Background and purpose: Previous studies have reported that carotid atherosclerosis frequently can be seen in coronary artery disease (CAD) patients. This study sought to determine the prevalence of compositional features in subclinical carotid atherosclerosis by MRI in CAD patients.
Methods: Ninety-six subjects with suspected CAD but free of neurological symptoms underwent coronary CT angiography and carotid MRI including 3-dimensional time-of-flight, T1-weighted, T2-weighted, and proton density-weighted sequences at 3 T within a 2-week interval. The coronary artery calcium score (CACS) and degree of stenosis were measured. Areas for carotid lumen, wall, total vessel, and percent wall volume (wall volume/total vessel volume) were measured. The prevalence of carotid calcification, lipid-rich necrotic core, intraplaque hemorrhage, and surface disruption in coronary stenosis and CACS categories were determined.
Results: Carotid percent wall volume was correlated with CACS (P=0.001). Both coronary stenosis and CACS were significantly associated with presence of carotid calcification (OR=5.79 for 1%-49% vs 0% stenosis; OR=10.23 for >50% vs 0% stenosis; OR=10.65 for CACS 1-399 vs CACS 0; and OR=20.28 for CACS >400 vs CACS 0; all P<0.05) and lipid-rich necrotic core (OR=10.29 for 1%-49% vs 0% stenosis; OR=4.66 for >50% vs 0% stenosis; OR=8.23 for CACS 1-399 vs CACS 0; and OR=11.87 for CACS >400 vs CACS 0; all P<0.05) High prevalence of lipid-rich necrotic core was found in low-grade coronary stenosis (75.6% in 1%-49% stenosis) and CACS (73.5% in CACS 1-399).
Conclusions: Carotid plaque burden and compositional features are significantly associated with CAD severity. The finding of high prevalence of lipid-rich necrotic core in patients with low-grade coronary stenosis and CACS suggests the need for early monitoring of carotid atherosclerosis in CAD patients.