Beyond residual stenosis: morphofunctional assessment following primary PCI in acute coronary syndrome

The role of wire-based physiology to guide and evaluate revascularisation in acute coronary syndrome (ACS) is still heavily debated. While fractional flow reserve (FFR)-guided complete revascularisation is superior to culprit-only revascularisation, multiple studies have recently failed to show an advantage of FFR-guided complete revascularisation over angiography-guided complete revascularisation1. The conflicting evidence underlying pressure-based assessment in ACS may be related to acute and temporary disturbances in the microcirculation. Image-derived physiology has the theoretical advantage of being less affected by microvascular involvement in the acute setting of ACS. Indeed, quantitative flow ratio (QFR) was largely unchanged for paired measurements in non-culprit lesions measured during primary percutaneous coronary intervention (PCI) or in a staged setting2. Furthermore, initial reports have documented the prognostic value of post-PCI QFR in ACS patients3. In addition to physiological lesion assessment, high-risk plaque features in non-culprit lesions that are not flow limiting (FFR>0.80) are associated with worse clinical outcome4. Hence, there may exist a complementary value of physiology and morphology for risk stratification.

In this issue of EuroIntervention, Osumi et al assessed the prognostic impact of...