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.

Carotid plaque morphology-An indicator for brain infarcts

Cerebrovascular adverse events are one of the most common causes for morbidity and mortality worldwide. Thromboembolism being the culprit behind a significant number of such events. An attempt has been made to ascertain the association of carotid plaque morphology in the occurrence of ischemic stroke. Heterogeneous plaques (Type 2 & 3) weremostly observed to be ipsilateral to the side of brain infarct, as compared to the contralateral side. Detection of heterogeneous plaques and plaque ulceration in patients may indicate future development of stroke. This study included 75 consecutive patients having anterior circulation infarct in MRI of the brain and atherosclerotic changes in extra cranial carotid system on Carotid Duplex scan. Plaque morphology ipsilateral to the brain infarct was compared to that on the contralateral side. Significantly higher number of heterogeneous plaques (Type 2 & 3) were present ipsilateral to the side of brain infarct, as compared to the contralateral side (p-value 0.004). Plaque ulceration was also observed to be present more frequently on the side of infarct (22.6% on the ipsilateral side and 5.4% on the contralateral side). Moreover, Diabetes mellitus and dyslipidemia were the most prevalent risk factors (78.2% and 65.2%, respectively) in patients with these types of plaques. Detection of heterogeneous plaques and plaque ulceration in patients may indicate future development of stroke, necessitating prompt and appropriate management protocols.Periodic screening of such patients with Carotid Duplex Ultrasonography is expected to be very helpful.

Smoking, ulcerated coronary plaques, and smoker’s paradox: A new hypothesis

Smoking accelerates the onset of acute coronary disease. Smoker’s paradox is the term applied to the observations that the short-term prognosis following an acute myocardial infarction is better in the smoker than in the nonsmoker. Efforts to explain these surprising observations have not been successful. The approach used in this study was to compare the pathologic findings in the coronary arteries following a complete histologic examination of the major branches of the epicardial coronary tree in smokers and nonsmokers. I found many ulcerated plaques in both smokers and nonsmokers, often without associated luminal stenosis or luminal thrombosis. These ulcerated plaques were discovered only on histologic examination and were consistently associated with dense foci of adventitial inflammatory cells. Based on these findings, the following hypothesis is proposed: Smoking injures the coronary artery endothelium, causing erosions, ulcerations, and a chronic inflammatory response in the arterial adventitia. These ulcerated plaques persist as chronically active, open ulcerations, constantly exposed to flowing blood, leading to increasing luminal stenosis as long as smoking continues. These ulcerated plaques eventually form the substrate for occlusive thrombosis and acute coronary events and are components of active, progressive, inflammatory, atherosclerotic disease. Premature acute coronary disease in the young smoker is due to accelerated plaque ulceration, luminal stenosis, and occlusive thrombosis. Smoker’s paradox can be explained by rapid resolution and healing of these potentially unstable ulcerated plaques when the patient is required to stop smoking during hospitalization for the acute myocardial infarction event.

Contrast-enhanced carotid ultrasound: current status

Unstable atherosclerotic plaques (ASP) are the cause of acute ischemia in the carotid and coronary systems. Numerous studies have shown a relationship between plaque instability, manifestations, echogenicity, histological findings and its neovascularization. The presence and extent of ASP neovascularization in the carotid arteries can be detected for the first time using contrast-enhanced carotid ultrasound. Contrast-enhanced carotid ultrasound does not have nephrotoxic effect; it also improves the accuracy of plaque ulceration detecting and determining the severity of stenosis. The article presents the opinions of the authors and international experts on contrast ultrasound of peripheral arteries. An analysis of the literature data and our own observations is presented. Significant parameters such as the doses, procedure onset time and duration, methods for the qualitative and quantitative assessment of plaque neovascularization are analyzed. The difficulties of contrast-enhanced ultrasound are described.

102Diagnosis of coronary plaque rupture, plaque erosion, and calcified nodule by using near-infrared spectroscopy intravascular ultrasound

Objectives This study sought to investigate the ability of near-infrared spectroscopy intravascular ultrasound (NIRS-IVUS) to differentiate among plaque rupture (PR), plaque erosion (PE), and calcified nodule (CN) in acute myocardial infarction (AMI) using an optical coherence tomography (OCT) diagnosis as a reference standard. Background In vivo, precise differentiation among PR, PE and CN is a major challenge for intravascular imaging. Methods The study enrolled 156 AMI patients who had a de novo culprit lesion in a native coronary artery. The culprit lesions were assessed by both NIRS-IVUS and OCT. Results OCT identified 112 PR, 29 PE, and 15 CN. IVUS-detected plaque ulceration showed a high specificity (100%) to identify OCT-PR although the sensitivity (62%) was intermediate. IVUS-detected convex calcium showed a high sensitivity (93%) and specificity (100%) to identify OCT-CN. In NIRS, the maximum lipid core burden index in 4 mm (maxLCBI4mm) was greatest in OCT-PR (values are median [interquartile range]) (671 [530 to 853]), followed by OCT-CN (355 [303 to 432]) and OCT-PE (283 [89 to 357]) (p<0.001). MaxLCBI4mm of <422 was the best cut-off to discriminate OCT-PE from OCT-PR and OCT-CN. The NIRS-IVUS classification algorithm using plaque ulceration, convex calcium, and maxLCBI4mm <422 showed a sensitivity and specificity of 96% and 95% for identifying OCT-PR, 93% and 95% for OCT-PE, and 93% and 100% for OCT-CN, respectively. NIRS-IVUS classification algorism Conclusion Lipid component assessed by NIRS-IVUS was different among OCT-PR, OCT-PE and OCT-CN. The NIRS-IVUS classification algorism was highly sensitive and specific for differentiating these unstable lesion types in AMI. Acknowledgement/Funding None

Carotid stenting with proximal cerebral protection in symptomatic low-grade vulnerable recurrent carotid stenosis

Background: Although the management of carotid disease is well established for symptomatic lesions ⩾70%, carotid revascularization for symptomatic low-grade (⩽50%) stenosis is not actually supported by data from randomized clinical trials. Such patients may occasionally have recurrent neurological symptoms despite optimal medical treatment owing to vulnerable plaques. In such cases, carotid artery stenting (CAS) may represent an option for treatment but this has not been tested in clinical trials. This study analyzed early and long-term outcomes of CAS performed in patients with low-grade symptomatic recurrent carotid stenosis. Methods: From a prospective registry of 322 carotid revascularization in symptomatic patients, 21 consecutive patients with low-grade symptomatic recurrent carotid stenosis who underwent CAS with proximal cerebral protection device Mo.Ma, after ruling out any other source of cerebral embolization, were involved in the study. All patients had suggestive evidence of unstable plaque or plaque ulceration. Results: Procedural technical success rate was 100%. No 30-day stroke or death occurred, and no patients had recurrent neurological events related to the revascularized hemisphere during follow up. No 30-day local complications were reported. No late carotid occlusions were detected. There was one late death, and no stroke-related deaths. Survival rates were 100% at 1 year and 96% at 3 years. Conclusions: This study shows that CAS is a well-tolerated, effective and durable treatment for patients with recurrent symptomatic low-grade carotid stenosis associated with a vulnerable plaque. Patients had excellent protection against further ischemic events and survived long enough.