Multimodality Imaging of Diseases of the Thoracic Aorta in Adults: From the American Society of Echocardiography and the European Association of Cardiovascular Imaging

Thromboatheromatous coarctation of the aorta diagnosed with intraoperative TOE during emergent open aneurysm clipping

A woman in her 50s presenting for emergent intracranial surgery was discovered to have a large incongruity in blood pressure between her right arm and her other extremities. Intraoperative rescue transoesophageal echocardiography (TOE) revealed a large thromboatheromatous burden in her descending aorta resulting in a functional coarctation. Usually diagnosed via CT imaging, we present what we believe to be the first published case diagnosed intraoperatively using TOE. After the diagnosis was made, blood pressure goals were adjusted to provide sufficient perfusion distally and her surgery was completed otherwise uneventfully.

Three-dimensional thoracic aorta principal strain analysis from routine ECG-gated computerized tomography: feasibility in patients undergoing transcatheter aortic valve replacement

BACKGROUND

Functional impairment of the aorta is a recognized complication of aortic and aortic valve disease. Aortic strain measurement provides effective quantification of mechanical aortic function, and 3-dimenional (3D) approaches may be desirable for serial evaluation. Computerized tomographic angiography (CTA) is routinely performed for various clinical indications, and offers the unique potential to study 3D aortic deformation. We sought to investigate the feasibility of performing 3D aortic strain analysis in a candidate population of patients undergoing transcatheter aortic valve replacement (TAVR).

METHODS

Twenty-one patients with severe aortic valve stenosis (AS) referred for TAVR underwent ECG-gated CTA and echocardiography. CTA images were analyzed using a 3D feature-tracking based technique to construct a dynamic aortic mesh model to perform peak principal strain amplitude (PPSA) analysis. Segmental strain values were correlated against clinical, hemodynamic and echocardiographic variables. Reproducibility analysis was performed.

RESULTS

The mean patient age was 81±6 years. Mean left ventricular ejection fraction was 52±14%, aortic valve area (AVA) 0.6±0.3 cm² and mean AS pressure gradient (MG) 44±11 mmHg. CTA-based 3D PPSA analysis was feasible in all subjects. Mean PPSA values for the global thoracic aorta, ascending aorta, aortic arch and descending aorta segments were 6.5±3.0, 10.2±6.0, 6.1±2.9 and 3.3±1.7%, respectively. 3D PSSA values demonstrated significantly more impairment with measures of worsening AS severity, including AVA and MG for the global thoracic aorta and ascending segment (p<0.001 for all). 3D PSSA was independently associated with AVA by multivariable modelling. Coefficients of variation for intra- and inter-observer variability were 5.8 and 7.2%, respectively.

CONCLUSIONS

Three-dimensional aortic PPSA analysis is clinically feasible from routine ECG-gated CTA. Appropriate reductions in PSSA were identified with increasing AS hemodynamic severity. Expanded study of 3D aortic PSSA for patients with various forms of aortic disease is warranted.

How can genetic diagnosis inform the decision of when to operate?

Genetic discovery for heritable thoracic aortic disease (HTAD) has been progressing at a brisk pace. Surgical management of thoracic aortic aneurysms and dissections has become more personalized, with genetic factors increasingly informing the decision of when to operate on patients. An improved understanding of genotype-phenotype correlations in patients with HTAD will ultimately lead to gene- and mutation-specific recommendations for surgical repair. Until more robust data from larger cohorts can inform our decisions, patients with HTAD should be seen by an aortic specialist for a tailored approach to elective surgical repair.

Perioperative transesophageal echocardiography for non-cardiac surgery

PURPOSE

The use of transesophageal echocardiography (TEE) has evolved to include patients undergoing high-risk non-cardiac procedures and patients with significant cardiac disease undergoing non-cardiac surgery. Implementation of basic TEE education in training programs has increased across a broad spectrum of procedures in the perioperative arena. This paper describes the use of perioperative TEE in non-cardiac surgery and provides an overview of the basic TEE examination.

PRINCIPAL FINDINGS

Perioperative TEE is used to monitor hemodynamic parameters in non-cardiac procedures where there is a high risk of hemodynamic instability. Its use extends to include moderate-risk procedures for patients with significant cardiac diseases such as low ejection fraction, hypertrophic cardiomyopathy, severe valve lesions, or congenital heart disease. Vascular procedures involving the aorta, blunt trauma, and liver transplantation are all examples of procedures that may benefit from TEE. Transesophageal echocardiography examination allows assessment of volume status, ventricular function, diagnosis of gross valvular pathology and pericardial tamponade, as well as close monitoring of cardiac output, response to therapy, and the impact of ongoing surgical manipulation. In patients with unexplained and unexpected hemodynamic instability, "rescue TEE" can be used to help identify the underlying cause.

