Medical and Health Sciences, Clinical Medicine, Cardiology and Cardiovascular Disease, Medicin och hälsovetenskap, Klinisk medicin, Kardiologi och kardiovaskulära sjukdomar

Background: Long-term data on safety and efficacy of instantaneous wave-free ratio (IFR) vs fractional flow reserve (FFR) in guiding percutaneous coronary intervention (PCI) is lacking. Objectives: This study sought to evaluate the 5-year clinical outcomes of IFR- vs FFR-guided PCI in a real-world setting. Methods: We assessed the 5-year outcomes of all patients undergoing IFR or FFR assessment between January 1, 2014, and February 16, 2022, using data from the SWEDEHEART (Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies) registry. Two-to-1 propensity score matching was used to adjust for differences between groups. Additional analyses adjusted for propensity score, PCI center, and baseline differences remaining after matching were conducted. The primary outcome was major adverse cardiac events (MACE) defined as first occurrence of all-cause death, myocardial infarction, or repeat revascularization within 5 years. Results: Among 16,152 (65.6%) of 24,623 FFR and 8,471 (34.4%) of 24,623 IFR patients, IFR led to more frequent deferral of revascularization (5,964 of 8,471 [70.4%] vs 10,615 of 24,623 [65.7%]; P < 0.001). There was no significant difference in Kaplan-Meier event rates in MACE at 5 years between patients who underwent IFR or FFR-guided revascularization (1,993 [31.3% (95% CI: 30.0%-32.6%)] vs 3,961 [31.9% (95% CI: 31.0%-32.8%)]; adjusted HR: 0.96; 95% CI: 0.82-1.12; P = 0.60), including all-cause death, cardiovascular death, cardiac death, coronary death, new myocardial infarction, or revascularization. Subgroup analysis of deferred and treated patients revealed no difference between groups regarding MACE or its individual components. Conclusions: In a large nationwide registry of patients undergoing physiology-based coronary revascularization, there were no significant differences in MACE or all-cause mortality between IFR and FFR-guided revascularization at 5 years.