Physician Approaches to Imaging and Revascularization for Acutely Symptomatic Carotid Stenosis: Insights from the Hot Carotid Qualitative Study

Background Evidence informing the choice between carotid endarterectomy and carotid artery stenting for acutely symptomatic carotid stenosis (“hot carotid”) is dated and does not factor in contemporary therapies or techniques. The optimal imaging modality is also uncertain. We explored the attitudes of stroke physicians regarding imaging and revascularization of patients with acute symptomatic carotid stenosis. Methods We used a qualitative descriptive methodology to examine decision‐making approaches and opinions of physicians regarding the choice of imaging and revascularization procedures for hot carotids. We conducted semistructured interviews with purposive sampling of 22 stroke physicians from 16 centers in 6 world regions and various specialties: 11 neurologists, 3 geriatricians, 5 interventional neuroradiologists, and 3 neurovascular surgeons. Results Qualitative analysis revealed several themes regarding clinical decision‐making for hot carotids. Whereas CT angiography was favored by most participants, timely imaging availability, breadth of information gained, and surgeon/interventionalist preferences were important themes influencing the choice of imaging modality. Carotid endarterectomy was generally favored over carotid artery stenting, but participants’ choice of intervention was influenced by healthcare system factors such as use of multidisciplinary vascular teams and operating room or angiography suite availability, and patient factors like age and infarct size. Areas of uncertainty included choice of imaging modality for borderline stenosis, utility of carotid plaque imaging, timing of revascularization, and the role of intervention with borderline stenosis or intraluminal thrombus. Conclusions This qualitative study highlights practice patterns common in different centers around the world, such as the general preference for CT angiography imaging and carotid endarterectomy over carotid artery stenting but also identified important differences in availability, selection, and timing of imaging and revascularization options. To gain widespread support, future carotid trials will need to accommodate identified variations in practice patterns and address areas of uncertainty, such as optimal timing of revascularization with modern best medical management and risk‐stratification with imaging features other than just degree of stenosis.

Periprocedural complications and risk factors after carotid stenting in patients with concomitant coronary artery disease

Backgrounds and purpose: To analyse the periprocedural CAS complications in patients with concomitant coronary disease. Material and methods: A prospective study analysed the frequency and characteristics of periprocedural complications after CAS in 329 patients, of whom 62.2% had symptomatic carotid stenosis > 50% and 37.8% had asymptomatic > 70%. The mean age was 70.2 (45-88) years, male/female ratio – 253/76. The degree of carotid stenosis was assessed angiographically according to NASCET criteria and was stratified by a newly proposed carotid score in three risk groups. Distal embolic protection was used in all patients. Results: Periprocedural complications were observed in 25/349 CAS interventions: TIA – 4.9%, major stroke – 0.6%, minor stroke – 1.4%, hyperperfusion syndrome – 0.3%. No MI and death were registered. Out of more than 20 factors analysed, previous MI (χ2 = 7,707; p = 0.021) and stroke (χ2 = 9,835, p = 0.043), “slow flow” (χ2 = 3.752; p = 0.001), residual stenosis> 20% (χ2 = 13.752; p = 0.001), radiation time (F = 13.323; p = 0.000), the amount of contrast used (F = 5.297; p = 0.006), contrast- induced OBN (χ2 = 25.845; p = 0.000), females with CKD (χ2 = 8.681; p = 0.013) or with a high carotid score (χ2 = 7.329; p = 0.026) were found to be predictors of complications. Conclusion: CAS is a safe procedure with low risk of MI and death in patients with concomitant coronary disease.

Association Between 18-FDG Positron Emission Tomography and MRI Biomarkers of Plaque Vulnerability in Patients With Symptomatic Carotid Stenosis