CONCLUSIONS

Perioperative TEE is emerging as a preferred tool to manage hemodynamics in high-risk procedures and in high-risk patients undergoing non-cardiac surgery. A rescue TEE examination protocol is a helpful approach for early identification of the etiology of hemodynamic instability.

A simple patient-tailored aortic arch tangential angle measuring method to achieve better clinical results for thoracic endovascular repair of type B aortic dissection

Background

To report a simple individual tailored aortic arch tangential angle (θ-AATA) measuring method and its clinical application efficacy in the endovascular treatment of type B aortic dissection (AD).

Methods

From January 2013 to December 2014, acute type B AD patients were prospectively enrolled and treated with endovascular therapy in our center. Among these patients, a specific method was applied to measure θ-AATA based on the axial images of the CT scan. The length of proximal landing zone (PLZ) of each patient was measured at the routinely applied left-anterior oblique (LAO) 45-degree and θ-AATA. Respective treatment strategies based on the length of the PLZ were planned accordingly, and the stent-graft was deployed under the fluoroscopy at θ-AATA. The occurrence of immediate type I endoleak was recorded during the completion angiogram, while the alignment of the proximal marks was determined under fluoroscopy at θ-AATA and at LAO-45-degree as well.

Results

Totally 76 patients with type B AD were prospectively enrolled. The average value of θ-AATA was 58.3±5.2 degrees, which was significantly larger than the routine 45 degrees (P<0.01). The mean landing zone length measured under θ-AATA (18.4±3.9 mm) was longer than that (15.9±3.1 mm) obtained at the routine LAO-45 degrees (P<0.05). Stent-grafts' deployment strategies were substantially changed accordingly. Alignment of the proximal marks was achieved in 72 patients (93.4%) under θ-AATA and only in two patients (2.7%) at LAO-45 degrees (P<0.01). All stent-grafts' implantation was successfully completed. No major type I endoleak was found in the immediate post-deployment angiography.

Conclusions

It is easy to apply this patient-tailored θ-AATA measuring method in clinical practice. This more precise measurement is benefit for more reasonable treatment strategy planning, more precise deployment, and therefore a better outcome.

Aortic elongation part I: the normal aortic ageing process

OBJECTIVES

Differentiation between normal and abnormal features of vascular ageing is crucial, as the latter is associated with adverse outcomes. The normal aortic ageing process is accompanied by gradual luminal dilatation and reduction of vessel compliance. However, the influence of age on longitudinal aortic dimensions and geometry has not been well studied. This study aims to describe the normal evolution of aortic length and shape throughout life.

METHODS

A total of 210 consecutive patients were prospectively enrolled in this cross-sectional single-centre study. All subjects underwent CT on a third-generation dual-source CT scanner. Morphometric measurements, including measurements of segmental length and tortuosity, were performed on three-dimensional models of the thoracic aorta.

RESULTS

The length of the thoracic aorta was significantly related to age (r=0.54) and increased by 59 mm (males) or 66 mm (females) between the ages of 20 and 80 years. Elongation was most pronounced in the proximal descending aorta, which showed an almost 2.5-fold length increase during life. The lengthening of the thoracic aorta was accompanied by a marked change of its geometry: whereas the aortic apex was located between the branch vessels in younger patients, it shifted to a more distalward position in the elderly.

CONCLUSIONS

The normal ageing process is accompanied by gradual aortic elongation and a notable change of aortic geometry. Part II of this two-part article investigates the hypothesis that excessive elongation could play a role in the occurrence of acute aortic dissection.

Aortic elongation part II: the risk of acute type A aortic dissection

Objectives

Prophylactic surgery for prevention of acute type A aortic dissection (ATAAD) is reserved for patients with an ascending aortic aneurysm ≥55 mm. Identification of additional risk predictors is warranted since over 70% of patients presenting with ATAAD have a non-dilated aorta or an aneurysm that would not have met the diameter criterion for preventative surgery. Aim of the study was to evaluate ascending aortic elongation as a risk factor for ATAAD and to compare aortic lengths between ATAAD patients and healthy controls.

Methods

Aortic lengths and diameters of ATAAD patients were measured on three-dimensional modelled computed tomography and adjusted to predissection dimensions in this cross-sectional single-centre study. Logistic regression was used to evaluate the relation between ATAAD and aortic dimensions. Lengths of different aortic segments were compared with a healthy control group using propensity score matching.

