Three-Dimensional Angiographic Characteristics versus Functional Stenosis Severity in Fractional and Coronary Flow Reserve Discordance: A DEFINE FLOW Sub Study

Background: Coronary angiography alone is insufficient to identify lesions associated with myocardial ischemia that may benefit from revascularization. Coronary physiology parameters may improve clinical decision making in addition to coronary angiography, but the association between 2D and 3D qualitative coronary angiography (QCA) and invasive pressure and flow measurements is yet to be elucidated. Methods: We associated invasive fractional flow reserve (FFR), coronary flow reserve (CFR) and coronary flow capacity (CFC) with 2D- and 3D-QCA in 430 intermediate lesions of 366 patients. Results: Overall, 2D-QCA analysis resulted in less severe stenosis severity compared with 3D-QCA analysis. FFR+/CFR- lesions had similar 3D-QCA characteristics as FFR+/CFR+ lesions. In contrast, vessels with FFR-/CFR+ discordance had 3D-QCA characteristics similar to those of vessels with concordant FFR-/CFR-. Contrarily, FFR+/CFR- lesions had CFC similar to that of as FFR-/CFR- lesions. Conclusions: Non-flow-limiting lesions (FFR+/CFR-) have 3D-QCA characteristics similar to those of FFR+/CFR+, but the majority are not associated with inducible myocardial ischemia as determined by invasive CFC. FFR-/CFR+ lesions have 3D-QCA characteristics similar to those of FFR-/CFR- lesions but are more frequently associated with a moderately to severely reduced CFC, illustrating the angiographic-functional mismatch in discordant lesions.