Objectives The purpose of this study was to assess the prevalence and quantify the Thin- cap fibroatheroma (TCFA) and ruptured plaques in patients with coronary artery disease using optical coherence tomography (OCT).
Background TCFA lesions are the most prevalent precursor of plaque rupture, and responsible for acute coronary syndromes. There is limited data regarding the frequency and distribution of TCFA in diseased coronary arteries.
Methods Coronary artery OCT was performed in 78 vessels in (47 patients), with stable angina (SA) or acute coronary syndrome (ACS). OCT plaque characteristics were derived using previously validated criteria. TCFA was defined as lipid rich (two or more quadrants) with thin fibrous cap (<65 μm).Comparison was performed between stable and unstable, and culprit and non culprit vessels.
Results There was a higher incidence of TCFA and plaque rupture (65% vs 24%, p=0.003, and 40% vs 15%, p=0.04) in ACS patients. This was reflected in higher lipid pool (2.66 vs 2.26 quadrants, p=0.04) and minimum fibrous cap thickness (52 μm vs 74 μm, p=0.001) in ACS patients. The mean numbers of TCFA (2.5) were similar in patients with SA and ACS. However, the maximal length of TCFA (2.63 mm vs 5.54 mm, p=0.026), and plaque rupture sites (p=0.046) were higher in ACS vessels. No relation ship was found between baseline characteristics and TCFA incidences and plaque rupture. We identified ACS (p=0.002), higher mean lipid pool (p=0.002), longer TCFA length (p=0.007), and higher number TCFA (p=0.02) as predictors of plaque rupture sites.
Conclusions In this in vivo study, we identified higher incidences of longer length TCFAs and plaque rupture sites associated with ACS.
- optical coherence tomography
- thin cap fibroatheroma
- plaque rupture