Results

Two-hundred and fifty patients were included in the study (ATAAD, n=40; controls, n=210). Ascending aortic length and diameter proved to be independent predictors for ATAAD (OR=5.3, CI 2.5 to 11.4, p<0.001 and OR=8.6, CI 2.4 to 31.0, p=0.001). Eighty patients were matched based on propensity scores (ATAAD n=40, controls n=40). The ascending aorta was longer and more dilated in ATAAD patients compared with healthy controls (78.6±8.8 mm vs 68.9±7.2 mm, p<0.001, 34.4 mm ±3.2. vs 39.4 mm ±5.7, p<0.001, respectively). No differences were found in lengths of the aortic arch and descending aorta.

Conclusions

Ascending aortic length could serve as an independent predictor for ATAAD. Future studies addressing indications for prophylactic surgery should also investigate aortic length.

Aortic elongation and the risk for dissection: the Tübingen Aortic Pathoanatomy (TAIPAN) project†

OBJECTIVES

We measured aortic dimensions, particularly length parameters, using 3D imaging with the aim of refining the risk-morphology for Stanford type A aortic dissection (TAD).

METHODS

Computer tomography angiography studies were analysed using the curved multiplanar reformats. At defined landmarks, the diameters and lengths of aortic segments were recorded. Three groups were compared retrospectively: patients actually suffering from a TAD (TAD-group; n  = 150), patients before suffering a TAD (preTAD-group n  = 15) and a healthy control group ( n  = 215). Receiver operating characteristic curves (ROCs) were analysed (control versus preTAD) to study the diagnostic value of the individual variables.

RESULTS

Median diameters of preTAD (43 mm) and TAD (50 mm) aortas were significantly ( P  < 0.001) larger than those of the control group (35 mm). Ninety-three percent of preTAD and 68% of TAD aortas were less than 55 mm in the mid-ascending aorta. The ascending aorta and the aortic arch were significantly longer in both preTAD and TAD aortas compared to control aortas ( P  < 0.001); in the control aortas the central line distance from the aortic valve to the brachiocephalic trunk was 93 mm. In preTAD aortas, it was 111 mm, and it was 117 mm in TAD aortas ( P  < 0.001). In ROC analysis, the area under the curve was 0.912 for the ascending diameter and 0.787 for the ascending and arch lengths.

CONCLUSIONS

TAD-prediction based on the aortic diameter is ineffective. Besides circumferential dilatation, ascending aorta elongation precedes TAD and appears to be a useful additional parameter for prognostication. We propose a diagnostic score involving ascending aorta diameter and length.

Impact of aortic plaque on progression rate and prognosis of aortic stenosis

BACKGROUNDS

Patients with aortic stenosis (AS) have a high prevalence of aortic plaque. However, no data exist regarding the clinical significance and prognostic value of aortic plaque in AS patients. This study examines the impact of aortic plaque on the rate of progression and clinical outcomes of AS.

METHODS

We retrospectively investigated 1812 transesophageal echocardiographic examinations between 2008 and 2015. We selected 100 consecutive patients (mean age; 75.1±7.4years) who showed maximal aortic jet velocity (AV-Vel) ≥2.0m/s by transthoracic echocardiography (TTE) and received follow-up TTE (mean follow-up duration 25±17months), and the mean progression rate of AV-Vel was calculated. Clinical and echocardiographic characteristics, including severity of aortic plaque, and cardiac events were examined.

RESULTS

At initial TTE, mean AV-Vel was 3.68±0.94m/s and mean aortic valve area 0.98±0.32cm². Mean progression rate of AV-Vel was 0.41m/s/year in 38 patients with severe aortic plaque, and -0.03m/s/year in the remaining 62 patients without severe aortic plaque. Severe aortic plaque (odds ratio[OR], 8.32) and hemodialysis (OR, 6.03) were independent predictors of rapid progression. The event-free survival rate at 3years was significantly lower in patients with severe aortic plaque than in those without (52% vs 82%, p=0.002). Severe aortic plaque (hazard ratio[HR], 2.89) and AV-Vel at initial TTE (HR, 3.28) were identified as independent predictors of cardiac events.

CONCLUSION

Severe aortic plaque was a predictor of rapid progression and poor prognosis in AS patients. Evaluation of aortic plaque provides additional information regarding surgical scheduling and follow-up.

