Long-term Safety of Revascularization Deferral Based on Instantaneous Wave-Free Ratio or Fractional Flow Reserve
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Published on: August 25, 2023
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.
