Post-stenotic aortic dilatation

The impact of ascending aorta dilatation on transcatheter aortic valve implantation outcomes

The impact of ascending aorta dilatation (AAD) on transcatheter aortic valve implantation (TAVI) outcomes, compared to non-AAD, remains unclear. This meta-analysis aims to compare the outcomes of TAVI between patients with and without AAD. We systematically searched PubMed, ScienceDirect, Web of Science, Springer, Cochrane, and Clinicaltrials.gov. for articles up to 25 March 2024 (PROSPERO ID CRD42024526311). A total of 204,078 patients from ten studies were included. Paravalvular regurgitation (RR 1.56 95 %CI: 1.32-1.84, p < 0.00001, I2 = 0 %) and aortic dissection (RR 3.55 95 %CI: 1.79-7.06, p = 0.0003, I2 = 40 %) were more common in AAD group. However, there were no differences in peri-procedural (RR 1.09, 95 %CI: 0.83-1.42, p = 0.53, I2 = 0 %) and 1-year (RR 0.79, 95 %CI: 0.51-1.23, p = 0.30, I2 = 0 %) mortality. Three-years (RR 0.88, 95 %CI: 0.54-1.44, p = 0.62) and five-years (RR 0.85, 95 %CI: 0.45-1.6, p = 0.61) follow-up showed comparable mortality between both groups. The other complications and the need for second valve implantation (RR 1.24, 95 %CI: 0.70-20.20, p = 0.48, I2 = 65 %) were similar between both groups. Despite the higher incidence of aortic dissection and paravalvular regurgitation in AAD than in non-AAD patients, these complications were not associated with worse short-term or long-term mortality. Therefore, TAVI remains a safe and effective option for AAD patients.

Evaluating a Novel AI Tool for Automated Measurement of the Aortic Root and Valve in Cardiac Magnetic Resonance Imaging

Objective Evaluating an artificial intelligence (AI) tool (AIATELLA, version 1.0; AIATELLA Oy, Helsinki, Finland) in interpreting cardiac magnetic resonance (CMR) imaging to produce measurements of the aortic root and valve by comparison of accuracy and efficiency with that of three National Health Service (NHS) cardiologists. Methods AI-derived aortic root and valve measurements were recorded alongside manual measurements from three experienced NHS consultant cardiologists (CCs) over three separate sites in the northeast part of the United Kingdom. The study utilised a comprehensive dataset of CMR images, with the intraclass correlation coefficient (ICC) being the primary measure of concordance between the AI and the cardiologist assessments. Patient imaging was anonymised and blinded at the point of transfer to a secure data server.  Results The study demonstrates a high level of concordance between AI assessment of the aortic root and valve with NHS cardiologists (ICC of 0.98). Notably, the AI delivered results in 2.6 seconds (+/- 0.532) compared to a mean of 334.5 seconds (+/- 61.9) by the cardiologists, a statistically significant improvement in efficiency without compromising accuracy. Conclusion AI's accuracy and speed of analysis suggest that it could be a valuable tool in cardiac diagnostics, addressing the challenges of time-consuming and variable clinician-based assessments. This research reinforces AI's role in optimising the patient journey and improving the efficiency of the diagnostic pathway.

Role of Computed Tomography Angiography in the Short-Term Follow-up of Aortic Coarctation Repair

INTRODUCTION

Coarctation of the aorta (CoA) is a narrowing of the thoracic aorta that often manifests as discrete stenosis but may be tortuous or in long segment. The study aimed to evaluate pre and post-surgical aspects of pediatric patients submitted to CoA surgical correction and to identify possible predisposing factors for aortic recoarctation.

METHODS

Twenty-five patients were divided into groups according to presence (N=8) or absence (N=17) of recoarctation after surgical correction of CoA and evaluated according to clinical-demographic profile, vascular characteristics via computed angiotomography (CAT), and other pathological conditions.

RESULTS

Majority of males (64%), ≥ 15 days old (76%), ≥ 2.5 kg (80%). There was similarity between groups with and without recoarctation regarding sex (male: 87% vs. 53%; P=0.277), age (≥ 15 days: 62.5 vs. 82%; P=0.505), and weight (≥ 2.5 kg: 87.5 vs. 76.5; P=0,492). Altered values of aortic root/Valsalva diameter, proximal transverse arch, and distal isthmus, and normal values for aorta prevailed in preoperative CAT. Normal values for the aortic root/Valsalva sinus diameter were observed with and without recoarctation, the same for both groups regarding ascending and descending aorta in postoperative CAT. No significant difference for altered values of proximal transverse arch and alteration in distal isthmus was observed.

CONCLUSION

No predictive risk for recoarctation was observed. CTA proved to be important in CoA diagnosis and management, since CoA is mainly related with altered diameter of aortic root/sinus of Valsalva and proximal and distal aortic arch/isthmus, however, it failed to show predictive risk for recoarctation.

Superior mesenteric aneurysm associated with median arcuate ligament syndrome and a single celiacomesenteric trunk

Median arcuate ligament syndrome (MALS) is known to promote arterial collateral circulation development from mesenteric vessel compression and can lead to the development of visceral aneurysms. These aneurysms are often diagnosed at the time of rupture and pose a significant morality risk without appropriate intervention. A celiacomesenteric trunk is a rare anatomic variant in which the celiac artery and superior mesenteric artery share a common origin and has been postulated as a risk factor for developing MALS. In this report, we present a novel case of MALS in a patient with a celiacomesenteric trunk and a superior mesenteric artery aneurysm.

Case Report: Myocardial dissection caused by ruptured sinus of Valsalva aneurysm in association with a bicuspid aortic valve

In this report, we present a case of left-right sinus fusion in a Ruptured sinus of Valsalva aneurysm (RSVA) that perforated into the myocardium, giving rise to myocardial dissection. The existence of an anomalous bicuspid aortic valve (BAV) is contemplated as a potential etiological element in this context. Employing multimodal imaging modalities, encompassing transthoracic echocardiography and computed tomography (CT), facilitated the visualization of a dissecting hematoma situated within the myocardium subsequent to the RSVA. Following this, our patient underwent an Cabrol surgical intervention, received patch repair, and underwent mitral valve annuloplasty, during which a three-year period transpired without the occurrence of any deleterious cardiac events. In summary, this report establishes the cornerstone for the surgical intervention of RSVA, shedding light on the efficacious handling of RSVA-associated myocardial dissection. It posits that the presence of a BAV may serve as a predisposing factor to RSVA rupture, potentially elevating the susceptibility to myocardial dissection. The utilization of diverse multimodal imaging methodologies played an indispensable role in the detection of a hematoma within the myocardial tissue subsequent to the RSVA rupture. The uneventful three-year postoperative follow-up of the patient underscores the efficacy of the undertaken interventions.

