2010 ACCF/AHA/AATS/ACR/ASA/SCA/SCAI/SIR/STS/SVM Guidelines for the Diagnosis and Management of Patients With Thoracic Aortic Disease: Executive Summary

Fully percutaneous treatment of an aberrant right subclavian artery and thoracic aortic aneurysm

Treatment of an aberrant right subclavian artery (arteria lusoria) aneurysm is traditionally performed surgically or via a hybrid approach. To our knowledge, a fully percutaneous approach has not yet been reported. We describe the fully endovascular exclusion of an aberrant right subclavian artery and thoracic aortic aneurysm. This approach has the potential advantage of avoiding complications of an open surgical repair, particularly in patients of advanced age and/or with multiple comorbidities.

Hypertensive Crisis, Burden, Management, and Outcome at a Tertiary Care Center in Karachi

Objectives. Hypertension, if uncontrolled, can lead to hypertensive crisis. We aim to determine the prevalence of hypertensive crisis, its management, and outcome in patients presenting to a tertiary care center in Karachi. Methods. This was a cross-sectional study conducted at the Aga Khan University, Karachi, Pakistan. Adult inpatients (>18 yrs) presenting to the ER who were known hypertensive and had uncontrolled hypertension were included. Results. Out of 1336 patients, 28.6% (387) had uncontrolled hypertension. The prevalence of hypertensive crisis among uncontrolled hypertensive was 56.3% (218). Per oral calcium channel blocker; 35.4% (137) and intravenous nitrate; 22.7% (88) were the most commonly administered medication in the ER. The mean (SD) drop in SBP in patients with hypertensive crisis on intravenous treatment was 53.1 (29) mm Hg and on per oral treatment was 43 (27) mm Hg. The maximum mean (SD) drop in blood pressure was seen by intravenous sodium nitroprusside; 80 (51) mm Hg in SBP. Acute renal failure was the most common complication with a prevalence of 11.5% (24). Conclusion. The prevalence of hypertensive crisis is high. Per oral calcium channel blocker and intravenous nitrate are the most commonly administered medications in our setup.

Impact of cardiovascular risk factors on vessel wall inflammation and calcified plaque burden differs across vascular beds: a PET-CT study

To evaluate the effect of age, gender and cardiovascular risk factors on vessel wall inflammation and the calcified plaque burden in different vascular beds as assessed by PET/CT. 315 patients (mean age: 57.8 years, 123 male and 192 female) who underwent whole body 18F-FDG PET/CT examinations were included in the study. Blood pool-corrected standardised uptake value (TBR) and the calcified plaque score (CPS, grade 0-4) were determined in the thoracic and abdominal aorta, both common carotid and both iliac arteries. The following cardiovascular risk factors were documented: Age ≥65 years (n = 114), male gender (n = 123), diabetes (n = 15), hyperlipidemia (n = 62), hypertension (n = 76), body mass index (BMI) ≥ 30 (n = 38), current smoker (n = 32). Effects of risk factors on TBR and CPS in different arterial beds were assessed using multivariate regression analysis. In the thoracic aorta TBR was independently associated with age ≥65 years and male gender, CPS was independently associated with age ≥65 years, male gender, hypertension and diabetes. In the abdominal aorta, TBR was independently associated with age ≥65 years and male gender, CPS with age ≥65 years, diabetes and smoking. Independent associations in the carotid arteries were found for age ≥65 years, male gender and BMI ≥ 30 in TBR and for age ≥65 and diabetes in CPS. In the iliac arteries, TBR was independently associated with age ≥65 and CPS with age ≥65, male gender, hypertension, diabetes and smoking. Findings of this PET/CT study demonstrate that the impact of cardiovascular risk factors on vessel wall inflammation and calcified plaque burden differs across vascular territories. Overall, CPS was more closely associated with cardiovascular risk factors compared to TBR.

Analysis of the thoracic aorta using a semi-automated post processing tool

OBJECTIVE

To evaluates a semi-automated method for Thoracic Aortic Aneurysm (TAA) measurement using ECG-gated Dual Source CT Angiogram (DSCTA).

