Functional and morphological characterization of coronary atherosclerosis

Area of Science:

• Cardiovascular Medicine
• Interventional Cardiology
• Medical Imaging

Background:

• Coronary artery hemodynamics and atherosclerotic plaque interplay is not fully understood.
• Pullback Pressure Gradient (PPG) is a novel metric for categorizing coronary artery disease (CAD) into focal or diffuse patterns.
• Understanding these patterns is crucial for effective percutaneous coronary intervention (PCI).

Purpose of the Study:

• To investigate the association between PPG and coronary atherosclerosis.
• To characterize coronary atherosclerosis using intravascular ultrasound (IVUS) in conjunction with PPG.
• To determine if PPG can predict plaque characteristics in hemodynamically significant lesions.

Main Methods:

• A pre-specified analysis of the PPG Global study (NCT04789317) was conducted.
• Stable patients with hemodynamically significant lesions (FFR ≤0.80) undergoing IVUS-guided PCI were included.
• PPG was calculated from manual FFR pullbacks, and CAD patterns were classified as focal or diffuse based on median PPG (0.62).

Main Results:

• A significant correlation (r=0.53, p<0.001) was found between PPG and plaque burden in 261 patients.
• Focal CAD (high PPG) showed higher plaque burden (83±6%) than diffuse CAD (76±8%, p<0.001).
• Attenuated plaques were more prevalent with high PPG (68% vs. 39%, p<0.001), while calcified plaques were more frequent with low PPG (60% vs. 78%, p=0.003).

Conclusions:

• High PPG in flow-limiting stenoses is associated with increased plaque burden.
• Focal disease (high PPG) is characterized by lipid-rich plaques.
• Diffuse disease (low PPG) is associated with a greater calcium burden.