Wall shear stress and pressure patterns in aortic stenosis patients with and without aortic dilation captured by high-performance image-based computational fluid dynamics

Spatial patterns of elevated wall shear stress and pressure due to blood flow past aortic stenosis (AS) are studied using GPU-accelerated patient-specific computational fluid dynamics. Three cases of moderate to severe AS, one with a dilated ascending aorta and two within the normal range (root diameter less than 4cm) are simulated for physiological waveforms obtained from echocardiography. The computational framework is built based on sharp-interface Immersed Boundary Method, where aortic geometries segmented from CT angiograms are integrated into a high-order incompressible Navier-Stokes solver. The key question addressed here is, given the presence of turbulence due to AS which increases wall shear stress (WSS) levels, why some AS patients undergo much less aortic dilation. Recent case studies of AS have linked the existence of an elevated WSS hotspot (due to impingement of AS on the aortic wall) to the dilation process. Herein we further investigate the WSS distribution for cases with and without dilation to understand the possible hemodynamics which may impact the dilation process. We show that the spatial distribution of elevated WSS is significantly more focused for the case with dilation than those without dilation. We further show that this focal area accommodates a persistent pocket of high pressure, which may have contributed to the dilation process through an increased wall-normal forcing. The cases without dilation, on the contrary, showed a rather oscillatory pressure behaviour, with no persistent pressure "buildup" effect. We further argue that a more proximal branching of the aortic arch could explain the lack of a focal area of elevated WSS and pressure, because it interferes with the impingement process due to fluid suction effects. These phenomena are further illustrated using an idealized aortic geometry. We finally show that a restored inflow eliminates the focal area of elevated WSS and pressure zone from the ascending aorta.

Implications of Bicuspid Aortic Valve Disease and Aortic Stenosis/Insufficiency as Risk Factors for Thoracic Aortic Aneurysm

Bicuspid Aortic Valves (BAV) are associated with an increased incidence of thoracic aortic aneurysms (TAA). TAA are a common aortic pathology characterized by enlargement of the aortic root and/or ascending aorta, and may become life threatening when left untreated. Typically occurring as the sole pathology in a patient, TAA are largely asymptomatic. However, in some instances, they are accompanied by aortic valve (AV) diseases: either congenital BAV or acquired in the form of Aortic Insufficiency (AI) or aortic stenosis (AS). When TAA are associated with aortic valve disease, determining an accurate and predictable prognosis becomes especially challenging. Patients with AV disease and concomitant TAA lack a widely accepted diagnostic approach, one that integrates our knowledge on aortic valve pathophysiology and encompasses multi-modality imaging approaches. This review summarizes the most recent scientific knowledge regarding the association between AV diseases (BAV, AI, AS) and ascending aortopathies (dilatation, aneurysm, and dissection). We aimed to pinpoint the gaps in monitoring practices and prediction of disease progression in TAA patients with concomitant AV disease. We propose that a morphological and functional analysis of the AV with multi-modality imaging should be included in aortic surveillance programs. This strategy would allow for improved risk stratification of these patients, and possibly new AV phenotypic-specific guidelines with more vigilant surveillance and earlier prophylactic surgery to improve patient outcomes.

Postoperative imaging of thoracic aortic repairs

Imaging plays a crucial role in the postoperative monitoring of thoracic aortic repairs. With the development of multiple surgical techniques to repair the ascending aorta and aortic arch, it can be a daunting challenge for the radiologist to diagnose potential pathologies in this sea of various techniques, each with their own normal postoperative appearance and potential complications. In this paper, we will provide a comprehensive review of the postoperative imaging in the setting of thoracic aortic repairs, including the role of imaging, components of thoracic aortic repairs, the normal postoperative appearance, and potential complications.

The Presence of Ascending Aortic Dilatation in Patients Undergoing Transcatheter Aortic Valve Replacement Is Negatively Correlated with the Presence of Diabetes Mellitus and Does Not Impair Post-Procedural Outcomes

Both relevant aortic valve stenosis (AS) and aortic valve insufficiency significantly contribute to structural changes in the ascending aorta (AA) and thus to its dilatation. In patients with severe AS undergoing transcatheter aortic valve replacement (TAVR), survival data regarding aortic changes and laboratory biomarker analyses are scarce.

METHODS

A total of 179 patients with severe AS and an available computed tomography were included in this retrospective study. AA was measured, and dilatation was defined as a diameter ≥ 40 mm. Thirty-two patients had dilatation of the AA. A further 32 patients from the present population with a normal AA were matched to the aortic dilatation group with respect to gender, age, body mass index and body surface area, and the resulting study groups were compared with each other. In addition to echocardiographic and clinical characteristics, the expression of cardiovascular biomarkers such as brain natriuretic peptide (BNP), soluble suppression of tumorigenicity-2 (sST2), growth/differentiation of factor-15 (GDF-15), heart-type fatty-acid binding protein (H-FABP), insulin-like growth factor binding protein 2 (IGF-BP2) and soluble urokinase-type plasminogen activator receptor (suPAR) was analyzed. Kaplan-Meier curves for short- and long-term survival were obtained, and Pearson's and Spearman's correlations were calculated to identify the predictors between the diameter of the AA and clinical parameters.

RESULTS

A total of 19% of the total cohort had dilatation of the AA. The study group with an AA diameter ≥ 40 mm showed a significantly low comorbidity with respect to diabetes mellitus in contrast to the comparison cohort with an AA diameter < 40 mm (p = 0.010). This result continued in the correlation analyses performed, as the presence of diabetes mellitus correlated negatively not only with the diameter of the AA (r = -0.404; p = 0.001) but also with the presence of aortic dilatation (r = -0.320; p = 0.010). In addition, the presence of AA dilatation after TAVR was shown to have no differences in terms of patient survival at 1, 3 and 5 years. There were no relevant differences in the cardiovascular biomarkers studied between the patients with dilated and normal AAs.

CONCLUSION

The presence of AA dilatation before successful TAVR was not associated with a survival disadvantage at the respective follow-up intervals of 1, 3 and 5 years. Diabetes mellitus in general seemed to have a protective effect against the development of AA dilatation or aneurysm in patients with severe AS.

Left vs. right radial approach for coronary catheterization: Relation to age and severe aortic stenosis

Background

Old age and the presence of aortic stenosis are associated with the unfolding of the intrathoracic aorta. This may result in increased difficulties navigating catheters from the right compared to the left radial approach.

Objective

To investigate whether increasing age or presence of severe aortic stenosis was associated with increased catheterization success rates from left (LRA) compared to right radial artery approach (RRA).

Methods

We compared coronary angiography success rates of RRA and LRA according to different age groups and in a subgroup of patients with severe aortic stenosis.