METHODS

This retrospective HIPAA compliant study was approved by our IRB. Transaxial maximum diameters of outer wall to outer wall were studied in fifty patients at seven anatomic locations of the thoracic aorta: annulus, sinus, sinotubular junction (STJ), mid ascending aorta (MAA) at the level of right pulmonary artery, proximal aortic arch (PROX) immediately proximal to innominate artery, distal aortic arch (DIST) immediately distal to left subclavian artery, and descending aorta (DESC) at the level of diaphragm. Measurements were performed using a manual method and semi-automated software. All readers repeated their measurements. Inter-method, intra-observer and inter-observer agreements were evaluated according to intraclass correlation coefficient (ICC) and Bland-Altman plot. The number of cases with manual contouring or center line adjustment for the semi-automated method and also the post-processing time for each method were recorded.

RESULTS

The mean difference between semi-automated and manual methods was less than 1.3mm at all seven points. Strong inter-method, inter-observer and intra-observer agreement was recorded at all levels (ICC ≥ 0.9). The maximum rate of manual adjustment of center line and contour was at the level of annulus. The average time for manual post-processing of the aorta was 19 ± 0.3 min, while it took 8.26 ± 2.1 min to do the measurements with the semi-automated tool (Vitrea version 6.0.0.1 software). The center line was edited manually at all levels, with most corrections at the level of annulus (60%), while the contour was adjusted at all levels with highest and lowest number of corrections at the levels of annulus and DESC (75% and 0.07% of the cases), respectively.

CONCLUSION

Compared to the commonly used manual method, semi-automated measurement of vessel dimensions is feasible in the thoracic aorta with the advantage of reduced post-processing time.

External aortic root support: a histological and mechanical study in sheep

OBJECTIVES

Personalized external aortic root support has completed initial evaluation and has technology appraisal in the UK for patients with Marfan syndrome for use as an alternative to root replacement. Its long-term success in preventing aortic dissection remains uncertain. Here, we report a study in sheep to establish whether the externally supporting mesh, as used clinically, is biologically incorporated. The strength of the resulting mesh/artery composite has been tested.

METHODS

The carotid artery of growing sheep (n=6) was enclosed in a mesh sleeve made of a polymer, polyethylene terephthalate. After a predefined interval of 4-6 months, a length of the artery was excised, including the sleeved and unsleeved portions, and was stress tested and examined histologically.

RESULTS

One animal died of pneumonia 7 days after implantation. Comparing sleeved with normal segments, the overall thickness was increased and there was a fibrotic sheet in the periarterial space. The overall vessel wall architecture was preserved in all specimens. Although media thickness of ensleeved arteries was smaller and in one animal mild oedema was found in one quadrant of the outer part of the media. There was a significant increase in stiffness and maximum tensile strength of the supported segments compared with normal arterial tissue.

CONCLUSIONS

Polyethylene terephthalate mesh, as used for the external support of the dilated aortic root in Marfan syndrome, becomes incorporated in the periadventitial tissue of the carotid artery of sheep. Limited thinning of the media, without any signs of inflammation or medial necrosis, was visible. There was a significantly greater tensile strength in the carotid artery/mesh composite compared with the unsleeved carotid artery.

Bicuspid aortic valve: inter-racial difference in frequency and aortic dimensions

OBJECTIVES

The objective of this study was to examine the similarities and differences in Caucasian (C) and African-American (AA) patients with bicuspid aortic valve (BAV) with respect to morphology, severity of aortic stenosis/insufficiency, and aortic dilation.

BACKGROUND

BAV is a common congenital valve abnormality, accounting for a large number of valve replacements.

METHODS

A total of 229 patients with the diagnostic code BAV were identified retrospectively from our computerized adult echocardiographic database, which consists of 91,896 studies performed at the University of Chicago Medical Center from 1998 to 2009, representing 40,878 patients. Of those, 183 patients with BAV were included in this retrospective BAV single-center cohort study and reanalyzed with a comprehensive assessment of aortic dimensions, aortic valve morphology and function, clinical cardiovascular risk factors, and patient characteristics.

