Factors associated with the elasticity of asymptomatic carotid plaques in hypertension Tibetan population

Aims Hypertension is a major risk factor for coronary, cerebrovascular, and the greatest cause of stroke. Half of stroke events are the result of cerebrovascular atherosclerosis, including carotid plaques. It is of major importance to detect which plaques are vulnerable, even though not yet ruptured. Due to the particularity of the Tibetan population, this study evaluated the elasticity of asymptomatic carotid plaques in Tibetan hypertension patients using shear wave elastography (SWE) and explored associated risk factors. Methods A total of 91 Tibetan patients were divided into normotension, grade 1-2, and grade 3 hypertension groups based on the level of blood pressure. All subjects underwent common duplex ultrasonic examination and SWE evaluation for carotid plaques. Elasticity of carotid plaque was assessed by Young’s modulus. Results The final analysis included 126 plaques as representative plaques according to Total Plaque Risk Score. The mean and maximum Young’s modulus in the grade 3 hypertension group were smaller, and more plaques with irregularity surface compared with the other two groups ( p < 0.05). Multivariate regression analysis showed drinking butter tea (β = −0.220, p = 0.009; β = −0.240, p = 0.004, respectively) was the independent factor associated with mean and maximum Young’s modulus. Conclusions SWE is feasible for measurement of Young’s modulus of carotid plaques. Plaques in the grade 3 hypertension group were more likely to become vulnerable ones. In hypertension Tibetan patients, drinking butter tea was an independent factor associated with mean and maximum Young’s modulus of asymptomatic carotid plaque.

531 Neuroimaging assessment of unilateral asymptomatic carotid artery stenosis: preliminary results of the carotid artery multi-modality imaging prognostic (camp) study

Aims Doppler ultrasound (DUS), CT angiography (CTA), and contrast-enhanced MR angiography (CEMRA) are all recommended techniques to evaluate the significance of carotid artery stenosis, although they may give discordant results. Plaque ulcerations may be present, but their role is still controversial. We aimed at assessing the concordance and level of agreement, as well as the prevalence of characteristics related to plaque ulceration and association to patients’ characteristics among different imaging diagnostic techniques. Methods and results Sixty-one patients with unilateral asymptomatic carotid artery stenosis (40–60% detected by DUS), enrolled in the ongoing CAMP study were prospectively evaluated with CEMRA and CTA. The level of agreement was calculated by the weighed kappa test. Plaque ulceration was defined as an intimal defect larger than 1 mm in width or 2 mm in depth, detected by CTA and/or CEMRA. Concordance rate was 71% for DUS–CTA, 51% for DUS–CEMRA, and 66% for CTA–CEMRA. Concordance among all noninvasive techniques was only 45%. Compared with DUS, the stenosis was downgraded by CTA in 17% and by CEMRA in 32% of cases. There was a moderate agreement between DUS–CTA {weighed kappa 0.49 [95% confidence interval (CI): 0.31–0.67]}, while agreement between DUS–CEMRA and CTA–CEMRA was fair [weighed kappa 0.15 (95% CI: −0.01–0.31) and 0.38 (95% CI: 0.14–0.62), respectively]. An ulcerated plaque was present in 39% of patients at CTA and/or CEMRA; compared with patients with non-ulcerated plaques, those with an ulcerated plaque had higher levels of C-reactive protein (CRP), and a trend to higher levels of high sensitivity cardiac troponin (cTn) T (Table), whereas the degree of stenosis was similar. Conclusions CTA and CEMRA tend to report a lower degree of stenosis compared with DUS. Concordance and level of agreement was higher for DUS and CTA. Plaque ulceration is common and is associated with a significant higher level of systemic inflammation, as detected by CRP and, possibly, cTn.