Participants in the study were patients being followed up in the Stroke Prevention Clinic or the Premature Atherosclerosis Clinic at University Hospital, London, Ontario, Canada. Participants were screened for this study by measurement of their carotid TPA. 15 WeBackground and Purpose-Carotid ultrasound evaluation of intima-media thickness (IMT) and plaque burden has been used for risk stratification and for evaluation of antiatherosclerotic therapies. Increasing evidence indicates that measuring plaque burden is superior to measuring IMT for both purposes. We compared progression/regression of IMT, total plaque area (TPA), and total plaque volume (TPV) as predictors of cardiovascular outcomes. Methods-IMT, TPA, and TPV were measured at baseline in 349 patients attending vascular prevention clinics; they had TPA of 40 to 600 mm 2 at baseline to qualify for enrollment. Participants were followed up for ≤5 years (median, 3.17 years) to ascertain vascular death, myocardial infarction, stroke, and transient ischemic attacks. Follow-up measurements 1 year later were available in 323 cases for IMT and TPA, and in 306 for TPV. Results-Progression

Conclusion:To potentially assess response to antiatherosclerotic therapy, measurement of total plaque volume is superior to both measurement of intima-media thickness (IMT) and total plaque area (TPA).Summary: Progression of IMT, TPA, and total plaque volume (TPV) have all been advocated as methods for risk prediction of cardiovascular events. In this study, the authors report a comparison of progression/ regression of carotid IMT, TPA, and TPV in patients attending vascular prevention clinics. The goal of the study was to determine which variable could be best used to assess response to antiatherosclerotic therapy. IMT, TPA, and TPV were measured at baseline in 349 patients attending vascular prevention clinics. To qualify for enrollment, a TPA of 40 to 600 mm 2 was required. Follow-up was for #5 years (median, 3.17 years). End points were vascular death, myocardial infarction, stroke, and transient ischemic attacks. Follow-up measurements at 1 year were available in 323 patients for IMT and TPA, and in 306 for TPV. Progression of TPV predicted stroke, death, or transient ischemic attack (TIA) (Kaplan-Meier log-rank P ¼ .001), stroke/death/myocardial infarction (MI) (P ¼ .008), and stroke/death/ TIA/MI (any cardiovascular event) (P ¼ .001). Progression of TPA weakly predicted stroke/death/TIA (P ¼ .097) but not stroke/death/MI (P ¼ .59) or any cardiovascular event (P ¼ .143). IMT also did not predict stroke/death/MI (P ¼ .13) or any cardiovascular event (P ¼ .455). With adjustment for coronary risk factors, TPV progression remained a significant predictor (P ¼ .001), but a change in TPA did not. Regression of IMT predicted events (P ¼ .004).Comment: The data suggest that TPV at the carotid bifurcation should be considered as the variable of choice to measure response to antiatherosclerotic therapy. Interestingly in this study, regression of IMT rather than progression predicted events. This may be consistent with the growing thought that IMT is more representative of hypertensive medial hypertrophy and is not truly representative of atherosclerosis (Finn AV et al, Arterioscler Thromb Vasc Biol 2010;30:177-81).

There is an urgent need for rapid, reliable, and cost-effective methods to monitor patients who are at high risk for adverse vascular events. Such methods may be used to target treatment to high-risk patients, thereby preventing vascular events.1 Ultrasound is a relatively inexpensive and widely available imaging method enabling quantitative imaging measurements of the carotid artery wall, including intima-media thickness, vessel wall volume, and plaque burden. It has been shown that carotid plaque burden measures, such as total plaque area or total plaque volume (TPV) and their changes over time, provide strong predictors of adverse events. Carotid ultrasound, by means of plaque echogenicity or texture, also provides a way to measure plaque composition. Lipid cores and intraplaque hemorrhage are thought to destabilize plaque, whereas calcifications have a stabilizing effect. 3,4 In ultrasound, lipid and hemorrhagic areas are more echolucent, whereas calcified and fibrous areas are echorich. 5 Ultrasound echogenicity has been shown to differentiate between symptomatic and asymptomatic subjects 6 and has been used to predict events. [7][8][9] More complex texture measures, with examples given in Table I in the online-only Data Supplement, provide information on the distribution of pixel intensities over the plaque. Incorporating such higher order texture parameters, such as coarseness or contrast, may provide more insight into the underlying tissue properties and has been used in several studies as well. [10][11][12] In previous studies, these higher order texture measures were shown to differentiate accurately between symptomatic and asymptomatic subjects 10 and performed better than a set of plaque shape parameters.11 In addition, they were more predictive of events than a combination of a history of events and plaque parameters, such as plaque area and gray scale median. 12In addition to single time-point measurements, progression of TPV was shown to be a strong predictor of events, 2 and changes in plaque texture were more sensitive to statininduced effects than changes in TPV. 13 On the basis of allBackground and Purpose-Carotid ultrasound atherosclerosis measurements, including those of the arterial wall and plaque, provide a way to monitor patients at risk of vascular events. Our objective was to examine carotid ultrasound plaque texture measurements and the change in carotid plaque texture during 1 year in patients at risk of events and to compare these with measurements of plaque volume and other risk factors as predictors of vascular events. Methods-We evaluated 298 patients with carotid atherosclerosis using 3-dimensional (3D) ultrasound at baseline and after 1 year and measured carotid plaque volume and 376 measures of plaque texture. Patients were followed up to 5 years (median [range], 3.12 [0.77-4.66]) for myocardial infarction, transient ischemic attack, and stroke. Sparse Cox regression was used to select the most predictive plaque texture measurements in independent training sets using a ...