Abstract Aortic Dissection Research Articles

P178 TYPE–A AORTIC DISSECTION IN MARFANOID HABITUS

Abstract Aortic dissection (AD) is the tearing of the tunica intima of the aortic wall with creation of a false lumen. Type–A AD, in which the intimal flaps originates in the aortic tract proximal to the left subclavian artery, is a surgical emergency because – if left untreated – it has mortality rates as high as 1–2% every hour, from the onset of symptoms. Certain collagenopathies, such as Marfan Syndrome, are a predisposing condition for AD. We describe the case of a 25–year–old man with Marfanoid habitus who came to the Emergency Room of our facility, with acute pulmonary oedema. He had been complaining about thoraco–abdominal pain, bloody mucus and worsening dyspnoea since the week before. Upon cardiology consultation, a transthoracic echocardiogram showed an aneurysm of the aortic root (70 mm) and the ascending aorta (90 mm), with dissection flap extended beneath the aortic valvular plane, with torrential aortic valve insufficiency and eccentric jet, a left ventricle severely dilated and a severe systolic dysfunction (EF 25%). On urgent CT angiography the dissection flap was observed to extend cranially to the right common carotid artery and caudally to the renal arteries. The patient then underwent cardiac surgery to replace the aortic valve with a mechanical prosthesis and the ascending aorta as per the Bentall procedure and to replace the aortic arch with reimplantation and debranching of the supra–aortic trunks. Four months after discharge, the patient presented again due to sustained ventricular tachycardia (SVT) which was interrupted by electric cardioversion. On this occasion, an ICD implant was indicated as a secondary prevention measure. After one month, recurrence of SVT was observed, which was successfully treated by the implanted ICD, and therefore indication was given for an electrophysiologic study and subsequent transcatheter radiofrequency ablation of the ventricular arrhythmia. The case presented is of particular interest as it highlights the crucial role of a rapid echocardiographic assessment focussed on making a diagnosis and directing treatment, despite a misleading clinical picture due to duration and atypicality of symptoms. It should also be stressed that an overall assessment of the patient, based on habitus and age, plays a major role in establishing a suspected diagnosis and guiding the patient towards the most appropriate treatment.

Cluster-Based Ensemble Learning Model for Aortic Dissection Screening.

Aortic dissection (AD) is a rare and high-risk cardiovascular disease with high mortality. Due to its complex and changeable clinical manifestations, it is easily missed or misdiagnosed. In this paper, we proposed an ensemble learning model based on clustering: Cluster Random under-sampling Smote–Tomek Bagging (CRST-Bagging) to help clinicians screen for AD patients in the early phase to save their lives. In this model, we propose the CRST method, which combines the advantages of Kmeans++ and the Smote–Tomek sampling method, to overcome an extremely imbalanced AD dataset. Then we used the Bagging algorithm to predict the AD patients. We collected AD patients’ and other cardiovascular patients’ routine examination data from Xiangya Hospital to build the AD dataset. The effectiveness of the CRST method in resampling was verified by experiments on the original AD dataset. Our model was compared with RUSBoost and SMOTEBagging on the original dataset and a test dataset. The results show that our model performed better. On the test dataset, our model’s precision and recall rates were 83.6% and 80.7%, respectively. Our model’s F1-score was 82.1%, which is 4.8% and 1.6% higher than that of RUSBoost and SMOTEBagging, which demonstrates our model’s effectiveness in AD screening.

Aortic Dissection Auxiliary Diagnosis Model and Applied Research Based on Ensemble Learning.