Results

A total of 21,259 coronary angiographies were evaluated. With increasing age, the first pass success rate from either radial access decreased significantly (p < 0.001). In patients aged <85 years, there was no difference between LRA and RRA. However, in patients aged ≥85 years, LRA was associated with significantly higher success rates compared to RRA (90.1 vs. 82.8%, p = 0.003). Patients aged ≥85 years received less contrast agent and had shorter fluoroscopy time when LRA was used [86.6 ± 41.1 vs. 99.6 ± 48.7 ml (p < 0.001) and 4.5 ± 4.1 min vs. 6.2 ± 5.7 min (p < 0.001), mean (±SD)]. In patients with severe aortic stenosis (n = 589) better first pass success rates were observed via LRA compared to the RRA route (91.9 vs. 85.1%, p = 0.037).

Conclusion

LRA, compared to RRA, is associated with a higher first-pass catheter success rate for coronary artery angiography in patients aged ≥85 years and those with severe aortic stenosis.

Aortic local biomechanical properties in ascending aortic aneurysms

Ascending aortic aneurysm (AsAA) is a high-risk cardiovascular disease with an increased incidence over years. In this study, we compare different risk factors based on the pre-failure behavior (from a biomechanical point of view) obtained ex-vivo from an equi-biaxial tensile test. A total of 100 patients (63 ± 12 years, 72 males) with AsAA replacement, were recruited. Equi-biaxial tensile tests of AsAA walls were performed on freshly sampled aortic wall tissue after ascending aortic replacement. The aneurysmal aortic walls were divided into four quadrants (medial, anterior, lateral, and posterior) and two directions (longitudinal and circumferential) were considered. The stiffness was represented by the maximum Young Modulus (MYM). Based on patient information, the following subgroups were considered: age, gender, hypertension, obesity, dyslipidemia, diabetes, smoking history, aortic insufficiency, aortic stenosis, coronary artery disease, aortic diameter and aortic valve type. In general, when the aortic diameter increased, the aortic wall became thicker. In terms of the MYM, the longitudinal direction was significantly higher than that in the circumferential direction. In the multivariant analysis, the impact factors of age (p = 0.07), smoking (p = 0.05), diabetes (p = 0.03), aortic stenosis (p = 0.02), coronary artery disease (p < 10^-3), and aortic diameters (p = 0.02) were significantly influencing the MYM. There was no significant MYM difference when the patients presented arterial hypertension, dyslipidemia, obesity, or bicuspid aortic valve. To conclude, the pre-failure aortic stiffness is multi-factorial, according to our population of 100 patients with AsAA. STATEMENT OF SIGNIFICANCE: : Our research on the topic of "Aortic local biomechanical properties in case of ascending aortic aneurysms" is about the biomechanical properties on one hundred aortic samples according to the aortic wall quadrants and the direction. More than ten factors and risks which may impact ascending aortic aneurysms have been studied. According to our knowledge, so far, this article involved the largest population on this topic. It will be our pleasure to share this information with all the readers.

Lymphocyte-to-monocyte ratio associated with severe post-stenotic aortic dilation in a case-control study

Background

Calcific aortic valve stenosis (CAVS) represents a serious health threat to elderly patients. Post-stenotic aortic dilation, a common feature in CAVS patients, might progress into aneurysm and even dissection, potential consequences of CAVS, and predicts a poor prognosis. This study sought to investigate the association of lymphocyte-to-monocyte ratio (LMR), an inflammatory biomarker, with severe post-stenotic aortic dilation in a case–control study in Chinese population.

Materials and methods

208 consecutive patients with CAVS were recruited retrospectively in a case–control study in Chinese population, from July 1, 2015 to June 31, 2018. LMR was statistically analyzed using the ROC curve and binary logistic regression analyses for its prognostic value in severe post-stenotic aortic dilation.

Results

LMR was significantly reduced in patients with severe post-stenotic aortic dilation (2.72 vs. 3.53, p = 0.002 < 0.05) compared to patients without severe post-stenotic aortic dilation. There was an inverse correlation observed between the maximal diameter of ascending aorta and LMR in the overall patients (r = − 0.217, p = 0.002 < 0.05). For post-stenotic aortic dilation, the prevalence of high-LMR group was statistically lower than that of low-LMR group (19.7% vs. 43.9%, p < 0.001). The maximal diameter of ascending aorta was significantly reduced in the high-LMR group (4.35 vs. 4.76, p = 0.003 < 0.05) compared to low-LMR group. Additionally, LMR was identified in the multivariate analysis independently associated with severe post-stenotic aortic dilation (AUC 0.743, 95% CI: [0.573–0.964], p = 0.025).

Conclusions

This study provided the evidence of an inverse correlation between severe post-stenotic aortic dilation and LMR. LMR is potentially independently associated with severe post-stenotic aortic dilation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02636-3.

Hemodynamics and Wall Shear Stress of Blood Vessels in Aortic Coarctation with Computational Fluid Dynamics Simulation

The purpose of this study was to identify the characteristics of blood flow in aortic coarctation based on stenotic shape structure, stenosis rate, and the distribution of the wall load delivered into the blood vessels and to predict the impact on aneurysm formation and rupture of blood vessels by using a computational fluid dynamics modeling method. It was applied on the blood flow in abdominal aortic blood vessels in which stenosis occurred by using the commercial finite element software ADINA on fluid-solid interactions. The results of modeling, with an increasing stenosis rate and Reynolds number, showed the pressure drop was increased and the velocity was greatly changed. When the stenosis rate was the same, the pressure drop and the velocity change were larger in the stenosis with a symmetric structure than in the stenosis with an asymmetric one. Maximal changes in wall shear stress were observed in the area before stenosis and minimal changes were shown in stenosis areas. The minimal shear stress occurred at different locations depending on the stenosis shape models. With an increasing stenosis rate and Reynolds number, the maximal wall shear stress was increased and the minimal wall shear stress was decreased. Through such studies, it is thought that the characteristics of blood flow in the abdominal aorta where a stenosis is formed will be helpful in understanding the mechanism of growth of atherosclerosis and the occurrence and rupture of the abdominal aortic flow.

Sinus of Valsalva Dimension and Clinical Outcomes in Patients Undergoing Transcatheter Aortic Valve Implantation

BACKGROUND

Ascending aortic root anatomy is routinely evaluated on pre-procedural multi-detector computed tomography (MDCT). However, its clinical significance has not been adequately studied. We aimed to investigate the impact of the sinus of Valsalva (SOV) dimension on clinical outcomes in patients undergoing transcatheter aortic valve implantation (TAVI).

METHODS

In a prospective TAVI registry, we retrospectively assessed SOV dimensions by pre-procedural MDCT. Patients were stratified according to tertiles of SOV diameter indexed to body surface area (SOVi). The primary endpoint was all-cause mortality at 1 year.

