Optimising Physiological Assessment Of Serial Coronary Artery Lesions Using An In Vitro 3-D Printed Model Of Tandem Stenoses

Introduction: Fractional Flow Reserve (FFR) is considered the optimal technique to assess physiological significance of coronary artery disease during angiography. However, the ability of pressure-derived indices to assess individual lesions is unclear due to potential haemodynamic interplay between serial stenoses. The most common technique uses trans-lesional change in FFR (ΔFFR) on pressure wire pullback to estimate significance of each lesion. We aimed to evaluate determinants of this interplay and incorporate these into a model predicting the true significance of a stenosis, once an accompanying stenosis is removed. Methods: Coronary arteries with tandem stenoses were modelled using 3D-printing in various configurations of lesion severity, length and separation. Using a validated in vitro model of coronary circulation, 52 configurations of tandem stenoses were assessed by pressure wire pullback and compared with tubes containing isolated stenoses. The functional significance of isolated stenoses (FFR...