Multinational Survey of Current Practice from Imaging to Treatment of Atherosclerotic Carotid Stenosis.

BACKGROUND: In the last 20-30 years, there have been many advances in imaging and therapeutic strategies for symptomatic and asymptomatic individuals with carotid artery stenosis. Our aim was to examine contemporary multinational practice standards. METHODS: Departmental Review Board approval for this study was obtained, and 3 authors prepared the 44 multiple choice survey questions. Endorsement was obtained by the European Society of Neuroradiology, American Society of Functional Neuroradiology, and African Academy of Neurology. A link to the online questionnaire was sent to their respective members and members of the Faculty Advocating Collaborative and Thoughtful Carotid Artery Treatments (FACTCATS). The questionnaire was open from May 16 to July 16, 2019. RESULTS: The responses from 223 respondents from 46 countries were included in the analyses including 65.9% from academic university hospitals. Neuroradiologists/radiologists comprised 68.2% of respondents, followed by neurologists (15%) and vascular surgeons (12.9%). In symptomatic patients, half (50.4%) the respondents answered that the first exam they used to evaluate carotid bifurcation was ultrasound, followed by computed tomography angiography (CTA, 41.6%) and then magnetic resonance imaging (MRI 8%). In asymptomatic patients, the first exam used to evaluate carotid bifurcation was ultrasound in 88.8% of respondents, CTA in 7%, and MRA in 4.2%. The percent stenosis upon which carotid endarterectomy or stenting was recommended was reduced in the presence of imaging evidence of "vulnerable plaque features" by 66.7% respondents for symptomatic patients and 34.2% for asymptomatic patients with a smaller subset of respondents even offering procedural intervention to patients with <50% symptomatic or asymptomatic stenosis. CONCLUSIONS: We found heterogeneity in current practices of carotid stenosis imaging and management in this worldwide survey with many respondents including vulnerable plaque imaging into their decision analysis despite the lack of proven benefit from clinical trials. This study highlights the need for new clinical trials using vulnerable plaque imaging to select high-risk patients despite maximal medical therapy who may benefit from procedural intervention.

Recent Advances in Vascular Imaging.

Recent advances in vascular imaging have enabled us to uncover the underlying mechanisms of vascular diseases both ex vivo and in vivo. In the past decade, efforts have been made to establish various methodologies for evaluation of atherosclerotic plaque progression and vascular inflammatory changes in addition to biomarkers and clinical manifestations. Several recent publications in Arteriosclerosis, Thrombosis, and Vascular Biology highlighted the essential roles of in vivo and ex vivo vascular imaging, including magnetic resonance image, computed tomography, positron emission tomography/scintigraphy, ultrasonography, intravascular ultrasound, and most recently, optical coherence tomography, all of which can be used in bench and clinical studies at relative ease. With new methods proposed in several landmark studies, these clinically available imaging modalities will be used in the near future. Moreover, future development of intravascular imaging modalities, such as optical coherence tomography-intravascular ultrasound, optical coherence tomography-near-infrared autofluorescence, polarized-sensitive optical coherence tomography, and micro-optical coherence tomography, are anticipated for better management of patients with cardiovascular disease. In this review article, we will overview recent advances in vascular imaging and ongoing works for future developments.

Multiphasic Computed Tomography Angiography Findings for Identifying Pseudo-Occlusion of the Internal Carotid Artery.

BACKGROUND AND PURPOSE: Differentiation between pseudo-occlusion and true occlusion of internal carotid artery (ICA) is important in treatment planning for acute ischemic stroke patients. We compared the findings of multiphasic computed tomography angiography between cervical ICA pseudo-occlusion and true occlusion at the cervical ICA in patients with anterior circulation acute ischemic stroke to determine their diagnostic value. METHODS: Thirty patients with nonvisualization of the proximal ICA were included. Diagnosis of pseudo- or true occlusion of the ICA was made based on digital subtraction angiography. Diagnostic performances of multiphasic computed tomography angiography findings-(1) a flame-shaped stump and (2) delayed contrast filling at the cervical ICA- were evaluated and compared. The Fisher exact test, χ2 test, or Wilcoxon rank-sum test and McNemar test were used in the data analysis. RESULTS: Twelve patients had true proximal ICA occlusion and 18 had pseudo-occlusion. Delayed contrast filling at the cervical ICA on multiphasic computed tomography angiography was found in all patients with pseudo-occlusion of the ICA, while 1 case of true occlusion showed delayed contrast filling (P<0.001). The presence of a flame-shaped stump was not significantly different between the pseudo- and true occlusion groups. The sensitivity of delayed contrast filling (0.94 [95% CI, 0.73-1]) was significantly higher than that of flame-shaped stump (0.75 [95% CI, 0.36-0.83]). CONCLUSIONS: We demonstrated that the delayed filling sign on multiphasic computed tomography angiography could be a useful and readily available finding for differentiating proximal ICA pseudo-occlusion from true occlusion.

