Safety of absolute coronary flow and microvascular resistance measurements by thermodilution

Assessment of the microcirculation of the heart has gained interest over recent years. This is partly due to the fact that up to 50% of patients with chest pain visiting the catheterisation laboratory do not present with significant epicardial stenosis (so-called angina with non-obstructive coronary artery disease [ANOCA])1. Most knowledge regarding microvascular resistance has come from non-invasive imaging, from invasive index of microvascular resistance2, or from Doppler wires3, all of which are semi-quanti tative and operator-dependent. Recently, direct quantitative measurement of coronary blood flow and microvascular resistance has become possible by ther-modilution with saline infusion, using a pressure-temperature guidewire and a multi-sidehole infusion catheter. Such measure ments have been validated versus positron emission tomography (PET)4, have a high reproducibility and are operator-independent5. Procedural safety has been reported previously5; however, long-term safety and absence of late complications have not yet been described. The present study evaluates the safety of absolute flow measurements, both periprocedural, at 30 days and up to one-year follow-up Europa Digital & Publishing 2021. All rights reserved. Copyright 2021, AIDIC Servizi S.r.l.