Atheromas of the thoracic aorta: clinical and therapeutic update

Predictive factors of thoracic aortic calcification in patients candidate for cardiac surgery

BACKGROUND

The presence of the severe thoracic aortic calcification (TAC) in cardiac surgery patients is associated with adverse post-operative outcome. However, the relationship between cardiovascular risk factors and aortic plaque burden remains unknown. The objective of this study was to determine the predictive factors of TAC in patients candidate for cardiac surgery.

METHODS

Patients who underwent thoracic CT scan prior to cardiac surgery between August 2020 to April 2021 were included. Of 556 patients, 209 (36.7%) had a thoracic aortic calcium score (TACS) ≥ 400 mm [3] and were compare with the remaining patients. Predictors of severe TAC were assessed through stepwise multivariable logistic regression analysis.

RESULTS

The patients with TACS ≥ 400 had a higher mean age (67.3 ± 7.1 vs. 55.7 ± 10.6; p < 0.001) with a higher frequency of diabetes mellitus (40.7% vs. 30.8%; p = 0.018), dyslipidemia (49.8% vs. 38.6%; p = 0.010), hypertension (60.8% vs. 44.7%; p < 0.001), opium addiction (18.2% vs. 11.2%; p = 0.023), peripheral vascular disease (PVD) (7.7% vs. 2.3%; p = 0.005) as compared with TACS < 400. The multiple determinants of TAC were PVD (OR = 2.86) followed by opium addiction, diabetes and age.

CONCLUSIONS

Thoracic CT scan prior to cardiac surgery for patients with older age, diabetes, opium addiction and PVD is recommended. Our study could serve as a foundation for future research endeavors aimed at establishing a risk score for TAC.

Protruding Aortic Plaque and Coronary Plaque Vulnerability

BACKGROUND

Protruding aortic plaque is known to be associated with an increased risk for future cardiac and cerebrovascular events. However, the relationship between protruding aortic plaque and coronary plaque characteristics has not been systematically investigated.

METHODS AND RESULTS

A total of 615 patients who underwent computed tomography angiography, and preintervention optical coherence tomography imaging were included. Coronary plaque characteristics were compared to evaluate coronary plaque vulnerability in patients with protruding aortic plaque on computed tomography angiography. 615 patients, the 186 (30.2%) patients with protruding aortic plaque were older and had more comorbidities such as hypertension, chronic kidney disease, and a prior myocardial infarction than those without. They also had a higher prevalence of coronary plaques with vulnerable features such as thin-cap fibroatheroma (85 [45.7%] versus 120 [28.0%], P<0.001), lipid-rich plaque (165 [88.7%] versus 346 [80.7%], P=0.014), macrophages (147 [79.0%] versus 294 [68.5%], P=0.008), layered plaque (117 [62.9%] versus 213 [49.7%], P=0.002), and plaque rupture (96 [51.6%] versus 111 [25.9%], P<0.001). Patients with protruding aortic plaque experienced more major adverse cardiac and cerebrovascular events, including all-cause mortality, nonfatal acute coronary syndromes, and stroke (27 [14.7%] versus 21 [4.9%], P<0.001; 8 [4.3%] versus 1 [0.2%], P<0.001; 5 [2.7%] versus 3 [0.7%], P=0.030; and 5 [2.7%] versus 2 [0.5%], P=0.013, respectively).

CONCLUSIONS

The current study demonstrates that patients with protruding aortic plaque have more features of coronary plaque vulnerability and are at increased risk of future adverse events.

Role of oncostatin-M in ECM remodeling and plaque vulnerability

Atherosclerosis is a multifactorial inflammatory disease characterized by the development of plaque formation leading to occlusion of the vessel and hypoxia of the tissue supplied by the vessel. Chronic inflammation and altered collagen expression render stable plaque to unstable and increase plaque vulnerability. Thinned and weakened fibrous cap results in plaque rupture and formation of thrombosis and emboli formation leading to acute ischemic events such as stroke and myocardial infarction. Inflammatory mediators including TREM-1, TLRs, MMPs, and immune cells play a critical role in plaque vulnerability. Among the other inflammatory mediators, oncostatin-M (OSM), a pro-inflammatory cytokine, play an important role in the development and progression of atherosclerosis, however, the role of OSM in plaque vulnerability and extracellular matrix remodeling (ECM) is not well understood and studied. Since ECM remodeling plays an important role in atherosclerosis and plaque vulnerability, a detailed investigation on the role of OSM in ECM remodeling and plaque vulnerability is critical. This is important because the role of OSM has been discussed in the context of proliferation of vascular smooth muscle cells and regulation of cytokine expression but the role of OSM is scarcely discussed in relation to ECM remodeling and plaque vulnerability. This review focuses on critically discussing the role of OSM in ECM remodeling and plaque vulnerability.

Mastering the Best Practices: A Comprehensive Look at the European Guidelines for Cardiopulmonary Bypass in Adult Cardiac Surgery

The successful outcome of a cardiac surgery procedure is significantly dependent on the management of cardiopulmonary bypass (CPB). Even if a cardiac operation is technically well-conducted, a patient may suffer CPB-related complications that could result in severe comorbidities, reduced quality of life, or even death. However, the role of clinical perfusionists in perioperative patient care, which is critical, is often overlooked. Therefore, the European Association for Cardio-Thoracic Surgery (EACTS), the European Association of Cardiothoracic Anaesthesiology (EACTA), and the European Board of Cardiovascular Perfusion (EBCP) have agreed to develop joint clinical practice guidelines (CPGs) for CPB due to its significant impact on patient care and significant variations in practice patterns between countries. The European guidelines, based on the EACTS standardized framework for the development of CPGs, cover the entire spectrum of CPB management in adult cardiac surgery. This includes training and education of clinical perfusionists, machine hardware, disposables, preparation for initiation of CPB, a complete set of procedures during CPB to help maintain end-organ function and anticoagulation, weaning from CPB, and the gaps in evidence and future research directions. This comprehensive coverage ensures that all aspects of CPB management are addressed, providing clinicians with a standardized approach to CPB management based on the latest evidence and best practices. To ensure better integration of these evidence-based recommendations into daily practice, this review aims to provide a general understanding of guideline development and an overview of essential treatment recommendations for CPB management.