RESULTS

Among 2066 consecutive patients undergoing TAVI between August 2007 and June 2018, 1554 patients were eligible for the present analysis. Patients in the large SOVi group were older (83 ± 6 vs 82 ± 6 vs 81 ± 6; P < .001) and had a higher Society of Thoracic Surgeons Predicted Risk of Mortality (6.3 ± 3.8 vs 5.1 ± 3.1 vs 4.9 ± 3.5; P < .001) than those in the other groups. Patients in the large SOVi group had a higher incidence of moderate or severe paravalvular regurgitation (11.9% vs 4.5% vs 3.5%; P < .001). At 1 year, a large SOVi was independently associated with an increased risk of mortality (HR: 1.62; 95% CI: 1.19-2.21; P = .002) and major or life-threatening bleeding (HR: 1.30; 95% CI: 1.02-1.65; P = .035).

CONCLUSIONS

Dilatation of the aortic root at the SOV was associated with adverse outcomes after TAVI. The assessment of the aortic root should be integrated into the risk stratification system in patients undergoing TAVI.

Two Cases of Quadricuspid Aortic Valve: Aortic Regurgitation and Degeneration

Background Quadricuspid aortic valve is rare and occasionally associated with aortic regurgitation and ascending aortic dilatation. Recent studies suggest an association of aortic regurgitation with ascending aortic medial degeneration.

Case Description Histologic evaluation of ascending aortic tissue of two individuals with regurgitant quadricuspid aortic valve, one dilated, one non-dilated, yielded comparable degeneration in the Media.

Conclusion Regurgitation of quadricuspid aortic valve may lead to the degeneration of Tunica media of the ascending aorta.

Plasma Exosomal Mir-423-5p Is Involved in the Occurrence and Development of Bicuspid Aortopathy via TGF-β/SMAD2 Pathway

OBJECTIVES

Patients with bicuspid aortic valve (BAV) are at increased risk for ascending aortic dilation (AAD). Our study was aimed at systemically analyzing the expression profile and mechanism of circulating plasma exosomal microRNAs (miRNAs) related to BAV and AAD.

METHODS

We isolated plasma exosomes from BAV patients (n=19), BAV patients with AAD (BAVAD, n=26), and healthy tricuspid aortic valve individuals with low cardiovascular risk (TAVnon, n=16). We applied a small RNA sequencing approach to identify the specific plasma exosomal miRNAs associated with BAV (n=8) and BAVAD (n=10) patients compared with healthy TAVnon (n=6) individuals. The candidate differentially expressed (DE) miRNAs were selected and validated by RT-qPCR in the remaining samples. GO and KEGG pathway enrichment analyses were performed to illustrate the functions of target genes. Western blot analysis and luciferase reporter assay were conducted in human aortic vascular smooth muscle cells (VSMCs) to verify the results of target gene prediction in vitro. Results: The expression levels of three up-regulated (miR-151a-3p, miR-423-5p, and miR-361-3p) and two down-regulated (miR-16-5p and miR-15a-5p) exosomal miRNAs were significantly altered in BAV disease. Additionally, miR-423-5p could be functionally involved in the occurrence and development of BAV and its complication BAVAD by regulating TGF-β signaling. miR-423-5p could target to SMAD2 and decreased the protein levels of SMAD2 and P-SMAD2.

CONCLUSION

Plasma exosomal miR-423-5p regulated TGF-β signaling by targeting SMAD2, thus exerting functions in the occurrence and development of BAV disease and its complication bicuspid aortopathy.

Dynamics of Blood Flows in Aortic Stenosis: Mild, Moderate, and Severe

Supraphysiologic high shear stresses created in calcific aortic stenosis (AS) are known to cause hemostatic abnormalities, however, the relationship between the complex blood flows over the severity of AS and hemostatic abnormalities still remains unclear. This study systematically characterized the blood flow in mild, moderate, and severe AS. A series of large eddy simulations (LES) validated by particle image velocimetry were performed on physiologically representative AS models with a peak physiologic flow condition of 18 liter per minute. Time-accurate velocity fields, transvalvular pressure gradient, and laminar viscous-and turbulent (or Reynolds) shear stresses (RSSmax) were evaluated for each degree of severity. The peak velocities of mild, moderate, and severe AS were on the order of 2.0, 4.0, and 8.0 m/s, respectively. Jet velocity in severe AS was highly skewed with extremely high velocity (as high as 8 m/s) and mainly traveled through the posterior aortic wall up to the aortic arch while still carrying a relatively high velocity, that is, >4 m/s. The mean laminar viscous wall shear stresses (WSS) for mild, moderate, and severe AS were on the order of 40, 100, and 180 Pa, respectively. The RSSmax were on the order of 260, 490, and 2,500 Pa for mild, moderate, and severe AS, respectively. This study may provide a link between altered flows in AS and hemostatic abnormalities such as acquired von Willebrand syndrome and hemolysis, thus, help diagnosing and timing of the treatment.

Analysis of the formation mechanism and occurrence possibility of Post-Stenotic Dilatation of the aorta by CFD approach

BACKGROUND AND OBJECTIVE

Post-Stenotic Dilatation (PSD), the common complication of coarctation of the aorta (COA), is a progressive disease involving aortic aneurysm and even rupture. However, there has been no definitive method that could investigate the mechanism of PSD formation, progression and rupture. The purpose of the present work is to analyze the mechanism behind PSD formation and to further assess the risk of COA patients with different coarctation degrees deteriorating into PSD.

METHOD

Three-dimensional non-Newtonian (Carreau-Yasuda) hemodynamic simulations are performed throughout the cardiac cycle, and a novel parameter (λ_ci¯ intensity) is proposed to evaluate the intensity of vortices within the aorta. The PSD geometry is reconstructed from Computed Tomography scans. To analyze the formation mechanism and occurrence possibility of PSD, the computer technology is utilized to restore the expansive and/or narrow regions to obtain its previous state (COA) and control group (Normal), and to modify the minimum diameter to obtain the aortas with different coarctation degrees. The clinical cases of pre- and post-operation are further introduced to verify the analysis.

RESULTS

Compared with the Normal, the vortical structures with higher swirling strength are generated and accumulated at the downstream of the coarctation segment after COA occurrence, and partially disappear in the wake of PSD formation. The sequence of λ_ci¯ intensity is COA > PSD > Normal and pre-operation > post-operation. With increasing the degree of coarctation, the λ_ci¯ intensity is higher and the jet-flow becomes more drastic.

CONCLUSIONS

The formation of PSD is caused by the vortical structures with higher swirling strength accumulating at the downstream of the coarctation segment. An increase in coarctation degree elevates the risk of PSD occurrence and even aneurysmal dilatation.

