New Patient-specific Functional Assessment of the Anomalous Aortic Origin of Coronary Arteries.

Overview

Anomalous Aortic Origin of the Coronary Arteries (AAOCA) is a rare congenital disease that may cause sudden death in young subjects. Frequently the first and only presentation is with an acute event (such as myocardial infarction or sudden cardiac deaths) during physical effort. Not only symptoms are often absent, but also provocative tests fail to induce ischemia or related signs, showing in most patients negative results. For these limitations, the decision to undergo corrective surgery is based on the morphologic characteristics without the support of a functional evaluation. The study focused on developing a personalized ischemic risk assessment with the aid of fluid dynamic simulations. The simulation system integrate clinical data from different diagnostic sources and integrate them with coronary blood flow evaluation at rest and during simulated physical effort.

Anomalous Aortic Origin of Coronary Arteries (AAOCA) is a congenital condition where one or more coronary vessels originate from an ectopic site within the aorta, such as the opposite or wrong sinus of Valsalva. Its prevalence in the general population, has been estimated between 0.03% and 0.23% depending on the variant evaluated. The anomalous left or right coronary artery, besides its origin, may take 5 different general courses: interarterial, prepulmonic, subpulmonic, retroaortic or retrocardiac. Each of these forms may be subject to cause myocardial ischemia and subsequent sudden death during physical and sport activity. In most cases, the disease is silent and does not show any symptoms before the sudden cardiac death event (SCD). Only a few AAOCA subjects report symptoms before SCD that usually occurs unexpectedly after a moderate or intense physical activity. It is extremely hard to study the causing factors in a clinical environment due to the stochastic nature of the myocardial ischemic event and the inability to reproduce the exact effort conditions. Even when a complete assessment is performed, there is no clinical exam that can reproduce sustained exercise conditions responsible for triggering ischemia and SCD. Even if such an exam would exist and provide adequate results, the risk of SCD exceeds the benefits of having a correct diagnosis. To overcome all the current diagnostic limitations the ideal diagnostic test has to investigate coronary blood supply, myocardial oxygen demand in relation to the physical activity (intensity and duration) required for triggering an ischemic event, without putting the subjects at risk. To date the only possible way to reproduce such conditions is a subject-specific virtual simulation of aortic root and coronary artery integrated with coronary blood flow simulation able to mimic pressure, flow, and oxygen demand characteristics similar to those of intense exercise, in relation to changes that anomalous coronary undergoes under such conditions.