Abstract 18168: Association of the Distance from the Coronary Ostium with Plaque Morphology in Patients with Acute Coronary Syndromes. An Optical Coherence Tomography Study.
Purpose: Atheromatic plaques located in proximal segments of coronary arteries are associated with increased incidence of acute thrombosis. It has been suggested that this discrepancy is due to morphological differences. We investigated by optical coherence tomography, whether specific morphological characteristics of culprit lesions (CLs) in patients with acute coronary syndromes (ACS) are associated with the location of the culprit lesion.
Methods: Sixty seven consecutive patients with ACS that underwent cardiac catheterization within 24 hours from symptom onset were enrolled. The culprit lesion was clearly identified angiographically and classified as proximal or distal depending on the distance from the coronary ostium. Optical coherence tomography study was then performed in all culprit lesions. Fibrous cap thickness (FCT) was measured at the thinnest part of the culprit lesion and presence of plaque rupture and thin cap fibroatheroma (TCFA) was recorded. A TCFA was defined as a plaque with cap thickness =<65 um.
Results: Thirty three culprit lesions were located in the distal part of coronary arteries and 34 proximally. A TCFA was identified in 62.7% of the patients, while the plaque was ruptured in 42 patients. In the group of distal culprit lesions, 48.5% had a TCFA (n=16), while in the group of proximal culprit lesions 76.5% (n=26) presented such morphology (p=0.02). Mean distance from the coronary ostium of plaques containing a TCFA was 28.0±20.5 vs 38.6±19.5 μm for plaques without a TCFA (p<0.05). A rupture was found in 82.3% of the proximal lesions (n=28) and in 42.4% (n=14) of the distal lesions (p<0.01). Ruptured plaques were located more proximally than non-ruptured plaques (distance from ostium: 26.2±19.4 vs. 41.7±19.4 μm, p<0.01).
Conclusions: Culprit lesions in proximal segments of coronary arteries are more often associated with TCFA and plaque rupture than plaques located in the distal part of coronary arteries. This study suggests that morphological discrepancies may account for the higher incidence of ACS in proximal lesions.
- © 2010 by American Heart Association, Inc.