Purpose: Pathologic studies suggest that unstable plaque morphology and inflammation are associated with cerebrovascular events. 18F-fluorodeoxyglucose positron emission tomography (18FDG-PET) is a validated technique for non-invasive imaging of inflammation-related plaque metabolism, and MRI can identify morphologic features of plaque instability. The aim of this study was to investigate the association of selected imaging characteristics of plaque vulnerability measured with MRI and PET in patients with symptomatic carotid stenosis.Methods: Patients from the BIOVASC study were selected based on the following inclusion criteria: (1) age ≥ 50 years; (2) recent (<30 days) ischaemic stroke (modified Rankin scale ≤3) or motor/speech/vision TIA; (3) ipsilateral internal carotid artery stenosis (≥5 0% lumen-narrowing); (4) carotid PET/CTA and MRI completed. Semi-automated plaque analysis of MRI images was performed to quantify morphologic features of plaque instability. PET images were co-registered with CTA and inflammation-related metabolism expressed as maximum standardised uptake value (SUVmax).Results: Twenty-five patients met inclusion criteria (72% men, mean age 65 years). MRI-measured plaque volume was greater in men (1,708–1,286 mm3, p = 0.03), patients who qualified with stroke (1,856–1,440 mm3, p = 0.05), and non-statin users (1,325–1,797 mm3, p = 0.03). SUVmax was associated with MRI-measured plaque lipid-rich necrotic core (LRNC) in the corresponding axial slice (rs = 0.64, p < 0.001) and was inversely associated with whole-plaque fibrous cap thickness (rs = −0.4, p = 0.02) and calcium volume (rs = −0.4, p = 0.03).Conclusion: This study demonstrated novel correlations of non-invasive imaging biomarkers of inflammation-related plaque metabolism with morphological MRI markers of plaque instability. If replicated, our findings may support the application of combined MRI and PET to detect vulnerable plaque in future clinical practise and randomised trials.

Risk factors and frequency of postprocedural hemodynamic instability after carotid artery stent placement

The frequency, risk factors and long term consequences of reflexive postprocedural hypotension (PH) following carotid artery stenting (CAS) are not well known. Prospective analysis of 30 patients with 6-month follow-up undergoing CAS with an emboli-protection device was performed. A validated 24-hour ABPM was taken 24 hours before and after CAS. PH was defined as systolic blood pressure (SBP) <90mm Hg, or decrease in mean arterial BP (MAP) of ≥20% or systolic BP (SBP) of ≥30 mm Hg of baseline BP reading. Neurological assessments were performed 24 hours after CAS and at 6 month follow-up visit. Median age was 69 years, 70% were male, 86% of patients had symptomatic carotid stenosis. Twenty patients (67%) experienced PH, 43% had transient bradycardia, 30% had both PH and bradycardia. The cumulated postprocedural mean SBP and DBP decreased from baseline 128/67 mm Hg to 108/54 mm Hg (p <0.01), mean day (69/min) and night HR (58/min) decreased to respectively 58/min and 49/min (p <0.01). We found no association of PH with age, ischemic heart disease, bifurcation involvement, balloon size, inflation pressure, longer lesion length. Patients with PH significantly (p <0.05) less often were treated with Ca-antagonist (25% vs 70%), more often had ipsilateral ulcerated plaque (85% vs 50%) and had hemodynamically significant stenosis of contralateral ICA (60% vs 30%). During 6 month follow-up only 1 case of neurological deterioration was noticed. PH was a common phenomenon after CAS, however it did not result in neurological complications. Patients at risk can be possibly identified through clinical and angiographic variables.

Circulating microRNAs in Symptomatic and Asymptomatic Carotid Stenosis

Background: Specific microRNAs (miRs) have been implicated in the pathophysiology of atherosclerosis and may represent interesting diagnostic and therapeutic targets in carotid stenosis. We hypothesized that the levels of specific circulating miRs are altered in patients with symptomatic carotid stenosis (sCS) in comparison to those in patients with asymptomatic carotid stenosis (aCS) planned to undergo carotid endarterectomy (CEA). We also studied whether miR levels are associated with plaque vulnerability and stability over time after CEA.Methods: Circulating levels of vascular-enriched miR-92a, miR-126, miR-143, miR-145, miR-155, miR-210, miR-221, miR-222, and miR-342-3p were determined in 21 patients with sCS and 23 patients with aCS before CEA and at a 90-day follow-up. Transcranial Doppler ultrasound for detection of microembolic signals (MES) in the ipsilateral middle cerebral artery was performed prior to CEA. Carotid plaques were histologically analyzed.Results: Mean levels of miRs were not considerably different between groups and were only marginally higher in sCS than aCS concerning miR-92a, miR-210, miR-145, and miR-143 with the best evidence concerning miR-92a. After adjustment for vascular risk factors and statin pre-treatment, the effect sizes remained essentially unchanged. At follow-up, however, these modest differences remained uncorroborated. There were no relevant associations between miR-levels and MES or histological plaque vulnerability features.Conclusions: This study does not provide evidence for strong associations between specific circulating miRs and symptomatic state in a collective of comprehensively characterized patients with carotid stenosis. Further work is needed to elucidate the role of circulating miRs as targets in advanced carotid atherosclerosis.