(186g) Novel Non-Invasive Quantification of Coronary Artery Stenosis

Coronary artery stenosis is an abnormal narrowing in a coronary artery caused by an atherosclerotic lesion that reduces lumen space. Accurate quantification of coronary stenosis is crucial in order to provide optimal medical care for patients. Fractional flow reserve (FFR) is the gold standard method to determine the severity of coronary stenosis but requires an invasive medical procedure. FFR is the ratio of maximal blood flow distal to a stenotic lesion to maximal flow in the same artery if hypothetically normal. Normal FFR is 1 and an FFR < 0.8 is considered hemodynamically significant. Here, we describe a novel noninvasive method to quantify flow in arteries with stenotic coronary lesions using computational fluid dynamics (CFD). In this study, blood flow was modeled as a multiphase fluid. The mean age of red blood cells (RBCs) were computed in coronary arteries with and without stenosis; age is defined here as the time a parcel of material has resided in the system from a defined starting boundary, in this case an arterial segment. The accumulation and hold-up of RBCs due to coronary stenosis cause an increase in mean age. Our study indicated that with increasing severity of coronary artery stenosis, there is a significant increase in RBCs mean age; importantly, the RBCs mean age can be more sensitive than FFR as the current gold standard for stenosis quantification. When applied to clinical practice, this could potentially allow practicing cardiologists to accurately quantify the severity of coronary stenosis without resorting to invasive catheter-based techniques.

Keywords: Blood Flow Modeling; Mean Age; Multiphase Modeling; Computational Fluid Dynamics.