Acute aortic syndrome

Initial Triage and Management of Patients with Acute Aortic Syndromes

The acute aortic syndromes (AAS) are life-threatening vascular compromises within the aortic wall. These include aortic dissection (AD), intramural hematoma (IMH), penetrating aortic ulcer (PAU), and blunt traumatic thoracic aortic injury (BTTAI). While patients classically present with chest pain, the presentation may be highly variable. Timely diagnosis is critical to initiate definitive treatment and maximize chances of survival. In high-risk patients, treatment should begin immediately, even while diagnostic evaluation proceeds. The mainstay of medical therapy is acute reduction of heart rate and blood pressure. Surgical intervention is often required but is informed by patient anatomy and extent of vascular compromise.

Penetrating aortic ulcer and aortic intramural hematoma: Treatment strategy

OBJECTIVES

The indication, timing, and choice of the treatment modality for penetrating aortic ulcers (PAUs) and intramural hematoma (IMH) are frequently challenging. This article reviews these pathologies and their relation to aortic dissection and proposes a diagnostic and treatment algorithm.

METHODS

A review of literature on diagnosis and treatment of PAU and IMH was conducted. The PubMed database was searched using the terms "penetrating aortic ulcer" and "aortic intramural hematoma". Articles were reviewed and the studies involving diagnosis and management of PAU and IMH were included. We subsequently proposed a management algorithm for PAU and IMH based on available evidence.

RESULTS

PAU and IMH are distinct entities from aortic dissection, although they carry a significant risk of progression into dissection, aneurysm, and rupture. PAU and IMH originating in zone 0 of the aorta generally require surgical treatment. When the origin is beyond zone 0, a trial of medical therapy is recommended. Progression of disease on imaging studies, persistent uncontrolled pain, and certain high-risk features warrant surgery. High-risk features signaling risk of disease progression include PAU with IMH, PAU depth more than 10 mm, PAU diameter more than 20 mm, IMH thickness more than 10 mm, and maximum initial aortic diameter more than 40 mm.

CONCLUSIONS

High-quality evidence regarding the treatment of PAU and IMH is lacking. These entities can have a malignant course when they are present with associated symptoms and/or when they have associated high-risk features on imaging. An aggressive surgical approach is necessary in that group of patients.

Progress of CT aortic angiography combined with coronary artery in the evaluation of acute aortic syndrome

Acute aortic syndrome (AAS) is a group of cardiovascular diseases that seriously threaten human life and health. AAS patients are often complicated with coronary artery disease and other related diseases, which require rapid and clear clinical diagnosis to avoid serious adverse events. In recent years, with the progress of science and technology, a variety of computer tomography (CT) angiography techniques have been applied in the clinic, and the diagnosis rate of AAS with coronary heart disease (CAD) has greatly increased. At the same time, the development of surgical technology and endovascular repair technology has significantly reduced the mortality and complication rate of AAS surgery. In the clinical diagnosis of AAS and related diseases, CT aortic angiography (CTA) combined with coronary CTA is increasingly applied to identify related diseases. Here, the current research progress on the technique of aortic CTA combined with coronary CTA is reviewed.

Inhibition of Sphingosine-1-Phosphate Receptor 2 Prevents Thoracic Aortic Dissection and Rupture

Background: Numerous pieces of evidence have indicated that thoracic aortic dissection (TAD) is an inflammatory disease. Sphingosine-1-phosphate receptor 2 (S1PR2) signaling is a driver in multiple inflammatory diseases. Here, we examined the S1PR2 expression in TAD lesions and explored the effect of interfering with S1PR2 on TAD formation and progression.

Methods: Aorta specimens and blood samples were collected from patients with TAD and matched controls. The expression of S1PR1, S1PR2, and S1PR3 was examined. The effect of inhibiting S1PR2 on TAD was evaluated in a TAD mouse model induced by β-aminopropionitrile fumarate (BAPN) and AngII. The presence of sphingosine kinase 1 (SPHK1), S1P, and neutrophil extracellular traps (NETs) was investigated. Further, the possible association between S1PR2 signaling and NETs in TAD was analyzed.

Results: In the aortic tissues of patients with TAD and a mouse model, the S1PR2 expression was significantly up-regulated. In the TAD mouse model, JTE013, a specific S1PR2 antagonist, not only blunted the TAD formation and aortic rupture, but also preserved the elastic fiber architecture, reduced the smooth muscle cells apoptosis level, and mitigated the aortic wall inflammation. Augmented tissue protein expression of SPHK1, citrullinated histone H3 (CitH3, a specific marker of NETs), and serum S1P, CitH3 were detected in TAD patients. Surgical repair normalized the serum S1P and CitH3 levels. Immunofluorescence staining revealed that S1PR2 colocalized with NETs. The protein expression levels of SPHK1 and serum S1P levels positively correlated with the protein expression and serum levels of CitH3, separately. Furthermore, JTE013 treatment reduced NETs accumulation.

