Not all plaque ruptures are born equal: an optical coherence tomography study.

Area of Science:

• Cardiovascular Medicine
• Interventional Cardiology
• Pathophysiology of Atherosclerosis

Background:

• Plaque rupture (PR) is a primary cause of coronary thrombosis in acute coronary syndrome (ACS).
• Chronic low-grade inflammation underlies atherosclerosis, but heightened plaque inflammation may directly trigger PR.
• Optical coherence tomography (OCT) enables assessment of plaque inflammation via macrophage infiltration (MØI).

Purpose of the Study:

• To investigate the role of plaque inflammation, specifically MØI, in PR among ACS patients using OCT.
• To correlate MØI with clinical and OCT-derived plaque characteristics.

Main Methods:

• Retrospective analysis of 56 ACS patients with OCT-identified PR.
• Classification of patients into MØI positive or negative based on OCT signal characteristics.
• Measurement of serum high-sensitivity C-reactive protein (CRP) on admission.
• Multivariate analysis to identify predictors of MØI.

Main Results:

• 66% of patients exhibited MØI at the site of PR.
• MØI was associated with higher CRP levels (>3 mg/dL) (92% vs. 47%, P=0.004).
• Patients with MØI had more lipid-rich plaques (86% vs. 50%, P=0.008), multifocal disease (59% vs. 10%, P<0.001), and MØI in remote lesions (97% vs. 0%, P<0.001).
• Hypertension was more prevalent in the no-MØI group (89% vs. 59%, P=0.021).
• Elevated CRP (>3 mg/dL) was the sole independent predictor of MØI (OR 8.72, P=0.007).

Conclusions:

• PR in ACS can arise from distinct inflammatory or non-inflammatory pathways.
• Macrophage infiltration, indicated by OCT, is a significant feature of inflammatory PR.
• Elevated CRP levels are a strong indicator of MØI in culprit plaques.