Characterization of aortic aging using 3D multi-parametric MRI-long-term follow-up in a population study

We comprehensively studied morphological and functional aortic aging in a population study using modern three-dimensional MR imaging to allow future comparison in patients with diseases of the aortic valve or aorta. We followed 80 of 126 subjects of a population study (20 to 80 years of age at baseline) using the identical methodology 6.0 ± 0.5 years later. All underwent 3 T MRI of the thoracic aorta including 3D T1 weighted MRI (spatial resolution 1 mm³) for measuring aortic diameter and plaque thickness and 4D flow MRI (spatial/temporal resolution = 2 mm³/20 ms) for calculating global and regional aortic pulse wave velocity (PWV) and helicity of aortic blood flow. Mean diameter of the ascending aorta (AAo) decreased and plaque thickness increased significantly in the aortic arch (AA) and descending aorta (DAo) in females. PWV of the thoracic aorta increased (6.4 ± 1.5 to 7.0 ± 1.7 m/s and 6.8 ± 1.5 to 7.3 ± 1.8 m/s in females and males, respectively) over time. Local normalized helicity volumes (LNHV) decreased significantly in the AAo and AA (0.33 to 0.31 and 0.34 to 0.32 in females and 0.34 to 0.32 and 0.32 to 0.28 in males). By contrast, helicity increased significantly in the DAo in both genders (0.28 to 0.29 and 0.29 to 0.30, respectively). 3D MRI was able to characterize changes in aortic diameter, plaque thickness, PWV and helicity during six years in our population. Aortic aging determined by 3D multi-parametric MRI is now available for future comparisons in patients with diseases of the aortic valve or aorta.

Three-dimensional transesophageal echocardiographic evaluation of aortic plaque after cerebrovascular event

INTRODUCTION AND OBJECTIVES

Transesophageal echocardiography (TEE) is crucial in order to assess aortic anatomy after stroke. Although routinely used to assess cardiovascular anatomy and function, three-dimensional echocardiography (3D TEE) is less used for aortic evaluation. We thus sought to assess prospectively whether additional information on aortic plaque morphology could be obtained with 3D TEE after an ischemic stroke.

METHODS

Patients within one week of a stroke (confirmed by brain computed tomography/magnetic resonance) underwent TEE and 3D findings were compared with two-dimensional (2D) (aorta plaque number, dimensions, area and the presence of debris and ulcerations). Patients were followed for two years for death or a new stroke.

RESULTS

We assessed 78 patients, 43 (55%) male, aged 62±14 years old, 92% in sinus rhythm. Aortic atheroma was found mainly in the descending aorta (50%); plaque thickness was similar for 2D TEE (0.29±0.03 cm) and 3D TEE (0.29±0.04 cm), whereas plaque area was slightly increased for 3D measurements (0.24±0.02 cm² versus 0.37±0.03 cm² respectively, p<0.05), with a strong correlation found both for aortic plaque thickness (r=0.91) and area (r=0.80) measurements. While aortic debris were equally seen with both techniques, 3D TEE defines the presence of ulcerations (six ulcerations unseen with 2D TEE better, p=0.03). There were 11 events (six deaths and five new strokes) during follow-up, unrelated to plaque characteristics.

CONCLUSION

To evaluate aortic plaque morphology, 3D TEE is superior to 2D TEE due to improved detection of ulcerated aortic plaque; this might provide additional information in patients after ischemic stroke.

Towards personalized antithrombotic management with drugs and devices across the cardiovascular spectrum

Intravascular thrombus formation and embolization are among the most frequent events leading to a number of cardiovascular conditions with high morbidity and mortality. The underlying causes are stasis of the circulating blood, genetic and acquired coagulation disorders, and reduced antithrombotic or prothrombotic properties of the vascular wall (Virchow's triad). In the venous system, intravascular thrombi can cause venous thrombosis and pulmonary and even peripheral embolism including ischaemic stroke [through a patent foramen ovale (PFO)]. Thrombi in the left atrium and its appendage or ventricle form in the context of atrial fibrillation and infarction, respectively. Furthermore, thrombi can form on native or prosthetic aortic valves, within the aorta (in particular at sites of ulcers, aortic dissection, and abdominal aneurysms), and in cerebral and peripheral arteries causing stroke and critical limb ischaemia, respectively. Finally, thrombotic occlusion may occur in arteries supplying vital organs such the heart, brain, kidney, and extremities. Thrombus formation and embolization can be managed with anticoagulants and devices depending on where they form and embolize and on patient characteristics. Vitamin K antagonists are preferred in patients with mechanical valves, while novel oral anticoagulants are first choice in most other cardiovascular conditions, in particular venous thromboembolism and atrial fibrillation. As anticoagulants are associated with a risk of bleeding, devices such as occluders of a PFO or the left atrial appendage are preferred in patients with an increased bleeding risk. Platelet inhibitors such as aspirin and/or P2Y12 antagonists are preferred in the secondary prevention of coronary artery disease, stroke, and peripheral artery disease either alone or in combination depending on the clinical condition. A differential and personalized use of anticoagulants, platelet inhibitors, and devices is recommended and reviewed in this article.

Bubble Test and Carotid Ultrasound to Guide Indication of Transesophageal Echocardiography in Young Patients With Stroke

Background and Purpose

Indication of transesophageal echocardiography (TEE) in patients ≤60 years with brain ischemia is uncertain.