Conclusion: Inhibiting S1PR2 attenuates TAD formation and prevents aortic rupture. Targeting S1PR2 may provide a promising treatment strategy against TAD.

Risk Factors for Postoperative Mortality in Patients with Acute Stanford Type A Aortic Dissection

OBJECTIVE

The present study explored the risk factors of postoperative mortality in patients with acute Stanford type A aortic dissection (AD).

METHODS

The study included 149 patients with acute Stanford type A AD who were treated at the Fourth Hospital of Hebei Medical University, China, from October 2016 to October 2018. The patients were divided into a death (n = 42) and survival group (n = 107) according to individual prognosis. Univariate analysis of all possible related risk factors was conducted; multivariate logistic regression analysis of the potential risk factors that showed statistical differences in the univariate analysis was also performed.

RESULTS

The results of the univariate analysis showed that a body mass index (BMI) ≥25 kg/m2, surgery duration, duration of cardiopulmonary bypass, duration of cardiopulmonary bypass assistance, total transfusion of red blood cells, postoperative APACHE II score, sequential organ failure assessment (SOFA) score, low cardiac output, acute kidney injury (AKI), hypoxemia, diffuse intravascular coagulation (DIC), hepatic failure and other related complications, as well as postoperative stay duration in the intensive care unit (ICU), were closely correlated with a poor prognosis among patients. Multivariate logistic regression analysis showed that a BMI ≥25 kg/m2, SOFA score >8, duration of cardiopulmonary bypass assistance >70 minutes, postoperative low cardiac output, and postoperative DIC were independent risk factors for postoperative death in patients with acute Stanford type A AD.

CONCLUSION

A BMI ≥25 kg/m2, SOFA score >8, duration of cardiopulmonary bypass assistance >70 min, postoperative DIC, and postoperative low cardiac output were the independent risk factors for postoperative death in acute Stanford type A AD. Intraoperative blood transfusion, postoperative hepatic failure, and AKI, among others, correlated with an increased risk of death but were not independent risk factors for death.

An unusual case of painless type A aortic dissection

The pathogenesis of acute aortic dissection (AAD) is not fully elucidated yet, but it was recently shown that inflammation contributes to the occurrence and development of both Stanford type A and type B AAD. We describe a rare case of a painless type A aortic dissection that occurred in an 85-year-old male, with moderate calcified aortic stenosis and a moderately dilated ascending aorta in 6-month clinical and echocardiographic follow-up. A chronic calculous cholecystitis with neutrophilic leukocytosis and severely increased C reactive protein was diagnosed in the last 3 months. In this patient, a chronic systemic inflammatory state might have contributed to generate the intimal entry tear in the aortic root. In particular, a neutrophil mobilization might have played a causative role in aortic rupture.

Serum Ceruloplasmin Is the Candidate Predictive Biomarker for Acute Aortic Dissection and Is Related to Thrombosed False Lumen: a Propensity Score-Matched Observational Case-Control Study

Acute aortic dissection (AAD), one of the fatal diseases observed at the department of vascular surgery, is associated with a great mortality rate at the early stage. Ceruloplasmin (CP) is the plasma protein that functions as a copper transporter. The current retrospective research was carried out to assess CP contents and to examine the possible part in diagnosing patients with AAD. In addition, propensity score matching (PSM) was also utilized for reducing the bias in case screening as well as the clinical confounders. Using PSM, this study included 85 pairs of AAD cases (Stanford A and B dissection) and matched controls, and their CP levels were also detected through enzyme-linked immunosorbent assay (ELISA). Additionally, the relative clinical data were extracted from participants included in this study. After PSM adjustment for clinical variables, including gender, age, body mass index (BMI), heart ratio (HR), smoking, hypertension, diabetes mellitus, coronary heart disease (CHD), and stroke, the serum CP contents among AAD cases were remarkably increased compared with those among the normal subjects. Besides, the CP contents showed independent association with the AAD risk. Typically, the CP level was significantly positively correlated with platelet (R = 0.329) or C-reactive protein (R = 0.340) level. Meanwhile, the area under the receiver operating characteristic (ROC) curve (AUC) was 0.929 when CP was used to diagnose AAD, and the best threshold value was 36.82mg/dL. Serum CP content significantly increased in cases with thrombosed false lumen (FL) relative to those in patent FL cases. Results of logistic regression analysis suggested that a greater CP content indicated an increased thrombosed FL risk (OR = 1.11; 95% CI: 1.01-1.23; P = 0.040). Findings in this study suggest that serum ceruloplasmin contents evidently increased among acute aortic dissection cases. CP shows close correlation with the inflammatory factors among AAD cases. Further, CP may serve as the candidate biomarker to diagnose AAD and to identify an increased risk of thrombosed false lumen.

