Acute Aortic Dissection

Assessing serum levels of SM22α as a new biomarker for patients with aortic aneurysm/dissection

Background

Aortic aneurysm/dissection (AAD) is now encountered more often because of the increasing prevalence of atherosclerosis and hypertension in the population. Despite many therapeutic improvements, in particular timely and successful surgery, in-hospital mortality rates are still higher. Timely identification of patients at high risk will help improve the overall prognosis of AAD. Since early clinical and radiological signs are nonspecific, there is an urgent need for accurate biomarkers. Smooth muscle 22α (SM22α) is a potential marker for AAD because of its abundant expression in vascular smooth muscle, which is involved in development of AAD.

Methods

We prepared three different mouse models, including abdominal aortic aneurysm, neointimal hyperplasia and atherosclerosis. SM22α levels were assessed in serum and vascular tissue of the mice. Next, the relationships between serum SM22α level and vascular lesion were studied in mice. Finally, serum from 41 patients with AAD, 107 carotid artery stenosis (CAS) patients and 40 healthy volunteers were tested for SM22α. Serum levels of SM22α were measured using an enzyme-linked immunosorbent assay (ELISA).

Results

Compared with the controls, serum SM22α levels were reduced in the models of aortic aneurysm, neointimal formation and atherosclerosis, and elevated in mice with ruptured aneurysm. Serum SM22α level was negatively correlated with apoptosis rate of vascular smooth muscle cells (VSMC), ratio of intima/ media (I/M) area and plaque size. Patients with AAD had significantly higher serum SM22α levels than patients with only CAS, or normal controls.

Conclusion

Serum SM22α could be a potential predictive marker for AAD, and regulation of VSMC is a possible mechanism for the effects of SM22α.

Acute Aortic Syndromes

Acute aortic syndromes, classified into aortic dissection, intramural hematoma, and penetrating aortic ulcer, are associated with high early mortality for which early diagnosis and management are crucial to optimize outcomes. Patients often present with nonspecific clinical symptoms and signs; therefore, it is important for providers to maintain a high index of suspicion for acute aortic syndromes. Electrocardiogram-gated computed tomographic angiography of the chest, abdomen, and pelvis is currently the most practical imaging modality for diagnosis and identification of complications. Evolution in surgical techniques and the development of aortic endografts have improved patient outcomes, but randomized trials are still needed.

Diagnostic value of monocyte to high-density lipoprotein ratio in acute aortic dissection in a Chinese han population

Background: Recently, considerable evidence pointed out monocyte to high-density lipoprotein ratio (MHR) is highly related to inflammatory related diseases. We aim to explore the level of MHR in acute aortic dissection (AAD) patients and determine whether MHR can be a novel diagnostic marker of AAD. Research design and methods: A total of 228 subjects including 128 AAD patients and 110 healthy control were enrolled. MHR levels and other serum samples were obtained at admission. Results: The baseline MHR levels were significantly higher in patients with AAD (p < 0.0001). A cutoff value of MHR >0.37 was associated with a sensitivity of 86.70% and a specificity of 93.60% for AAD. MHR levels were positively correlated with the time from symptom onset (R² = 0.0318, p = 0.0003). Additionally, the area under the curve (AUC) was increased to 0.979 in patients whose time from onset of symptoms >24 h, with a sensitivity of 98.04% and a specificity of 93.64%. Multivariate logistic regression demonstrated that MHR levels, history of hypertension, and coronary artery disease (CHD) emerged as independent predictors of AAD. Expert Opinion: MHR has a high diagnostic value in AAD patients, especially in those whose time from onset of symptoms >24 h.

Identification of Vinculin as a Potential Diagnostic Biomarker for Acute Aortic Dissection Using Label-Free Proteomics

Acute aortic dissection (AAD) is an emergent vascular disease. Currently, its diagnosis depends on clinical and radiological investigations but lacking of serum biomarkers. In this study, we aimed to identify potential serum biomarkers for AAD using label-free proteomics approach. A total of 90 serum samples were collected from three groups: patients with acute aortic dissection (AAD, n = 30), patients with acute myocardial infarction (AMI, n = 30), and healthy controls (n = 30), and the first four samples from each group were selected for label-free proteomics analysis. Using label-free approach, a total of 22 differentially expressed proteins were identified in the serum samples of the AAD group, of which 15 were upregulated and 7 were downregulated as compared to the AMI and healthy control groups. The most prominent increased protein was vinculin, which was selected to validate in total samples. The level of vinculin was significantly elevated in AAD patients (15.8 ng/ml, IQR: 9.3-19.9 ng/ml) than that in AMI patients (8.6 ng/ml, IQR:5.3-11.4 ng/ml) and healthy volunteers (5.3 ng/ml, IQR:2.8-7.6 ng/ml), P < 0.0001. Furthermore, the concentration of vinculin both increased in type A and B dissection. At the early stage of AAD, vinculin maintained a high level to 48 hours compared with that of AMI. Our study demonstrated that vinculin may play a role in the early diagnosis of AAD.