Methods

This prospective double-blinded study included patients with cryptogenic acute ischemic stroke or transient ischemic attack (TIA) ≥18 and ≤60 years. After routine diagnostics, all patients underwent patent foramen ovale (PFO) screening by transcranial Doppler (TCD) bubble test, carotid ultrasound for atherosclerosis screening (intima-media-thickness >0.90 mm or plaques), and TEE. We calculated sensitivity, specificity, positive predictive values (PPV), and negative predictive values (NPV) of the combined non-invasive ultrasound to predict therapy-relevant TEE findings.

Results

We included 240 consecutive patients (median 51 years, 39% women) of which 68 (28.3%) had both a negative bubble test and no carotid atherosclerosis. Of these, 66 (97.1%) had unremarkable TEE findings; in one patient a small PFO was found and closed subsequently, in another patient a 4.9 mm thick aortic atheroma was found, and double platelet inhibition initiated. Of the other 172 (71.7%) patients, 93 (54%) had PFO and 9 (5.2%) complex aortic plaques. No other therapy-relevant findings were present in both groups. Non-invasive ultrasound had a sensitivity of 98.0%, specificity of 47.8%, NPV of 97.1%, and PPV of 58.1% for therapy-relevant TEE findings.

Conclusions

Bubble test and carotid ultrasound could be used for the individual decision for/against TEE in patients with cryptogenic stroke ≤60 years. If they are unremarkable, TEE can be omitted with high safety regarding secondary prevention. If bubble test is positive and/or carotid ultrasound shows atherosclerosis, TEE should be carried out if PFO or aortic atheroma are potentially relevant for further patient management.

Aortic thrombosis: the forgotten source of ischemic stroke. A case report and systematic review of the literature

Ischemic stroke represents one of the most important health problems in industrialized countries, both for epidemiological and socio-economic impact. The presence of thrombi in the aorta is rare and its treatment has not been uniquely defined. Here we report the case of an 82-years-old man with aortic thrombosis and acute ischemic stroke.

The impact of computed tomography-derived aortic atheroma volume on prognosis after transcatheter aortic valve replacement

BACKGROUND

The impact of the extent of aortic atheroma on patients' prognosis after transcatheter aortic valve replacement (TAVR) has not been completely evaluated. This study aimed to evaluate the prognostic value of the aortic atheroma volume (AAV) derived from computed tomography, and the effect of its differences among the segments of the aorta, in patients undergoing TAVR.

METHODS

In total, 143 patients with symptomatic severe aortic stenosis who underwent pre-procedural computed tomography before TAVR procedure indication were evaluated. AAV was calculated by measuring the aortic lumen and vessel volume using every 1-mm axial image and was further divided into thoracic (TAAV) and abdominal segments (AbAAV).

RESULTS

During a median follow-up of 651 days, 24 all-cause and 14 cardiac deaths occurred. In the Kaplan-Meier analysis, the high AAV group had significantly higher all-cause and cardiac mortalities than the low AAV group (p = 0.016 and 0.023, respectively). Regarding segmental AAV, all-cause and cardiac mortalities did not have significant differences between the high and low TAAV groups. Moreover, all-cause and cardiac mortalities were significantly higher in the high AbAAV group than in the low AbAAV group (p = 0.0043 and 0.023, respectively). The multivariable analysis showed that only AbAAV was an independent predictor for all-cause mortality (hazard ratio: 1.06, p = 0.046).

CONCLUSION

AAV was significantly associated with the mortality after TAVR. The current study suggests the pre-procedural assessment of AAV is valuable in predicting prognosis after TAVR. However, further investigation with a larger sample size is needed to validate our findings.

Transesophageal echocardiography for cardiovascular risk estimation in patients with sepsis and new-onset atrial fibrillation: a multicenter prospective pilot study

Background

Echocardiographic parameters have been poorly investigated for estimating cardiovascular risk in patients with sepsis and new-onset atrial fibrillation. We aim to assess the prevalence of transesophageal echocardiographic abnormalities and their relationship with cardiovascular events in mechanically ventilated patients with sepsis and new-onset atrial fibrillation.

Methods

In this prospective multicenter pilot study, left atrial/left atrial appendage (LA/LAA) dysfunction, severe aortic atheroma, and left ventricular systolic dysfunction were assessed using an initial transesophageal echocardiographic study, which was repeated after 48–72 h to detect LA/LAA thrombus formation. The study outcome was a composite of cardiovascular events at day 28, including arterial thromboembolic events (ischemic stroke, non-cerebrovascular arterial thromboembolism, LA/LAA thrombus), major bleeding, and all-cause death.

Results

The study population comprised 94 patients (septic shock 63%; 35% women; median age 69 years). LA/LAA dysfunction, severe aortic atheroma, and left ventricular systolic dysfunction were detected in 17 (19%), 22 (24%), and 27 (29%) patients, respectively. At day 28, the incidence of cardiovascular events was 46% (95% confidence interval [CI]: 35 to 56). Arterial thromboembolic events and major bleeding occurred in 7 (7%) patients (5 ischemic strokes, 1 non-cerebrovascular arterial thromboembolism, 2 left atrial appendage thrombi) and 18 (19%) patients, respectively. At day 28, 27 patients (29%) died. Septic shock (hazard ratio [HR]: 2.36; 95% CI 1.06 to 5.29) and left ventricular systolic dysfunction (HR: 2.06; 95% CI 1.05 to 4.05) were independently associated with cardiovascular events.

Conclusions

Transesophageal echocardiographic abnormalities are common in mechanically ventilated patients with sepsis and new-onset atrial fibrillation, but only left ventricular systolic dysfunction was associated with cardiovascular events at day 28.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00934-1.