Aortic dissection (AD), a dangerous disease threatening to human beings, has a hidden onset and rapid progression and has few effective methods in its early diagnosis. At present, although CT angiography acts as the gold standard on AD diagnosis, it is so expensive and time-consuming that it can hardly offer practical help to patients. Meanwhile, the artificial intelligence technology may provide a cheap but effective approach to building an auxiliary diagnosis model for improving the early AD diagnosis rate by taking advantage of the data of the general conditions of AD patients, such as the data about the basic inspection information. Therefore, this study proposes to hybrid five types of machine learning operators into an integrated diagnosis model, as an auxiliary diagnostic approach, to cooperate with the AD-clinical analysis. To improve the diagnose accuracy, the participating rate of each operator in the proposed model may adjust adaptively according to the result of the data learning. After a set of experimental evaluations, the proposed model, acting as the preliminary AD-discriminant, has reached an accuracy of over 80%, which provides a promising instance for medical colleagues.

A RARE CASE OF AN ACUTE ON CHRONIC THORACOABDOMINAL AORTIC DISSECTION

Aortic dissection (AD) is a rare cardiovascular emergency with a high rate of mortality. Most patients present with typical signs and symptoms of AD. However, atypical presentation increases risk of delay in diagnosis and treatment. Patients may present with syncope, seizures or other neurological symptoms which may deceive the diagnosis of AD. Dissection can be in the acute or chronic phase, but there has been no documentation of an acute dissection which occurs in a chronic dissection. We hereby to report a case of an acute on chronic thoraco-abdominal dissection.

Abstract 351: Focal Adhesion Kinase Promotes Tissue Destruction in Aortic Dissection in Mice

Aortic dissection (AD) is a fatal disease due to the sudden destruction of the aortic medial layer. Currently, Molecular pathogenesis of AD is unknown. We investigated the role of focal adhesion kinase (FAK), a mechanosensitive signal transducer, in AD pathogenesis. We created a mouse model of AD with a continuous infusion of beta-aminopropionitrile (150 mg/kg/day), a collagen crosslink inhibitor, and angiotensin II (1,000 ng/kg/min) (BAPN + Ang II) by osmotic pumps. This AD model showed about 60% mortality within 2 weeks due to AD rupture. Immunohistochemical staining for activated FAK revealed that FAK was inactive in normal mouse aorta, but was strongly activated in the aortic walls after BAPN + Ang II infusion. Immunofluorescence staining showed that FAK was activated mainly in smooth muscle cells after the BAPN + Ang II challenge. Western blot analysis revealed that FAK was activated in 3 days after BAPN + Ang II infusion before AD development, followed by transient reduction at day 7, and re-activation after AD development at day 14. We examined the effect of PND-1186, an orally available FAK inhibitor, on the severity as determined by the AD lesion length and the mortality of AD. Mice were administered with either vehicle or PND-1186 (150 mg/kg twice daily by oral gavage) during the BAPN + Ang II challenge (n=20 for each group). Administration of PND-1186 resulted in significant reduction in the lesion length of AD (vehicle; 12.5 ± 1.65 mm, PND; 7.46 ± 1.88 mm, P<0.05). The suppressive effect of PND-1186 was most significant in the aortic arch (vehicle; 2.13 ± 0.29 mm, PND; 0.85 ± 0.22 mm, P<0.01). Furthermore, PND-1186 significantly improved the survival rate of mice from 40.0% to 80.0% (P<0.01). Transcriptome analysis indicated that destruction and inflammation of tissue were suppressed by PND-1186 administration. These findings indicated that FAK plays an important role in AD pathogenesis, possibly by transducing the pathological stress to the tissue destructive response in the aortic walls. We propose that FAK is a potential therapeutic target to limit the fatal destruction of aortic walls in AD.

