Fractional flow reserve (FFR) is the invasive standard of reference in identifying haemodynamically significant stenoses, those that are able to induce reversible myocardial ischaemia. Although defined as the ratio of maximum blood flow in a stenotic coronary to maximum blood flow if the same coronary would be normal, FFR is expressed as the ratio of two pressures: the distal coronary pressure measured by an intracoronary pressure guidewire and the proximal coronary or aortic pressure measured at the tip of the guiding catheter during maximal coronary hyperaemia. A threshold value of FFR less than or equal to 0.80 is currently recommended to indicate or defer coronary revascularization. In fact, a FFR-guided revascularization strategy has been shown to be safe and effective in reducing adverse events in a number of anatomical lesion subsets, including intermediate coronary stenoses, left main stenoses, multivessel disease, bifurcation lesions, sequential stenoses, stented vessels, and bypass grafts. There is growing interest in the use of FFR also in the setting of acute coronary syndrome. In patients with acute ST-elevation myocardial infarction, FFR has been adopted to assess intermediate stenoses incidentally found in non-culprit coronaries, and may be useful to guide the completeness of revascularization in the presence of multivessel disease. Finally, FFR is emerging as a novel potential area for invasive functional assessment of coronary atherosclerotic disease in patients with aortic stenosis, due to the increasing indications to transcatheter aortic valve implantation.
Economic Evaluation of Fractional Flow Reserve–Guided Percutaneous Coronary Intervention in Patients With Multivessel Disease
