0043: FFR Gray zone and clinical outcome

Abstract

Fractional flow reserve (FFR) invasively assesses the ischemic potential of coronary stenosis.FFR value of 0.75 has been referred to the ischemic FFR threshold validated against non-invasive functional testing; while an FFR value of 0.80 has guided clinical decision making in multicenter clinical trials. Revascularization in case of FFR values in the gray zone between 0.75-0.80 is still debatable. We investigated the clinical outcome of patients with an isolated stenosis and FFR value in the gray zone. From 1997 to 2013, we retrospectively included all patients with single segment disease at coronary angiography and FFR between 0.70-0.85. We defined the following FFR groups: a) 0.70-0.75; b) 0.76-0.80 (gray zone); c) 0.81-0.85. Study endpoints was death, myocardial infarction and revascularization up to 5 years follow up. Out of 17380 patients undergoing FFR measurement: 2781 (16%) patients presented lesions with FFR in the gray zone; 1459 were included: 449 treated with percutaneous revascularization (PCI) and 1010 with medical therapy (MT). Clinical characteristics were similar among patients treated with PCI or MT, with exception of more frequent male gender in PCI group [p=0.002]. Diameter stenosis and FFR value were lower in PCI group (p<0.0001). At 5-years, compared to PCI group, MACE was more frequent in MT group with FFR 0.70-0.75 (11 [21%] vs. 53 [12%], p=0.026), while no difference was observed in MT groups with FFR 0.75-0.80 and 0.81-0.85. Within the MT group, a progressive increase in MACE was observed in 3 FFR strata (FFR, 0.81-0.85: 58 [8%] vs. FFR, 0.76-0.80: 35 [13%] vs. FFR, 0.70-0.75: n=11 [21%], p<0.0001). Patients with stenosis located in proximal-mid coronary segments and FFR in the gray zone of 0.75-0.80 demonstrate a MACE rate that is still higher than than observed in patients above the 0.80 clinical threshold. These data suggest that FFR £0.80 is valid to guide clinical decision making. Abstract 0043 – Figure