Calculation of Prognostic Scores, Using Delayed Imaging, Outperforms Baseline Assessments in Acute Intracerebral Hemorrhage.

Background and Purpose- Patients with intracerebral hemorrhage (ICH) are often subject to rapid deterioration due to hematoma expansion. Current prognostic scores are largely based on the assessment of baseline radiographic characteristics and do not account for subsequent changes. We propose that calculation of prognostic scores using delayed imaging will have better predictive values for long-term mortality compared with baseline assessments. Methods- We analyzed prospectively collected data from the multicenter PREDICT study (Prediction of Hematoma Growth and Outcome in Patients With Intracerebral Hemorrhage Using the CT-Angiography Spot Sign). We calculated the ICH Score, Functional Outcome in Patients With Primary Intracerebral Hemorrhage (FUNC) Score, and modified ICH Score using imaging data at initial presentation and at 24 hours. The primary outcome was mortality at 90 days. We generated receiver operating characteristic curves for all 3 scores, both at baseline and at 24 hours, and assessed predictive accuracy for 90-day mortality with their respective area under the curve. Competing curves were assessed with nonparametric methods. Results- The analysis included 280 patients, with a 90-day mortality rate of 25.4%. All 3 prognostic scores calculated using 24-hour imaging were more predictive of mortality as compared with baseline: the area under the curve was 0.82 at 24 hours (95% CI, 0.76-0.87) compared with 0.78 at baseline (95% CI, 0.72-0.84) for ICH Score, 0.84 at 24 hours (95% CI, 0.79-0.89) compared with 0.76 at baseline (95% CI, 0.70-0.83) for FUNC, and 0.82 at 24 hours (95% CI, 0.76-0.88) compared with 0.74 at baseline (95% CI, 0.67-0.81) for modified ICH Score. Conclusions- Calculation of the ICH Score, FUNC Score, and modified ICH Score using 24-hour imaging demonstrated better prognostic value in predicting 90-day mortality compared with those calculated at presentation.

Cardiac Computed Tomography: Assessment of Coronary Inflammation and Other Plaque Features.

Unstable coronary plaques that are prone to erosion and rupture are the major cause of acute coronary syndromes. Our expanding understanding of the biological mechanisms of coronary atherosclerosis and rapid technological advances in the field of medical imaging has established cardiac computed tomography as a first-line diagnostic test in the assessment of suspected coronary artery disease, and as a powerful method of detecting the vulnerable plaque and patient. Cardiac computed tomography can provide a noninvasive, yet comprehensive, qualitative and quantitative assessment of coronary plaque burden, detect distinct high-risk morphological plaque features, assess the hemodynamic significance of coronary lesions and quantify the coronary inflammatory burden by tracking the effects of arterial inflammation on the composition of the adjacent perivascular fat. Furthermore, advances in machine learning, computational fluid dynamic modeling, and the development of targeted contrast agents continue to expand the capabilities of cardiac computed tomography imaging. In our Review, we discuss the current role of cardiac computed tomography in the assessment of coronary atherosclerosis, highlighting its dual function as a clinical and research tool that provides a wealth of structural and functional information, with far-reaching diagnostic and prognostic implications.

Noncontrast MR angiography: An update.