RESULTS

Of the 183 patients with BAV, 138 were C and 45 were AA. Our echocardiographic database encompasses approximately 65% AA, 31% C, and 4% other races, for an estimated frequency of BAV in AA patients of 0.17% and a frequency in C patients of 1.1% (p = 0.001). There were no significant inter-racial differences regarding sex, height, weight, hyperlipidemia, diabetes, tobacco use, cardiac medications, and left ventricular ejection fraction. The AA cohort was older (age 50 ± 17 years vs. 43 ± 17 years, p < 0.05) and had a higher prevalence of hypertension (51% vs. 24%, p < 0.05). After adjusting for comorbidities, aortic dimensions were larger in C (C vs. AA: annulus, 2.4 ± 0.4 vs. 2.1 ± 0.4 cm; sinuses of Valsalva, 3.4 ± 0.7 vs. 3.1 ± 0.6 cm; sinotubular junction, 3.0 ± 0.6 vs. 2.6 ± 0.5 cm; and ascending aorta, 3.5 ± 0.7 vs. 3.2 ± 0.5 cm; all p values <0.05).

CONCLUSIONS

This is the first study to report racial differences among patients with BAV with reduced aortic dimensions in AA patients despite the presence of more risk factors, suggestive of marked heterogeneity in the BAV population and indicating race as a potential disease modifier in BAV.

The role of mandatory lifelong annual surveillance after thoracic endovascular repair

Thoracic endovascular aortic repair (TEVAR) has become an attractive and well-accepted option for the management of the various thoracic aortic pathologies that vascular surgeons are confronted with. As in the abdominal aorta, current management trends include the treatment of younger patients with longer life expectancies, raising the issue of postoperative surveillance. There are several relevant differences between these anatomic areas when it comes to surveillance, including the relative inaccessibility of the thoracic aorta to ultrasound interrogation and the increased variability of thoracic aortic pathologies and post-TEVAR complications. In addition, concerns regarding radiation-induced carcinogenesis and contrast-induced nephropathy reduce the enthusiasm of many surgeons for regular computed tomography surveillance. Most agree that surveillance is important after TEVAR, but the method, duration, and frequency of that surveillance is much less clear and is the topic of this debate.

Fatal aortic dissection in a patient with giant cell arteritis: a case report and review of the literature

Giant cell arteritis may lead to catastrophic, large-vessel complications from chronic vascular wall inflammation without prompt diagnosis and treatment. We describe a rare case of acute aortic dissection without preceding aneurysm secondary to histologically confirmed giant cell arteritis (GCA) in an 85-year-old female with a four-year history of polymyalgia rheumatica and temporal arteritis diagnosed per biopsy six months prior to presentation. The literature is reviewed and the clinical implications of this case are discussed.

Cardiovascular magnetic resonance as an alternate method for serial evaluation of proximal aorta: comparison with echocardiography

Thoracic aortic disease is a known cause of aortic dilatation and poses significant risk of aortic dissection and rupture. Serial assessment of aortic root dimensions is traditionally performed using echocardiography, which is limited with older age and following surgery, due to poor acoustic windows. Although diastolic measurements are utilized as standard practice in decision making of adult aortopathy, systolic diameters are utilized in pediatric practice. Three-dimensional steady-state free precision (3D-SSFP) has shown promise as an alternate method for providing accurate and reproducible aortic measurements. The agreement between proximal aorta measurements by diastolic 3D-SSFP and echocardiography (both systole and diastole) was examined in 40 subjects. The maximum inner diameters at aortic annulus, root and sinotubular junction demonstrated excellent agreement between 3D-SSFP and echocardiography for all the 3 levels. The best agreement was observed for diastolic root dimensions with a mean difference of +0.01 cm, limits of agreement being -0.26 to +0.28 cm. Three D-SSFP can be used interchangeably with echocardiography in the serial assessment of the aortic root size. Careful attention to obtain an imaging plane utilizing 3D multiplanar reformatting is critical to maximize the agreement between the two imaging modalities.