Impact of hypertension on short- and long-term survival of patients who underwent emergency surgery for type A acute aortic dissection

Background

To explore the clinical characteristics and prognosis of patients with hypertension underwent emergency surgery for type A acute aortic dissection (TA-AAD).

Methods

The present study enrolled 712 consecutive patients diagnosed with TA-AAD and received aortic repair surgery at our hospital between January 2014 to December 2018. Clinical characteristics of enrolled patients were retrospectively reviewed. Patients were grouped by preexisting hypertension history and matched with propensity scores matching method. Patients’ clinical characteristics were compared and analyzed before and after propensity scoring. To identify predictors for long-term mortality rate, Kaplan-Meier survival estimation and Cox proportional hazard analysis were performed.

Results

A total of 492 patients (69.1% of all patients in the cohort) were included in the hypertensive group and they had increased age and weight compared to patients in the non-hypertensive group. Between two groups, preoperative leukocyte count and serum creatinine level were found significant different (P<0.05). After propensity scoring, 128 pairs (256 patients) were successfully matched. Our analysis showed that there was no significant difference of ventilation duration, 30-day mortality rate, intensive care unit stay and hospitalization time between two groups. However, our data suggested that hypertensive patients presented with less intra-operative aortic valve involvement. There was a significant difference in long-term survival rate (P=0.037) between two groups. Cox regression analysis demonstrated that hypertension was an independent risk factor [hazard ratio (HR), 3.040; 95% confidence interval (CI), 1.124–8.227; P=0.029].

Conclusions

Our data suggested that TA-AAD patients complicated with hypertension had increased age and weight compared to non-hypertensive patients. Concomitant hypertension identified upon hospital administration was an independent risk factor for long-term survival in TA-AAD patients while did not influence the 30-day mortality rate.

Immunological therapeutics in acute aortic syndrome

Acute aortic syndrome is a group of interlinked conditions with common presenting symptoms, including aortic dissection, penetrating atherosclerotic ulcer, and intramural hematoma. Pharmacological management of acute aortic syndrome is a growing area, with key themes to address the underlying inflammatory pathways believed to be the cause. Research into interleukins, matrix metalloproteinases, and granulocyte macrophage colony-stimulating factor are just some of the many immunological properties being investigated and translated into medical therapies. Stem cell experiments may indicate further advances in the pathologies of acute aortic syndrome. The study of pharmacogenomics to improve treatment across different genomes is also a novel area outlined in this paper.

Deficiency of CD44 prevents thoracic aortic dissection in a murine model

Thoracic aortic dissection (TAD) is a life-threatening vascular disease. We showed that CD44, a widely distributed cell surface adhesion molecule, has an important role in inflammation. In this study, we examined the role of CD44 in the development of TAD. TAD was induced by the continuous infusion of β-aminopropionitrile (BAPN), a lysyl oxidase inhibitor, and angiotensin II (AngII) for 7 days in wild type (WT) mice and CD44 deficient (CD44^-/-) mice. The incidence of TAD in CD44^-/- mice was significantly reduced compared with WT mice (44% and 6%, p < 0.01). Next, to evaluate the initial changes, aortic tissues at 24 hours after BAPN/AngII infusion were examined. Neutrophil accumulation into thoracic aortic adventitia in CD44^-/- mice was significantly decreased compared with that in WT mice (5.7 ± 0.3% and 1.6 ± 0.4%, p < 0.01). In addition, BAPN/AngII induced interleukin-6, interleukin-1β, matrix metalloproteinase-2 and matrix metalloproteinase-9 in WT mice, all of which were significantly reduced in CD44^−/− mice (all p < 0.01). In vitro transmigration of neutrophils from CD44^−/− mice through an endothelial monolayer was significantly decreased by 18% compared with WT mice (p < 0.01). Our findings indicate that CD44 has a critical role in TAD development in association with neutrophil infiltration into adventitia.

Computed Tomographic Angiography for Risk Stratification in Patients with Acute Chest Pain - The Triple Rule-out Concept in the Emergency Department

BACKGROUND

Acute chest pain is one of the most common reasons for Emergency Department (ED) visits and hospital admissions. As this could represent the first symptom of a lifethreatening condition, urgent identification of the etiology of chest pain is of utmost importance in emergency settings. Such high-risk conditions that can present with acute chest pain in the ED include Acute Coronary Syndromes (ACS), Pulmonary Embolisms (PE) and Acute Aortic Syndromes (AAS).