The role of echocardiography in the embolic stroke of undetermined source

: Echocardiography plays an important role both in the diagnosis and the treatment/prevention of embolic stroke of undetermined source and should be performed as soon as possible for preventing ischemic stroke recurrencies, which occur more frequently during the first week after the first ischemic event. Early identification of the cause of a transient ischemic attack or stroke is indeed a primary goal for the neurologist in the Stroke Unit and requires specific diagnostic strategies. Echocardiography, together with other diagnostic tools such as carotid and transcranial ultrasounds, provides this information promptly. In particular, echocardiography might be able to detect the main sources of the embolic stroke, such as atrial fibrillation, ventricular akinesia, aortic atheroma plaques and/or cardiac shunts. The present review discusses the importance and the practical role of echocardiography as a crucial diagnostic tool for detecting the main source of emboli in the setting of the acute stroke.

Who Should Rather Undergo Transesophageal Echocardiography to Determine Stroke Etiology: Young or Elderly Stroke Patients?

Introduction: The indication of transesophageal echocardiography (TEE) in acute stroke is unclear. Thus, we systematically studied the impact of TEE on determining stroke etiology and secondary prevention in patients of different age-groups with cryptogenic stroke.

Methods: Four hundred and eighty five consecutive patients with acute retinal or cerebral ischemia were prospectively included and underwent routine stroke workup including TEE. Stroke etiology was identified according to the TOAST classification and patients were divided in those with determined and cryptogenic stroke etiology without TEE results. Then, the frequency of high- and potential-risk sources in TEE was evaluated in <55, 55–74, and ≥75 year-old patients with cryptogenic stroke etiology.

Results: Without TEE, stroke etiology was cryptogenic in 329(67.8%) patients and TEE determined possible etiology in 158(48.4%) of them. In patients aged <55, 55–74, ≥75, TEE detected aortic arch plaques ≥4 mm thickness in 2(1.2%), 37(23.0%), and 33(40.2%) and plaques with superimposed thrombi in 0(0.0%), 5(3.1%), and 7(8.5%); left atrial appendage peak emptying flow velocity ≤30cm/s in 0(0.0%), 1(0.6%), and 2(2.4%), spontaneous echo contrast in 0(0.0%), 1(0.6%), and 6(7.3%), endocarditis in 0(0.0%), 0(0.0%), and 1(1.2%) and patent foramen ovale (PFO) plus atrial septum aneurysm (ASA) in 18(20.9%), 32(19.9%), and 14(17.1%), respectively. TEE changed secondary prevention in 16.4% of these patients following guidelines of 2010/11 and still 9.4% when applying the guidelines of 2020.

Conclusions: TEE was highly valuable for determining stroke etiology and influenced individual secondary prevention based on available treatment guidelines and expert opinion in most cases. In young patients the impact of TEE was limited to the detection of septal anomalies. By contrast, in older patients TEE detected high numbers of complex aortic atheroma and potential indicators of paroxysmal atrial fibrillation.

Percutaneous thrombectomy of mural aortic thrombus using intravascular ultrasound guidance

Mural aortic thrombus is a challenging clinical problem with significant potential complications. Particularly precarious are situations with involvement of the visceral segment of the aorta. We describe a technique for percutaneous thrombectomy of mural aortic thrombus using intravascular ultrasound to guide an angled mechanical thrombectomy catheter in conjunction with a continuous aspiration system (Indigo mechanical thrombectomy system; Penumbra, Alameda, Calif). Use of this technique in three patients with challenging cases of mural aortic thrombus is discussed. All patients were treated successfully and without complication using this technique.

Thoracic Aortic Calcification: Diagnostic, Prognostic, and Management Considerations

Thoracic aortic calcification (TAC) is associated with adverse cardiovascular outcomes, and for the cardiovascular imager, is predominantly encountered in 4 settings: 1) incidentally, for example, during a coronary artery calcium scan; 2) as part of dedicated screening; 3) in the evaluation of an embolic event; or 4) in procedural planning. This review focuses on TAC in these contexts. Within atherosclerosis, TAC is common, variable in extent, and begins in the intima with a patchy distribution. In metabolic disorders, aortitis, and radiation-associated cardiovascular disease, calcification preferentially involves the media and is often more concentric. As an incidental finding, atherosclerotic TAC provides limited incremental discriminative value, and current data do not support screening. After an embolic event, the demonstration of thoracic atheroma provides diagnostic clarity, but has limited treatment implications. Before any procedure, the plan often changes if the most severe form of TAC, a porcelain aorta, is discovered.

Management and clinical outcome of concomitant pulmonary embolism and paradoxical saddle aortic arch embolism

A 65-year-old man presented in a peri-arrest situation after collapse, he was found hypoxic with ischaemic arms. CT imaging showed massive bilateral pulmonary embolisms (PEs) and an aortic arch embolus extending from brachiocephalic trunk to left subclavian artery. Following intravenous thrombolysis, repeat imaging revealed that the aortic embolus had migrated distally into both axillary arteries and had occluded the right carotid from origin to skull base. Bilateral upper limb embolectomies were carried out from the brachial arteries together with forearm fasciotomies. Left hemianopia related to a right middle cerebral artery territory infarct was managed conservatively; forearm fasciotomy wounds were primarily closed and the patient was discharged on lifelong anticoagulation. A transoesophageal echocardiogram revealed a patent foramen ovale. This case demonstrates a very unusual presentation of concomitant PE and paradoxical saddle aortic arch embolism. A multidisciplinary approach has resulted in an excellent clinical outcome for this complex patient.

Aortic Regurgitation as a Risk Factor for Coronary Embolization from Complex Atheromatous Aortic Plaques: A Clinical Case

Patients with mobile aortic arch atheroma and severe aortic regurgitation may be at higher risk of systemic embolism. We report the case of a 68-year-old male patient with complex aortic arch plaque with superimposed thrombus, in which an acute inferior ST-elevation myocardial infarction occurred. In the reported case, coronary embolism may have been caused by flaked aortic plaque and/or superimposed thrombus, which was possibly carried by aortic regurgitation flow. It is a very rare mechanism by which a coronary embolism is possible from an aortic complex plaque.

