Royal Philips has announced the enrollment of the first patient in its global DEFINE GPS study, a large-scale clinical trial investigating whether guidance by instantaneous wave-free ratio (iFR) measurements co-registered on angiograms leads to superior outcomes in percutaneous coronary intervention (PCI) procedures compared to the current standard of care.
The first patient was enrolled at St. Francis Hospital in New York by Principal Investigator Dr. Allen Jeremias. The study will be conducted across 100 sites worldwide and is expected to include up to 3,200 participants, making it one of the largest studies ever sponsored by Philips.
Study Design and Objectives
DEFINE GPS (Distal Evaluation of Functional performance with Intravascular sensors to assess the Narrowing Effect: Guided Physiologic Stenting) will evaluate whether combining iFR measurements with Philips' Image Guided Co-Registration System – SyncVision – can enhance PCI guidance and improve treatment outcomes.
The randomized controlled trial compares patient outcomes after PCI procedures guided by iFR data co-registered on the angiogram versus procedures guided by angiogram alone. This approach aims to address a significant clinical challenge: despite advances in PCI techniques, approximately 20-30% of patients continue to experience recurring chest pain one year after treatment.
Dr. Gregg W. Stone, Chairman of the DEFINE GPS trial and Director of Academic Affairs for the Mount Sinai Heart Health System, emphasized the importance of the study: "While the benefits of physiology prior to PCI are unquestioned, this large-scale trial will definitively demonstrate whether after an angiographically successful PCI procedure the identification and treatment of unsuspected residual ischemia by routine iFR assessment can further improve patient event-free survival."
Clinical Significance and Background
European and U.S. clinical guidelines already endorse physiological measurement of coronary function in PCI procedures. Unlike fractional flow reserve (FFR), iFR avoids the use of hyperemic agents such as adenosine that can adversely affect some patients, while using the same pressure guide wires and equipment.
The DEFINE GPS study builds on findings from the earlier DEFINE PCI trial, which evaluated the potential of treating residual ischemia to improve clinical outcomes for coronary stent patients.
"Conducting rigorous clinical science is how we advance patient care, and, like the seminal FAME study that was carried out over 10 years ago, I believe DEFINE GPS has the potential to change the current standard of care in PCI," said Dr. Jeremias. "With DEFINE GPS we will be able to definitively determine if a physiology-based PCI approach results in superior patient outcomes compared to standard angioplasty."
Technical Approach
Under the current standard of care, clinicians navigate a balloon catheter and coronary stent to the treatment area using interventional X-ray guidance (coronary angiogram). In the DEFINE GPS study, an iFR pullback measurement will be overlaid on the angiogram to provide more precise information on where to treat within the vessel.
The study will also use iFR to measure if the treatment succeeds in restoring sufficient blood flow to prevent ischemia or if further intervention is warranted. This approach aims to provide a more comprehensive assessment of coronary function before, during, and after the procedure.
Philips' Investment in Evidence-Based Innovation
Chris Landon, Senior Vice President and General Manager Image Guided Therapy Devices at Philips, highlighted the company's commitment to evidence-based medicine: "This major study will provide a definitive answer to the question of whether a functional guidance strategy throughout the procedure demonstrates superior outcomes and reduces costs. The study has the potential to drive a significant improvement in clinical practice."
The SyncVision system used in the study is part of Philips' Image Guided Therapy System – Azurion, which includes advanced imaging systems, coronary imaging catheters, atherectomy and crossing devices, specialty balloons, and pressure wires.
The Cardiovascular Research Foundation is overseeing core lab and clinical event committee activities for the trial, which represents a significant investment by Philips in generating robust clinical evidence for its innovations.
Implications for Future Practice
If successful, the DEFINE GPS study could establish a new standard of care for PCI procedures, potentially improving outcomes for millions of patients with coronary artery disease worldwide. By addressing the persistent problem of recurring chest pain after seemingly successful interventions, the approach could significantly enhance quality of life for patients and reduce the need for repeat procedures.
The study reflects a growing trend toward precision-guided interventions in cardiology, where physiological measurements are increasingly used to complement anatomical imaging for more personalized and effective treatment strategies.
