Abstract 10116: Association Between Biomechanical Stresses of Atherosclerotic Carotid Plaques and Subsequent Ischaemic Cerebrovascular Events
Background: High resolution magnetic resonance (MR) imaging has been successfuly used to assess morphology of carotid atherosclerotic plaques. It also provides excellent information about plaque geometry which can be used for their biomechanical stress assessment. Various studies have suggested that biomechanical stress profiles are different for stable and unstable plaques, however, direct evidence of the association of these stresses with subsequent cerebrovascular ischaemic events remains unexplored.
Methods: Seventy-five patients with previous history of symptomatic carotid artery disease underwent high resolution MR imaging of their carotid arteries in a 1.5 Tesla MR system. The carotid plaque characteristics such as fibrous cap (FC) rupture, presence of plaque haemorrhage (PH) etc were delineated for the index artery using standard multicontrast carotid-MR-imaging pulse sequences. Finite element analysis-based maximum critical stress analysis of the carotid plaques was performed using the plaque geometry from in vivo MR images. These patients were followed up prospectively for 2 years. The clinical end point for the study was an ischemic cerebrovascular event in the region supplied by the index carotid artery. The association of the time to a cerebrovascular event with MRI-ascertained carotid artery characteristics and biomechanical stresses was analyzed.
Results: During a median follow-up duration of 457 days, 37% of patients (n=28) experienced an ischaemic event in the territory of the index carotid artery. Cox regression analysis indicated that FC disruption [p=0.01], presence of PH [p=0.009] and M-CStressPL [p=0.02] were associated with the development of subsequent cerebrovascular events.
Conclusions: Biomechanical structural stresses, FC rupture and PH have association with subsequent cerebrovascular events, in previously symptomatic patients with carotid artery disease. High resolution carotid MR imaging can identify these features of vulnerable plaques and can be used for risk stratification of such patients.
- © 2010 by American Heart Association, Inc.