Aortic Arch Endarterectomy Associated with On-Pump Cardiac Surgery in Patients with a Mobile Arch Atheroma

We describe aortic arch endarterectomy performed concomitantly with on-pump cardiac surgery in 2 patients with grade V arch atherosclerosis. In both patients, transesophageal echocardiographic findings led to the diagnosis of severe arch atherosclerosis associated with a mobile atheromatous plaque in the aortic arch. The severe arch atherosclerosis was managed with endarterectomy under deep hypothermic circulatory arrest. In patients with severe grade V atherosclerosis in the aortic arch, performing endarterectomy simultaneously with primary cardiac surgery may be justified as a way to reduce the risk of peripheral embolism, including cerebrovascular accidents, with minimal additional surgical risk.

Cholesterol crystal embolism to the gastrointestinal tract: a catastrophic case

Cholesterol crystal embolism is a rare and easily overlooked cause of colonic ischemia. The gastrointestinal tract is the third most common organ system affected by cholesterol emboli, second only to kidney and skin. Here we present a catastrophic case of gastrointestinal cholesterol crystal embolism leading to extensive post-operative bowel infarction and ultimately death. For a practicing pathologist, careful attention to the vessels of any ischemic bowel and recognition of the subtle but distinct angular imprint of cholesterol crystals facilitates prompt identification of the atheroemboli. In some cases, early identification may help mitigate further tissue damage. In more acute and severe cases, identification of the cholesterol crystal emboli may be important primarily for documentation of procedural complications.

Retrograde aortic blood flow as a mechanism of stroke: MR evaluation of the prevalence in a population-based study

OBJECTIVES

Retrograde blood flow from complex atheroma in the descending aorta (DAo) has only recently been described as a potential mechanism of stroke. However, prevalence of this mechanism in the general population and the exact factors influencing stroke risk are unclear.

METHODS

One hundred twenty-six consecutively recruited inhabitants of Freiburg, Germany, between 20 and 80 years of age prospectively underwent 3-T MRI. Aortic plaque location and thickness were determined by 3D T1 MRI (1 mm³). 4D flow MRI (spatial/temporal resolution 2 mm³/20 ms) and dedicated software were used to determine prevalence and extent of flow reversal and potential embolization from DAo plaques. Flow was correlated with baseline characteristics and echocardiographic and MRI parameters (aortic diameter, wall thickness, and pulse wave velocity).

RESULTS

The maximum length of retrograde blood flow connecting the DAo with the left subclavian artery (LSA) increased from 16.1 ± 8.3 mm in 20-29-year-old to 24.7 ± 11.7 mm in 70-80-year-old subjects, correlated with age (r = 0.37; p < 0.001), and was lower in females (p = 0.003). Age was the only independent predictor of increased flow reversal. Complex DAo plaques ≥ 4-mm thickness were found in eight subjects (6.3%) and were connected with the LSA, left common carotid artery, and brachiocephalic trunk in 8 (100%), 1 (12.5%), and 0 (0%) cases, respectively.

CONCLUSIONS

Retrograde blood flow from the DAo was very frequent. However, potential retrograde embolization was rare due to the low incidence of complex DAo plaques. The magnitude of flow reversal and prevalence of complex atheroma increased with age. Thus, older patients with aortic atherosclerosis are especially vulnerable to this stroke mechanism.

KEY POINTS

• 4D flow MRI allows in vivo visualization and quantification of individual and three-dimensional blood flow patterns within the thoracic aorta including retrograde components. • This population-based study showed that blood flow reversal from the proximal descending aorta to the brain-supplying great arteries is very frequent and able to reach all brain territories. The extent of such flow reversal increases with age and with the extent of aortic atherosclerosis. • The combination of blood flow reversal with plaque rupture in the proximal descending aorta constitutes a potential stroke mechanism that should be considered in future trials and in the management of stroke patients in clinical routine.

Aortic Mural Thrombus in the Non-atherosclerotic Aorta of Patients with Multiple Hypercoagulable Factors

An aortic mural thrombus (AMT) on a non-atherosclerotic wall is a rare but important cause of arterial thromboembolism. We herein report two cases of AMT in the thoracic aorta. Both showed multiple hypercoagulable factors (case 1: protein S deficiency and positive finding of anti-cardiolipin antibody; case 2: protein C deficiency, gastric cancer, and cisplatin-based chemotherapy) and were successfully treated with anticoagulation. Hypercoagulable states, including malignancy, can influence the formation of AMT; therefore, the accurate assessment of a hypercoagulable condition is necessary when we encounter patients with AMT.

Determination of aortic stiffness using 4D flow cardiovascular magnetic resonance - a population-based study

BACKGROUND

Increased aortic stiffness is an independent predictor of cardiovascular disease. Optimal measurement is highly beneficial for the detection of atherosclerosis and the management of patients at risk. Thus, it was our purpose to selectively measure aortic stiffness using a novel imaging method and to provide reference values from a population-based study.

METHODS

One hundred twenty six inhabitants of Freiburg, Germany, between 20 and 80 years prospectively underwent 3 Tesla cardiovascular magnetic resonance (CMR) of the thoracic aorta. 4D flow CMR (spatial/temporal resolution 2mm3/20ms) was executed to calculate aortic pulse wave velocity (PWV) in m/s using dedicated software. In addition, we calculated distensibility coefficients (DC) using 2D CINE CMR imaging of the ascending (AAo) and descending aorta (DAo). Segmental aortic diameter and thickness of aortic plaques were determined by 3D T1 weighted CMR (spatial resolution 1mm3).

RESULTS

PWV increased from 4.93 ± 0.54 m/s in 20-30 year-old to 8.06 ± 1.03 m/s in 70-80 year-old subjects. PWV was significantly lower in women compared to men (p < 0.0001). Increased blood pressure (systolic r = 0.36, p < 0.0001; diastolic r = 0.33, p = 0.0001; mean arterial pressure r = 0.37, p < 0.0001) correlated with PWV after adjustment for age and gender. Finally, PWV increased with increasing diameter of the aorta (ascending aorta r = 0.20, p = 0.026; aortic arch r = 0.24, p = 0.009; descending aorta r = 0.26, p = 0.004). Correlation of PWV and DC of the AAo and DAo or the mean of both was high (r = 0.69, r = 0.68, r = 0.73; p < 0.001).

