We read the review by van Nunen and Tonino [1] with great interest. We would like to discuss some views on fractional flow reserve (FFR) in stable coronary artery disease (CAD). The optimal treatment of stable CAD remains great controversial. Some studies, including The Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) [2] and the… (More)