Circulating microRNAs: a novel potential biomarker for diagnosing acute aortic dissection

Acute aortic dissection (AAD) is a catastrophic emergency with high mortality and misdiagnosis rate. We aimed to determine whether circulating microRNAs allow to distinguish AAD from healthy controls and chest pain patients without AAD (CP). Plasma microRNAs expression were determined in 103 participants, including 37 AAD patients, 26 chronic aortic dissection patients, 17 healthy volunteers, 23 patients without AAD. We selected 16 microRNAs from microarray screening as candidates for further testing via qRT-PCR. The results showed that plasma miR-15a in patients with AAD (n = 37) had significantly higher expression levels than it from control group (n = 40; P = 0.008). By receiver operating characteristic curve analysis, the sensitivity was 75.7%; the specificity was 82.5%; and the AUC was 0.761 for detection of AAD. Furthermore, 37 patients with AAD had significantly higher plasma expression levels of let-7b, miR-15a, miR-23a and hcmv-miR-US33-5p compared with 14 CP patients of 40 controls (P = 0.000, 0.000, 0.026 and 0.011, respectively). The corresponding sensitivity were 79.4%, 75.7%, 91.9% and 73.5%, respectively; the specificity were 92.9%, 100%, 85.7% and 85.7%, respectively; and the AUCs of these microRNAs were 0.887, 0.855, 0.925 and 0.815, respectively. These data indicate that plasma miR-15a and miR-23a have promising clinical value in diagnosing AAD.

Brain Strokes Related to Aortic Aneurysma - the Analysis of three Cases

Brain stroke connected with aortic blood flow disturbances is a rare disease and its incidence is difficult to assume. Nevertheless, 10-50% of patients with aortic dissection may not experience any pain. In case of 18-30% patients with aortic dissection neurological signs are first disease presentation and among them ischemic stroke is the most common. The most popular aortic dissection classification is with use of Stanford system. Type A involves the ascending aorta and type B is occurring distal to the subclavian artery. Aortic dissection risk factors include hypertension, cystic medionecrosis, bicuspid aortic valve and Marfan's or Ehlers-Danlos syndrome.

Spectrum of Abdominal Aortic Disease in a Tertiary Health Care Setup: MDCT Based Observational Study

INTRODUCTION

Abdominal aortic disease is an important cause of clinical disability that requires early detection by imaging methods for prompt and effective management. Understanding regional disease pattern and prevalence has a bearing on healthcare management and resource planning. Non-invasive, conclusive imaging strategy plays an important role in the detection of disease. Multi-Detector Computed Tomography (MDCT) with its technological developments provides affordable, accurate and comprehensive imaging solution.

AIM

To evaluate regional demography of abdominal aortic disease spectrum detected using MDCT imaging data in a tertiary hospital.

MATERIALS AND METHODS

A descriptive study was conducted based on MDCT imaging data of patients who were investigated with clinical diagnosis of abdominal aortic disease, from March 2008-2010, over a period of 24 months. Patients were examined with the contrast-enhanced MDCT examination. Morphological diagnosis of the aortic disease was based on changes in relative aortic caliber, luminal irregularity, presence of wall calcification, dissection or thrombus and evidence of major branch occlusion. Patients were categorized into four groups based on imaging findings. MDCT information and associated clinical parameters were examined and correlated to management of patient. Descriptive statistical data, namely mean, standard deviation and frequency of disease were evaluated.

RESULTS

A total of 90 out of 210 patients (43%) were detected with the abdominal aortic abnormality defined by imaging criteria. Group I, comprising of patients with atherosclerosis -including those with complications, constituted 65.5% of the patients. Group II represented patients with aneurysms (45.5%). Group III, consisting of 32.2% of the patients, contained those with dissections. The rest of the patients, including patients with aorto-arteritis, were classified as group IV. Eight patients with aneurysm and one patient with aorto-arteritis were considered for surgical treatment. Ten patients with dissection underwent endovascular procedure. Rest of the patients was managed conservatively.