CONCLUSIONS

4D flow CMR was successfully applied to calculate aortic PWV and thus aortic stiffness. Findings showed a high correlation with distensibility coefficients representing local compliance of the aorta. Our novel method and reference data for PWV may provide a reliable biomarker for the identification of patients with underlying cardiovascular disease and optimal guidance of future treatment in studies or clinical routine.

A Large Grade 5 Mobile Aortic Arch Atheromatous Plaque: Cause of Cerebrovascular Accident

Aortic atheromas (aortic atheromatous plaques) are defined by an irregular thickening of the intima ≥2 mm, and a complex plaque is defined as a protruding atheroma ≥4 mm with or without an attached mobile component. Stroke incidence is approximately 25% in patients with mobile plaques of the aortic arch and 2% in patients with quiescent nonmobile plaques. Antiplatelet agents, oral anticoagulants, and statins have been suggested in the management of atheromas. We present an 80-year-old male, with non-ST-segment elevation myocardial infarction (NSTEMI) and chronic dysarthria, found to have an acute cerebrovascular accident (CVA) secondary to embolism from a large 12 mm aortic arch plaque, treated medically with oral antiplatelet therapy, anticoagulation, and statin therapy.

Distribution of Thoracic Aortic Calcifications in Patients Undergoing Coronary Artery Bypass Grafting

Background

In procedures involving surgical maneuvers such as cannulation, clamping, or proximal anastomosis where aortic manipulation is inevitable, a preliminary assessment of atherosclerotic plaques bears clinical significance. In the present study, our aim was to evaluate the frequency and distribution of aortic calcifications in patients undergoing coronary artery bypass grafting (CABG) surgery to propose a morphological classification system.

Methods

A total of 443 consecutive patients with coronary artery disease were included in this study. Preoperative non-contrast enhanced computed tomography images, in-hospital follow-up data, and patient characteristics were retrospectively evaluated.

Results

Whereas 33% of patients had no calcifications at any site in the aorta, 7.9%, 75.4%, and 16.7% had calcifications in the ascending aorta, aortic arch, and descending aorta, respectively. Focal small calcifications were the most common type of lesions in the ascending aorta (3.9%), whereas 9 patients (1.4%) had porcelain ascending aorta. We defined four types of patients with increasing severity and extent of calcifications.

Conclusions

Based on the frequency and distribution of calcifications in the thoracic aorta, we propose a classification system from least to most severe for coronary artery disease patients who are candidates for CABG.

Risk Factors of Aortic Plaque Progression Evaluated by Long-Term Follow-Up Data With Transesophageal Echocardiography

There are few longitudinal data regarding aortic plaque. This study aimed to examine chronological changes in aortic plaques with transesophageal echocardiography (TEE), and to clarify the risk factors of aortic plaque progression. Among 2,675 consecutive patients who underwent TEE, we retrospectively investigated 252 patients who underwent follow-up TEE with an interval >3 years. The thickness and morphology of aortic plaques were examined. Chronological changes in aortic plaques were investigated by comparing baseline and follow-up TEE. Clinical factors, laboratory data, and medications were evaluated. Among 252 study patients, the grade of aortic plaques was unchanged in 213 (group U), but progression was observed in 32 (group P) and regression in 7 patients (group R). Patients in group P were older; they had a higher prevalence of coronary artery disease, hypertension, smoking habit, and moderate or severe plaque at baseline TEE; more patients were using statins and no warfarin; and they had higher creatinine levels than those in group U. In multivariate analysis, moderate or severe plaques at baseline TEE were the strongest predictor of plaque progression. Among 50 patients who showed moderate or severe plaque at baseline TEE, smoking habit and no anticoagulation therapy were predictors of plaque progression. In conclusion, aortic plaques should be followed up using TEE in patients with moderate or severe plaque at baseline TEE.

The Evolving Role and Use of Echocardiography in the Evaluation of Cardiac Source of Embolism

This report will review the role of echocardiography in the diagnosis of cardiac sources of embolism. Embolism of cardiac origin accounts for around 15%–30% of ischemic strokes. The diagnosis of a cardioembolic source of stroke is frequently uncertain and relies on the identification of a potential cardiac source of embolism in the absence of significant autochthonous cerebrovascular occlusive disease. Transthoracic and/or transesophageal echocardiography serves as a cornerstone in the evaluation, diagnosis, and management of these patients. This article reviews potential cardiac sources of embolism and discusses the role of echocardiography in clinical practice. Recommendations for the use of echocardiography in the diagnosis of cardiac sources of embolism are given including major and minor conditions associated with the risk of embolism.

Aortic Arch Atheroma: Stroke Reduction in Cardiac Surgical Patients

Cardiac surgery is increasingly performed on elderly patients with extensive coronary artery abnormalities who have impaired left ventricular function, decreased physiologic reserve, and multiple comorbid conditions. Considerable numbers of these patients develop perioperative neurologic complications ranging from subtle cognitive dysfunction to more evident postoperative confusion, delirium, and, less commonly, clinically apparent stroke. Magnetic resonance imaging studies have elucidated that a considerable number of patients have new ischemic brain infarcts, particularly after conventional coronary artery bypass graft surgery. Mechanisms of cerebral injury during and after cardiac surgery are discussed. Intraoperative transesophageal echocardiography and epiaortic scanning for detection of atheromatous disease of the proximal thoracic aorta is paramount in identifying patients at high risk from neurologic injury. It is important to recognize that our efforts to minimize neurologic injury should not be limited to the intraoperative period. Particular efforts should be directed to temperature management, glycemia control, and pharmacologic neuroprotection extending into the postoperative period. Preoperative magnetic resonance angiography may be of value for screening patients with significant atheroma of the proximal thoracic aorta. It is likely that for patients with no significant atheromatous disease, conventional coronary artery revascularization is the most effective long-term strategy, whereas patients with atheromatous thoracic aorta may be better managed with beating heart surgery, hybrid techniques, or medical therapy alone. Patient stratification based on the aortic atheromatic burden should be addressed in future trials designed to tailor treatment strategies to improve long-term outcomes of coronary heart disease and reduce the risks of perioperative neurologic injury.

