both invasive and non-invasive coronary physiology aim to simplify and improve diagnosis of ischemic heart disease.The strong fundament of FFR is discussed in this issue by Corcoran and colleagues [4], who provide a state-ofart review summarizing the theoretical, experimental and clinical basis for FFR measurement. Over the years, it has become clear that conventional coronary anatomy parameters revealed by coronary angiography or intracoronary imaging cannot represent the complex nature of coronary physiology, and thereby do not allow appropriate characterization of the hemodynamic significance of coronary artery disease. Chu and colleagues [5] performed a systematic review of studies reporting accuracy of anatomical parameters in predicting significant FFR and highlighted the importance of study population composition in the diagnostic performance of anatomical parameters. Large scatters, and hence poor diagnostic value of anatomical parameters, were observed in patients with intermediate coronary stenosis where FFR is regarded most useful in determining the need for revascularization in daily practice.Considering the benefit of FFR-guided intervention and the relative complexity of the technology, various efforts have been directed towards simplification of assessment and interpretation of FFR, as well as the development of novel concepts to simplify the assessment of physiological coronary disease severity. Corcoran and colleagues [6] present the validation results of a "smart minimum" FFR algorithm in an unselected all-comer population of patients with intermediate coronary stenoses, aiming to simplify interpretation of FFR in the catheterization laboratory. Meimoun and colleagues [7] report on a comparison of the instantaneous wave-free ratio (iFR) and non-invasive coronary flow reserve for the identification of hemodynamically relevant coronary disease in the left anterior descending coronary artery, using FFR as the reference standard. iFR Over the past years, clinical evidence has pointed to the value of routine integration of coronary physiology in the cardiac catheterization laboratory to optimize