Bicuspid Aortic Valve Registry of the Italian Society of Echocardiography and Cardiovascular Imaging (REgistro della valvola aortica bicuspide della società italiana di ECocardiografia e CArdiovascular imaging): Rationale and Study Design

Background:

Bicuspid aortic valve (BAV) is the most common congenital heart disease, affecting 0.5%–2% of the general population. It is associated not only with notable valvular risk (aortic stenosis and/or regurgitation, endocarditis) but also with aortopathy with a wide spectrum of unpredictable clinical presentations, including aneurysmal dilation of the aortic root and/or ascending thoracic aorta, isthmic coarctation, aortic dissection, or wall rupture.

Methods:

The REgistro della Valvola Aortica Bicuspide della Società Italiana di ECocardiografia e CArdiovascular Imaging is a retrospective (from January 1, 2010)/prospective, multicenter, observational registry, expected to enroll 3000 patients with definitive diagnosis of BAV made by transthoracic and/or transesophageal echocardiography, computed tomography, cardiovascular magnetic resonance, or at surgery. Inclusion criteria were definitive diagnosis of BAV. Patients will be enrolled regardless of the presence and severity of aortic valve dysfunction or aortic vessel disease and the coexistence of other congenital cardiovascular malformations. Exclusion criteria were uncertain BAV diagnosis, impossibility of obtaining informed consent, inability to carry out the follow-up. Anamnestic, demographic, clinical, and instrumental data collected both at first evaluation and during follow-up will be integrated into dedicated software. The aim is to derive a data set of unselected BAV patients with the main purpose of assessing the current clinical presentation, management, and outcomes of BAV.

Conclusions:

A multicenter registry covering a large population of BAV patients could have a profound impact on the understanding of the natural history of this disease and could influence its management.

Ascending aortic size in aortic coarctation depends on aortic valve morphology: Understanding the bicuspid valve phenotype

BACKGROUND

In roughly half of patients with coarctation of the aorta (CoA), the aorta may be enlarged. It is uncertain whether enlargement is independent of aortic valve morphology. We sought to compare aortic size in CoA with a tricuspid valve (TAV) to those with bicuspid aortic valve (BAV).

METHODS

Sixty-eight CoA patients and 20 healthy controls with prior cardiac magnetic resonance (CMR) imaging were included. CMR was retrospectively reanalyzed to measure aortic root and mid-ascending aorta. The maximum aortic diameter was compared between CoA with TAV, CoA with BAV, and control groups.

RESULTS

CoA with TAV patients (n=27) had smaller aortic root diameters than CoA with BAV (n=41) (32±4.9 vs. 37±5.8mm, p=0.001), despite being older (40 vs. 32years, p=0.01). Similarly, TAV CoA patients had a smaller mid-ascending aortic diameter (28±4.5 vs. 33±6.9mm, p=0.019) than BAV patients. TAV CoA was similar to controls in all metrics. Twenty-four patients (35%) with CoA had dilated aortas (>37mm), of which 79% had BAV. A history of hypertension did not predict larger aortic root or mid-ascending aortic dimensions.

CONCLUSIONS

In patients with CoA, TAV is associated with smaller aortic size compared to those with BAV, and similar to healthy controls. Aortic size in CoA is independent of hypertension. Therefore, aortopathy associated with BAV is likely a reflection of the BAV phenotype rather than CoA or its physiologic effects. This distinction may have implications for the frequency and types of monitoring and treatment of CoA patients.

Ascending Aortic Dimensions in Former National Football League Athletes

BACKGROUND

Ascending aortic dimensions are slightly larger in young competitive athletes compared with sedentary controls, but rarely >40 mm. Whether this finding translates to aortic enlargement in older, former athletes is unknown.

METHODS AND RESULTS

This cross-sectional study involved a sample of 206 former National Football League (NFL) athletes compared with 759 male subjects from the DHS-2 (Dallas Heart Study-2; mean age of 57.1 and 53.6 years, respectively, P<0.0001; body surface area of 2.4 and 2.1 m², respectively, P<0.0001). Midascending aortic dimensions were obtained from computed tomographic scans performed as part of a NFL screening protocol or as part of the DHS. Compared with a population-based control group, former NFL athletes had significantly larger ascending aortic diameters (38±5 versus 34±4 mm; P<0.0001). A significantly higher proportion of former NFL athletes had an aorta of >40 mm (29.6% versus 8.6%; P<0.0001). After adjusting for age, race, body surface area, systolic blood pressure, history of hypertension, current smoking, diabetes mellitus, and lipid profile, the former NFL athletes still had significantly larger ascending aortas (P<0.0001). Former NFL athletes were twice as likely to have an aorta >40 mm after adjusting for the same parameters.