Both computed tomography (CT) angiography (CTA) and contrast-enhanced MR angiography (CEMRA) have proven to be useful and accurate cross-sectional imaging modalities over a wide range of vascular territories and vascular disorders. A key advantage of MRA is that, unlike CTA, it can be performed without the administration of a contrast agent. In this review article we consider the motivations for using noncontrast MRA, potential contrast mechanisms, imaging techniques, advantages, and drawbacks with respect to CTA and CEMRA, and the level of evidence for using the various MRA techniques. In addition, we explore new developments that promise to expand the reliability and range of clinical applications for noncontrast MRA, along with functional MRA capabilities not available with CTA or CEMRA. Level of Evidence: 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;49:355-373.

Emerging Role of Coronary Computed Tomography Angiography in Lipid-Lowering Therapy: a Bridge to Image-Guided Personalized Medicine.

PURPOSE OF REVIEW: To summarize the current status of coronary computed tomography angiography (CTA) in the assessment of coronary plaques and discuss the ability of serial coronary CTA to quantitatively measure changes in the plaque burden in response to lipid-lowering therapy. RECENT FINDINGS: Recent advances in coronary CTA have allowed identification of high-risk coronary features in acute coronary syndrome and measurement of changes in the coronary plaque burden with good reproducibility. Statin therapy may delay plaque progression and change some plaque features. However, the clinical relevance of quantitative changes in coronary plaques and the optimal methods to reduce the plaque burden remain unclear. Despite guideline-directed lipid-lowering therapy, adverse events still occur in substantial numbers of patients receiving statins. Coronary CTA is noninvasive and has high diagnostic performance in patients with coronary artery disease, making change in the plaque burden an applicable biomarker for individualized assessment of future risk.

Endovascular Iliocaval Stent Reconstruction for Iliocaval Thrombosis: A Multi-Institutional International Practice Pattern Survey.

BACKGROUND: Limited guidelines for the treatment and management of acute and chronic iliocaval thrombosis are published in the literature. The purpose of this report is to present global iliocaval stent reconstruction practices by interventionalists. METHODS: A 45-question survey focusing on iliocaval stent reconstruction evaluation was distributed through the Open Forum and Venous Disease Service Line of the Society of Interventional Radiology Connect website from June 20, 2017 until September 7, 2017 and the Cardiovascular and Interventional Radiological Society of Europe electronic newsletter on August 11, 2017. RESULTS: One hundred seven complete responses were received from interventional radiologists in the United States, 2 from South America, and 2 from Central America. 92.5% performed iliocaval reconstruction, and 79.8% performed the procedure for both acute and chronic iliocaval thrombosis. 82.8% completed a standardized physician assessment tool, and 91.9% obtained computed tomography (CT) venography before the procedure. 64.6% used intravascular ultrasound to guide reconstruction. 41.4% found blunt recanalization successful for >75% of patients. 63.6% used sharp recanalization for <25% of patients. 97.0% and 90.9% used uncovered and self-expanding stents, respectively. Wallstents were used most commonly. Most common stent diameters were 24-mm in the inferior vena cava, 14-mm in the common iliac vein, and 12-mm in the external iliac vein. 48.5% and 21.2% prescribed 2 and 3 anticoagulants after stent placement, respectively. 62.6% found iliocaval reconstruction provided symptomatic clinical improvement for iliocaval thrombosis in >75% of patients. 72.7% estimated their 1-year primary stent patency to be >75%. CONCLUSIONS: Iliocaval reconstruction is performed by many interventionalists; however, there are global inconsistencies in practices, suggesting a need for further research and guideline development.

Evidence-based Surgery of Aortic Regurgitation: Results of a Questionnaire in German-speaking Countries.

BACKGROUND: evidence-based medicine (EBM) approaches have reached broad acceptance, both in conservative and surgical disciplines. The aim of this study is to clarify the role of EBM in a rare condition of aortic regurgitation (AR) with surgical indication. METHODS: A purpose-built Internet-based questionnaire was sent to 607 cardiovascular surgeons in Germany, Austria, and Switzerland. A virtual 64-year-old patient's medical history was presented, including two ultrasound images and one computed tomography scan, showing a 58-mm aortic root aneurysm and a severe trileaflet regurgitant aortic valve. Participants had to choose their preferred therapeutic strategy from a list. Additionally, demographics including nationality, the center size, and the frequency of similar types of patients referred to their departments were collected. RESULTS: Of 607 questionnaires, 100 were returned (16%). One participant was excluded due to conflicting answers. Most surgeons (n = 84; 84%) chose a valve-sparing root replacement (VSRR). A Bentall procedure was preferred by 13 surgeons (13%). Two surgeons voted for aortic valve replacement combined with partial root resection. The decision-making process was not significantly influenced by center size, nationality, or frequency of patients. CONCLUSION: Applying the current guidelines to our virtual study patient, 84% of participants acted accordingly choosing VSRR. Remarkably, 14% of these surgeons see less than 10 and 43% see not more than 20 comparable patients per year. Since the guidelines reserve VSRR for competent centers, those numbers as well as the guidelines themselves should be further discussed.

