in the usual care arm versus 6.0% in the ADP arm, meeting non-inferiority, an analysis the investigators describe as complementary to the primary result. Usual care was far from angiography alone: 45.7% of usual-care patients received physiological assessment. 

In the primary intention-to-treat analysis, the one-year POCE, combining death, stroke, myocardial infarction and revascularization, occurred in 7.4% with ADP and 6.1% with usual care. The upper confidence bound (3.4%) exceeded the prespecified 3.2% margin, so non-inferiority was not met. The difference was driven mainly by spontaneous myocardial infarction (3.0% vs 1.7%), largely in non-target vessels. An interim analysis of the first 1,270 patients, published in the European Heart Journal in 2026, had met its non-inferiority boundary. 

When the Strategy Was Not Followed 

In the ADP arm, 168 patients (15.8%) deviated from the strategy: ADP was not performed in at least one lesion, or its treatment recommendation was not followed, explaining the difference between the intention-to-treat and per-protocol findings. The takeaway for the cath lab is clear: make coronary physiology a routine part of clinical decision-making. Assess lesions systematically, use physiological findings to guide treatment decisions, and ensure that the results translate into action. The true clinical value of physiology lies not just in measuring, but in consistently acting on what the measurements reveal.   

“This is the first study that compares angio-based physiology versus usual care in an all-comers population, including about 30% ACS patients. said Prof. Serruys, established professor of Interventional Medicine & Innovation at University of Galway, principal investigator of PIONEER IV. The intention-to-treat analysis is our primary answer, and we report it as such. The difference was mainly driven by spontaneous MI in non-culprit lesions. Further, in the prespecified per-protocol analysis, the angio-FFR strategy was found to be non-inferior to usual care, with largely overlapping event curves. What I have learned from this Pioneer IV study is the critical importance of adherence to the suggested angio-FFR-guided PCI strategies”.

Physiology Before and After the Stent 

According to its investigators, PIONEER IV is the first randomized outcome trial to test ADP both for lesion selection and post-PCI optimization against contemporary usual care. ADP was performed before PCI in 95.8% of ADP-arm patients and after stenting in 83.4%, without additional wires or hyperemic agents. 

“As the highest-enrolling center, we saw how naturally angiography-derived physiology fits into the procedure, before and after stenting, without adding a wire”, said Dr. Joanna J. Wykrzykowska of University Medical Center Groningen, principal investigator and steering committee member of PIONEER IV. “But you need to have the discipline to use it properly, and then with results that you can rely on to the benefit of the patient.” 

From Diagnosis to Intervention 

“PIONEER IV gives the field an honest answer: angiography-derived physiology performs when the relevant lesions are measured and the result is acted on,” said Maya Barley, CEO of Medis Medical Imaging. “Our focus is on making consistent use the easy path in every cath lab, and on carrying quantitative information from diagnosis to intervention.” 

Since the trial, Medis QFR® has advanced from version 2.1 to 3.1, which uses AI to select the end-diastolic frame and align the two angiographic projections to make analysis faster and simpler. At EuroPCR 2026, version 3.1 showed 85–90% fewer large discrepancies between observers. QFR® holds a Class I recommendation in the 2024 ESC Guidelines, and Medis QFR® 3.1 is FDA-cleared and CE-marked. 

PIONEER IV follows the P4 trial, presented on November 1, in which CT-guided PCI was non-inferior to IVUS guidance (target-vessel failure 4.1% vs 4.6%). In P4, Medis software brought the CT plan into the cath lab; Medis QGuideCT® is now FDA-cleared [K260523]. 

About PIONEER IV 

PIONEER IV (NCT04923191) is a multicenter, single-blind, randomized, all-comers non-inferiority trial. Patients were assigned 1:1 to ADP-guided PCI (n=1,063) or usual care (n=1,067), with the HT Supreme™ sirolimus-eluting stent (SINOMED) used in both arms. The trial was sponsored by the University of Galway with research grants from SINOMED and Medis Medical Imaging. 

About Medis Medical Imaging 

For more than 35 years, Medis Medical Imaging has delivered advanced post-processing software for cardiovascular imaging. From MR and CT to X-ray- and angiography-based physiology, Medis equips clinicians with intuitive, scientifically validated tools that enhance diagnostic confidence and streamline workflows. In coronary artery disease, Medis connects diagnosis and intervention, from CT-based plaque and lesion analysis to angiography-derived physiology in the cath lab. Medis’ portfolio, including QFR®, supports clinicians in delivering high-quality, patient-centered cardiovascular care.  

Media contact: Gregory Rousselot, Marketing Manager Interventional Cardiology, Medis Medical Imaging, GRousselot@medisimaging.com