Differential Prognostic Value of Revascularization for Coronary Stenosis With Intermediate FFR by Coronary Flow Reserve

Objectives: The authors sought to evaluate comparative prognosis between deferred versus performed percutaneous coronary intervention (PCI) according to coronary flow reserve (CFR) values of patients with intermediate fractional flow reserve (FFR). Background: For coronary stenosis with intermediate FFR, the prognostic value of PCI remains controversial. The prognostic impact of PCI may be different according to CFR in patients with intermediate FFR. Methods: From the ILIAS Registry (Inclusive Invasive Physiological Assessment in Angina Syndromes Registry, N = 2,322), 400 patients (412 vessels) with intermediate FFR (0.75-0.80) were selected. Patients were stratified into preserved CFR (>2.0, n = 253) and depressed CFR (≤2.0, n = 147) cohorts. Per-vessel clinical outcomes during 5 years of follow-up were compared between deferred versus performed PCI groups in both cohorts. The primary outcome was target vessel failure (TVF), a composite of cardiac death, target vessel myocardial infarction, or target vessel revascularization. Results: Among the study population, PCI was deferred for 210 patients (219 vessels, 53.2%) (deferred group) and performed for 190 patients (193 vessels, 46.8%) (performed group). The risk of TVF was comparable between the deferred and performed groups (12.8% vs 14.2%; adjusted HR: 1.403; 95% CI: 0.584-3.369; P = 0.448). When stratified by CFR, PCI was performed in 39.1% (100/261 vessels) of the preserved CFR cohort and 61.9% (93/151 vessels) of the depressed CFR cohort. Within the preserved CFR cohort, the risk of TVF did not differ significantly between the deferred and performed groups (11.0% vs 13.9%; adjusted HR: 0.770; 95% CI: 0.262-2.266; P = 0.635). However, in the depressed CFR cohort, the deferred group had a significantly higher risk of TVF than the performed group (17.2% vs 14.2%; adjusted HR: 4.932; 95% CI: 1.312-18.53; P = 0.018). A significant interaction was observed between CFR and the treatment decision (interaction P = 0.049). Results were consistent after inverse probability weighting adjustment. Conclusions: In patients with intermediate FFR of 0.75 to 0.80, the prognostic value of PCI differed according to CFR, with a significant interaction. PCI was associated with a lower risk of TVF compared with the deferral strategy when CFR was depressed (≤2.0), but there was no difference when CFR was preserved (>2.0). CFR could be used as an additional risk stratification tool to determine treatment strategies in patients with intermediate FFR.