Association of Vessel Fractional Flow Reserve (vFFR) with Luminal Obstruction and Plaque Characteristics as Detected by Optical Coherence Tomography (OCT) in Patients With NSTE-ACS: the FAST OCT Study.

Abstract

There is a paucity of data on the performance of angiography-derived vessel fractional flow reserve (vFFR) in coronary artery lesions of patients presenting with non-ST-segment elevation acute coronary syndrome (NSTE-ACS). Optical coherence tomography (OCT) allows for visualization of lumen dimensions and plaque integrity with high resolution. The aim of the present study was to define the association between vFFR and OCT findings in intermediate coronary artery lesions in patients presenting with NSTE-ACS. The FAST OCT study was a prospective, multicenter, single-arm study. Patients presenting with NSTE-ACS with intermediate to severe coronary artery stenosis in one or multiple vessels with TIMI 3 flow suitable for OCT imaging were eligible. Complete pre-procedural vFFR and OCT data were available in 226 vessels (in 188 patients). A significant association between vFFR and minimal lumen area (MLA) was observed, showing an average decrease of 20.4% (95% CI -23.9% - -16.7%) in MLA per 0.10 decrease in vFFR (adjusted p<0.001). vFFR≤0.80 showed a sensitivity of 56.7% and specificity of 92.5% to detect MLA≤2.5 mm². Conversely, vFFR had a poor to moderate discriminative ability to detect plaque instability (sensitivity, 46.9% specificity 71.6%). In patients with NSTE-ACS, vFFR is significantly associated with OCT-detected MLA and a vFFR≤0.80 is highly predictive for the presence of significant disease based on OCT. Conversely, the sensitivity of vFFR≤0.80 to detect OCT-assessed significant disease was low, indicating that the presence of significant OCT findings cannot be ruled out based on a negative vFFR. NCT04683133.