Fluid-structure interaction analysis of a patient-specific right coronary artery with physiological velocity and pressure waveforms

Coupled fluid-structure interaction (FSI) analysis of the human right coronary artery (RCA) has been carried out to investigate the effects of wall compliance on coronary hemodynamics. A 3-D model of a stenosed RCA was reconstructed based on multislice computerized tomography images. A velocity waveform in the proximal RCA and a pressure waveform in the distal RCA of a patient with a severe stenosis were acquired with a catheter delivered wire probe and applied as boundary conditions. The arterial wall was modeled as a Mooney-Rivlin hyperelastic material. The predicted maximum wall displacement (3.85mm) was comparable with the vessel diameter (∼4mm), but the diameter variation was much smaller, 0.134 mm at the stenosis and 0.486mm in the distal region. Comparison of the computational results between the FSI and rigid-wall models showed that the instantaneous wall shear stress (WSS) distributions were affected by diameter variation in the arterial wall; increasing systolic blood pressure dilated the vessel and consequently lowered WSS, whereas the opposite occurred when pressure started to decrease. However, the effects of wall compliance on time-averaged WSS (TAWSS) and oscillatory shear 2.7% respectively). index (OSI) were insignificant (4.5 and difference in maximum TAWSS and OSI,