Intraplaque hemorrhage assessed by high-resolution magnetic resonance imaging and C-reactive protein in carotid atherosclerosis
Received 15 March 2007; accepted 3 July 2007. published online 08 October 2007.
Background
Carotid intraplaque hemorrhage is a marker of atheroma instability. Noninvasive assessment of bleeding can be performed by high-resolution magnetic resonance imaging (MRI), but its association with inflammatory markers has not been clearly demonstrated.
Methods
We evaluated consecutive carotid endarterectomy patients that underwent high-resolution MRI, independent evaluation of neurologic symptoms, C-reactive protein measurement, and histologic analysis. Intraplaque hemorrhage was determined by the presence of a hyperintense MRI signal (T1-weighted sequence).
Results
The study included 70 predominantly male (66%) and hypertensive (89%) patients (89%) aged 66 ± 9 years old. MR angiography identified 15 patients (21.5%) with stenosis between 50% and 69%, 15 (21.5%) with stenosis between 70% and 90%, and 40 (57%) with stenosis >90%. High-resolution MRI depicted a hyperintense signal suggestive of intraplaque bleeding in 45 subjects (64%). All patients who had had transient ischemic attacks >90 days before the surgery showed a hyperintense signal on MRI (P = .007). Age, gender, traditional cardiovascular risk factors, and history of myocardial infarction or peripheral arterial disease were similar in patients with or without signs of intraplaque bleeding on MRI. There was excellent agreement between acute or recent hemorrhage on histologic and MRI findings (κ coefficient, 0.91; 95% confidence interval, 0.81 to 1.00). Only one of 45 patients (2%) with a hyperintense signal on MRI did not have acute or recent hemorrhage in the histologic analysis (P < .001). High-sensitivity C-reactive protein levels were similar for different degrees of carotid stenosis as assessed by MR angiography, but they were significantly higher in clinically unstable patients (P = .006) and in those with a positive hyperintense MRI signal (P = .01). In an aggregated analysis of neurologic symptoms and MRI findings, we found a progressive increase of high-sensitivity C-reactive protein levels (P = .02).
Conclusions
Intraplaque hemorrhage evaluated by MRI identified neurologically unstable patients with increased levels of high-sensitivity C-reactive protein regardless of the degree of carotid stenosis.
aDivision of Adult Cardiovascular Surgery, Cardiovascular Sciences of the Federal University of Rio Grande do Sul, Puerto Alegre, Brazil
bDivision of Pathology, Cardiovascular Sciences of the Federal University of Rio Grande do Sul, Puerto Alegre, Brazil
cDivision of Rheumatology, Cardiovascular Sciences of the Federal University of Rio Grande do Sul, Puerto Alegre, Brazil
dDivision of Neurology, Cardiovascular Sciences of the Federal University of Rio Grande do Sul, Puerto Alegre, Brazil
eCenter for Diagnostic Imaging of the Pontifical Catholic University of Rio Grande do Sul’s São Lucas Hospital, Puerto Alegre, Brazil
fCardiology Division of the Hospital de Clínicas de Porto Alegre, Puerto Alegre, Brazil.
Correspondence: Luis E. Rohde, MD, Post-graduate Program in Cardiology and Cardiovascular Sciences of the Federal University of Rio Grande do Sul, Rua Ramiro Barcelos 2350, Rm 2060, Second Floor, Porto Alegre 90035 903 Brazil.
ABSTRACT