Perioperative Echocardiography in the Adult With Congenital Heart Disease

Survival of patients with congenital heart disease has significantly improved over the last 2 decades, confronting interventionalists, surgeons, anesthesiologists, cardiologists, and intensivists with often unfamiliar complex pathophysiology in the perioperative setting. Aside from cardiac catheterization, echocardiography has become the main imaging modality in the hospitalized adult with congenital heart disease. The great variety of congenital lesions and their prior surgical management challenges practitioners to generate optimal imaging, reporting, and interpretation of these complex anatomic structures. Standardization of echocardiographic studies can not only provide significant benefits in the surveillance of these patients, but also facilitate understanding of pathophysiologic mechanism and assist clinical management in the perioperative setting. Knowledge in obtaining and interpreting uniform imaging protocols is essential for the perioperative clinician. In this publication, the authors review current international consensus recommendations on echocardiographic imaging of adults with congenital heart disease and describe the fundamental components by specific lesion. The authors will emphasize key aspects pertinent to the clinical management when imaging these patients in the perioperative setting. The goal of this review is to familiarize the perioperative physician on how to structure and standardize echocardiographic image acquisition of congenital heart disease anatomy for optimal clinical management.

Comparison of the geometry of the left ventricle outflow tract, the aortic root and the ascending aorta in patients with severe tricuspid aortic stenosis versus healthy controls

The purpose of this study was to assess by multislice computed tomography (MSCT) imaging geometry of the ascending aorta, the aortic root, the aortic annulus and the left ventricle outflow tract (LVOT) in aortic stenosis (AS) patients, to compare aortic root morphology in patients with AS with healthy controls and to evaluate sex differences. Fifty patients with severe AS and 50 age- and gender-matched controls who underwent MSCT were included in the study. The dimensions of the LVOT, the aortic annulus, the aortic root, the ascending aorta, and the volume of the aortic root were retrospectively assessed and a comparison was made between patients with severe tricuspid AS and controls. Patients with tricuspid AS in comparison with controls had smaller dimensions of the sinus of Valsalva resulting in reduction of the aortic root volume, whereas the dimensions of the other structures were comparable. MSCT revealed larger annular, LVOT and the sinus of Valsalva dimensions and the aortic root volume in men than women. Men with AS differed from healthy men only in regard to the dimensions of the sinus of Valsalva, while women showed significant differences also in the LVOT, and the aortic annulus. MSCT showed accurately aortic root remodeling in tricuspid AS patients and indentified sex-dependent differences. Women with tricuspid AS differ from healthy women more than men did. A high degree of the variability in the aortic root dimensions requires further careful research.

Clinical-pathological correlations of BAV and the attendant thoracic aortopathies. Part 2: Pluridisciplinary perspective on their genetic and molecular origins

Bicuspid aortic valve (BAV) arises during valvulogenesis when 2 leaflets/cusps of the aortic valve (AOV) are fused together. Its clinical manifestations pertain to faulty AOV function, the associated aortopathy, and other complications surveyed in Part 1 of the present bipartite-series. Part 2 examines mainly genetic and epigenetic causes of BAV and BAV-associated aortopathies (BAVAs) and disease syndromes (BAVD). Part 1 explored the heterogeneity among subsets of patients with BAV and BAVA/BAVD, and investigated abnormal fluid dynamic stress and strain patterns sustained by the cusps. Specific BAV morphologies engender systolic outflow asymmetries, associated with abnormal aortic regional wall-shear-stress distributions and the expression/localization of BAVAs. Understanding fluid dynamic factors besides the developmental mechanisms and underlying genetics governing these congenital anomalies is necessary to explain patient predisposition to aortopathy and phenotypic heterogeneity. BAV aortopathy entails complex/multifactorial pathophysiology, involving alterations in genetics, epigenetics, hemodynamics, and in cellular and molecular pathways. There is always an interdependence between organismic developmental signals and genes-no systemic signals, no gene-expression; no active gene, no next step. An apposite signal induces the expression of the next developmental gene, which needs be expressed to trigger the next signal, and so on. Hence, embryonic, then post-partum, AOV and thoracic aortic development comprise cascades of developmental genes and their regulation. Interdependencies between them arise, entailing reciprocal/cyclical mutual interactions and adaptive feedback loops, by which developmental morphogenetic processes self-correct responding to environmental inputs/reactions. This Survey can serve as a reference point and driver for further pluridisciplinary BAV/BAVD studies and their clinical translation.

Effect of Aortic Valve Disease on 3D Hemodynamics in Patients With Aortic Dilation and Trileaflet Aortic Valve Morphology

BACKGROUND

The effect of different expressions of aortic valve disease on 3D aortic hemodynamics is unclear.

PURPOSE

To investigate changes in aortic hemodynamics in patients with dilated ascending aorta (AAo) but different severity of aortic valve stenosis (AS) and/or regurgitation (AR).

STUDY TYPE

Retrospective.

POPULATION

A total of 111 subjects (86 patients with AAo diameter ≥ 40 mm and 25 healthy controls, all with trileaflet aortic valve [TAV]). Patients were further stratified by TAV dysfunction: n = 9 with combined moderate or severe AS and AR (ASR, 56 ± 13 years), n = 14 with moderate or severe AS (AS, 64 ± 14 years), n = 33 with moderate or severe AR (AR, 62 ± 14 years), n = 30 with neither AS nor AR (no AS/AR, 63 ± 9 years).

FIELD STRENGTH/SEQUENCE

4D flow MRI on 1.5/3T systems for the in vivo analysis of aortic blood flow dynamics.

ASSESSMENT

Data analysis included grading of 3D AAo vortex/helix flow and AAo flow eccentricity as well as quantification of systolic peak velocities and wall shear stress (WSS).

STATISTICAL TESTS

Continuous variables were compared by one-way analysis of variance or Kruskal-Wallis, followed by a pairwise Tukey or Dunn test if there was a significant difference.

RESULTS

All patients demonstrated markedly elevated vortex and helix flow compared with controls (P < 0.05). Peak velocities were significantly elevated in ASR, AS, and AR patients compared with controls (P < 0.05). Increased flow eccentricity was observed in entire AAo for AR, at the mid and distal AAo for ASR and AS, and at the proximal AAo for no AS/AR. Compared with controls, WSS in the AAo was significantly elevated in ASR and AS patients (P < 0.05) and reduced in no AS/AR patients (P < 0.05).

DATA CONCLUSION

The presence of TAV dysfunction is associated with aberrant hemodynamics and altered WSS, which may play a role in the development of aortopathy.

LEVEL OF EVIDENCE

3 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2020;51:481-491.

Differences in Pressure Within the Sac of Human Ruptured and Nonruptured Cerebral Aneurysms

BACKGROUND

Hemodynamics plays a critical role in the development, growth, and rupture of intracranial aneurysms. This data could be vital in determining individual aneurysm rupture risk and could facilitate our understanding of aneurysms.

OBJECTIVE

To present the largest prospective cross-sectional cohort study of intrasaccular pressure recordings of ruptured and nonruptured intracranial aneurysms and describe the hemodynamic differences that exist between ruptured and nonruptured aneurysms.

