Landmark Fractional Flow Reserve Trials

Fractional flow reserve (FFR) has become widely used for physiologic assessment of intermediate coronary lesions. The Fractional Flow Reserve to Determine Appropriateness of Angioplasty in Moderate Coronary Stenoses (DEFER) trial established the safety of deferring angioplasty for moderate lesions that are not functionally significant. DEFER and Fractional Flow Reserve versus Angiography for Multivessel Evaluation 1 trials established the feasibility of FFR-guided intervention in stable and unstable patients with moderate coronary lesions, translating to improved clinical outcome and reduced number of unnecessary stents. This article reviews the trials establishing FFR as an important tool for on-the-table functional assessment of coronary lesions.