Identifying When Steady-State Flow Simulations In Patient-Specific Coronaries Recapitulate Pulsatile Flow Dynamics.

Area of Science:

• Cardiovascular Research
• Biomedical Engineering
• Computational Medicine

Background:

• Computational models offer non-invasive monitoring of coronary artery disease (CAD) biomarkers, complementing traditional invasive methods.
• High computational cost of precise in silico models, particularly those using pulsatile flow dynamics, limits widespread clinical adoption.
• Pulsatile flow simulations in computational fluid dynamics (CFD) are vital for capturing dynamic hemodynamic changes but are computationally intensive.

Purpose of the Study:

• To evaluate the necessity of complex pulsatile CFD models versus simpler steady-state models for capturing hemodynamic metrics in CAD.
• To determine if steady-state simulations can accurately represent patient-specific hemodynamic profiles at critical clinical time points.
• To assess the computational efficiency and accuracy trade-offs between steady-state and pulsatile flow simulations in stenosed coronary arteries.

Main Methods:

• Comparison of steady-state and pulsatile CFD simulations in 12 patients with stenosed coronary arteries.
• Analysis of hemodynamic metrics including fractional flow reserve (FFR), velocity, vorticity, and wall shear stress.
• Evaluation of metric comparability and distribution between simulation types across the cardiac cycle.

Main Results:

• Steady-state and pulsatile simulations showed comparable magnitudes and distributions of hemodynamic metrics, especially during diastole.
• The choice of inlet waveform had minimal influence on the comparability of results between simulation types.
• Steady-state simulations demonstrated sufficient accuracy for metrics like FFR while significantly reducing computational cost.

Conclusions:

• Steady-state CFD simulations are adequate for accurately assessing key hemodynamic metrics like FFR in CAD, particularly during diastole.
• Pulsatile simulations may be necessary for capturing complex systolic dynamics, but steady-state models offer a computationally efficient alternative for broader clinical use.
• Selective application of simplified steady-state models can facilitate CFD integration into clinical practice for managing coronary artery disease.