METHODS

During endovascular treatment, a standard 1.8-Fr 200 m length microcatheter was navigated into the dome of the aneurysm prior to coil embolization. With the microcatheter centralized within the dome of the aneurysm, an arterial pressure transducer was attached to the proximal end of the microcatheter to measure the stump pressure inside the aneurysm dome.

RESULTS

In 68 aneurysms (28 ruptured, 40 nonruptured), we observed that ruptured cerebral aneurysms had a lower systolic and mean arterial pressure compared to nonruptured cohort (P = .0008). Additionally, the pulse pressures within the dome of ruptured aneurysms were significantly more narrow than that of unruptured aneurysms (P = .0001). These findings suggest that there may be an inherent difference between ruptured and nonruptured aneurysms and such recordings obtained during routine digital subtraction angiography could potentially become a widely applied technique to augment risk stratification of aneurysms.

CONCLUSION

Our preliminary data present new evidence distinguishing ruptured from unruptured aneurysms that may have a critical role as a predictive parameter to stratify the natural history of nonruptured intracranial aneurysms and as a new avenue for future investigation.

Should Sinus of Valsalva be Replaced in Patients with Dilated Ascending Aorta and Aortic Valve Diseases?

INTRODUCTION

The aim of this study is to investigate the change in the dimension of sinus of Valsalva in patients who underwent supracoronary ascending aorta replacement with aortic valve replacement.

METHODS

A total of 81 patients who underwent supracoronary ascending aorta replacement with aortic valve replacement were included. Ten of 81 patients died during the follow-up. The patients were divided into three groups according to the aortic valve diseases. Group I (n=17) included patients with bicuspid valves, group II (n=30) included patients with stenotic degenerative valves, and patients with aortic regurgitation constituted group III (n=24). In preoperative and follow-up periods, the sinus of Valsalva diameter of the patients was evaluated by echocardiographic examination. The mean age was 54.1±15.1 years. Twenty-eight (34.6%) patients were female and 12 (14.8%) patients were in New York Heart Association functional class III.

RESULTS

There was no early mortality. Late mortality was developed in 10 (12.4%) patients, 8 (9.9%) due to non-cardiac reasons. Late follow-up was obtained in 71 patients with a mean of 60±30.1 months postoperatively. During follow-up, the increase in the diameter of the sinus of Valsalva was significant in Group I (P<0.01), while in Group II and III it was insignificant (P>0.05).

CONCLUSION

To avoid the risks associated with sinus of Valsalva dilatation, it is reasonable to replace the sinus of Valsalva in the setting of aortic valve replacement and ascending aorta replacement for bicuspid aortic valve with a dilated ascending aorta and relatively normal sinuses of Valsalva in young patients.

Evaluation and Management of Aortic Stenosis for the Emergency Clinician: An Evidence-Based Review of the Literature

INTRODUCTION

Aortic stenosis is a common condition among older adults that can be associated with dangerous outcomes, due to both the disease itself and its influence on other conditions.

OBJECTIVE

This review provides an evidence-based summary of the current emergency department (ED) evaluation and management of aortic stenosis.

DISCUSSION

Aortic stenosis refers to significant narrowing of the aortic valve and can be caused by calcific disease, congenital causes, or rheumatic valvular disease. Symptoms of advanced disease include angina, dyspnea, and syncope. Patients with these symptoms have a much higher mortality rate than asymptomatic patients. Initial evaluation should include an electrocardiogram, complete blood count, basic metabolic profile, coagulation studies, troponin, brain natriuretic peptide, type and screen, and a chest radiograph. Transthoracic echocardiogram is the test of choice, but point-of-care ultrasound has been found to have good accuracy when a formal echocardiogram is not feasible. Initial management should begin with restoring preload and ensuring a normal heart rate, as both bradycardia and tachycardia can lead to clinical decompensation. For patients with high blood pressure and heart failure symptoms, nitrate agents may be reasonable, but hypotension should be avoided. Dobutamine can increase inotropy. For hypotensive patients, vasopressors should be used at the lowest effective dose. The treatment of choice is valve replacement, but extracorporeal membrane oxygenation and percutaneous balloon dilatation of the aortic valve have been described as temporizing measures.

CONCLUSION

Aortic stenosis is an important condition that can lead to dangerous outcomes and requires prompt recognition and disease-specific management in the ED.

Genome-wide analysis yields new loci associating with aortic valve stenosis

Aortic valve stenosis (AS) is the most common valvular heart disease, and valve replacement is the only definitive treatment. Here we report a large genome-wide association (GWA) study of 2,457 Icelandic AS cases and 349,342 controls with a follow-up in up to 4,850 cases and 451,731 controls of European ancestry. We identify two new AS loci, on chromosome 1p21 near PALMD (rs7543130; odds ratio (OR) = 1.20, P = 1.2 × 10⁻²²) and on chromosome 2q22 in TEX41 (rs1830321; OR = 1.15, P = 1.8 × 10⁻¹³). Rs7543130 also associates with bicuspid aortic valve (BAV) (OR = 1.28, P = 6.6 × 10⁻¹⁰) and aortic root diameter (P = 1.30 × 10⁻⁸), and rs1830321 associates with BAV (OR = 1.12, P = 5.3 × 10⁻³) and coronary artery disease (OR = 1.05, P = 9.3 × 10⁻⁵). The results implicate both cardiac developmental abnormalities and atherosclerosis-like processes in the pathogenesis of AS. We show that several pathways are shared by CAD and AS. Causal analysis suggests that the shared risk factors of Lp(a) and non-high-density lipoprotein cholesterol contribute substantially to the frequent co-occurence of these diseases.

Aortic valve stenosis (AS) is the most common valvular heart disease. Here the authors identify two new AS loci that also associate with bicuspid aortic valve, aortic root diameter and/or coronary artery disease implicating both developmental abnormalities and atherosclerosis-like processes in AS.

Transcatheter Aortic Valve Implantation in Morphologically Complex Root Aneurysms

Performing transcatheter aortic valve implantation in the presence of aneurysmatic aortopathy is widely contraindicated but needs to be taken into account as a bailout strategy in selected patients. Deliberate preoperative assessment of measurements becomes the crucial key element in this context. After meticulous valve selection, retrograde access is obtained through the right subclavian artery additionally serving as a backup arterial cannulation site in case of conversion. Transcatheter aortic valve implantation is then performed through the transapical route. Transcatheter aortic valve implantation in complex aneurysmatic aortic morphology is feasible in highly selected patients after comprehensive preoperative evaluation. The present article describes our initial experience, safeguards, and technical details.

Influence of the tilt angle of Percutaneous Aortic Prosthesis on Velocity and Shear Stress Fields

Background

Due to the nature of the percutaneous prosthesis deployment process, a variation in its final position is expected. Prosthetic valve placement will define the spatial location of its effective orifice in relation to the aortic annulus. The blood flow pattern in the ascending aorta is related to the aortic remodeling process, and depends on the spatial location of the effective orifice. The hemodynamic effect of small variations in the angle of inclination of the effective orifice has not been studied in detail.