DISCUSSION

The concept of Triple Rule-out Computed Tomographic Angiography (TRO-CTA) for patients presenting with acute chest pain in the ED is based on the use of coronary computed tomographic angiography as a single imaging technique, able to diagnose or exclude three lifethreatening conditions in one single step: ACS, AAS and PE. TRO-CTA protocols have been proved to be efficient in the ED for diagnosis or exclusion of life-threatening conditions and for differentiation between various etiologies of chest pain, and application of the TRO-CTA protocol in the ED for acute chest pain of uncertain etiology has been shown to improve the further clinical evaluation and outcomes of these patients.

CONCLUSION

This review aims to summarize the main indications and techniques used in TRO protocols in EDs, and the role of TRO-CTA protocols in risk stratification of patients with acute chest pain.

Lower body ischaemic time is a risk factor for acute kidney injury after surgery for type A acute aortic dissection

OBJECTIVES

Postoperative acute kidney injury (AKI) is known as a risk factor for death after surgery for Stanford type A acute aortic dissection under hypothermic circulatory arrest. It may also adversely affect long-term survival. We searched for modifiable risk factors for postoperative AKI, focusing on lower body ischaemic time.

METHODS

We reviewed 191 patients undergoing surgical repair for Stanford type A acute aortic dissection. The distal anastomosis depended on excluding the primary tear location, resulting in ascending/hemiarch (n = 119), partial arch (n = 18) and total arch replacement (n = 54). We defined an increase in the serum creatinine level to ≧2 times the baseline level as AKI. The incidence of AKI was investigated with multivariate analysis of its risk factors.

RESULTS

Postoperative AKI was observed in 49 patients (26%), 31% of whom required renal replacement therapy. The overall hospital mortality rate was 8.5%. Postoperative AKI, preoperative shock and organ malperfusion were predictors of hospital death. Multivariate stepwise logistic regression analysis identified age, body mass index, preoperative chronic kidney disease and lower body ischaemic time as risk factors for postoperative AKI.

CONCLUSIONS

Although surgical repair for Stanford type A acute aortic dissection showed favourable results, the incidence of postoperative AKI is still high, closely associated with hospital death. Lower body ischaemic time should be recognized specifically as a modifiable surgical risk factor for postoperative AKI.

Preoperative hypoxemia in patients with type A acute aortic dissection: a retrospective study on incidence, related factors and clinical significance

Background

Pre-operative hypoxemia (HO) is a serious complication occurring in acute type A aortic dissection (AAD) patients.

Methods

This was a retrospective study of 505 patients who underwent Stanford type A acute aortic dissection surgery in Anzhen hospital, Beijing, China, between January 2015 to February 2018. Patients were divided into a HO(+) group (PaO₂/FiO₂ ≤300) and a HO(-) group (PaO₂/FiO₂ >300) according to preoperative arterial blood gas (ABG) analysis. The incidence of preoperative hypoxemia in patients undergoing surgery for AAD was calculated as the main outcome. Multivariable binary logistic regression analysis was used to identify independent prognostic factors of HO.

Results

Preoperative HO occurred in 46.5% (235/505) of patients. Mean patient age was 47.8±9.6 years, and 189 (80.4%) were male. Multivariable logistic regression analysis showed a correlation between preoperative serum level of fibrinogen [95% confidence interval (CI), 0.95-0.99], white blood cell count (WBC) (95% CI, 1.07-1.18), systolic blood pressure (95% CI, 0.98-1.00), history of smoking (95% CI, 1.05-2.11) and pleural effusion (95% CI, 1.14-2.71) with preoperative HO. The HO(+) group had a significantly higher mortality than the HO(-) group (8.1% vs. 5.9%, P=0.38). The median of intubation time (P<0.01), the length of stay in the intensive care unit (P<0.01) and the length of hospital stay (P<0.01) were significantly longer in patients with HO. The activity of daily living scale score was significantly lower in the HO(+) group (P<0.01).

Conclusions

AAD patients were easy to have pre-operative HO, which had a higher morbidity than those without HO. Altered fibrinogen, WBC, systolic blood pressure levels, positive smoking history, and pleural effusion were associated with the presence of HO. More monitoring and treatment should be given to these patients.

Factors Associated with Low Admission Platelet Count in Adults with Acute Aortic Dissection

Purpose: Platelets are crucial components of the coagulation processes, and low admission platelet count (PLC) is associated with adverse clinical outcomes in patients with Stanford type A acute aortic dissection (AAD).

Methods: A total of 130 consecutive patients undergoing Stanford type A AAD surgery in Beijing Anzhen Hospital were enrolled between January 2013 and July 2014. Preoperative clinical and laboratory data from patients were collected. Multiple regression analyses were used to determine the independent factors of low admission platelets.