CONCLUSION

Aortic disease was observed in 43% of investigated patients. Atherosclerosis with and without aortic aneurysm constituted the largest group. MDCT provided comprehensive information about the lesion and associated complications. In view of the wider availability and desired imaging qualities, MDCT provided optimal information for diagnosis and management of aortic pathology. Majority of our patients (90%) were treated conservatively.

A case of ascending aortic dissection mimicking acute myocardial infarction and complicated with pericardial tamponade

Acute aortic dissection (AD) is the most common life-threatening disorder affecting the aorta with an incidence that ranges between 5 to 30 cases per million people per year. The symptoms of aortic dissection may be variable and can mimic other more common conditions such as myocardial ischemia. We report a case of a 60-year-old male who presented with inferior wall ST-elevation myocardial infarction (MI). Emergent coronary angiography revealed an ascending aortic dissection with normal coronary arteries. In addition, his aortic dissection was complicated with pericardial tamponade. The patient was managed with an immediate surgical repair, after that he had an uncomplicated postoperative course and was discharged in a stable condition. This case report illustrates the importance of having a high index of suspicion for AD in cases of chest pain. If AD is suspected in a patient with acute coronary syndrome (ACS), confirming the diagnosis with the appropriate imaging studies should be done as quickly as possible, as misdiagnosis with ACS may lead to the inappropriate administration of thrombolytic or anticoagulant agents resulting in catastrophic outcomes.

Genetic variants in FBN-1 and risk for thoracic aortic aneurysm and dissection

Objectives

A recent genome wide association study (GWAS) by LeMaire et al. found that two single nucleotide polymorphisms (SNPs), rs2118181 and rs10519177 in the FBN-1 gene (encoding Fibrillin-1), were associated with thoracic aortic dissection (TAD), non-dissecting thoracic aortic aneurysm (TAA), and thoracic aortic aneurysm or dissection (TAAD); the largest effect was observed for the association of rs2118181 with TAD. We investigated whether rs2118181 and rs10519177 were associated with TAD, TAA, and TAAD in the Yale study.

Methods

The genotypes of rs2118181 and rs10519177 were determined for participants in the Yale study: 637 TAAD cases (140 TAD, 497 TAA) and 275 controls from the United States, Hungary, and Greece. The association of the genotypes with TAD, TAA and TAAD were assessed using logistic regression models adjusted for sex, age, study center and hypertension.

Results and Conclusions

In the Yale study, rs2118181 was associated with TAD: compared with non-carriers, carriers of the risk allele had an unadjusted odds ratio for TAD of 1.80 (95% CI 1.15–2.80) and they had odds ratio for TAD of 1.87 (95% CI 1.09–3.20) after adjusting for sex, age, study center and hypertension. We did not find significant differences in aortic size, a potential confounder for TAD, between rs2118181 risk variant carriers and non-carriers: mean aortic size was 5.56 (95% CI: 5.37–5.73) for risk variant carriers (CC+CT) and was 5.48 (95% CI: 5.36–5.61) for noncarriers (TT) (p = 0.56). rs2118181 was not associated with TAA or TAAD. rs10519177 was not associated with TAD, TAA, or TAAD in the Yale study. Thus, the Yale study provided further support for the association of the FBN-1 rs2118181SNP with TAD.

Acute aortic dissection with tear in ascending aorta not diagnosed until necropsy or operation (for another condition) and comparison to similar cases receiving proper operative therapy

Acute aortic dissection (AD) with a tear in ascending aorta (AA) is recognized to masquerade occasionally as another condition, and therefore the proper diagnosis is never made or made too late. During a recent 3-year period (2009 to 2011) at Baylor University Medical Center at Dallas, 30 patients with acute AD with tear in AA were diagnosed: 23 (77%) were diagnosed clinically and underwent proper urgent operative therapy; the remaining 7 (23%) with AD with tear in AA were not diagnosed until operation (for another condition) or necropsy or retrospectively by review of antemortem computed tomographic scan after death. The number of patients with AD from tear in AA whose cardiac condition was not diagnosed clinically and who died in the hospital but did not have an autopsy is unclear. Because the autopsy rate in most United States hospitals, including Baylor University Medical Center, is now <5%, many cases of AD are probably not diagnosed and thus its frequency is being underestimated. In conclusion, ≥ 7 of 30 patients (23%) with acute AD with a tear in AA were not diagnosed until necropsy or operation (for another condition) or retrospectively by computed tomography during a 3-year period at a large tertiary medical center showing that this condition continues to be underdiagnosed, and when not diagnosed correctly is usually rapidly fatal. Because the autopsy rate today is so low, the percentage not diagnosed clinically is probably >23%.