Objective

To implement an in vitro simulation to characterize the hydrodynamic blood flow pattern associated with small variations in the effective orifice inclination.

Methods

A three-dimensional aortic phantom was constructed, reproducing the anatomy of one patient submitted to percutaneous aortic valve implantation. Flow analysis was performed by use of the Particle Image Velocimetry technique. The flow pattern in the ascending aorta was characterized for six flow rate levels. In addition, six angles of inclination of the effective orifice were assessed.

Results

The effective orifice at the -4º and -2º angles directed the main flow towards the anterior wall of the aortic model, inducing asymmetric and high shear stress in that region. However, the effective orifice at the +3º and +5º angles mimics the physiological pattern, centralizing the main flow and promoting a symmetric distribution of shear stress.

Conclusion

The measurements performed suggest that small changes in the angle of inclination of the percutaneous prosthesis aid in the generation of a physiological hemodynamic pattern, and can contribute to reduce aortic remodeling.

Spontaneous isolated dissection of the superior mesenteric artery and aneurysm formation resulting from segmental arterial mediolysis: a case report

Background

Spontaneous isolated dissection of the superior mesenteric artery (SMA) can lead to bowel ischemia, aneurysm rupture, or even death. Studies have suggested that mechanical or hemodynamic stress on the vascular wall of the SMA may be a contributor, but its pathogenesis is unclear.

Case presentation

A 57-year-old Japanese man with a history of untreated hypertension and hyperuricemia was admitted to our hospital with the sudden onset of severe epigastric pain. Laboratory findings showed elevated white blood cell count and C-reactive protein, and contrast-enhanced computed tomography (CT) of the abdomen demonstrated arterial dissection with luminal stenosis and aneurysm formation at the distal portion of the SMA after the branching of the jejunal artery, and intravenous nicardipine was administered. The patient’s epigastric pain resolved spontaneously but recurred on day 6 of his hospital stay. Contrast-enhanced abdominal CT revealed an enlarged aneurysm with wall thinning. Because of the risk of aneurysm rupture, the decision was made to perform aneurysmectomy and bowel resection on day 6. Histologic examinations revealed two separate dissecting lesions: one latent and the other resulting in aneurysm formation. Both lesions showed characteristics of segmental arterial mediolysis (SAM) with lack of arterial media, absence of internal and external elastic laminae and intimal proliferation.

Conclusions

Histologic findings in the present case suggest that mechanical or hemodynamic stress on the vascular wall and SAM-related vascular vulnerability may concomitantly contribute to the onset of isolated SMA dissection.

Characteristics of Carotid Artery Structure and Mechanical Function and Their Relationships with Aortopathy in Patients with Bicuspid Aortic Valves

Patients with a bicuspid aortic valve (BAV) often have proximal aortic dilatation and systemic vascular dysfunction. We hypothesized that BAV patients would have different carotid artery structural and functional characteristics compared to tricuspid aortic valve (TAV) patients. In 28 patients with surgically confirmed BAV and 27 patients with TAV, intima media thickness (IMT), number of plaques, fractional area change (FAC), global circumferential strain (GCS), and standard deviation of CS (SD-CS) in both common carotid arteries were assessed using duplex ultrasound and velocity vector imaging (VVI). Patients with BAV were younger and had less co-morbidity, but showed a significantly larger ascending aorta (43.3 ± 7.5 vs. 37.0 ± 6.2 mm, p < 0.001) and a higher prevalence of aortopathy (61 vs. 30%, p = 0.021) than those with TAV. BAV patients showed a significantly lower IMT and fewer plaques. Although FAC and GCS were not significantly different between the two groups, they tended to be lower in the BAV group when each group was divided into three subgroups according to age. There was a significant age-dependent increase in IMT and decreases in FAC and GCS in the TAV group (p = 0.005, p = 0.001, p = 0.002, respectively), but this phenomenon was not evident in the BAV group (p = 0.074, p = 0.248, p = 0.394, respectively). BAV patients with aortopathy showed a higher SD-CS than those without aortopathy (p = 0.040), reflecting disordered mechanical function. In conclusion, BAV patients have different carotid artery structure and function compared with TAV patients, suggesting intrinsic vascular abnormalities that are less affected by established cardiovascular risk factors and more strongly related to the presence of aortopathy.

Dehiscence of a pulmonary bioprosthesis with a focal dissection of the pulmonary artery in a patient with congenital pulmonic stenosis

Pulmonary valve replacement (PVR) is the most common adult congenital cardiac operation performed. Valve degeneration leading to prosthetic stenosis and/or regurgitation is a long-term risk in this population and may be associated with paravalvular leak (PVL). Complications involving the proximal pulmonary artery, including dissection, are less clearly defined. Herein, we report the case of a 30-year-old patient with a history of multiple pulmonary valve interventions secondary to congenital pulmonic stenosis, who developed dehiscence of a bioprosthetic PVR associated with significant paravalvular leak (PVL) and further complicated by a focal dissection of the proximal pulmonary artery.

Bicuspid Aortic Valve: An Unusual Cause of Aneurysm of Left Coronary Sinus of Valsalva

Bicuspid aortic valve is traditionally considered an innocuous congenital anomaly. Due to a better and widespread availability of non-invasive imaging techniques, it has come to the fore that 30% of these cases develop complications, viz., valve abnormality (aortic regurgitation and stenosis), and aneurysm of aortic root and ascending aorta. Sinus of Valsalva aneurysm is an uncommon complication of bicuspid aortic valve and more so those arising from the left coronary sinus are the rarest. These complications generally occur in the third or fourth decade of life. We present a case of the left sinus of Valsalva aneurysm in conjunction with bicuspid aortic valve and ascending aorta aneurysm at a very young age in a girl in her early adolescence. This case is to remind the paediatricians about the not so "innocuous image", but the serious implications of the bicuspid aortic valve and to regularly follow these cases for early diagnosis of potential complications so as to prevent catastrophic outcomes.

Correlation between coronary artery calcium score and aortic diameter in a high-risk population of elderly male hypertensive patients

BACKGROUND

Studies on the relationship between coronary artery calcium and aortic diameter are scarce. The aim of the current study was to evaluate the correlation between coronary artery calcium score (CACS) and maximal thoracic and abdominal aortic diameters in a population of elderly (>65 years) male hypertensive patients at high risk for coronary artery disease.

PATIENTS AND METHODS

From June 2012 to April 2013, we prospectively enrolled 393 male hypertensive patients older than 65 years of age who had no history of aortic aneurysm. Coronary artery calcium and maximal diameters of the ascending thoracic aorta (ATAmax), descending thoracic aorta (DTAmax), and abdominal aorta (AAmax) were measured using noncontrast computed tomography imaging. Aortic diameters are indexed to body surface area (BSA). Participants were divided into five groups according to CACS (0, 1-10, 10-100, 100-400, and >400).