Hybrid intravascular imaging: recent advances, technical considerations, and current applications in the study of plaque pathophysiology.

Cumulative evidence from histology-based studies demonstrate that the currently available intravascular imaging techniques have fundamental limitations that do not allow complete and detailed evaluation of plaque morphology and pathobiology, limiting the ability to accurately identify high-risk plaques. To overcome these drawbacks, new efforts are developing for data fusion methodologies and the design of hybrid, dual-probe catheters to enable accurate assessment of plaque characteristics, and reliable identification of high-risk lesions. Today several dual-probe catheters have been introduced including combined near infrared spectroscopy-intravascular ultrasound (NIRS-IVUS), that is already commercially available, IVUS-optical coherence tomography (OCT), the OCT-NIRS, the OCT-near infrared fluorescence (NIRF) molecular imaging, IVUS-NIRF, IVUS intravascular photoacoustic imaging and combined fluorescence lifetime-IVUS imaging. These multimodal approaches appear able to overcome limitations of standalone imaging and provide comprehensive visualization of plaque composition and plaque biology. The aim of this review article is to summarize the advances in hybrid intravascular imaging, discuss the technical challenges that should be addressed in order to have a use in the clinical arena, and present the evidence from their first applications aiming to highlight their potential value in the study of atherosclerosis.

Regional variation in patient selection and treatment for carotid artery disease in the Vascular Quality Initiative.

OBJECTIVE: Previous studies involving large administrative data sets have revealed regional variation in the demographics of patients selected for carotid endarterectomy (CEA) and carotid artery stenting (CAS) but lacked clinical granularity. This study aimed to evaluate regional variation in patient selection and operative technique for carotid artery revascularization using a detailed clinical registry. METHODS: All patients who underwent CEA or CAS from 2009 to 2015 were identified in the Vascular Quality Initiative (VQI). Deidentified regional groups were used to evaluate variation in patient selection, operative technique, and perioperative management. χ2 analysis was used to identify significant variation across regions. RESULTS: A total of 57,555 carotid artery revascularization procedures were identified. Of these, 49,179 patients underwent CEA (asymptomatic: median, 56%; range, 46%-69%; P < .01) and 8376 patients underwent CAS (asymptomatic: median, 36%; range, 29%-51%; P < .01). There was significant regional variation in the proportion of asymptomatic patients being treated for carotid stenosis <70% in CEA (3%-9%; P < .01) vs CAS (3%-22%; P < .01). There was also significant variation in the rates of intervention for asymptomatic patients older than 80 years (CEA, 12%-27% [P < .01]; CAS, 8%-26% [P < .01]). Preoperative computed tomography angiography or magnetic resonance angiography in the CAS cohort also varied widely (31%-83%; P < .01), as did preoperative medical management with combined aspirin and statin (CEA, 53%-77% [P < .01]; CAS, 62%-80% [P < .01]). In the CEA group, the use of shunt (36%-83%; P < .01), protamine (32%-89%; P < .01), and patch (87%-99%; P < .01) varied widely. Similarly, there was regional variation in frequency of CAS done without a protection device (1%-8%; P < .01). CONCLUSIONS: Despite clinical benchmarks aimed at guiding management of carotid disease, wide variation in clinical practice exists, including the proportion of asymptomatic patients being treated by CAS and preoperative medical management. Additional intraoperative variables, including the use of a patch and protamine during CEA and use of a protection device during CAS, displayed similar variation in spite of clear guidelines. Quality improvement projects could be directed toward improved adherence to benchmarks in these areas.

Underuse of risk assessment and overuse of computed tomography pulmonary angiography in patients with suspected pulmonary thromboembolism.

