A new CFD based non-invasive method for functional diagnosis of coronary stenosis

Xinzhou Xie,Didi Wen,Songyun Xie,Yabing Li,Minwen Zheng

doi:10.1186/s12938-018-0468-6

Abstract

BackgroundAccurate functional diagnosis of coronary stenosis is vital for decision making in coronary revascularization. With recent advances in computational fluid dynamics (CFD), fractional flow reserve (FFR) can be derived non-invasively from coronary computed tomography angiography images (FFRCT) for functional measurement of stenosis. However, the accuracy of FFRCT is limited due to the approximate modeling approach of maximal hyperemia conditions. To overcome this problem, a new CFD based non-invasive method is proposed.MethodsInstead of modeling maximal hyperemia condition, a series of boundary conditions are specified and those simulated results are combined to provide a pressure-flow curve for a stenosis. Then, functional diagnosis of stenosis is assessed based on parameters derived from the obtained pressure-flow curve.ResultsThe proposed method is applied to both idealized and patient-specific models, and validated with invasive FFR in six patients. Results show that additional hemodynamic information about the flow resistances of a stenosis is provided, which cannot be directly obtained from anatomy information. Parameters derived from the simulated pressure-flow curve show a linear and significant correlations with invasive FFR (r > 0.95, P < 0.05).ConclusionThe proposed method can assess flow resistances by the pressure-flow curve derived parameters without modeling of maximal hyperemia condition, which is a new promising approach for non-invasive functional assessment of coronary stenosis.

Highlights

Accurate functional diagnosis of coronary stenosis is vital for decision making in coronary revascularization
Determining the functional significance of a coronary stenosis plays a pivotal role in decision making in coronary revascularization [1]
As the flow rate increases, the pressure drops across the stenosis section increases for both concentric and eccentric models, and a larger AS% will lead to a more rapid increase in pressure drop

Summary

Introduction

Accurate functional diagnosis of coronary stenosis is vital for decision making in coronary revascularization. The accuracy of FFRCT is limited due to the approximate modeling approach of maximal hyperemia conditions To overcome this problem, a new CFD based non-invasive method is proposed. Significant stenosis generally causes angina symptoms, and is associated with inducible ischemia and impaired outcome. Fractional flow reserve (FFR) is considered as the gold standard for assessment of functional measurement of stenosis [2, 3]. It is a pressure derived index and defined as the ratio between the distal and proximal pressure of the stenosis at maximal hyperemia [4]. FFR-guided strategy has been proved to be safety and has been demonstrated to be both cost-effective

Methods

Results

Conclusion