What can intracoronary pressure measurements tell us about flow reserve? : pressure-bounded coronary flow reserve and example application to the randomized DEFER trial

Objective: We propose a novel technique called pressure-bounded coronary flow reserve (pb-CFR) and demonstrate its application to the randomized DEFER trial. Background: Intracoronary flow reserve assessment remains underutilized relative to pressure measurements partly due to less robust tools. Methods: While rest and hyperemic intracoronary pressure measurements cannot quantify CFR exactly, they do provide upper and lower bounds. We validated pb-CFR invasively against traditional CFR, then applied it to high fractional flow reserve (FFR ≥ 0.75) lesions in DEFER randomized to revascularization or medical therapy. Results: pb-CFR showed an 84.4% accuracy to predict invasive CFR < 2 or CFR ≥ 2 in 107 lesions. In its proof of concept application to DEFER lesions with FFR ≥ 0.75, the 28 with pb-CFR < 2 compared to 28 with pb-CFR ≥ 2 had a non-significant reduction in freedom from angina (61% vs. 71% at 5 years, P = 0.57) and a non-significantly higher rate of major adverse cardiac events (MACE, 25% vs. 15%, P = 0.34). Lesions with FFR ≥ 0.75 but pb-CFR < 2 showed no difference in freedom from angina (61% vs. 50%, P = 0.54) or MACE (25% vs. 38%, P = 0.27) between the 28 randomized to medical therapy and the 16 randomized to revascularization. Conclusions: pb-CFR offers a new method for studying FFR/CFR discordances using regular pressure wire measurements. As an example application, DEFER suggested that low pb-CFR with high FFR may be a risk marker for more angina and worse outcomes, but that this risk cannot be modified by revascularization

Deferral vs. performance of percutaneous coronary intervention of functionally non-significant coronary stenosis: 15-year follow-up of the DEFER trial

Aims Stenting an angiographically intermediate but functionally non-significant stenosis is controversial. Nevertheless, it has been questioned if deferral of a functionally non-significant lesion on the basis of fractional flow reserve (FFR) measurement, is safe, especially on the long term. Five-year follow-up of the DEFER trial showed that outcome after deferral of percutaneous coronary intervention (PCI) of an intermediate coronary stenosis based on FFR = 0.75 is excellent and was not improved by stenting. The aim of this study was to investigate the validity of this position on the very long term. Met hods and resul ts In 325 patients scheduled for PCI of an intermediate stenosis, FFR was measured just before the planned intervention. If FFR was = 0.75, patients were randomly assigned to deferral (Defer group; n = 91) or performance (Perform group; n = 90) of PCI. If FFR was, 0.75, PCI was performed as planned (Reference group; n = 144). Clinical follow-up was 15 years. There were no differences in baseline clinical characteristics between the randomized groups. Complete 15-year follow-up was obtained in 92% of patients. After 15 years of follow-up, the rate of death was not different between the three groups: 33.0% in the Defer group, 31.1% in the Perform group, and 36.1% in the Reference group (Defer vs. Perform, RR 1.06, 95% CI: 0.69 1.62, P = 0.79). The rate of myocardial infarction was significantly lower in the Defer group (2.2%) compared with the Perform group (10.0%), RR 0.22, 95% CI: 0.05 0.99, P = 0.03. Conclusion Deferral of PCI of a functionally non-significant stenosis is associated with a favourable very long-term follow-up without signs of late 'catch-up' phenomenon

Percutaneous coronary intervention of functionally nonsignificant stenosis : 5-year follow-up of the DEFER Study

Objectives The purpose of this study was to investigate the appropriateness of stenting a functionally nonsignificant stenosis. Background Percutaneous coronary intervention (PCI) of an intermediate stenosis without evidence of ischemia is often performed, but its benefit is unproven. Coronary pressure-derived fractional flow reserve (FFR) is an invasive index used to identify a stenosis responsible for reversible ischemia. Methods In 325 patients scheduled for PCI of an intermediate stenosis, FFR was measured just before the planned intervention. If FFR was =0.75, patients were randomly assigned to deferral (Defer group; n = 91) or performance (Perform group; n = 90) of PCI. If FFR wa

Deferral vs. performance of percutaneous coronary intervention of functionally non-significant coronary stenosis:15-year follow-up of the DEFER trial

\u3cp\u3eAims Stenting an angiographically intermediate but functionally non-significant stenosis is controversial. Nevertheless, it has been questioned if deferral of a functionally non-significant lesion on the basis of fractional flow reserve (FFR) measurement, is safe, especially on the long term. Five-year follow-up of the DEFER trial showed that outcome after deferral of percutaneous coronary intervention (PCI) of an intermediate coronary stenosis based on FFR = 0.75 is excellent and was not improved by stenting. The aim of this study was to investigate the validity of this position on the very long term. Met hods and resul ts In 325 patients scheduled for PCI of an intermediate stenosis, FFR was measured just before the planned intervention. If FFR was = 0.75, patients were randomly assigned to deferral (Defer group; n = 91) or performance (Perform group; n = 90) of PCI. If FFR was, 0.75, PCI was performed as planned (Reference group; n = 144). Clinical follow-up was 15 years. There were no differences in baseline clinical characteristics between the randomized groups. Complete 15-year follow-up was obtained in 92% of patients. After 15 years of follow-up, the rate of death was not different between the three groups: 33.0% in the Defer group, 31.1% in the Perform group, and 36.1% in the Reference group (Defer vs. Perform, RR 1.06, 95% CI: 0.69 1.62, P = 0.79). The rate of myocardial infarction was significantly lower in the Defer group (2.2%) compared with the Perform group (10.0%), RR 0.22, 95% CI: 0.05 0.99, P = 0.03. Conclusion Deferral of PCI of a functionally non-significant stenosis is associated with a favourable very long-term follow-up without signs of late 'catch-up' phenomenon.\u3c/p\u3

Deferral vs. performance of percutaneous coronary intervention of functionally non-significant coronary stenosis : 15-year follow-up of the DEFER trial

AIMS: Stenting an angiographically intermediate but functionally non-significant stenosis is controversial. Nevertheless, it has been questioned if deferral of a functionally non-significant lesion on the basis of fractional flow reserve (FFR) measurement, is safe, especially on the long term. Five-year follow-up of the DEFER trial showed that outcome after deferral of percutaneous coronary intervention (PCI) of an intermediate coronary stenosis based on FFR ≥ 0.75 is excellent and was not improved by stenting. The aim of this study was to investigate the validity of this position on the very long term. METHODS AND RESULTS: In 325 patients scheduled for PCI of an intermediate stenosis, FFR was measured just before the planned intervention. If FFR was ≥0.75, patients were randomly assigned to deferral (Defer group; n = 91) or performance (Perform group; n = 90) of PCI. If FFR was <0.75, PCI was performed as planned (Reference group; n = 144). Clinical follow-up was 15 years. There were no differences in baseline clinical characteristics between the randomized groups. Complete 15-year follow-up was obtained in 92% of patients. After 15 years of follow-up, the rate of death was not different between the three groups: 33.0% in the Defer group, 31.1% in the Perform group, and 36.1% in the Reference group (Defer vs. Perform, RR 1.06, 95% CI: 0.69-1.62, P = 0.79). The rate of myocardial infarction was significantly lower in the Defer group (2.2%) compared with the Perform group (10.0%), RR 0.22, 95% CI: 0.05-0.99, P = 0.03. CONCLUSION: Deferral of PCI of a functionally non-significant stenosis is associated with a favourable very long-term follow-up without signs of late 'catch-up' phenomenon