Unpreventable Maternal Death In Spite Of the Advances in Antenatal Care; a Case Report

Aortic dissection (AoD) is a very rare but potentially fatal entity during pregnancy. The incidence of acute aortic dissection during pregnancy is about 0.4 cases per 100 000 persons yearly. A 28-year-old 38-week primi was referred to the hospital following sudden onset of burning epigastric pain which developed while returning from the routine visit to the cardiologist. She was treated for gastritis in the ward and a few hours later she developed shortness of breath, tight chest pain and tachycardia. Emergency LSCS was done and a live baby was delivered and she had sudden cardiac arrest soon after the extubation, in spite of the intensive resuscitation measures including six units of blood transfusion. She was diagnosed with mild aortic regurgitation and trivial mitral regurgitation before the pregnancy and was referred to the cardiologist during the first trimester and was confirmed with low cardiac risk. She was seen by the cardiologist during all 3 trimesters and was concluded with low cardiac risk. The autopsy revealed 2750 ml of blood in the chest cavity and 750 ml of blood in the abdominal cavity. There was a collection of blood which was infiltrated into the mediastinal tissues around the aorta. There were macroscopic features of aortic dissection and the microscopy of the aorta revealed degeneration of tunica media, a through and through tear on intima with leakage of blood into the surrounding tissues. This case report illustrates that the pregnancy itself is a risk factor for the development of AoD which leads to the catastrophic disorder in pregnancy.

A Diagnostic Conundrum in a Localized Ascending Aortic Aneurysm

Aortic dissection (AD) is an uncommon life-threatening emergency. Its development is usually subtle and easily missed. On the other hand, an aneurysm nearly always requires immediate surgical intervention. Both interventions are technically different and pose their own challenges. We experienced a distinct case of AD of the ascending aorta in a 65-year-old lady, who presented with a sudden onset of severe chest pain and shortness of breath. Thoracic aortic aneurysm was suspected as computed tomography revealed a saccular aneurysm of the proximal ascending aorta with no involvement of the valve and aortic branches. Surgery was decided after considering the risk of rupture and mortality. However, a diagnosis of localized aortic dissection was discovered and repaired accordingly. We discuss the pitfalls of diagnostic modalities and the techniques of surgical repair.

Aortic Dissection as a Complication in Patients on Maintenance Haemodialysis: Two Cases Report

Aortic dissection (AD) is a rare disease that may result in a fatal outcome. Uremic patients are often associated with factors susceptible to AD. We herein report two cases of AD occurring in maintenance haemodialysis patients. The two male Chinese had history of smoking and poor uncontrolled hypertension for many years. One patient died of the aortic wall rupture with conservative treatment. The other patient had a history of myocardial infarction and long-term administration of anti-platelet drugs. The patient survives after prompt stenting and continuous maintenance haemodialysis. It is important to improve our understanding about aortic dissection (AD) in haemodialysis patients because of the high mortality and morbidity. Once a patient on maintenance haemodialysis is diagnosed with AD, surgery or endovascular graft exclusion should be considered according to the actual situation of individual patients, and the mode of dialysis should be converted in conservation treatment patients.

Variants of genes encoding collagens and matrix metalloproteinase system increased the risk of aortic dissection

Aortic dissection (AD) is a devastating, heterogeneous condition of aorta. The homeostasis between collagens and matrix metalloproteases (MMPs)/tissue inhibitors of MMPs (TIMPs) system in the extracellular matrix plays an important role for structure and functions of aorta. However, our knowledge on association between variants of genes in this system and pathogenesis of AD is very limited. We analyzed all yet known coding human genes of collagens (45 genes), MMPs/TIMPs (27 genes) in 702 sporadic AD patients and in 163 matched healthy controls, by using massively targeted next-generation and Sanger sequencing. To define the pathogenesis of potential disease-causing candidate genes, we performed transcriptome sequencing and pedigree co-segregation analysis in some genes and generated Col5a2 knockout rats. We identified 257 pathogenic or likely pathogenic variants which involved 88.89% (64/72) genes in collagens-MMPs/TIMPs system and accounted for 31.05% (218/702) sporadic AD patients. In them, 84.86% patients (185/218) carried one variant, 12.84% two variants and 2.30% more than two variants. Importantly, we identified 52 novel probably pathogenic loss-of-function (LOF) variants (20 nonsense, 16 frameshift, 14 splice sites, one stop-loss, one initiation codon) in 11.06% (50/452) AD patients, which were absent in 163 controls (P=2.5×10−5). Transcriptome sequencing revealed that identified variants induced dyshomeostasis in expression of collagens-TIMPs/MMPs systems. The Col5a2−/− rats manifested growth retardation and aortic dysplasia. Our study provides a first comprehensive map of genetic alterations in collagens-MMPs/TIMPs system in sporadic AD patients and suggests that variants of these genes contribute largely to AD pathogenesis.

