October 15, 2020
1-Year DEFINE PCI Data Presented for Philips' iFR-Guided Interventions
October 15, 2020—Royal Philips announced that the 1-year results of the DEFINE PCI study were presented at TCT Connect, the 32nd annual Transcatheter Cardiovascular Therapeutics scientific symposium of the Cardiovascular Research Foundation held online October 14-18, 2020.
The DEFINE PCI study assessed the level of residual ischemia, or reduced blood flow to the heart muscle, found in patients after a percutaneous coronary intervention (PCI). The assessment was carried out using the company's blinded instant wave-Free Ratio (iFR) pullback measurement.
According to the company, the data suggest that iFR coregistration can help physicians identify precise locations causing ischemia, plan stent length, and place a virtual stent to predict physiologic improvement before the intervention is performed.
The blinded acute data of DEFINE PCI revealed that 24% of patients with angiographically successful PCI still had residual ischemia. In approximately 82% of these patients, the residual ischemia was the result of a focal, potentially treatable lesion. The data suggest patients could have benefited from planning tools like iFR coregistration to find potentially treatable lesions that are often not identified by angiography alone.
Philips reported that the DEFINE PCI data show that patients whose baseline ischemia was more effectively treated (post-PCI iFR ≥ 0.95) had improved outcomes and less recurrent angina at 1 year. Additionally, the 1-year data showed that an optimal post-PCI iFR of ≥ 0.95 was associated with improved event-free survival, including 68% fewer clinical events than patients with less than optimal post-PCI iFR values (1.8% vs 5.7%; P = .04).
“In DEFINE PCI, we noted that if all lesions causing focal ischemia had been treated up-front, the rate of significant ischemia could theoretically be reduced from 24% to 5%," commented DEFINE PCI principal investigator Allen Jeremias MD, in the company's announcement. “Now with the 1-year data, we find that patients with more complete resolution of ischemia do better clinically."
Dr. Jeremias continued, "To some that may not be a surprising finding, but we are conducting the science because, today, most interventionalists are only using physiology as a “who-to-treat” tool. Beyond who we should treat, tools like iFR can guide 'how' and 'where' to treat within a vessel and then confirm results after stent placement. It’s difficult to know which lesions will produce a significant physiological gradient and which won’t. If you don’t measure, really there’s no way of telling.”
Manesh Patel, MD, an investigator of the DEFINE PCI study, stated, "The goal is to get patients as close to normal, physiologically, as possible. We’ve known this for a while, but we haven’t had the mature technology to deliver on this. We now have technology such as iFR coregistration to determine the risk-benefit of revascularization as well as when, how, and where we should treat—and that should lead to better outcomes for patients.”
In 2019, initial study results of the DEFINE PCI study were presented at the American College of Cardiology’s 68th Annual Scientific Session, held March 16–18, 2019, in New Orleans, Louisiana. The initial study result including 500 patients showed that one in four patients treated with standard of care PCI left the catheterization lab with residual ischemia (iFR < 0.9).
The company also noted that in February 2020, Philips announced DEFINE GPS, a randomized, controlled prospective trial that will assess the clinical effectiveness of iFR coregistration guidance to minimize post-PCI ischemia in patients. The study, which will include up to 3,000 participants at approximately 100 sites globally, is designed to evaluate whether a physiology-based PCI approach results in superior patient outcomes compared to standard angioplasty. Enrolment is expected to begin in Q1 2021.
The Cardiovascular Research Foundation in New York, New York, is overseeing core lab and clinical event committee activities in both DEFINE PCI and DEFINE GPS, advised Royal Philips.