CONCLUSIONS

Ascending aortic dimensions were significantly larger in a sample of former NFL athletes after adjusting for their size, age, race, and cardiac risk factors. Whether this translates to an increased risk is unknown and requires further evaluation.

Increased Aortic Diameters on Multidetector Computed Tomographic Scan Are Independent Predictors of Incident Adverse Cardiovascular Events: The Framingham Heart Study

BACKGROUND

Adverse aortic remodeling, such as dilation, is associated with multiple cardiovascular disease (CVD) risk factors. We sought to determine whether measures of enlarged aortic diameters improve prediction of incident adverse CVD events above standard CVD risk factors in a community-dwelling cohort.

METHODS AND RESULTS

Participants from the Framingham Offspring and Third Generation Cohorts (n=3318; aged 48.9±10.3 years), who underwent noncontrast thoracic and abdominal multidetector computed tomography during 2002 to 2005, had complete risk factor profiles, and were free of clinical CVD, were included in this study. Diameters were measured at 4 anatomically defined locations: the ascending thoracic aorta, descending thoracic aorta, the infrarenal abdominal aorta, and lower abdominal aorta. Adverse events comprised CVD death, myocardial infarction, coronary insufficiency, index admission for heart failure, and stroke. Each aortic segment was dichotomized as enlarged (diameter ≥upper 90th percentile for age, sex, and body surface area) or not enlarged; the hazard of an adverse event for an enlarged segment was determined using multivariable-adjusted Cox proportional hazards models. Over a mean 8.8±2.0 years of follow-up, there were 177 incident adverse CVD events. In models adjusted for traditional CVD risk factors, enlarged infrarenal abdominal aorta (hazard ratio=1.57; 95% confidence interval=1.06 to 2.32) and lower abdominal aorta (hazard ratio=1.53; 95% confidence interval=1.00 to 2.34) were associated with an increased hazard of CVD events. Enlarged ascending thoracic aorta and descending thoracic aorta were not significantly associated with CVD events.

CONCLUSIONS

Among community-dwelling adults initially free of clinical CVD, enlarged infrarenal abdominal aorta and lower abdominal aorta, on noncontrast multidetector computed tomography scans, are independent predictors of incident adverse CVD events above traditional risk factors alone.

Incorrect Diagnosis of Type A Aortic Dissection Attributed to Motion Artifact During Computed Tomographic Angiography: A Case Report

Early diagnosis of aortic dissection is important to reduce mortality, with surgical management representing standard treatment. Current methods of diagnosing type A aortic dissection include computed tomography angiography (CTA), magnetic resonance imaging, catheter-based arteriography, and transesophageal echocardiography. While each method has merits, there exists potential for false-positive findings. We present a case of a patient who was diagnosed with type A aortic dissection by CTA, but was found to not have an aortic dissection by transesophageal echocardiography under general anesthesia, preventing an unnecessary sternotomy. The echocardiographic findings suggested CTA artifact.

Aortic Diameter Growth in Children With a Bicuspid Aortic Valve

Knowledge of aortic growth in patients with bicuspid aortic valve (BAV) is essential to identify patients at risk for dissection, but data on children remain unclear. We retrospectively evaluated the aortic diameters of all pediatric BAV patients, identified through an echocardiographic database (2005 to 2013). Medical records were reviewed and aortic diameters re-measured on echocardiographic images at diagnosis and if available on variable mid- and endpoints follow-up. Dilatation (z-score >2) was based on 2 different z-score equation methods (Gautier/Campens). In 234 of the total 250 BAV patients, aortic diameters were analyzed; median age was 6.1 years (interquartile range 1.7 to 10), of which 63% were male. Aortic coarctation was present in 81 (36%) patients, 23% had a ventricular septal defect. BAV morphology according to Sievers was as follows: type 0 in 128 patients (55%), type 1 in 96 (41%), and type 2 in 10 (4%). Ascending aortic (AA) dilatation was present in 24% (Gautier) and 36% (Campens) at inclusion. Median follow-up was 4.7 years. The AA was the only location where mean z-scores progressed significantly with age: 0.06 (Gautier) and 0.09 (Campens) units per year between ages 5 and 15 years. Associations for higher AA z-scores at older age were an initial z-score >2 (p <0.001) and aortic valve stenosis (p <0.05). Neither dissection nor preventive aortic surgery occurred. In conclusion, only the AA seems at risk for complication, although no aortic complications occurred in this pediatric BAV cohort. BAV morphology seems associated with larger AA z-scores and valvular dysfunction.

