Abstract 11845: Proximal Culprit Lesions of Acute Coronary Syndromes are Characterized by High-Risk Morphological Characteristics by Optical Coherence Tomography
Purpose: Ex vivo studies have shown clustering of plaques with high-risk morphology in the proximal segments of the coronary arteries. We investigated in patients with ACS by optical coherence tomography (OCT), whether the morphological characteristics of the culprit lesion are associated with the location of the culprit lesion.
Methods: We included 67 patients with ACS that underwent cardiac catheterization within 24 hours from symptom onset. Distance of the culprit lesion from the coronary ostium was measured with quantitative coronary angiography. OCT study was performed in all culprit lesions and plaque rupture was identified. ROC curve for prediction of plaque rupture by ostial distance was calculated and the optimal discriminating value was used to classify the lesions in two groups: proximal culprit lesions and distal culprit lesions. Differences in morphological characteristics were then assessed between the groups.
Results: ROC analysis revealed that distance from ostium has good ability in classifying patients into patients with rupture and patients without rupture (AUC=0.719, p<0.01; optimal discriminating value 30.54mm, sensitivity=71.1%, specificity=68.2%). Consequently, the 38 culprit lesions located within 30mm from the ostium were defined as proximal and the remaining 29 culprit lesions were defined as distal. Proximal culprit lesions had greater incidence of rupture (81.6% vs. 48.3%, p<0.05) and TCFA (78.9% vs. 51.7%, p<0.05), and had lower minimal cap thickness (52±26 μ m vs. 64±26 μ m, p<0.05) than distal culprit lesions. No significant differences were found in the lipid content (p=0.27), or in the incidence of thrombus (p=0.19) or calcification (p=0.80). Proximal culprit lesions had greater distal reference lumen area (9.51±3.74mm2 vs. 7.89±2.71mm2, p=0.05) and a trend towards greater minimal lumen area (2.03±1.65mm2 vs.1.50±1.14mm2, p=0.13), but no differences were detected in the degree of area stenosis by OCT (77.3±15.9% vs. 79.7±14.4%, p=0.53).
Conclusions: Culprit lesions of ACS associated with plaque rupture are located more proximally than non-ruptured culprit lesions. Furthermore, proximal culprit lesions seem to be associated with more complex plaque morphology than distal culprit lesions.
- © 2011 by American Heart Association, Inc.