Burden of Aortic Dissection in Minorities: The Way Forward

Aortic dissection (AD) is a catastrophic but potentially preventable medical emergency. Delay in diagnosis and treatment of AD contributes to its high morbidity and mortality, especially in this population. We conducted a review of articles that describe the risk factors, gaps in management, and outcomes of AD in U.S. minority populations. Very few data exist on prospective, population-based AD, especially in underserved minority populations. AD confers significant burden on both the patient and the health system. From the economic and public health standpoint, disparities in access to health disproportionately affect minorities and can give rise to needless costs. Most of the risk factors for AD in minorities are modifiable and addressing them in a timely manner using a bidirectional approach ("Upstream" and "Downstream") could be cost-effective in reducing the burden of AD. Community health Workers (CHWs) have been shown to be effective in coordinating care for other emergency medical conditions in minorities but not for AD. We propose the integration of the CHWs and patientcentered medical home (PCMH) models into the care coordination effort for preventive and follow-up care of AD patients. Our main objective is to draw the attention of clinicians, researchers and policy makers to the current challenges of AD in minorities and sensitize them to our proposed evidence-based patient-centered, multidisciplinary community-based framework for addressing the burden of AD, in addition to conducting more prospective, population-based AD research in underserved minority populations.

INCIDENCE AND STRUCTURAL PREDICTORS OF AORTIC DISSECTION AMONG PATIENTS WITH GENETICALLY MEDIATED AORTIC ANEURYSMS: MULTICENTER FOLLOW-UP RESULTS FROM THE GENTAC (NATIONAL REGISTRY OF GENETICALLY TRIGGERED THORACIC AORTIC ANEURYSMS AND CARDIOVASCULAR CONDITIONS) REGISTRY

Aortic dissection (AD) is a serious complication of thoracic aortic aneurysm (TAA). Current day incidence and location of AD with genetically-mediated TAA are unknown. The population comprised adult GenTAC participants. Clinical assessment was done for AD within 1 month of registry enrollment, and

A rare clinical presentation of aortic dissection

Aortic dissection (AoD) is one of the most common catastrophes involving the aorta. Nevertheless, early diagnosis remains to be a challenge in the emergency department (ED), particularly in young individuals. The diagnosis of acute AoD is often delayed secondarily to its propensity to masquerade as other illnesses (i.e., renal colic, spinal-cord injury, and acute cauda equina syndrome) that result in acute lower-back pain (LBP). Here, we report a 38-year-old man who presented to our ED because of acute LBP with one leg numbness and weakness. It was subsequently found to have acute Type A AoD. This young man was diagnosed early in the ED and treated promptly without major adverse sequelae. We highlight that ED physicians should always keep high alertness in vascular emergencies (i.e., acute AoD), whilst engaging a patient with an acute-onset severe LBP with one leg numbness and weakness.

Chronic type B aortic dissection in association with Hemolyticuremic syndrome in a child

Aortic dissection (AD) is a potentially life-threatening medical emergency usually encountered in the elderly. Here, we report a 9-year-old child who was incidentally detected to have asymptomatic chronic type B dissecting aneurysm of aorta when he presented with relapse of Hemolytic uremic syndrome (HUS) without any genetic abnormalities like Marfan or Ehler-Danlos syndrome. To the best of our knowledge, this is the first case of AD associated with HUS in a child without any known associated genetic or inherited risk factors.