Angio- or Microcatheter- Quantified FFR Virtual PCI Versus Angio-guided PCI in the Achievement of an Optimal Post-PCI FFR

Despite the accumulating evidence regarding functional indices utility in setting the indication to and planning percutaneous coronary interventions (PCI), the use of functional assessment in clinical practice is still limited. This is especially true in the post-PCI setting, probably due to lack of evidence and/or specific guidelines/recommendations on how to "react" to a suboptimal post-PCI functional result.

New indices and tools have been developed in an effort to overcome the barriers to a widespread adoption of functional assessment.

All these technological advances brought physiology to a new level transitioning from a binary interpretation of the functional evaluation - positive or negative - to a longitudinal analysis of the whole vessel. The reconstruction of a "physiological map" enables to quantify the physiological impact of each coronary segment/lesion and to identify the mechanisms underlying the suboptimal physiology result at the vessel level. This ability can be translated in simple manoeuvres able to improve the final physiology results and then the patient's prognosis.

The inherent limit of post-PCI physiology is to add measurement and consequent actions after the end of the procedure and not upfront. In addition, it is associated with the increase in procedural time and costs. Thus, a broad application of post-PCI physiology, although clinically meaningful, is difficult.

On the contrary, the systematic application of angiography-derived FFR before stenting to simulate PCI results according to different treatment strategies (virtual PCI) would be an interesting alternative to achieve a fully physiology-guided and optimized procedure. The powerful technological development lays in the possibility to simulate the treatment of one or more lesion, in order to estimate the residual functional value post-PCI: the so-called virtual PCI. These tools are particularly effective in multi-vessel disease patients and in tandem serial stenosis, allowing to individualize the treatment of those lesions related to poor clinical outcomes and avoiding superfluous coronary interventions.