Characterization of hemodynamics in anomalous aortic origin of coronary arteries using patient-specific modeling
Simbarashe G Chidyagwai1, Madhurima Vardhan1, Michael Kaplan2
1Department of Biomedical Engineering, Duke University, Durham, NC, United States of America.
Insights
Anomalous aortic origin of coronary arteries (AAOCA) in athletes can cause sudden cardiac death. This study found higher blood flow stress in AAOCA patients, which surgery corrected, suggesting a hemodynamic cause for ischemia.
Area of Science:
- Cardiovascular Medicine
- Biomedical Engineering
- Sports Cardiology
Background:
- Anomalous aortic origin of coronary arteries (AAOCA) is a congenital heart defect linked to sudden cardiac death (SCD) in young athletes.
- The precise mechanisms driving SCD in AAOCA, particularly during exercise, remain largely undetermined.
- Computational fluid dynamics (CFD) offers a method to explore hemodynamic alterations in pathological anatomies.
Purpose of the Study:
- To investigate the hemodynamic effects of interarterial AAOCA using patient-specific simulations.
- To assess the impact of exercise on hemodynamics in AAOCA patients.
- To evaluate the hemodynamic consequences of surgical correction (coronary unroofing) in AAOCA.
Main Methods:
- Patient-specific computational fluid dynamics (CFD) simulations were employed.
- Simulations were conducted for interarterial AAOCA at baseline and during simulated exercise.
- Hemodynamic parameters, including time-averaged wall shear stress (TAWSS) and oscillatory shear index (OSI), were analyzed pre- and post-surgery.
Main Results:
- AAOCA models demonstrated significantly higher interarterial TAWSS compared to controls.
- The oscillatory shear index (OSI) did not show significant impact in AAOCA.
- Coronary unroofing surgery effectively normalized elevated TAWSS, reducing it in the postoperative state.
Conclusions:
- Elevated TAWSS in AAOCA patients suggests a potential hemodynamic factor contributing to exercise-induced coronary ischemia.
- Surgical correction via coronary unroofing can mitigate these adverse hemodynamic conditions.
- CFD simulations provide valuable insights into the pathophysiology of AAOCA and the efficacy of surgical interventions.
Abstract:
The anomalous aortic origin of coronary arteries (AAOCA) is a congenital disease that can lead to sudden cardiac death (SCD) during strenuous physical activity. Despite AAOCA being the second leading cause of SCD among young athletes, the mechanism behind sudden cardiac death remains mostly unknown. Computational fluid dynamics provides a powerful tool for studying how pathologic anatomy can affect different hemodynamic states. The present study investigates the effect of AAOCA on patient hemodynamics. We performed patient-specific hemodynamic simulations of interarterial AAOCA at baseline and in the exercise state using our massively parallel flow solver. Additionally, we investigate how surgical correction via coronary unroofing impacts patient blood flow. Results show that patient-specific AAOCA models exhibited higher interarterial time-averaged wall shear stress (TAWSS) values compared to the control patients. The oscillatory shear index had no impact on AAOCA. Finally, the coronary unroofing procedure normalized the elevated TAWSS by decreasing TAWSS in the postoperative patient. The present study provides a proof of concept for the potential hemodynamic factors underlying coronary ischemia in AAOCA during exercise state.
