The Role of Anatomical Factors, Plaque Morphology, and Confounders on the Assessment of Coronary Haemodynamics and Clinical Outcomes: A Multi-modal Analysis

Abstract

Aim: To establish the role of anatomical factors, plaque morphology, and confounding factors on assessing coronary haemodynamics and clinical outcomes, using a variety of imaging and haemodynamic modalities.

Methods:

Coronary geometry and plaque morphology were assessed using multiple imaging modalities. Coronary artery haemodynamics were measured using invasive coronary physiology modalities. To further clarify the impact of coronary geometry on haemodynamics, a computational fluid dynamic (CFD) study was performed. Confounding factors of invasive coronary physiology and the impact of these confounders on clinical outcomes were evaluated in this thesis.

Results:

- Plaque morphology does not independently impact coronary artery haemodynamics, beyond its contribution to overall plaque burden.

- Eccentric coronary lesions (particularly cross-sectional eccentricity) are more likely to result in a haemodynamically significant FFR and are associated with increased helical flow intensity.

- Factors associated with an iFR positive, FFR negative (iFR+FFR-) pattern of discordant physiology include low CFR and a greater distal reference vessel area.

- Diabetes is associated with positive FFR and iFR and is an independent predictor of target lesion failure (TLF) following deferred revascularisation based on negative FFR.

- FFR is more likely to be positive in the Left Anterior Descending artery (LAD) than the Right Coronary Artery (RCA) or Circumflex (Cx) artery, although this does not translate into significant differences in TLF between the three major epicardial territories.

- Complex plaque geometries including surface roughness and plaque eccentricity are associated with increased oscillatory and helical flow. The presence of plaque and stenoses are associated with disturbed coronary flow patterns that are key predisposing factors in plaque transformation and plaque rupture.