(87f) Non-Invasive Detection and Assessment of Coronary Stenosis Using Mean Age of Blood Flow
We developed a new method and metric to non-invasively detect and assess coronary stenosis (blocked arteries) based on mean age of blood flow through diseased arterial segments. The mean age of blood was first computed using CFD in model coronary arteries with varying degrees of stenosis and then in 100 patients who underwent the invasive FFR procedure accepted as the gold standard of clinical diagnosis. The CFD model was validated by predicting mean age within 1.3% of the nominal mean flow time (volume divided by flow rate) in normal arteries. A dimensionless form of the age metric accounts for differences in segment volume and flow rate, and is indicative of the increase in age as compared to the nominal age for a given arterial segment. Blood age in diseased arteries increased as much as 60% relative to the expected nominal mean age, and the increase is due to flow characteristics as blood exits the constricted area, specifically small regions of recirculatory flow just past the stenosis. Acceleration and deceleration of blood due to the pulsing flow contributes to holdup in this region. Our blood age metric correlated strongly with the invasive FFR metric, withAUC, specificity, sensitivity all greater than 90%. More importantly, our metric agreed with the decision of the invasive FFR metric on whether or not to intervene with a stent in 98/100 cases. When applied to clinical practice, this could potentially allow practicing cardiologists to accurately assess and quantify the severity of coronary stenosis without resorting to invasive catheter-based techniques.