Guidelines for the Use of Echocardiography in the Evaluation of a Cardiac Source of Embolism

Embolism from the heart or the thoracic aorta often leads to clinically significant morbidity and mortality due to transient ischemic attack, stroke or occlusion of peripheral arteries. Transthoracic and transesophageal echocardiography are the key diagnostic modalities for evaluation, diagnosis, and management of stroke, systemic and pulmonary embolism. This document provides comprehensive American Society of Echocardiography guidelines on the use of echocardiography for evaluation of cardiac sources of embolism. It describes general mechanisms of stroke and systemic embolism; the specific role of cardiac and aortic sources in stroke, and systemic and pulmonary embolism; the role of echocardiography in evaluation, diagnosis, and management of cardiac and aortic sources of emboli including the incremental value of contrast and 3D echocardiography; and a brief description of alternative imaging techniques and their role in the evaluation of cardiac sources of emboli. Specific guidelines are provided for each category of embolic sources including the left atrium and left atrial appendage, left ventricle, heart valves, cardiac tumors, and thoracic aorta. In addition, there are recommendation regarding pulmonary embolism, and embolism related to cardiovascular surgery and percutaneous procedures. The guidelines also include a dedicated section on cardiac sources of embolism in pediatric populations.

Plasma thrombin-cleaved osteopontin as a potential biomarker of acute atherothrombotic ischemic stroke

We investigated whether thrombin-cleaved osteopontin N-terminal is useful as a blood biomarker of acute atherothrombotic ischemic stroke. Acute ischemic stroke patients were prospectively evaluated with brain magnetic resonance imaging and cardiac evaluations for etiological diagnosis according to the Trial of Org 10172 in Acute Stroke Treatment classification. They were divided into the atherothrombotic and non-atherothrombotic groups. Thrombin-cleaved osteopontin N-terminal, osteopontin, matrix metalloproteinase-9, S100B, C-reactive protein and D-dimer levels were measured from blood samples collected at admission. After excluding patients who met the exclusion criteria or had stroke of other/undetermined etiology, 60 of the 100 patients initially enrolled were included in the final analysis. The ischemic stroke subtypes were atherothrombotic (n=28, 46.7%), cardioembolic (n=19, 31.7%) and lacunar (n=13, 21.7%). Thrombin-cleaved osteopontin N-terminal and matrix metalloproteinase-9 levels were significantly higher in the atherothrombotic than in the non-atherothrombotic group (median (interquartile range): 5.83  (0.0-8.6 ) vs. 0.0  (0.0-3.3) pmol l^-1, P=0.03 and 544   (322-749 ) vs. 343   (254-485) ng ml^-1, P=0.01, respectively). After adjustment for the prevalence of hypertension, diabetes and dyslipidemia, thrombin-cleaved osteopontin N-terminal levels of >5.47 pmol l^-1 (odds ratio, 16.81; 95% confidence interval, 3.53-80.10) and matrix metalloproteinase-9 levels of >605.5 ng ml^-1 (6.59; 1.77-24.60) were identified as independent predictors of atherothrombosis. Within 3 h from stroke onset, only thrombin-cleaved osteopontin N-terminal independently predicted atherothrombosis and thus may add valuable, time-sensitive diagnostic information in the early evaluation of ischemic stroke, especially the atherothrombotic subtype.

Association of Dietary Factors with Progression of AA in Stroke/TIA Patients

OBJECTIVE

To investigate the effect of dietary factors such as calorie intake and dietary fats on the progression of aortic arch atheroma (AA).

BACKGROUND

In stroke/TIA patients, progression of AA is associated with recurrent vascular events.

DESIGN/METHODS

Consecutive patients with measurable (>1 mm) AA atheroma on baseline transesophageal echocardiogram (TEE) evaluation consented to a protocol mandated follow-up TEE at 12 months. Patients that had adequate paired AA images were assessed for progression, defined as Δ ≥ 1 grade worsening (based on plaque thickness over 12 months). Stroke risk factors and fasting lipid profile were assessed at baseline. The patient's nutritional intake was measured at baseline using the Gladys Block Food Frequency Questionnaire.

RESULTS

One-hundred-nine patients (70 strokes, 33 TIAs) had sequential TEEs, of whom 27% (N=30) progressed and 73% (N=79) did not. Patients with progression had higher daily calorie (1778 ± 623 vs. 1378 ± 406 Calories, p=0.008), fat (76 ± 33 vs. 52 ± 23 grams, p=0.0002), carbohydrate (208 ± 78 vs. 169 ± 57 grams, p=0.01) and protein (73 ± 26 vs. 57 ± 21 grams, p=0.005) intake. On Further analysis among different fats showed a higher consumption of saturated fats (25 ± 12 vs. 17 ±8 grams, p=0.00051) as well as unsaturated fats (44 ± 20 vs. 30 ± 13 grams, p=0.002). These differences remained significant after we adjusted for the medication use. However the significance of these differences was attenuated after adjusting for the calorie intake. Cholesterol consumption did not differ between the progression and no-progression group (262 ± 125 vs. 213 ± 149 mg, p=0.2).

CONCLUSIONS/RELEVANCE

Calorie intake plays a significant role in the progression of AA. Further studies are needed to confirm these findings and determine the specific dietary modifications that may prevent AA progression and associated recurrent vascular events.

