Coronary physiology in the catheterisation laboratory: an A to Z practical guide

Abstract

Coronary revascularisation, either percutaneous or surgical, aims to improve coronary flow and relieve myocardial ischaemia. The decision-making process in patients with coronary artery disease (CAD) remains largely based on invasive coronary angiography (ICA), even though until recently ICA could not assess the functional significance of coronary artery stenoses. Invasive wire-based approaches for physiological evaluations were developed to properly assess the ischaemic relevance of epicardial CAD. Fractional flow reserve (FFR) and later, instantaneous wave-free ratio (iFR), were shown to improve clinical outcomes in several patient subsets when used for coronary revascularisation guidance or deferral and for procedural optimisation of percutaneous coronary intervention (PCI) results. Despite accumulating evidence and positive guideline recommendations, the adoption of invasive physiology has remained quite low, mainly due to technical and economic issues as well as to operator-resistance to change. Coronary image-based computational physiology has been recently developed, with promising results in terms of accuracy and a reduction in computational time, costs, radiation exposure and risks for the patient. Lastly, the integration of intracoronary imaging and physiology allows for individualised PCI treatment, aiming at complete relief of ischaemia through optimised morpho-functional immediate procedural results. Instead of a conventional state-of-the-art review, this A to Z dictionary attempts to provide a practical guide for the application of coronary physiology in the catheterisation laboratory, exploring several methods, their pitfalls, and useful tips and tricks.

In Vivo Validation of a Novel Computational Approach to Assess Microcirculatory Resistance Based on a Single Angiographic View

“…Similar results were previously reported, suggesting that the agreement between angiography-derived IMR and invasive IMR was very close in NSTEMI and CCS, whereas it was less accurate in the STEMI setting. The inherently higher biological variability of IMR in a STEMI setting could explain such a difference, as the absolute numerical IMR values were less well correlated with the standard of reference in the case of extreme CMD [13,14,35]. This might be related to the hyper-sympathetic activation and the profound structural microvascular deterioration since the early phases (i.e., microvascular clotting, leukocyte adhesion and distal embolization) [13,14,35].…”

“…The inherently higher biological variability of IMR in a STEMI setting could explain such a difference, as the absolute numerical IMR values were less well correlated with the standard of reference in the case of extreme CMD [13,14,35]. This might be related to the hyper-sympathetic activation and the profound structural microvascular deterioration since the early phases (i.e., microvascular clotting, leukocyte adhesion and distal embolization) [13,14,35]. Thus, in the setting of functional CMD, the use of hyperemic angiograms to compute AMR might be considered, as previously reported for the FFR/QFR disagreement [36].…”

Integrated Assessment of Computational Coronary Physiology From a Single Angiographic View in Patients Undergoing TAVI

“…25 Conversely, inconsistent unpredictable variations of iFR and other nonhyperemic indexes were reported between pre- and post-TAVI. 6,20,26 Based on a substudy of the NOTION-3 (Third Nordic Aortic Valve Intervention) including 50 vessels with FFR and 36 vessels with resting full-cycle ratio measured pre- and 6 months after TAVI, Sabbah et al 5 showed that resting full-cycle ratio improved significantly (0.88–0.92; P =0.003), whereas FFR remained unchanged (0.84–0.86; P =0.72). Moreover, a low rate of lesion reclassification was seen with FFR (FFR-positive 22%–30%; P =0.219) compared with resting full-cycle ratio (resting full-cycle ratio-positive 64%–33%; P =0.003).…”

“…19 Moreover, PW-based physiological assessment is associated with increased procedural costs, radiation, contrast medium exposure, as compared with computational physiological assessment derived from a single angiographic projection. 20 The use of coronary physiology in the management of SAS has the potential for simplifying the clinical management of patients with bystander CAD, by reducing the need for stenting, number of stents used, and for dual antiplatelet therapy. The effectiveness of an FFR-guided revascularization in reducing the number of vessels with significant disease and improving survival without major adverse cardiac events was previously reported in retrospective studies.…”

Fractional flow reserve and non-hyperemic indices: Essential tools for percutaneous coronary interventions

“…All these major trials support the class IA recommendation to assess the hemodynamic relevance of intermediate coronary artery disease by FFR and as class IIB in multivessel disease evaluation[ 8 ]. In fact, both the European and American guidelines state that patients undergoing coronary angiography without prior ischemia assessment should have invasive hemodynamic test (FFR or NHPR) to optimize the revascularization strategy[ 40 ].…”