Aortic Elongation and Stanford B Dissection: The Tübingen Aortic Pathoanatomy (TAIPAN) Project

OBJECTIVE/BACKGROUND

Aortic elongation has not yet been considered as a potential risk factor for Stanford type B dissection (TBD). The role of both aortic elongation and dilatation in patients with TBD was evaluated.

METHODS

The aortic morphology of a healthy control group (n = 236) and patients with TBD (n = 96) was retrospectively examined using three dimensional computed tomography imaging. Curved multiplanar reformats were used to examine aortic diameters at defined landmarks and aortic segment lengths.

RESULTS

Diameters at all landmarks were significantly larger in the TBD group. The greatest diameter difference (56%) was measured in dissected descending aortas (p < .001). The segment with the most considerable difference between the study groups with regard to elongation was the non-dissected aortic arch of patients with TBD (36%; p < .001). Elongation in the aortic arch was accompanied by a diameter increase of 21% (p < .001). In receiver-operating curve analysis, the area under the curve was .85 for the diameter and .86 for the length of the aortic arch.

CONCLUSIONS

In addition to dilatation, aortic arch elongation is associated with the development of TBD. The diameter and length of the non-dissected aortic arch may be predictive for TBD and may possibly be used for risk assessment in the future. This study provides the basis for further prospective evaluation of these parameters.

Operative strategies to reduce cerebral embolic events during on- and off-pump coronary artery bypass surgery: A stratified, prospective randomized trial

OBJECTIVE

To determine the impact of different aortic clamping strategies on the incidence of cerebral embolic events during coronary artery bypass grafting (CABG).

METHODS

Between 2012 and 2015, 142 patients with low-grade aortic disease (epiaortic ultrasound grade I/II) undergoing primary isolated CABG were studied. Those undergoing off-pump CABG were randomized to a partial clamp (n = 36) or clampless facilitating device (CFD; n = 36) strategy. Those undergoing on-pump CABG were randomized to a single-clamp (n = 34) or double-clamp (n = 36) strategy. Transcranial Doppler ultrasonography (TCD) was performed to identify high-intensity transient signals (HITS) in the middle cerebral arteries during periods of aortic manipulation. Neurocognitive testing was performed at baseline and 30-days postoperatively. The primary endpoint was total number of HITS detected by TCD. Groups were compared using the Mann-Whitney U test.

RESULTS

In the off-pump group, the median number of total HITS were higher in the CFD subgroup (30.0; interquartile range [IQR], 22-43) compared with the partial clamp subgroup (7.0; IQR, 0-16; P < .0001). In the CFD subgroup, the median number of total HITS was significantly lower for patients with 1 CFD compared with patients with >1 CFD (12.5 [IQR, 4-19] vs 36.0 [IQR, 25-47]; P = .001). In the on-pump group, the median number of total HITS was 10.0 (IQR, 3-17) in the single-clamp group, compared with 16.0 (IQR, 4-49) in the double-clamp group (P = .10). There were no differences in neurocognitive outcomes across the groups.

CONCLUSIONS

For patients with low-grade aortic disease, the use of CFDs was associated with an increased rate of cerebral embolic events compared with partial clamping during off-pump CABG. A single-clamp strategy during on-pump CABG did not significantly reduce embolic events compared with a double-clamp strategy.

Imaging of the Postsurgical Thoracic Aorta: A State-of-the-Art Review

Techniques for repair of the aorta currently include open and endovascular methods, hybrid approaches, minimally-invasive techniques, and aortic branch vessel reimplantation or bypass. Collaboration among radiologists and vascular and cardiothoracic surgeons is essential. An awareness of the various surgical techniques, expected postoperative appearance, and potential complications is essential for radiologists. This review will cover the postoperative appearance of the thoracic aorta with a focus on the ascending aorta. The value of three-dimensional image evaluation will also be emphasized.

Aortic intramural hemorrhage: A distinct disease entity with mystery

Aortic intramural hemorrhage (IMH) is one of the disease processes that comprise the spectrum of acute aortic syndrome (AAS) with clinical manifestations and a mortality rate similar to those of classic aortic dissection (AD). However, IMH should be considered as a distinct disease entity rather than a precursor to classic dissection because of differences in their pathology, etiology, natural history, and imaging findings. Multidetector computed tomography (CT) is recommended as the first-line diagnostic imaging modality for IMH, but transesophageal echocardiography (TEE) and magnetic resonance imaging (MRI) are also helpful. There is still debate over the appropriate treatment of IMH. Medical treatment of type B IMH appears effective and safe, while surgical treatment is recommended for type A IMH. Thoracic endovascular aortic repair (TEVAR) is a promising treatment for selected patients, and more clinical evidence needs to be assembled.