BACKGROUND: Evidence suggests the potential overuse of computed tomography pulmonary angiography (CTPA) in patients with suspected pulmonary thromboembolism (PTE) in the absence of consistent use of pre-test clinical prediction rules and D-dimer assays. AIM: To evaluate use and diagnostic utility of clinical prediction rules and D-dimer assay in patients with suspected PTE and quantify potentially avoidable overuse of CTPA in low risk patients. METHODS: A total of 344 consecutive patients undergoing CTPA at a tertiary hospital was studied with regards to the use of D-dimer assays and clinical prediction rules for PTE. For each patient, a modified Wells score (mWS), revised Geneva score and PISA model were calculated retrospectively; performance characteristics for each rule for PTE were determined with reference to results of CTPA. Results for the mWS and D-dimer assays (when performed) were used to estimate the overuse of CTPA according to risk category. RESULTS: Use of a clinical prediction rule was documented in only 5.0% of cases. Of 269 low-risk patients who had a calculated mWS ≤4, only 64 (23.8%) had a D-dimer assay performed, with 30 (11.1%) having a PTE on CTPA. Among 75 patients with an mWS >4, 23 (30.7%) had a PTE on CTPA (P < 0.001). Compared to other prediction rules, an mWS>4 had the highest positive predictive value (31.0%) for PTE; all rules demonstrated similar negative predictive values for low-risk scores (87-89%). After adjusting for an 11% false negative rate for PTE in patients with low-risk mWS, overuse of CTPA was reported in up to 190 (55.2%) patients. CONCLUSION: More than 50% of patients with suspected PTE may be subject to unwarranted use of CTPA in the absence of pre-test clinical prediction rules coupled with D-dimer assays.

Pragmatic approach to chest pain patients discharged with undetectable high-sensitivity troponin T and normal electrocardiogram: the STABS + CT protocol.

A strategy that discharges chest pain patients with negative high-sensitivity troponin and non-ischaemic electrocardiography changes may still result in 0.44% of patients experiencing myocardial infarction within 30 days. We observed that a pragmatic approach that systematically discharged 25 patients on cardio-protective medications of aspirin, metoprolol and atorvastatin followed with prompt (<10 days) coronary computed tomography angiography resulted in no major adverse cardiac event and adverse drug reaction 30 days post-presentation. The strategy resulted in three patients (12%) ultimately diagnosed with likely unstable angina, which required planned coronary intervention in two patients and medical management in one patient. No unplanned readmissions for chest pains were noted from initial presentation through to 6-month follow up.

CardioPulse: The future of coronary computer tomography angiography.

Stephan Achenbach reviews the history of coronary computer tomography angiography and discusses its further evolution.

Temporal Trends in Intravenous Thrombolysis in Acute Ischemic Stroke: Experience from a Tertiary Care Center in India.

BACKGROUND: Acute ischemic stroke (AIS) is a time-dependent treatable cause of morbidity and mortality. Despite the increasing stroke incidence in developing countries, parallel increasing stroke thrombolysis rates have not been documented. AIM: This study aims to determine trends in patient characteristics and rates of recombinant tissue plasminogen activator (rtPA) use in AIS patients in a tertiary care center in northern India. METHODS: All AIS patients presenting within 8 hours of symptoms onset from January 2011 to December 2015 were enrolled and analyzed. RESULTS: A total of 867 AIS patients presented within 8 hours of symptoms onset. Out of 593 eligible patients, 189 (31.87%) underwent intravenous thrombolysis (IVT) with rtPA within 4.5 hours of the window period. Patients (undergoing) IVT had onset-to-door times of 2 hours or less (23.81%), 2-3 hours (33.86%), and 3.0-4.5 hours (42.33%). IVT rates in 2 hours or less of symptom onset increased from 22% to 25% and IVT rates in 2-3 hours increased from 38.9% to 43.8%. Door-to-computerized tomographic time (median 27 versus 11 minutes, P = .0001) and door-to-needle time (median 83 versus 67 minutes, P = .011) improved, with a significant improvement of computerized tomography imaging time within 25 minutes of arrival (from 50% to 78.4%, P = .014). Post-IVT symptomatic hemorrhage was noted in 5 patients (2.65%). The median National Institutes of Health Stroke Scale score at presentation was 11, whereas a favorable modified Rankin Scale score (0-1) at 3 months was seen in 39.68%. CONCLUSIONS: Encouraging trends in IVT over the years may be indicative of increasing community awareness of stroke and improving quality of stroke care in developing countries such as India.