Evidence, lack of evidence, controversy, and debate in the provision and performance of the surgery of acute type A aortic dissection

Acute type A aortic dissection is a lethal condition requiring emergency surgery. It has diverse presentations, and the diagnosis can be missed or delayed. Once diagnosed, decisions with regard to initial management, transfer, appropriateness of surgery, timing of operation, and intervention for malperfusion complications are necessary. The goals of surgery are to save life by prevention of pericardial tamponade or intra-pericardial aortic rupture, to resect the primary entry tear, to correct or prevent any malperfusion and aortic valve regurgitation, and if possible to prevent late dissection-related complications in the proximal and downstream aorta. No randomized trials of treatment or techniques have ever been performed, and novel therapies-particularly with regard to extent of surgery-are being devised and implemented, but their role needs to be defined. Overall, except in highly specialized centers, surgical outcomes might be static, and there is abundant room for improvement. By highlighting difficulties and controversies in diagnosis, patient selection, and surgical therapy, our over-arching goal should be to enfranchise more patients for treatment and improve surgical outcomes.

Biomarkers in acute aortic dissection and other aortic syndromes

Acute aortic syndromes have an incidence of >30 per million per annum and a high mortality without definitive treatment. Survival may relate to the speed of diagnosis. Although pain is the most common symptom, there is a large fraction of patients in whom the diagnosis may be mistaken or overlooked. Currently, a high index of clinical suspicion is the chief prompt that diverts a patient into a definitive algorithm of imaging investigations. Although there is no point-of-care biochemical test that can be reliably used to positively identify dissection, biomarkers are available that could accelerate the diagnostic pathway and thereby expedite treatment.

Bedside diagnosis of extensive aortic dissection

Acute aortic dissection (AAD) is a disease of relatively low incidence but very high mortality. Its presenting symptoms and signs are highly variable and frequently overlap with other less critical etiologies. The majority of patients expire prior to presentation to the Emergency Department. However, an even further complication is that nearly one-third of patients with AAD are misdiagnosed on initial evaluation. Standard imaging modalities for diagnosis of dissection include trans-esophageal echocardiography, CM and magnetic resonance imaging. All of these are expensive, time consuming and may not be readily available in a point of care setting. We present a case of an extensive AAD identified in a young patient with abdominal pain and neurological deficits. Point of care ultrasound allowed the identification of an intimal flap in multiple locations and resulted in rapid diagnosis and treatment.

Three-dimensional Contrast-enhanced MR Angiography of Aortic Dissection: A Pictorial Essay

Aortic dissection is a catastrophic aortic disorder with high morbidity and mortality rates. Prognosis and treatment vary with different types of aortic dissection; therefore, prompt and accurate diagnosis is essential. Ultrasonography is widely available and can be used even in relatively unstable patients. However, it has limited diagnostic accuracy and cannot provide three-dimensional (3D) display images for treatment planning. Both computed tomographic (CT) angiography and 3D contrast material-enhanced magnetic resonance (MR) angiography can accurately demonstrate aortic dissection, with CT having the advantages of wider availability and shorter imaging times. However, contrast-enhanced MR angiography is more suitable in medically stable patients, does not involve nephrotoxic contrast agent or ionizing radiation, and offers greater ease and speed of postprocessing. In clinical practice, contrast-enhanced MR angiography can provide high-quality imaging data suitable for 3D reconstructions. It also has excellent spatial and contrast resolution and allows studies to be performed in multiple vascular phases, making it valuable for the diagnosis and classification of aortic dissection and in providing information that is helpful for treatment planning. Three-dimensional contrast-enhanced MR angiography with postprocessing is a fast, accurate, and noninvasive technique that may prove to be the optimal imaging modality in medically stable patients with aortic dissection.

