Fractional Flow Reserve (FFR) Estimation from OCT-Based CFD Simulations: Role of Side Branches

Area of Science:

• Cardiovascular physiology
• Medical imaging analysis
• Computational fluid dynamics

Background:

• Computational fluid dynamics (CFD) is vital for assessing arterial disease and surgical outcomes.
• Optical coherence tomography (OCT) derived artery models often omit side branches, potentially affecting hemodynamic assessments.
• Fractional flow reserve (FFR) is a critical clinical index for evaluating stenosis severity.

Purpose of the Study:

• To investigate the influence of coronary artery side branches on FFR estimation.
• To determine the impact of side branch diameter and location on FFR values.
• To provide guidance on incorporating side branches into hemodynamic assessments.

Main Methods:

• Utilized CFD simulations with idealized and OCT-reconstructed coronary artery models.
• Employed an electrical analogy of blood flow to analyze side branch effects.
• Examined the influence of side branch diameter and location relative to stenosis.

Main Results:

• Side branches reduce overall vessel tree resistance, increasing inlet flow.
• Downstream side branches significantly lower FFR values.
• Upstream side branches have a minimal effect on FFR.
• Side branches exceeding one-third of the main vessel diameter warrant inclusion in FFR calculations.

Conclusions:

• Side branch inclusion is essential for accurate FFR estimation, particularly for larger branches.
• The location of side branches relative to stenosis critically influences FFR.
• Findings can enhance treatment planning and be applied to other imaging modalities.