Aortic Volumetry at Contrast-Enhanced Magnetic Resonance Angiography: Feasibility as a Sensitive Method for Monitoring Bicuspid Aortic Valve Aortopathy

OBJECTIVES

Bicuspid aortic valve patients can develop thoracic aortic aneurysms and therefore require serial imaging to monitor aortic growth. This study investigates the reliability of contrast-enhanced magnetic resonance angiography (CEMRA) volumetry compared with 2-dimensional diameter measurements to identify thoracic aortic aneurysm growth.

MATERIALS AND METHODS

A retrospective, institutional review board-approved, and Health Insurance Portability and Accountability Act-compliant study was conducted on 20 bicuspid aortic valve patients (45 ± 8.9 years, 20% women) who underwent serial CEMRA with a minimum imaging follow-up of 11 months. Magnetic resonance imaging was performed at 1.5 T with electrocardiogram-gated, time-resolved CEMRA. Independent observers measured the diameter at the sinuses of Valsalva (SOVs) and mid ascending aorta (MAA) as well as ascending aorta volume between the aortic valve annulus and innominate branch. Intraobserver/interobserver coefficient of variation (COV) and intraclass correlation coefficient (ICC) were computed to assess reliability. Growth rates were calculated and assessed by Student t test (P < 0.05, significant). The diameter of maximal growth (DMG), defined as the diameter at SOV or MAA with the faster growth rate, was recorded.

RESULTS

The mean time of follow-up was 2.6 ± 0.82 years. The intraobserver COV was 0.01 for SOV, 0.02 for MAA, and 0.02 for volume (interobserver COV: 0.02, 0.03, 0.04, respectively). The ICC was 0.83 for SOV, 0.86 for MAA, 0.90 for DMG, and 0.95 for volume. Average aortic measurements at baseline and (follow-up) were 42 ± 3 mm (42 ± 3 mm, P = 0.11) at SOV, 46 ± 4 mm (47 ± 4 mm, P < 0.05) at MAA, and 130 ± 23 mL (144 ± 24 mL, P < 0.05). Average size changes were 0.2 ± 0.6 mm/y (1% ± 2%) at SOV, 0.5 ± 0.8 mm/y (1% ± 2%) at MAA, 0.7 ± 0.7 mm/y (2% ± 2%) at DMG, and 6 ± 3 mL/y (4% ± 3%) with volumetry.

CONCLUSIONS

Three-dimensional CEMRA volumetry exhibited a larger effect when examining percentage growth, a better ICC, and a marginally lower COV. Volumetry may be more sensitive to growth and possibly less affected by error than diameter measurements.

An update on transesophageal echocardiography views 2016: 2D versus 3D tee views

In 1980, Transesophageal Echocardiography (TEE) first technology has introduced the standard of practice for most cardiac operating rooms to facilitate surgical decision making. Transoesophageal echocardiography as a diagnostic tool is now an integral part of intraoperative monitoring practice of cardiac anaesthesiology. Practice guidelines for perioperative transesophageal echocardiography are systematically developed recommendations that assist in the management of surgical patients, were developed by Indian Association of Cardiac Anaesthesiologists (IACTA). This update relates to the former IACTA practice guidelines published in 2013 and the ASE/EACTA guidelines of 2015. The current authors believe that the basic echocardiographer should be familiar with the technical skills for acquiring 28 cross sectional imaging planes. These 28 cross sections would provide also the format for digital acquisition and storage of a comprehensive TEE examination and adds 5 more additional views, introduced for different clinical scenarios in recent times. A comparison of 2D TEE views versus 3D TEE views is attempted for the first time in literature, in this manuscript. Since, cardiac anaesthesia variability exists in the precise anatomic orientation between the heart and the oesophagus in individual patients, an attempt has been made to provide specific criteria based on identifiable anatomic landmarks to improve the reproducibility and consistency of image acquisition for each of the standard cross sections.

Dynamic Changes in Aortic Vascular Stiffness in Patients Bridged to Transplant With Continuous-Flow Left Ventricular Assist Devices

OBJECTIVES

The aim of this study was to measure aortic vascular stiffness from orthotopic heart transplant (OHT) patients exposed to varying types of flow as a result of the presence or absence of left ventricular assist device (LVAD) support pre-OHT.

