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Long-term Safety of Revascularization Deferral Based on Instantaneous Wave-Free Ratio or Fractional Flow Reserve
Troels Yndigegn1, Sasha Koul1, Rebecca Rylance1
1Department of Cardiology, Clinical Sciences, Lund University, Lund, Sweden.
Insights
Deferring coronary revascularization is safe using either instantaneous wave-free ratio (iFR) or fractional flow reserve (FFR) guidance. Long-term outcomes in a large real-world population showed no significant difference between the two methods.
Area of Science:
- Cardiology
- Interventional Cardiology
- Physiology
Background:
- Coronary revascularization decisions are critical for managing ischemic heart disease.
- Instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR) are physiological indices used to guide these decisions.
- Previous studies suggest deferral guided by either method is safe, but real-world long-term data are needed.
Purpose of the Study:
- To assess and compare the long-term safety and outcomes of deferring coronary revascularization based on iFR versus FFR guidance.
- To evaluate major adverse cardiac events (MACE) in a large, real-world cohort of patients managed with either iFR or FFR.
Main Methods:
- A retrospective analysis of 11,324 patients undergoing coronary angiography between 2013-2017 from the SWEDEHEART registry.
- Patients with at least one coronary lesion deferred from percutaneous coronary intervention (PCI) based on iFR (>0.89) or FFR (>0.80) were included.
- The primary outcome was a composite of MACE (all-cause death, nonfatal MI, unplanned revascularization), analyzed using multivariable-adjusted Cox proportional hazards models.
Main Results:
- The study included 1,998 patients in the iFR group and 9,326 in the FFR group, with a median follow-up of 2 years.
- Cumulative MACE rates were 26.7% for iFR and 25.9% for FFR.
- Adjusted analysis revealed no significant difference in MACE between the iFR and FFR groups (adjusted hazard ratio: 0.947; 95% CI, 0.84-1.08; P = .39), with no interaction found in subgroups.
Conclusions:
- Deferral of coronary revascularization guided by iFR demonstrates similar long-term safety compared to FFR.
- These findings support the use of iFR as a reliable physiological index for guiding revascularization decisions in routine clinical practice.
- The study confirms the safety of deferring intervention in intermediate coronary lesions when assessed with either iFR or FFR.
Background:
Deferral of coronary revascularization is safe whether guided by instantaneous wave-free ratio (iFR) or by fractional flow reserve (FFR). We aimed to assess long-term outcomes in patients deferred from revascularization based on iFR or FFR in a large real-world population.
Methods:
From 2013 through 2017, 201,933 coronary angiographies were registered in the Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies (SWEDEHEART). We included all patients (n = 11,324) with at least 1 coronary lesion deferred from PCI during an index procedure using iFR (>0.89; n = 1998) or FFR (>0.80; n = 9326). The primary outcome was major adverse cardiac events (MACE) defined as the composite of all-cause death, nonfatal myocardial infarction, or unplanned revascularization. A multivariable-adjusted Cox proportional hazards model was used, with analysis for interaction of prespecified subgroups.
Results:
Patients presented with stable angina pectoris (iFR 46.9% vs FFR 48.6%), unstable angina or non-ST-elevation myocardial infarction (iFR 37.7% vs FFR 33.1%), ST-elevation myocardial infarction (iFR 1.9% vs FFR 1.6%), and other indications (iFR 12.5% vs FFR 15.7%). The median follow-up was 2 years for both iFR and FFR groups. At the conclusion of the study, the cumulative MACE risks were 26.7 for the iFR group and 25.9% for FFR group. In the adjusted analysis, no difference was found between the 2 groups (adjusted hazard ratio: iFR vs FFR, 0.947; 95% CI, 0.84-1.08; P = 39). Consistent with the overall findings, the prespecified subgroups showed no interaction with the FFR/iFR results.
Conclusions:
Deferral of revascularization showed similar long-term safety whether based on iFR or on FFR.
