Post-PCI coronary physiology: clinical outcomes and can we optimize?

Invasive coronary physiology is well-established for identifying stable lesions appropriate for revascularization with percutaneous coronary intervention (PCI). Furthermore, fractional flow reserve (FFR)-guided PCI is associated with better clinical outcomes compared with routine angiography-guided PCI. The rise of intravascular imaging-guided PCI has generated great interest in optimizing the technical results of a PCI procedure, and this has now extended to an interest in optimizing coronary physiology following PCI. In this review, we examine the relationship between post-PCI physiology and clinical outcomes, including relief from angina, a relationship which is independent of the initial FFR value. In addition, we highlight the utility of pullback coronary pressure assessment for identifying mechanisms of suboptimal final FFR, such as patient characteristics (diffuse atherosclerosis), PCI technique, and certain artifacts in pressure-wire measurements. It is our view that the final FFR value can only be modestly improved, or optimized, with respect to clinical outcomes. The most significant clinical impact is obtained from the change in FFR (ΔFFR) from before to after PCI, which can be anticipated ahead of time by operators and used to guide lesion selection, or exclusion, for PCI.