Abstract 14374: Characteristics of Plaque Disruption by IVUS in Women Presenting with MI without Obstructive CAD
Background: In a prospective study, we recently demonstrated plaque disruption (PD; rupture and ulceration) in 38% of women with MI without angiographically obstructive CAD. Baseline clinical characteristics did not correlate with the presence of PD. Detailed intravascular ultrasound (IVUS) characteristics have not been described in this population.
Methods: Gray-scale IVUS was performed by protocol in the artery thought most likely to be the culprit based on clinical and angiographic findings and one other artery (n=42 patients prospectively enrolled; 114 vessels including left main). Qualitative and quantitative analysis was performed by a blinded core laboratory. Plaque burden, plaque area, lumen area stenosis, eccentricity, and remodeling index were calculated at the site of disrupted plaque and worst plaque in each artery.
Results (Table): Among 16 patients, there were 14 plaque ruptures and 5 plaque ulcerations in a total of 18 vessels (2 patients had plaque rupture in 2 vessels; 1 patient had a distinct rupture and ulceration in the same vessel). Plaque disruption occurred in 6 fibrofatty, 10 fibrous, and 3 fibrocalcific plaques. Soft plaque was observed in no vessels with PD and 19/96 vessels without PD (p=0.03). There was no documented thrombus. Maximum plaque area, plaque burden, and area stenosis were greater in vessels with PD, but eccentricity or remodeling index were similar. PD was not located at the site of largest plaque area in any patient. Disrupted plaques had lower plaque burden and area stenosis and were less eccentric than the worst plaque in the same artery, with no difference in remodeling.
Conclusions: In women presenting with MI and without obstructive CAD, plaque disruption is common. Disruption tended to occur in arteries with more plaque, but did not occur at the location of the worst plaque in that vessel. Additional studies incorporating more advanced modalities may provide more insight into vulnerability of plaque in this population.
- © 2012 by American Heart Association, Inc.