Noninvasive Imaging of Flow and Vascular Function in Disease of the Aorta

With advancements in technology and a better understanding of human cardiovascular physiology, research as well as clinical care can go beyond dimensional anatomy offered by traditional imaging and investigate aortic functional properties and the impact disease has on this function. Linking the knowledge of the histopathological changes with the alterations in aortic function observed on noninvasive imaging results in a better understanding of disease pathophysiology. Translating this to clinical medicine, these noninvasive imaging assessments of aortic function are proving to be able to diagnose disease, better predict risk, and assess response to therapies. This review is designed to summarize the various hemodynamic measures that can characterize the aorta, the various noninvasive techniques, and applications for various disease states.

Combined non-invasive assessment of endothelial shear stress and molecular imaging of inflammation for the prediction of inflamed plaque in hyperlipidaemic rabbit aortas

AIMS

To evaluate the incremental value of low endothelial shear stress (ESS) combined with high-resolution magnetic resonance imaging (MRI)- and computed tomography angiography (CTA)-based imaging for the prediction of inflamed plaque.

METHODS AND RESULTS

Twelve hereditary hyperlipidaemic rabbits underwent quantitative analysis of plaque in the thoracic aorta with 256-slice CTA and USPIO-enhanced (ultra-small superparamagnetic nanoparticles, P904) 1.5-T MRI at baseline and at 6-month follow-up. Computational fluid dynamics using CTA-based 3D reconstruction of thoracic aortas identified the ESS patterns in the convex and concave curvature subsegments of interest. Subsegments with low baseline ESS exhibited significant increase in wall thickness and plaque inflammation by MRI, in non-calcified plaque burden by CTA, and developed increased plaque size, lipid and inflammatory cell accumulation (high-risk plaque features) at follow-up by histopathology. Multiple regression analysis identified baseline ESS and inflammation by MRI to be independent predictors of plaque progression, while receiver operating curve analysis revealed baseline ESS alone or in combination with inflammation by MRI as the strongest predictor for augmented plaque burden and inflammation (low ESS at baseline: AUC = 0.84, P < 0.001; low ESS and inflammation by molecular MRI at baseline: AUC = 0.89, P < 0.001).

CONCLUSION

Low ESS predicts progression of plaque burden and inflammation as assessed by non-invasive USPIO-enhanced MRI. Combined non-invasive assessment of ESS and imaging of inflammation may serve to predict plaque with high-risk features.

Exophytic Atheroma Mimicking Papillary Fibroelastoma Adjacent to the Aortic Valve

Follow-up echocardiography in a 69-year-old man with alcoholic cardiomyopathy showed a mass above the aortic valve near the left coronary ostium. Transesophageal echocardiography and computed tomography suggested a papillary fibroelastoma with a high risk of embolism. At operation we found an exophytic atheroma adjacent to the left coronary artery orifice. The atheroma was removed, and the patient made an uneventful recovery. We describe this very rare case of an exophytic atheroma mimicking a papillary fibroelastoma situated at the left coronary orifice.

Reconstruction of the descending thoracic aorta by multiview compounding of 3-D transesophageal echocardiographic aortic data sets for improved examination and quantification of atheroma burden

A robust and efficient approach to reconstruction of the descending thoracic aorta from contiguous 3-D transesophageal echocardiographic (TEE) images is proposed. An ad hoc image acquisition protocol was designed to acquire ordered and partially overlapped 3-D TEE data sets, followed by dedicated image processing to align and fuse all acquired data sets. Alignment strategy implemented pairwise rigid registration guided by a priori knowledge, and it was validated using artificially misaligned images. Image fusion was finally performed to enable visualization and analysis of extended field-of-view of the acquired aorta. The application of different fusion techniques was also investigated. The method was applied to a population of 17 consecutive patients. Qualitative and quantitative results supported the feasibility and accuracy of the proposed approach. In a clinical scenario, its application could allow the quantitative assessment of aortic plaque burden in the descending thoracic aorta from 3-D TEE images.

Correlation between plaque vulnerability of aorta and coronary artery: an evaluation of plaque activity by direct visualization with angioscopy

This study investigated the relationship between the degree of atherosclerotic changes in the descending thoracic aorta (TA) and the coronary artery using angioscopy. Twenty-five consecutive patients undergoing angioscopy of the TA and coronary angiography were enrolled in this study. Participants were divided into three groups according to the angioscopic grading of the TA: white plaque group (W-group), yellow plaque group (Y-group) and intensive yellow, ruptured plaque with ulceration and/or thrombus group (RP-group). The maximum plaque grade, plaque score, number of yellow plaques, frequency of yellow-plaque grades by coronary angioscopy, and SYNTAX score by coronary angiography were evaluated. Brachial-artery pulse wave velocity and high-sensitivity C-reactive protein level tended to be higher in the RP-group than in the other groups, although the differences were not statistically significant. The SYNTAX score was significantly higher in the RP-group than in the W-group (W-group 4.0 ± 3.6 vs. RP-group 17.5 ± 10.0, P = 0.045). In addition, the angioscopic maximum plaque grade, plaque score, and number of yellow plaques in the RP-group were significantly higher than in the W-group (maximum plaque grade W-group 0.8 ± 0.4 vs. RP-group 1.8 ± 0.8, P = 0.026; plaque score W-group 1.0 ± 1.2 vs. RP-group 4.0 ± 1.4, P = 0.014; and number of yellow plaques W-group 1.0 ± 1.2 vs. RP-group 2.5 ± 0.5, P = 0.023). The yellow-plaque grade in the coronary artery was correlated significantly with the plaque grading of TA (P = 0.043). Our study suggests that the angioscopic progression of aortic atherosclerosis is closely associated with vulnerability to and the extent of coronary stenosis, indicating that vulnerability toward atherosclerotic plaque development occurs simultaneously in the coronary tree and systemic arteries.