Safety of absolute coronary flow and microvascular resistance measurements by thermodilution

Introduction

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-quantitative and operator-dependent.

Recently, direct quantitative measurement of coronary blood flow and microvascular resistance has become possible by thermodilution with saline infusion, using a pressure-temperature ...