Results: Adjusted multiple regression analysis showed that age (β: −1.069, 95% confidence interval [CI]: −2.109, −0.029), sex (β: −29.973, 95% CI: −56.512, −3.433), tissue factor pathway inhibitor (TFPI; β: 0.197, 95% CI: 0.039, 0.354), fibrinogen degradation product (FDP) (β: −0.476, 95% CI: −0.879, −0.074), and attack time (β: 11.125, 95% CI: 7.963, 14.287) were significantly associated with admission PLC. Admission PLC increased with attack time up to the 3 days (β: 16.2, 95% CI: 12.1, 20.2).

Conclusions: We found that increasing age, male patients, patients with lower serum levels of TFPI and higher serum levels of FDP, and patients with a shorter attack time were significantly associated with lower PLC at admission. Moreover, the turning point of attack time is 3 days after the onset of dissection.

Aortic dissection after mitral valve replacement: the role of intraoperative echocardiography in this diagnosis

According to the most recent guidelines, the use of intraoperative transesophageal echocardiography in valvular surgeries is well established, as well as its use in the diagnosis, management, and rescue of perioperative complications. The aim of this case report is to illustrate a condition in which its intraoperative use had a positive influence on the outcome.

[Aortic dissection after mitral valve replacement: the role of intraoperative echocardiography in the diagnosis]

According to the most recent guidelines, the use of intraoperative transesophageal echocardiography in valvular surgeries is well established, as well as its use in the diagnosis, management, and rescue of perioperative complications. The aim of this case report is to illustrate a condition in which its intraoperative use had a positive influence on the outcome.

Protection of xenon against postoperative oxygen impairment in adults undergoing Stanford Type-A acute aortic dissection surgery: Study protocol for a prospective, randomized controlled clinical trial

OBJECTIVES

The available evidence shows that hypoxemia after Stanford Type-A acute aortic dissection (AAD) surgery is a frequent cause of several adverse consequences. The pathogenesis of postoperative hypoxemia after AAD surgery is complex, and ischemia/reperfusion and inflammation are likely to be underlying risk factors. Xenon, recognized as an ideal anesthetic and anti-inflammatory treatment, might be a possible treatment for these adverse effects.

METHODS/DESIGN

The trial is a prospective, double-blind, 4-group, parallel, randomized controlled, a signal-center clinical trial. We will recruit 160 adult patients undergoing Stanford type-A AAD surgery. Patients will be allocated a study number and will be randomized on a 1:1:1:1 basis to receive 1 of the 3 treatment options (pulmonary inflated with 50% xenon, 75% xenon, or 100% xenon) or no treatment (control group, pulmonary inflated with 50% nitrogen). The aims of this study are to clarify the lung protection capability of xenon and its possible mechanisms in patients undergoing the Stanford type-A AAD surgery.

DISCUSSION

This trial uses an innovative design to account for the xenon effects of postoperative oxygen impairment, and it also delineates the mechanism for any benefit from xenon. The investigational xenon group is considered a treatment intervention, as it includes 3 groups of pulmonary static inflation with 50%, 75%, and 100% xenon. It is suggested that future trials might define an appropriate concentration of xenon for the best practice intervention.

Potential Sunitinib-Induced Coronary Artery and Aortic Dissections

Small-molecule multitargeted tyrosine kinase inhibitor (TKI) therapy is used in different types of cancer. These drugs have been associated with cardiovascular toxicity, including aortic dissection. To our knowledge, this is the first time that a coronary dissection potentially associated with a TKI treatment has been described.

Acute aorta, overview of acute CT findings and endovascular treatment options

Acute aortic pathologies include acute aortic syndrome (aortic dissection, intramural hematoma, penetrating aortic ulcer), impending rupture, aortic aneurysm rupture and aortic trauma. Acute aortic syndrome, aortic aneurysm rupture and aortic trauma are life-threatening conditions requiring prompt diagnosis and treatment. The basic imaging modality for "acute aorta" is CT angiography with typical findings for these aortic pathologies. Based on the CT, it is possible to classify aortic diseases and anatomical classifications are essential for the planning of treatment. Currently, endovascular treatment is the method of choice for acute diseases of the descending thoracic aorta and is increasingly indicated for patients with ruptured abdominal aortic aneurysms.

The polymorphisms in angiotensin-converting enzyme and angiotensin-converting enzyme 2 are not associated with thoracic aortic diseases and coronary heart disease

Introduction:

The polymorphisms of the angiotensin-converting enzyme (ACE) and angiotensin-converting enzyme 2 (ACE2) genes have been demonstrated to be involved in some cardiovascular diseases. We hypothesised that the polymorphisms of ACE and ACE2 relate to the formation of thoracic aortic diseases and coronary heart disease.

