Resolution of coronary ‘mother’-’daughter’ configurations by multi-artery FFR method – a comparison with basic FFR method

Author(s): Ilan A. Yaeger

Background: A sizable coronary artery and its small side-branch are usually termed ‘mother’- ’daughter’ configuration. In the intermediate stenosis severity range resolution of such configurations might not be trivial. Numerical simulation by the novel Multi-artery FFR method will be presented. Such configurations can be also resolved by the basic FFR method. The objective is a comparison between the two methods and exhibition of the effect of stenosis-stenosis interactions.

Methods: A ‘mother’ artery stenotic at locations preceding and following the split-off point of stenotic ‘daughter’ artery is considered. Multi-artery FFR method is applied to an equivalent 3-artery configuration. The difference between a stenotic single artery in a virtual stand-alone position (with FFR=FFRtrue) and the same artery within a configuration of interacting stenotic arteries with a different actual FFR (denoted FFRreal) is discussed.

Results: An artery in seemingly acceptable condition (FFRtrue~0.93) may have unacceptable actual FFR (FFRreal~0.65) requiring revascularization (see example in article). The Multi-artery FFR method has the advantage of predicting post-revascularization FFRreal of each artery from initial intracoronary pressure data whereas basic FFR method can yield post-revascularization FFRreal of each artery only after revascularizations are actually made.

Conclusions: Multi-artery FFR method mathematics used by the PCI practitioner is simple. It can be used in real time to obtain the current status of stenotic ‘mother’-’daughter’ configuration and its final optimal resolution. The basic single-artery FFR method is also applicable in such a scenario. A comparison between the two methods favors the Multi-artery FFR method essentially for its capability to predict revascularization outcomes.