Bicuspid aortic valve disease and ascending aortic aneurysms: gaps in knowledge

The bicuspid aortic valve is the most common congenital cardiac anomaly in developed nations. The abnormal bicuspid morphology of the aortic valve results in valvular dysfunction and subsequent hemodynamic derangements. However, the clinical presentation of bicuspid aortic valve disease remains quite heterogeneous with patients presenting from infancy to late adulthood with variable degrees of valvular stenosis and insufficiency and associated abnormalities including aortic coarctation, hypoplastic left heart structures, and ascending aortic dilatation. Emerging evidence suggests that the heterogeneous presentation of bicuspid aortic valve phenotypes may be a more complex matter related to congenital, genetic, and/or connective tissue abnormalities. Optimal management of patients with BAV disease and associated ascending aortic aneurysms often requires a thoughtful approach, carefully assessing various risk factors of the aortic valve and the aorta and discerning individual indications for ongoing surveillance, medical management, and operative intervention. We review current concepts of anatomic classification, pathophysiology, natural history, and clinical management of bicuspid aortic valve disease with associated ascending aortic aneurysms.

Stanford type a aortic dissection in pregnancy: a diagnostic and management challenge

BACKGROUND

In women under the age of 40, over 50% of type A aortic dissections occur in the obstetric population. This is a complex situation, with potential catastrophic outcomes for mother and child. Time to diagnosis is often delayed by a low degree of suspicion, atypical presentation and difficulties investigating pregnant women. Management requires early involvement of multiple teams and appreciation of potential complications. We report our experience (the largest series described) and describe our surgical strategy.

METHODS

A retrospective search of the cardiothoracic surgical database at our centre from 2002 to 2010 identified five pregnant women with type A dissections.

RESULTS

Median time to diagnosis was 18.5 h (range 5.5-150 h) and median time from diagnosis to arrival in the operating theatre was 1.5 h (range 0.5-54 h). Four patients underwent concomitant Caesarean section and dissection repair. There was one maternal death and one unrelated foetal death.

CONCLUSION

Occurrence of type A aortic dissection in pregnant women is uncommon but potentially catastrophic. A high index of suspicion and timely investigations are necessary to expedite definitive management. Sound surgical strategies and collaboration with appropriate teams are necessary to optimise outcome.

Inferior myocardial infarction secondary to aortic dissection associated with bicuspid aortic valve

Aortic dissection (AD) is a life-threatening condition and may present with symptoms which mimic myocardial infarction, leading to misdiagnosis and inappropriate use of anticoagulant and thrombolytic therapy. A 40-year-old woman with no prior history presented in our emergency department with sudden chest pain. Electrocardiography (ECG) showed a ST-segment elevation in leads II, III and avF, suggesting an acute inferior myocardial infarction. The patient was given anticoagulation and antiplatelet treatment. Coronary angiography, transthoracic echocardiography and computed tomography were performed. The patient was diagnosed with DeBakey I aortic dissection extending from ascending aorta to iliac artery, and associated with bicuspid aortic valve.Surgical treatments with a replacement of the ascending aorta, aortic valve replacement and coronary artery bypass grafting were successfully performed. Early imaging examination, if possible, might assist the diagnosis and guide the management of this disease. The condition of myocardial infarction secondary to aortic dissection is discussed.

Bicuspid aortic valve and thoracic aortic aneurysm: three patient populations, two disease phenotypes, and one shared genotype

Bicuspid aortic valve (BAV) and thoracic aortic aneurysm (TAA) are two discrete cardiovascular phenotypes characterized by latent progressive disease states. There is a clear association between BAV and TAA; however the nature and extent of this relationship is unclear. There are both distinct and overlapping developmental pathways that have been established to contribute to the formation of the aortic valve and the aortic root, and the mature anatomy of these different tissue types is intimately intertwined. Likewise, human genetics studies have established apparently separate and common contributions to these clinical phenotypes, suggesting complex inheritance and a shared genetic basis and translating 3 patient populations, namely, BAV, TAA, or both, into a common but diverse etiology. A better understanding of the BAV-TAA association will provide an opportunity to leverage molecular information to modify clinical care through more sophisticated diagnostic testing, improved counseling, and ultimately new pharmacologic therapies.