Methods:

A total of 86 patients (four groups: thoracic aortic dissection; thoracic aortic aneurysm; coronary heart disease; and control group) were recruited. The ACE I/D polymorphism and the ACE2 (A8790G) polymorphism were measured in all patient samples.

Results:

There were no significant differences in groups with regard to either the ACE I/D polymorphism or the ACE2 (A8790G) polymorphism.

Conclusion:

The polymorphisms of the ACE and ACE2 genes are not associated with thoracic aortic dissection, thoracic aortic aneurysm and coronary heart disease.

Potential Mechanism of Post-Acute Aortic Dissection Inflammatory Responses: The Role of mtDNA from Activated Platelets

BACKGROUND

Acute aortic dissection (AD) is a lethal cardiovascular disease with severe inflammatory complications. Considering the proinflammatory properties of plasma mitochondrial DNA (mtDNA), we postulate that plasma mtDNA from activated platelets may be responsible for post-acute AD inflammatory responses.

METHODS

We consecutively enrolled 68 patients with acute AD as well as matched hypertensive and healthy participants. Blood samples were collected on admission for blood routine tests, mtDNA assay, and inflammatory cytokine analysis. A computed tomography scan was used to evaluate the extent of dissections.

RESULTS

Our results demonstrate that plasma mtDNA, platelet activation, and inflammatory levels were remarkably higher in acute AD patients than in hypertensive or healthy participants. These parameters were also higher in the Stanford A group than in the Stanford B group (p < 0.05). Bivariate correlation analysis demonstrated positive associations between mtDNA and inflammatory levels (tumor necrosis factor-α: r = 0.577; interleukin-6: r = 0.632), mtDNA and platelet activation (r = 0.642), and platelet activation and the extent of dissection (r = 0.635).

CONCLUSION

Our study suggests that acute AD-induced tunica media exposure causes platelet activation, which leads to the initiation of inflammatory responses via the release of mtDNA into the circulation. Our study provides a novel fundamental basis and a potential therapeutic target for the prevention and treatment of post-AD inflammatory responses.

A penetrating atherosclerotic ulcer rupture in the ascending aorta with hemopericardium: a case report

Background

Acute aortic syndrome, including classic aortic dissection, intramural aortic hematoma, and penetrating atherosclerotic ulcer (PAU), is a term used to describe a group of conditions with similar clinical symptoms, but with different pathophysiological mechanisms. PAU is a lesion that penetrates the internal elastic lamina through the media. It is usually located in the descending aorta and rarely observed in the ascending aorta.

Case presentation

A 76-year-old man with a history of essential hypertension was brought to the emergency department (ED) because of a sudden-onset chest pain at rest. He had not been taking his medication as ordered. His vital signs in the ED were a blood pressure of 82/60 mmHg, heart rate of 158 beats per min, respiratory rate of 22 breaths per min, and a body temperature of 37.2 °C. An electrocardiogram did not show an ST segment elevation, and cardiac enzymes were within normal limits. No widening mediastinum was found on chest radiography, but a large pericardial effusion with an impending cardiac tamponade was revealed on echocardiography. The diagnosis of PAU rupture in the ascending aorta with hemopericardium was made with chest computed tomography. An emergent sternotomy and ascending aorta reconstruction were performed. A ruptured ulcerative plaque through the intima to the adventitia without flap dissection in the ascending aorta was confirmed. The patient was discharged 18 days after the operation.

Conclusions

Although PAU in the ascending aorta is uncommon, it is commonly lethal when it ruptures. With the current advances in endovascular techniques and devices, endovascular repair of PAU in the ascending aorta is currently recommended only for high-risk patients unsuitable for open repair. However, we anticipate that endovascular repair may become feasible in patients with PAU in the ascending aorta in the future.

Recommendations for accurate CT diagnosis of suspected acute aortic syndrome (AAS)--on behalf of the British Society of Cardiovascular Imaging (BSCI)/British Society of Cardiovascular CT (BSCCT)

Accurate and timely assessment of suspected acute aortic syndrome is crucial in this life-threatening condition. Imaging with CT plays a central role in the diagnosis to allow expedited management. Diagnosis can be made using locally available expertise with optimized scanning parameters, making full use of recent advances in CT technology. Each imaging centre must optimize their protocols to allow accurate diagnosis, to optimize radiation dose and in particular to reduce the risk of false-positive diagnosis that may simulate disease. This document outlines the principles for the acquisition of motion-free imaging of the aorta in this context.

