Helical Flow in Healthy and Diseased Patient-specific Coronary Bifurcations

Area of Science:

• Cardiovascular hemodynamics
• Biomedical engineering
• Medical imaging analysis

Background:

• Helical flow (HF) is observed in healthy and diseased coronary bifurcations.
• HF has demonstrated a protective effect against atherosclerosis in other blood vessels.
• The specific role of HF in patient-specific human coronary arteries requires further investigation.

Purpose of the Study:

• To investigate the role and impact of helical flow (HF) in both healthy and diseased patient-specific human coronary artery bifurcations.
• To explore the relationship between HF intensity, distribution, and hemodynamic factors like time-averaged wall shear stress (TAWSS).

Main Methods:

• Computational fluid dynamics (CFD) simulations were performed on 16 patient-specific coronary artery bifurcations.
• Eight models represented healthy arteries, and eight represented diseased arteries with idealized narrowing.
• Analysis focused on HF patterns and TAWSS distribution within these models.

Main Results:

• Higher HF intensity generally correlated with a reduced percentage of vessel area exposed to adverse TAWSS in both healthy and diseased models.
• HF intensity and distribution varied significantly based on the complex geometry of patient-specific models.
• The presence of coronary artery disease notably impacted downstream HF patterns and TAWSS distributions.

Conclusions:

• Helical flow (HF) may play a protective role in coronary arteries by mitigating adverse hemodynamic conditions.
• HF patterns and their relationship with TAWSS are significantly influenced by the geometry of coronary bifurcations and the presence of disease.
• Understanding HF and its hemodynamic interplay could lead to HF being used as a more accurate in vivo predictor for atherosclerotic plaque formation and progression compared to current near-wall wall shear stress measures.