Philips’ iFR Compared With FFR in Analysis of Real-World, Long-Term SWEDEHEART Data

October 26, 2023—Royal Philips announced the latest results demonstrating the safety of the company’s instant wave-free ratio (iFR) in the guidance of percutaneous coronary intervention (PCI). Philips’ iFR is a pressure-derived index to assess coronary blockages during interventional procedures while avoiding the use of hyperemic agents.

Matthias Götberg, MD, from the Department of Cardiology, Clinical Sciences, Lund University, in Lund, Sweden, presented the results during a late-breaking science session at TCT 2023, the 35th annual Transcatheter Cardiovascular Therapeutics scientific symposium held October 23-26 in San Francisco, California.

According to the company, a longitudinal analysis from the National SWEDEHEART Quality Registry of more than 42,000 patients undergoing coronary procedures, showed no difference between iFR and fractional flow reserve (FFR) in major adverse cardiac events (MACE). That analysis, “Long-term Safety of Revascularization Deferral Based on Instantaneous Wave-Free Ratio or Fractional Reserve,” which compared patient outcomes using iFR and FFR in the diagnosis and treatment of heart disease, was published last year by Dr. Götberg et al in Journal of the American College of Cardiology (2022;79:965–974).

The previously published analysis of the 5-year outcomes of the iFR-SWEDEHEART randomized trial found iFR and FFR to be equally safe and effective with respect to risks for MACE. The cumulative MACE risks for each group differentiated by 1.6% at 5 years (iFR, 21.5% vs FFR, 19.9%; hazard ratio, 1.09; 95% CI, 0.90-1.33). There was no difference in risk for death, heart attack, or new revascularization.

The SWEDEHEART registry results presented by Dr. Götberg at TCT 2023 showed that patients in the iFR group had more risk factors compared with the FFR group but when adjusted for known confounders there was no difference in 5-year MACE between patients who underwent iFR or FFR-guided revascularization (32.2% vs 31.3%; adjusted HR, 0.99; 95% CI, 0.93–1.05; P = .65). Furthermore, the outcome was similar in the individual components of MACE (death, heart attack, new revascularization) as well as in both deferred and treated subgroups.

“These new findings once again confirm the safety of iFR,” commented Dr. Götberg in the Philips’ press release. “We continue to see that iFR-guided treatment offers consistent outcomes, reduces costs, and provides a better patient experience. The data from this new analysis provides additional confidence in the safety of iFR for physicians.”

The company stated that iFR is considered the gold standard for hyperemia-free physiologic assessment for measuring pressure in diagnostic and interventional procedures. Similar to FFR, clinicians use iFR with angiographic images to assess coronary blockages. However, by avoiding administrating a hyperemic agent, patient discomfort can be reduced by 95.7% and enables iFR to detect disease processes downstream from the major blood vessels.

Philips’ iFR has received a Class IA recommendation from the American College of Cardiology, American Heart Association, Society for Cardiovascular Angiography & Interventions, and European Society of Cardiology, noted the company.