Lumican as a novel potential clinical indicator for acute aortic dissection: A comparative study, based on multi-slice computed tomography angiography

The aim of the present study was to investigate the association between serum lumican levels and acute aortic dissection (AAD) severity. A total of 82 patients with chest or back pain and 30 healthy volunteers were recruited. Among the patients, there were 70 cases of AAD and 12 cases of intramural hematoma (IMH). AAD severity was determined using multi-slice computed tomography angiography (MSCTA). Serum was collected from the patients upon admission, and lumican levels were detected using an enzyme-linked immunosorbent assay. In addition, correlation analyses were conducted between lumican levels and AAD severity by designing a 'SCORE X, RANGE Y' system to measure the number of affected vital arteries and vertical range of false lumen, based on the MSCTA. Lumican levels differed significantly among the AAD patients (2.32±4.29 ng/ml), IMH patients (0.72±0.32 ng/ml) and healthy volunteers (0.85±0.53 ng/ml; P=0.003). In the AAD patients presenting within 12-72 h of symptom onset, the Spearman's rho correlation coefficient between lumican and SCORE or RANGE was 0.373 (P=0.046) and 0.468 (P=0.010), respectively. The present results suggest that lumican may be a potential marker for aiding the diagnosis and screening for AAD, and may be used to predict the severity of AAD.

Association between Diabetes and Risk of Aortic Dissection: A Case-Control Study in a Chinese Population

Background

It is well-recognized that diabetes represents a powerful independent risk factor for cardiovascular diseases. However, very few studies have investigated the relationship between diabetes and risk of aortic dissection (AD).

Aim

The aim of this case-control study was to evaluate the association between diabetes and risk of AD in Chinese population.

Methods

A hospital-based case-control study, consisting of 2160 AD patients and 4320 controls, was conducted in a Chinese population. Demographic, clinical characteristics and risk factors were collected. Diabetes rate of patients with overall AD, Stanford type A AD and type B AD group was compared with that of corresponding matched control groups. Logistic regression analysis was used to estimate the odds ratios (OR) and 95% confidence intervals (95% CI) for relationship between diabetes and AD risk.

Results

The prevalence of diabetes was lower in AD cases than that of control subjects, whether it is the overall AD, type A AD or type B AD group (4.7% vs. 10.0%, 2.9% vs. 8.8%, 5.9% vs. 10.9%, all P<0.001). Furthermore, in multivariate model, diabetes was found to be associated with lower AD risk, which not only applies to the overall AD (OR = 0.2, 95%CI: 0.15–0.26), but also type A AD (OR = 0.12, 95% CI: 0.07–0.20) and type B AD (OR = 0.25, 95%CI: 0.18–0.33).

Conclusions

We observed the paradoxical inverse relationship between DM and risk of AD in the Chinese population. These results suggest diabetes may play a protective role in the development of AD. However, further studies are needed to enrich related evidence, especially with regard to underlying mechanisms for these trends.

Relationship between acute kidney injury before thoracic endovascular aneurysm repair and in-hospital outcomes in patients with type B acute aortic dissection

Objective

Acute kidney injury (AKI) frequently occurs after catheter-based interventional procedures and increases mortality. However, the implications of AKI before thoracic endovascular aneurysm repair (TEVAR) of type B acute aortic dissection (AAD) remain unclear. This study evaluated the incidence, predictors, and in-hospital outcomes of AKI before TEVAR in patients with type B AAD.

Methods

Between 2009 and 2013, 76 patients were retrospectively evaluated who received TEVAR for type B AAD within 36 h from symptom onset. The patients were classified into no-AKI vs. AKI groups, and the severity of AKI was further staged according to kidney disease: improving global outcomes criteria before TEVAR.

Results

The incidence of preoperative AKI was 36.8%. In-hospital complications was significantly higher in patients with preoperative AKI compared with no-AKI (50.0% vs. 4.2%, respectively; P < 0.001), including acute renal failure (21.4% vs. 0, respectively; P < 0.001), and they increased with severity of AKI (P < 0.001). The maximum levels of body temperature and white blood cell count were significantly related to maximum serum creatinine level before TEVAR. Multivariate analysis showed that systolic blood pressure on admission (OR: 1.023; 95% CI: 1.003–1.044; P = 0.0238) and bilateral renal artery involvement (OR: 19.076; 95% CI: 1.914–190.164; P = 0.0120) were strong predictors of preoperative AKI.

Conclusions

Preoperative AKI frequently occurred in patients with type B AAD, and correlated with higher in-hospital complications and enhanced inflammatory reaction. Systolic blood pressure on admission and bilateral renal artery involvement were major risk factors for AKI before TEVAR.

Time-dependent changes of plasma inflammatory biomarkers in type A aortic dissection patients without optimal medical management

Objectives

To investigate the time-dependent changes in plasma levels of interleukin-6, C-reactive protein, and tumor necrosis factor-α in patients with type A aortic dissection (TAAD) who received unoptimal medical management since the onset of dissections.

