Three-year outcomes after deferral of revascularization based on instantaneous wave-free ratio or fractional flow reserve: insights from the J-CONFIRM Registry

Abstract

Abstract Background The safety of deferral of revascularization based on instantaneous wave-free ratio (iFR) is established in randomized controlled trials. However, there is little data regarding long-term outcomes after deferral of revascularization based on iFR in real-world practice. Purpose We sought to assess clinical outcomes after deferral of revascularization based on iFR in clinical practice as compared with those based on fractional flow reserve (FFR). Methods This is a post hoc analysis of the J-CONFIRM registry (long-term outcomes of Japanese patients with deferral of coronary intervention based on fractional flow reserve in multicenter registry), in which 1262 patients with 1447 lesions deferred the revascularization based on FFR. Of these, both FFR and iFR were measured in 399 patients with 452 lesions. The patients were classified into the two groups: the iFR group (iFR >0.89; 308 patients with 348 lesions) and the FFR group (FFR >0.80; 740 patients with 855 lesions). The primary study endpoint was the 3-year target vessel failure (TVF) including cardiac death, target-vessel related myocardial infarction (TVMI), and clinically driven target vessel revascularization (CDTVR). Results Mean iFR was 0.96±0.04 in the iFR group. Mean FFR was significantly lower in the iFR group than in the FFR group (0.87±0.05 vs. 0.89±0.05, p=0.002). The iFR group included 35 lesions (11.4%) with FFR ≤0.80. At 3 years, the rate of TVF on a lesion basis were not significantly different between the iFR and FFR groups (8.8% vs. 6.1%, p=0.10), whereas CDTVR rate was significantly higher in the iFR group than in the FFR group (8.5% vs. 5.3%, p=0.044). Cardiac death and TVMI on a patient basis rarely occurred in both groups during the 3-year follow-up (0.33% vs. 0.77%, p=0.47; 0.66% vs. 0.56%, p=0.85, respectively). Conclusion At 3 years, TVF rate in deferred lesions was numerically higher in the iFR group than in the FFR group, driven by a higher rate of CDTVR. However, cardiac death and TVMI was very rare in both groups, highlighting the safety of both iFR- and FFR-based deferral of revascularization in daily practice. Funding Acknowledgement Type of funding source: None