Long-Term Study Reveals Comparable Outcomes for iFR and FFR in Coronary Revascularization: DEFINE FLAIR Trial

The primary outcome measures included five-year major adverse cardiac events (MACE), which is a composite of all-cause death, nonfatal myocardial infarction, and unplanned revascularization, along with the individual components of this combined endpoint.

The following were the key findings of the study:

• At the 5-year follow-up, no significant differences were observed between the iFR group (mean age 65.5 years, 77.5% male) and the FFR group (mean age 65.2 years, 74.3% male) regarding major adverse cardiac events (MACE), with rates of 21.1% for iFR and 18.4% for FFR (hazard ratio [HR], 1.18).
• Although all-cause mortality was slightly higher in the iFR group, this increase was not attributed to myocardial infarction (6.3% in iFR versus 6.2% in FFR; HR, 1.01) or unplanned revascularization (11.9% in iFR versus 12.2% in FFR; HR, 0.98).
• Patients for whom revascularization was deferred based on either iFR or FFR exhibited similar MACE rates (17.9% for iFR versus 17.5% for FFR; HR, 1.03), with comparable rates of individual MACE components, including all-cause death.
• Among those who underwent revascularization following physiological assessment, the incidence of MACE was higher in the iFR group at 24.6%, compared to 19.2% in the FFR group (HR, 1.36).

"The 5-year follow-up results indicated that an iFR-based strategy was not statistically different from an FFR strategy in guiding revascularization concerning major adverse cardiovascular events," the researchers concluded.

Reference:

Escaned J, Travieso A, Dehbi H, et al. Coronary Revascularization Guided With Fractional Flow Reserve or Instantaneous Wave-Free Ratio: A 5-Year Follow-Up of the DEFINE FLAIR Randomized Clinical Trial. JAMA Cardiol. Published online October 16, 2024. doi:10.1001/jamacardio.2024.3314