Patients enrolled into this prospective registry will be derived from Stable Coronary Artery disease or Acute Coronary Syndrome (ACS) population undergoing cardiac catheterization. Patients with ACS may be evaluated by functional assessment in the non-culprit stenosis during the index PCI revascularization or in a staged procedure. The registry will enroll patients in whom physiological assessment (iFR/FFR) is particularly helpful in identifying haemodynamically significant stenosis: MVD patients defined by patients with lesions > 40% and <100% in 2 or more vessels.

• The Volcano iFR®-FFR option, which is a measurement modality for the Volcano system that provides the capability to make FFR and instantaneous wave-Free Ratio™ (iFR®) measurements (CE-Marked). iFR® is a pressure-derived, hyperemia-free index for the assessment of coronary stenosis relevance. This option consists of an FFR-iFR® specific patient interface module (PIM-FFR) which can be connected to the Volcano system - VOLCANO s5 or s5i™ platform equipped with iFR® option. This PIM-FFR is compatible with all Volcano pressure measurement guide wires.

Percentage of stenosis properly classified by iFR® in terms of hemodynamic severity compare to FFR in MVD patients. Hemodynamic severity will be established with an FFR value <=0,80.

Changes in iFR® and FFR pre angioplasty and post angioplasty in MVD patients.

Percentage of MVD patients in whom the decision strategy of revascularization changed after iFR® compare to the decision based on diagnostic angiogram only.