1. Division of Cardiovascular Medicine, Stanford University School of Medicine and Stanford Cardiovascular Institute, Stanford, CA, USA
Based on the sound mathematical principles underpinning its derivation and the wealth of clinical outcome data supporting its use, fractional flow reserve (FFR) has become the reference standard for evaluating the functional significance of epicardial coronary artery stenoses in patients with stable ischaemic heart disease. Percutaneous coronary intervention (PCI) for stenoses with an FFR value ≤0.80 improves clinical outcomes and quality of life compared with medical therapy1,2. On the other hand, patients with lesions with an FFR value >0.80 do just as well, if not better, when treated medically1,3. Most of these data, however, are derived from patients with stable ...