DEFINE PCI Study Assesses Philips' iFR Guidance Technology
March 17, 2019—Royal Philips announced that results of the DEFINE PCI study, which assessed the level of residual ischemia found in patients after percutaneous coronary interventions (PCI), were presented at the American College of Cardiology’s (ACC) 68th Annual Scientific Session, being held March 16–18 in New Orleans, Louisiana.
The study was sponsored by Philips and was led by investigators from the Cardiovascular Research Foundation in New York, New York; Duke Clinical Research Institute in Durham, North Carolina; and the Imperial College London in London, United Kingdom.
The company reported that the DEFINE PCI study involved approximately 500 patients enrolled at centers throughout the United States and Europe. Investigators found that one in four patients treated with standard-of-care PCI left the catheterization lab with residual ischemia (instantaneous wave-free ratio [iFR] < 0.9), as demonstrated by using a blinded iFR pullback measurement, which is Philips’ new physiologic guidance technology.
Philips explained that physiologic guidance tools such as iFR pullback measurements combined with Philips’ SyncVision iFR Co-registration enable physicians to precisely identify, locate, and treat the ischemia, offering promise to further improve PCI outcomes.
According to Philips, the DEFINE PCI study showed that the current approach to PCI has limitations for identifying the locations of physiologically significant arterial lesions in patients with coronary artery disease.
Of the patients with residual ischemia, the study showed that 81.6% of those patients had an untreated focal stenosis. Further analysis showed that if all focal stenoses had been identified and successfully treated, only one in 20 patients would still have residual ischemia. This indicates that if the precise locations causing ischemia are better detected before stenting, patient outcomes may be improved.
In the company's announcement, DEFINE PCI Principal Investigator Allen Jeremias, MD, commented, “The findings from the DEFINE PCI study reveal an opportunity for physicians to optimize procedural results and potentially help more people fully benefit from PCI.”
Gregg W. Stone, MD, added, “The fact that nearly one-quarter of patients had residual ischemia despite an angiographically successful result, mostly due to focal lesions that can easily be treated, has important implications for improving outcomes of patients undergoing stent implantation globally.”
The company noted that iFR is well established for determining whether a vessel is indicated for treatment through the landmark DEFINE-FLAIR and IFR-SWEDEHEART outcome studies, both presented in 2017 at ACC's 66th annual scientific session in Washington, DC, and published in The New England Journal of Medicine. The 1-year patient outcomes were consistent with fractional flow reserve, while iFR involved less procedural time, reduced patient discomfort, and reduced cost.
SyncVision iFR Co-registration advances physiology by mapping the pressure profile of the whole vessel onto the angiogram, providing physiologic guidance for where to treat within the vessel. With iFR Co-registration, physicians can identify the precise locations causing ischemia, plan stent length and placement with a virtual stent, and predict physiologic improvement. SyncVision with iFR Co-registration provides physicians with a full physiologic image allowing them to see clearly and treat optimally, stated Royal Philips.