Intravascular Imaging Versus Physiology Assessment for Intermediate Lesions During PCI

Coronary artery disease (CAD) is the leading cause of mortality, with percutaneous coronary intervention (PCI) constituting the gold standard treatment. However, in an important proportion of the cases, lesion severity is debatable since conventional angiography provides only a two-dimensional representation of the vessel lumen and fails to quantify ischemic significance or plaque morphology. In these cases, several adjunctive tools considering physiology and imaging guidance may assist in quantifying the severity of the disease. Imaging modalities such as intravascular ultrasonography (IVUS) and optical coherence tomography (OCT), as well as physiology such as fractional flow reserve (FFR) and instantaneous wave-free (iFR), revolutionized revascularization strategy by linking anatomical stenosis to its functional consequence on myocardial perfusion. The present review summarizes and contrasts the available evidence for physiology and imaging guidance, considering the assessment of intermediate lesions during PCI and providing insights for their use in specific lesion subsets.