Abstract 19181: Assessment of the Progression of Coronary Atherosclerosis at Bifurcations With Intravascular Ultrasound Virtual Histology and Optical Coherence Tomography
Objectives: To evaluate the progression of plaques at bifurcations, with intravascular ultrasound virtual histology (IVUS-VH) and optical coherence tomography (OCT).
Background: Pathological findings revealed that plaques characterized by a large pool of necrotic core with an overlying fibrous cap < 65 μm are more prone to rupture.
Methods: We performed IVUS-VH and OCT at baseline and 6 months follow-up, in 56 bifurcations from 24 patients admitted for stable, unstable angina. All the patients were treated with standard of care. For each bifurcation, the distal rim of the ostium of the side branch, the in-bifurcation segment and the distal rim frames were analyzed. Plaques were classified according to compositional analysis by IVUS-VH and fibrous cap thickness by OCT. These plaque types are reported as follows: per location within the bifurcation and per bifurcation, defined as the worst plaque type detected among the three frames considered
Results: At baseline, 27 NC rich plaques were found (6 were TCFAs). At follow-up two fibroatheromas (FA) plaques became fibrotic and fibrocalcific (regressed), and a TCFA became FA (regressed); 2 FAs became TCFAs (progressed) and 22 did not changed; 4 new NC rich lesions developed from fibrotic and fibrocalcific plaques. Most (83%) thin capped lesions did not change at six month follow-up. At both time points, % NC content was larger at proximal segment as compared to distal. From baseline to follow-up, there were no significant changes in %NC at distal (p = 0.261), in-bifurcation (p = 0.199) and at proximal rim (p = 0.280). Also at both time points, the fibrous cap was thinner at the proximal rim compared to the distal rim. And from baseline to follow-up, there were no significant changes in fibrous cap thickness in the three locations. At 6 months, there were no major cardiovascular events.
Conclusion: At six months follow-up, in a population treated with standard of care, most necrotic core rich plaques remained without significant changes. These imaging observations at bifurcations reflect the clinical stability (i.e. absence of clinical events) observed in this population.
- © 2010 by American Heart Association, Inc.