An Evaluation of a Physiology-guided PCI Optimisation Strategy

There has recently been renewed interest in the measurement of post percutaneous coronary intervention (PCI) Fractional Flow Reserve (FFR). Previous studies have suggested that post-PCI FFR values ≥0.90 are associated with better clinical outcomes for patients but the available data suggest that despite angiographically satisfactory results, this is actually achieved in less than 40% of cases. The main mechanisms for sub-optimal post-PCI FFR measurements have been proposed to be suboptimal stent deployment, unmasking of a second lesion in the target vessel post PCI, residual diffuse disease in the untreated segments and pressure drift (a technical artefact of pressure wire technology). Using post-PCI FFR to guide stent optimisation and/or further intervention in the target vessel has been shown to increase the frequency of achieving optimal post-PCI FFR results (and therefore presumably better clinical outcomes). However, there are additional costs involved in the routine use of post-PCI FFR and it is not clear just how often it is even possible to increase the initial post-PCI FFR to ≥0.90. This uncertainty means that it is currently difficult to either recommend the routine use of post-PCI FFR or justify its cost. The investigators propose a prospective study to assess the feasibility of achieving post-PCI FFR ≥0.90 during standard PCI procedures in consecutive patients. The study would also attempt to elucidate the mechanisms for sub-optimal FFR results when they occur. The investigators anticipate using the data from this developmental study to support a subsequent funding application for a definitive phase 3 study of the impact of FFR targeted PCI on clinical outcomes.