Design and methods

Plasma levels of interleukin-6, C-reactive protein, and tumor necrosis factor-α were detected by ELISA and immuno-turbidimetric assay in 92 TAAD patients at hospital admission. Blood samples from 78 patients with uncontrolled hypertension and 82 healthy volunteers were also analyzed as controls. The occurrence of TAAD-related complication and its relationship with the plasma levels of these inflammatory biomarkers was also investigated.

Results

The concentrations of inflammatory mediators were significant higher in TAAD than those in the uncontrolled hypertension and the healthy group. The time to peak plasma level of IL-6.and TNF-α was shorter than that of CRP in TAAD group. In the TAAD group, 51 patients suffered TAAD-related complications, and their plasma level of CRP was significantly higher than that in patients without TAAD-related complications (94.5 ± 58.8 mg/L versus 47.4 ± 47.8 mg/L, p < 0.001). Also, CRP levels strongly correlated with the value of PaO₂/FiO₂ ratio (r = −0.69, p < 0.001) and creatinine (r = 0.60, p < 0.001). The time to the peak level of CRP was shorter and the duration of persistently high CRP level was longer in the complication group than those in the complication-free group.

Conclusions

Elevated and persistently high levels of plasma CRP, IL-6 and TNF-α were associated with progressively development of the TAAD. The changing pattern of CRP might be a marker for diagnosis and prophylactic treatment of complications. Our findings suggested a critical role of the inflammation in the progression of dissection and TAAD-related complications.

Adventitial CXCL1/G-CSF expression in response to acute aortic dissection triggers local neutrophil recruitment and activation leading to aortic rupture

RATIONALE

In-hospital outcomes are generally acceptable in patients with type B dissection; however, some patients present with undesirable complications, such as aortic expansion and rupture. Excessive inflammation is an independent predictor of adverse clinical outcomes.

OBJECTIVE

We have investigated the underlying mechanisms of catastrophic complications after acute aortic dissection (AAD) in mice.

METHODS AND RESULTS

When angiotensin II was administered in lysyl oxidase inhibitor-preconditioned mice, AAD emerged within 24 hours. The dissection was initiated at the proximal site of the descending thoracic aorta and propagated distally into an abdominal site. Dissection of the aorta caused dilatation, and ≈70% of the mice died of aortic rupture. AAD triggered CXCL1 and granulocyte-colony stimulating factor expression in the tunica adventitia of the dissected aorta, leading to elevation of circulating CXCL1/granulocyte-colony stimulating factor levels. Bone marrow CXCL12 was reduced. These chemokine changes facilitated neutrophil egress from bone marrow and infiltration into the aortic adventitia. Interference of CXCL1 function using an anti-CXCR2 antibody reduced neutrophil accumulation and limited aortic rupture post AAD. The tunica adventitia of the expanded dissected aorta demonstrated high levels of interleukin-6 (IL-6) expression. Neutrophils were the major sources of IL-6, and CXCR2 neutralization significantly reduced local and systemic levels of IL-6. Furthermore, disruption of IL-6 effectively suppressed dilatation and rupture of the dissected aorta without any influence on the incidence of AAD and neutrophil mobilization.

CONCLUSIONS

Adventitial CXCL1/granulocyte-colony stimulating factor expression in response to AAD triggers local neutrophil recruitment and activation. This leads to adventitial inflammation via IL-6 and results in aortic expansion and rupture.

Novel findings: Expression of angiotensin-converting enzyme and angiotensin-converting enzyme 2 in thoracic aortic dissection and aneurysm

INTRODUCTION

Angiotensin-converting enzyme (ACE) and ACE2 are key regulators of the renin-angiotensin system, which has been shown to participate in a series of cardiovascular diseases. We hypothesized that dysregulated gene expression of ACE and ACE2 contribute to the formation of thoracic aortic dissection and aneurysm.

MATERIALS AND METHODS

We assessed ACE plasma concentration in 73 patients with acute thoracic aortic dissection (n=34), aneurysm (n=18), coronary heart disease (n=21) and 13 healthy volunteers. ACE and ACE2 gene expression in available aortic tissues was also examined by using quantitative real-time polymerase chain reaction.

RESULTS

In patients with acute aortic dissection, ACE plasma concentration and its mRNA level in aortic tissue were markedly reduced compared with those in patients with aneurysm, coronary heart disease and healthy controls. The level of ACE2 gene expression in dissection samples was also significantly lower than that in aneurysm (8.01±7.44, p<0.01) and coronary heart disease groups (9.61±11.54, p<0.01). A strong correlation was observed between the gene expressions of ACE and those of ACE2, and ACE to ACE2 ratio was significantly elevated in dissection tissues.

CONCLUSIONS

Imbalanced down-regulation of ACE and ACE2 mRNA expression levels may play an important role in the development and progression of thoracic aortic aneurysmal dilatation and subsequently dissection.