5-Year Outcomes of PCI Guided by Measurement of Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve

J Am Coll Cardiol. 2022 Mar 15;79(10):965-974. doi: 10.1016/j.jacc.2021.12.030.


Background: Instantaneous wave-free ratio (iFR) is a coronary physiology index used to assess the severity of coronary artery stenosis to guide revascularization. iFR has previously demonstrated noninferior short-term outcome compared to fractional flow reserve (FFR), but data on longer-term outcome have been lacking.

Objectives: The purpose of this study was to investigate the prespecified 5-year follow-up of the primary composite outcome of all-cause mortality, myocardial infarction, and unplanned revascularization of the iFR-SWEDEHEART trial comparing iFR vs FFR in patients with chronic and acute coronary syndromes.

Methods: iFR-SWEDEHEART was a multicenter, controlled, open-label, registry-based randomized clinical trial using the Swedish Coronary Angiography and Angioplasty Registry for enrollment. A total of 2,037 patients were randomized to undergo revascularization guided by iFR or FFR.

Results: No patients were lost to follow-up. At 5 years, the rate of the primary composite endpoint was 21.5% in the iFR group and 19.9% in the FFR group (HR: 1.09; 95% CI: 0.90-1.33). The rates of all-cause death (9.4% vs 7.9%; HR: 1.20; 95% CI: 0.89-1.62), nonfatal myocardial infarction (5.7% vs 5.8%; HR: 1.00; 95% CI: 0.70-1.44), and unplanned revascularization (11.6% vs 11.3%; HR: 1.02; 95% CI: 0.79-1.32) were also not different between the 2 groups. The outcomes were consistent across prespecified subgroups.

Conclusions: In patients with chronic or acute coronary syndromes, an iFR-guided revascularization strategy was associated with no difference in the 5-year composite outcome of death, myocardial infarction, and unplanned revascularization compared with an FFR-guided revascularization strategy. (Evaluation of iFR vs FFR in Stable Angina or Acute Coronary Syndrome [iFR SWEDEHEART]; NCT02166736).

Keywords: coronary physiology; fractional flow reserve; instantaneous wave-free ratio; percutaneous coronary intervention.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Coronary Syndrome* / complications
  • Acute Coronary Syndrome* / diagnosis
  • Acute Coronary Syndrome* / therapy
  • Coronary Angiography
  • Coronary Stenosis* / surgery
  • Fractional Flow Reserve, Myocardial*
  • Humans
  • Myocardial Infarction* / complications
  • Myocardial Infarction* / diagnosis
  • Myocardial Infarction* / epidemiology
  • Percutaneous Coronary Intervention*
  • Severity of Illness Index

Associated data

  • ClinicalTrials.gov/NCT02166736