BACKGROUND

The effects of continuous-flow LVADs (CF-LVADs) on vascular properties are unknown, but may contribute to the pathophysiology of CF-LVAD complications such as stroke, hypertension, and bleeding.

METHODS

Echocardiograms were reviewed from 172 OHT patients immediately before LVAD and at 3 time points post-OHT: baseline, 6 months, and 1 year. For each study, pulse pressure and aortic end-systolic and end-diastolic dimensions were used to calculate aortic strain, distensibility, and stiffness index. Patients were categorized into 3 groups based on the presence or absence of a LVAD and a pulse pre-OHT: No LVAD (n = 111), LVAD No Pulse (n = 30), and LVAD With Pulse (n = 31).

RESULTS

The aortic stiffness index among LVAD No Pulse patients increased from 2.8 ± 1.1 pre-CF-LVAD to 10.9 ± 4.7 immediately post-OHT (p < 0.001). This aortic stiffness index was also significantly higher compared with No LVAD (3.4 ± 1.1; p < 0.001) and LVAD With Pulse (3.7 ± 1.4; p < 0.001) immediately post-OHT with attenuation of these differences by 1 year post-OHT. Similar findings were noted for the other indices of aortic stiffness.

CONCLUSIONS

Aortic stiffness is markedly increased immediately post-OHT among patients bridged with CF-LVADs, with attenuation of this increased stiffness over the first year after transplant. These results suggest that aortic vascular properties are dynamic and may be influenced by alterations in flow pulsatility. As more patients are supported with CF-LVADs and as newer pump technology attempts to modulate pulsatility, further research examining the role of alterations in flow patterns on vascular function and the potential resultant systemic sequelae are needed.

A case of circumferential type A aortic dissection with intimal intussusception diagnosed using repeat transthoracic echocardiography examination

Case

Sometimes it is difficult to diagnose circumferential aortic dissection with enhanced computed tomography alone. A 58-year-old woman presented with sudden-onset chest discomfort and loss of consciousness. Transthoracic echocardiogram showed mild aortic regurgitation. Enhanced computed tomography scans showed no obvious intimal tear or flap at the proximal ascending aorta, but an intimal flap was observed from the aortic arch to both common iliac arteries. Stanford type B dissection was tentatively diagnosed. Repeat detailed transthoracic echocardiography examination showed an intimal tear and flap at the ascending aorta; prolapse into the left ventricle caused severe aortic regurgitation. Type A aortic dissection was definitively diagnosed; emergent operation showed a circumferential intimal tear originating from the ascending aorta.

Outcome

The ascending aorta was replaced; aortic regurgitation disappeared. The patient was discharged in a good condition 58 days postoperatively.

Conclusion

Dynamic evaluations with transthoracic echocardiography should be carried out to diagnose circumferential aortic dissection.

Thoracic Aortic Aneurysm Growth: Role of Sex and Aneurysm Etiology

BACKGROUND

Thoracic aortic aneurysm (TAA) outcomes are worse in women than men, although reasons for sex differences are unknown. Because faster TAA growth is a risk factor for acute aortic syndromes, we sought to determine the role of sex and aneurysm etiology on TAA growth.

METHODS AND RESULTS

Eighty-two consecutive unoperated subjects with TAA who had serial aneurysm measurements were recruited. In multivariable linear regression the association of female sex with aneurysm growth rate was assessed after adjustment for potential confounders. We also tested the interaction term sex×aneurysm etiology in the prediction of TAA growth. Seventy-four percent of subjects were men; mean±SD age was 62.4±11.9 years in men and 67.7±10.7 years in women (P=0.06). Forty-seven (57%) subjects had degenerative TAAs, and the remainder had heritable TAAs. Absolute baseline aneurysm size and follow-up time were not different between men and women. Aneurysm growth rate was 1.19±1.15 mm/y in women and 0.59±0.66 mm/y in men (P=0.02). Female sex remained significantly associated with greater aneurysm growth in multivariable analyses (β±SE: 0.35±0.12, P=0.005). In addition, female sex was associated with faster TAA growth only among those with degenerative TAA (β±SE: 0.33±0.08, P=0.0002) and not among those with heritable TAA (P=0.79), with a significant sex×etiology interaction (P=0.001).

CONCLUSIONS

TAA growth rates are greater in women than men, and this difference is specific to women with degenerative TAAs. Our findings may explain sex differences in TAA outcomes and provide a foundation for future investigations of this topic.