Angiography versus Hemodynamics to Predict the Natural History of Coronary Stenoses: A FAME 2-Substudy

Background —Among patients with documented stable coronary artery disease (CAD) and in whom no revascularization was performed, we compared the respective values of angiographic diameter stenosis (DS) and of fractional flow reserve (FFR) in predicting natural history. Methods —The present analysis included the 607 patients from the Fractional flow reserve versus angiography in multivessel evaluation 2 (FAME 2) trial in whom no revascularization was performed. FFR varied from 0.20 to 1.00 (average 0.74 ± 0.16) and DS (by QCA) varied from 8% to 98% (average 53 ± 15). The primary end point, defined as VOCE (Vessel oriented clinical endpoint) at 2 years, was a composite of prospectively adjudicated cardiac death, vessel-related myocardial infarction, vessel-related urgent and not urgent revascularization. The stenoses were divided into 4 groups according to FFR and %DS values: Positive Concordance (PC: FFR≤0.80; DS≥50%); Negative Concordance (NC: FFR>0.80; DS 0.80; DS≥50%). Results —The rate of VOCE was highest in the PC group (Log Rank: X 2 =80.96; p=0.001), and lowest in the NC group. The rate of VOCE was higher in the PM group than in the NM group (H.R. 0.38, 95% C.I. 0.21 - 0.67; p=0.001). There was no significant difference in VOCE between the PC and the PM (both groups with FFR≤0.80, H.R. 0.77, 95% C.I. 0.57 - 1.09; p=0.149) and no significant difference in rate of VOCE between the NM and NC (both groups with FFR>0.80, H.R. 1.89, 95% C.I. 0.96 - 3.74; p=0.067). Conclusions —In patients with stable coronary disease, physiology (FFR) is a more important determinant of the natural history of coronary stenoses than anatomy (DS). Clinical Trial Registration —URL: https://clinicaltrials.gov Unique Identifier: NCT01132495.