Unlike coronary angiography alone, fractional flow reserve (FFR) assists interventional cardiologists in accurately determining whether coronary atherosclerotic plaques are responsible for myocardial ischemia, and need to be revascularized. FFR is unparalleled in diagnostic accuracy when compared to nonhyperemic indices and noninvasive techniques. It continues to be the gold standard for detection of ischemia-inducing coronary stenoses. FFR-guided PCI has been found to be superior to angiography-guided PCI and over medical therapy alone.

FAME 2 trial investigators clearly demonstrated that in patients with stable CAD, FFR-guided PCI, as compared with medical therapy alone, improved the outcome. A meta-analysis supported current guidelines advising FFR-guided PCI strategy for CAD. FFR-guided PCI was found to be associated with lower MACE/MACCE, death, MI, repeat revascularization, and death or MI than angiography-guided PCI strategy.

Revascularization guided by FFR in patients with CAD and stenoses >50% yields better outcomes than revascularization based on a visual analysis of angiographic stenosis severity alone. DEFER and FAME trials have shown that in patients with stable CAD, conservative management of stenoses that could be angiographically severe, but are not hemodynamically relevant, is safe.

FFR is, therefore, an ideal tool to guide treatment in CAD.