Aortic dissection presenting as concomitant stroke and STEMI

Aortic dissection is a disease of immediate consequence,as mortality of a proximal dissection is in excess of 50% when left untreated. Early recognition of the dissection event can lead to faster definitive correction with surgical and/or novel percutaneous approaches. Widely varying signs and symptoms can, however, make this diagnosis a challenge, further complicated by the fact that no specific imaging modality is ideal, nor immediately available, in all cases. Care must be taken inpatients where methodical evaluation is difficult,including physical exam, standard electrocardiogram and chest X-ray, before more definitive imaging. This is a case of aortic dissection that is presented as concomitant ST elevation myocardial infarction and embolic stroke, in which the patient received thrombolytics before diagnosis of the dissection itself. This arguably may have worsened her clinical course.

Frequency of and inappropriate treatment of misdiagnosis of acute aortic dissection

Acute aortic syndrome (AAS) comprises acute aortic dissection, intramural hematoma, and penetrating ulcer of the aorta. The importance of accurate, rapid diagnosis and intervention for AAS is underscored by its clinical and epidemiologic overlap with acute coronary syndrome and by the risks of inappropriate treatment with antithrombotic agents. To explore these concerns, the recognition, management, and outcomes of AAS in the contemporary experience of a tertiary referral center were reviewed. Sixty-six consecutive patients with AAS admitted from January 2000 to December 2004 were identified, and their records reviewed. Misdiagnosis occurred in 39% (n = 26) and was associated with longer time to correct diagnosis (mean +/- SEM 51 +/- 12 vs 15 +/- 5 hours, p = 0.003). Acute coronary syndrome was the most common misdiagnosis, resulting in inappropriate treatment with acetylsalicylic acid in 26 (100%), clopidogrel in 1 (4%), heparin in 22 (85%), and fibrinolytic agents in 3 (12%). Exposure to antithrombotic agents was associated with higher rates of major bleeding (38% vs 13%) and a trend toward greater in-hospital mortality (27% vs 13%) (p = 0.02 for combined end point). Antithrombotic agent administration was also associated with increased hemorrhagic pericardial fluid (50% vs 25%), hemorrhagic pleural effusion (15% vs 3%), and hemodynamic instability (30% vs 13%) (p = 0.02 for combined end point). In conclusion, AAS is frequently confused with acute coronary syndrome, leading to delayed diagnosis and clinically significant bleeding as a consequence of inappropriate treatment with antithrombotic agents.

Acute type A aortic dissection: an update on a still challenging disease

The aim of this report is to offer a concise review of the current knowledge of type A aortic dissection aetiology and pathogenesis, to propose an updated diagnostic algorithm, to provide descriptions of current surgical and endovascular techniques for treatment, and to emphasise criteria for patient follow-up. Additional information regarding the institutional experience developed in a tertiary university hospital with a 25-year exposure to aortic dissection is also included to provide a comprehensive view of a clinical entity that still challenges physicians and surgeons.

Clinical presentation is the main predictor of in-hospital death for patients with acute type a aortic dissection admitted for surgical treatment: A 25 years experience

BACKGROUND

This retrospective analysis assessed the hypothesis that clinical status on admission more than other variables related to surgical or post-operative management may influence in-hospital mortality after surgical treatment of acute type A aortic dissection.

METHODS

Between January 1979 and April 2004, 311 patients, mean age of 59.5+/-13 years (range, 18 to 88 years), with acute type A aortic dissection were referred for surgery. Logistic regression analysis was applied to demographics, etiological, clinical, and surgical variables, to identify independent predictors of in hospital death.

RESULTS

In hospital mortality rate was 23%. Univariate analysis showed older age (p=0.03, OR1.02/yrs), cardiac tamponade (p=0.001; OR 2.43), hypotension (p=0.0001; OR 8), myocardial ischemia (p=0.005; OR 7), acute renal failure (p=0.0001; OR 4.16), limb ischemia (p=0.0002; OR 3.3), neurological deficits pre-op (p=0.0001; OR 8.5), and mesenteric ischemia (p=0.003) as independent predictors of in-hospital death. Multivariate analysis identified the following presenting variables as predictors of in-hospital death: hypotension (p=0.003; OR 7.4), myocardial ischemia (p=0.03; OR 5.8), mesenteric ischemia (p=0.009), acute renal failure (p=0.0001; OR 3.9), neurological deficits (p=0.0001; OR 7.7). In-hospital mortality for the group of patients presenting with at least one of the tested pre-operative complications (N=158; 51%) was 33% vs 12% (p=00001). No other variables emerged as significant for in-hospital death.

CONCLUSION

In an era of standardized surgical technique, expeditious referral and intervention by lowering preoperative dissection-related complications and co-morbidities might represent the most efficacious tool to improve results.