Medicare Utilization of CT Angiography from 2001 through 2014: Continued Growth by Radiologists.

PURPOSE: To examine changes in utilization of computed tomography (CT) angiography nationally and changing relative specialty roles in examination interpretation. MATERIALS AND METHODS: Service-specific claims data for region-specific CT angiography examinations were identified using Medicare Physician Supplier Procedure Summary Master Files from 2001 through 2014. Longitudinal national utilization rates were calculated using annual Medicare enrollment data for 2001-2013. Procedure volumes by specialty group and site of service were analyzed. RESULTS: Total annual claims for CT angiography for Medicare fee for service beneficiaries increased from 64,846 to 1,709,088 (compound annual growth rate [CAGR] 29%) between 2001 and 2014. Per 1,000 beneficiaries, overall CT angiography utilization increased annually from 2.1 in 2001 to 47.6 in 2013. Overall interpretation market share increased 4% (91%-95%) for radiology. Cardiology increased from 1% in 2001 to 6% in 2007 but decreased annually to 2% in 2014. Vascular surgery market share remained < 1% throughout the study period. Growth of CT angiography in the emergency department (ED) outpaced all other sites of service, increasing from 11% to 28% (CAGR 38%). The chest was the dominant body region imaged with CT angiography, increasing from 36,984 to 914,086 (CAGR 28%). CONCLUSIONS: Utilization of CT angiography in the Medicare population increased markedly for 2001-2014, particularly in the ED, with radiologists remaining dominant providers. The chest is the most common body region imaged with CT angiography.

CT myocardial perfusion imaging: current status and future directions.

Computed tomography (CT) imaging of the heart has advanced rapidly, and it is now possible to perform a comprehensive assessment at a low radiation dose. CT myocardial perfusion imaging can provide additive information to CT coronary angiography, and is particularly useful in patients with heavily calcified coronary arteries or coronary artery stents. A number of protocols are now available for CT myocardial perfusion including static, dynamic, and dual-energy techniques. This review will discuss the current status of CT myocardial perfusion imaging, its clinical application, and future directions for this technology.

Trends in the Diagnosis and Outcomes of Traumatic Carotid and Vertebral Artery Dissections among Medicare Beneficiaries.

BACKGROUND: Early identification of carotid and vertebral artery dissections has been advocated to reduce stroke among trauma patients. We sought to characterize trends in the diagnosis of traumatic carotid and vertebral artery dissections and association changes in stroke rate among Medicare beneficiaries. METHODS: Using Medicare claims, we created a cohort of 5,961 beneficiaries admitted with a new traumatic carotid or vertebral artery dissection from 2001 to 2012. We calculated rates of stroke during hospitalization and 90 days of discharge. We calculated rates of carotid imaging using computed tomography-angiography, carotid duplex, and plain angiography index hospitalization. To study concurrent secular trends, we created a secondary cohort of patients admitted after any traumatic injury from 2001 to 2012 and determined rates of stroke and carotid imaging within this cohort. RESULTS: From 2001 to 2012, incidence of traumatic carotid dissection increased 72% among Medicare beneficiaries (1.1-1.76 per 100,000 patients; rate ratio [RR], 1.72; 95% CI, 1.6-1.9, P < 0.001). Among patients diagnosed with traumatic carotid or vertebral artery dissections, the combined in-hospital and 90-day stroke rate did not change significantly (4.9% in 2001; 5.2% in 2012; RR, 1.06; 95% CI, 0.93-1.20; P = 0.094). Likewise, there was little change in mortality (10.3%; RR, 1.01; 95% CI, 0.95-1.06; P = 0.88). Among all trauma patients, the use of computed tomography angiography has increased 16-fold (2-35 per 100,000 patients; RR, 16.7; 95% CI, 13-19; P < 0.0001). CONCLUSIONS: Despite increased diagnosis of carotid or vertebral artery dissection, there has been little change in stroke risk among trauma patients. Efforts to more effectively target imaging and treatment for these patients are necessary.