RESULTS

The mean ATAmax/BSA, DTAmax/BSA, and AAmax/BSA were 22.0±2.7, 16.3±1.9, and 13.0±2.9 mm, respectively. On multivariate analysis, ATAmax/BSA was associated independently with age, diabetes, and history of aortic valve replacement (all P<0.001). DTAmax/BSA was associated independently with age (P<0.001). However, there were no significant correlations between thoracic aorta diameter and CACS. In contrast, AAmax/BSA was associated independently with CACS as well as age and history of smoking (P=0.014, 0.003, and 0.019, respectively). Abdominal aortic aneurysm (>30 mm) was more prevalent in patients with a CACS of 400 or more compared with the others (14 vs. 3%, P<0.001).

CONCLUSION

CACS was associated with increased abdominal aorta diameter, but not with thoracic aorta diameter. Therefore, screening for an abdominal aortic aneurysm is warranted in patients with a high risk of coronary artery disease and a high CACS. However, the necessity for thoracic aortic aneurysm screening is not clear in these patients.

The effects of positioning of transcatheter aortic valves on fluid dynamics of the aortic root

Transcatheter aortic valve implantation is a novel treatment for severe aortic valve stenosis. Due to the recent use of this technology and the procedural variability, there is very little data that quantify the hemodynamic consequences of variations in valve placement. Changes in aortic wall stresses and fluid retention in the sinuses of Valsalva can have a significant effect on the clinical response a patient has to the procedure. By comprehensively characterizing complex flow in the sinuses of Valsalva using digital particle image velocimetry and an advanced heart-flow simulator, various positions of a deployed transcatheter valve with respect to a bioprosthetic aortic valve (valve-in-valve) were tested in vitro. Displacements of the transcatheter valve were axial and directed below the simulated native valve annulus. It was determined that for both blood residence time and aortic Reynolds stresses, it is optimal to have the annulus of the transcatheter valve deployed as close to the aortic valve annulus as possible.

Haemodynamic outcome at four-dimensional flow magnetic resonance imaging following valve-sparing aortic root replacement with tricuspid and bicuspid valve morphology

OBJECTIVE

To provide a more complete characterization of aortic blood flow in patients following valve-sparing aortic root replacement (VSARR) compared with presurgical cohorts matched by tricuspid and bicuspid valve morphology, age and presurgical aorta size.

METHODS

Four-dimensional (4D) flow magnetic resonance imaging (MRI) was performed to analyse three-dimensional (3D) blood flow in the thoracic aorta of n = 13 patients after VSARR with reimplantation of native tricuspid aortic valve (TAV, n = 6) and bicuspid aortic valve (BAV, n = 7). Results were compared with presurgical age and aortic size-matched control cohorts with TAV (n = 10) and BAV (n = 10). Pre- and post-surgical aortic flow was evaluated using time-resolved 3D pathlines using a blinded grading system (0-2, 0 = small, 1 = moderate and 2 = prominent) analysing ascending aortic (AAo) helical flow. Systolic flow profile uniformity in the aortic root, proximal and mid-AAo was evaluated using a four-quadrant model. Further analysis in nine analysis planes distributed along the thoracic aorta quantified peak systolic velocity, retrograde fraction and peak systolic flow acceleration.

RESULTS

Pronounced AAo helical flow in presurgical control subjects (both BAV and TAV: helix grading = 1.8 ± 0.4) was significantly reduced (0.2 ± 0.4, P < 0.001) in cohorts after VSARR independent of aortic valve morphology. Presurgical AAo flow was highly eccentric for BAV patients but more uniform for TAV. VSARR resulted in less eccentric flow profiles. Systolic peak velocities were significantly (P < 0.05) increased in post-root repair BAV patients throughout the aorta (six of nine analysis planes) and to a lesser extent in TAV patients (three of nine analysis planes). BAV reimplantation resulted in significantly increased peak velocities in the proximal AAo compared with root repair with TAV (2.3 ± 0.6 vs 1.6 ± 0.4 m/s, P = 0.017). Post-surgical patients showed a non-significant trend towards higher systolic flow acceleration as a surrogate measure of reduced aortic compliance.

CONCLUSIONS

VSARR restored a cohesive flow pattern independent of native valve morphology but resulted in increased peak velocities throughout the aorta. 4D flow MRI methods can assess the clinical implications of altered aortic flow dynamics in patients undergoing VSARR.

Concomitant replacement of the dilated ascending aorta during aortic valve replacement; does it increase the perioperative morbidity and mortality risks?

BACKGROUND

Concerns of increased surgical risks with ascending aortic replacement have led surgeons to manage post-stenotic aortic dilatation more conservatively during aortic valve replacement (AVR). The present study aimed to assess the prognostic implications and surgical risks of replacing the dilated aorta during AVR.

METHODS

Between January 1999 and March 2010, 134 patients who received surgery for aortic stenosis and post-stenotic dilatation (aorta size ≥40 mm) were included in the present study. AVR was performed in 92 patients (AVR group) while aortic valve and ascending aorta replacement (AVR + aorta group) were performed in 42 patients. Overall survival was compared between the two groups using Cox proportional hazard model after adjustment with inverse-probability-of-treatment weighting.

RESULTS

The mean follow-up duration was 3.5 ± 3 years. There were no significant differences in the operative mortality and morbidity between the two groups. The late cardiac deaths were also not significantly different between the two groups (p = 1.00). In the AVR group, the ascending aortic expansion rate which was 0.18 mm/year over a mean follow-up duration of 2.3 ± 2.2 years by echocardiography showed a positive correlation with time (r = 0.3, p = 0.08). A relatively greater aortic expansion rate was identified as a risk factor for late mortality (p = 0.015, HR 1.08 (CI: 1.02 to 1.15).

CONCLUSIONS

Concomitant replacement of the dilated ascending aorta during AVR did not increase the immediate postoperative morbidity or mortality risks and tended to exert a long-term beneficial effect on the risk of late mortality.

4D flow MRI

Traditionally, magnetic resonance imaging (MRI) of flow using phase contrast (PC) methods is accomplished using methods that resolve single-directional flow in two spatial dimensions (2D) of an individual slice. More recently, three-dimensional (3D) spatial encoding combined with three-directional velocity-encoded phase contrast MRI (here termed 4D flow MRI) has drawn increased attention. 4D flow MRI offers the ability to measure and to visualize the temporal evolution of complex blood flow patterns within an acquired 3D volume. Various methodological improvements permit the acquisition of 4D flow MRI data encompassing individual vascular structures and entire vascular territories such as the heart, the adjacent aorta, the carotid arteries, abdominal, or peripheral vessels within reasonable scan times. To subsequently analyze the flow data by quantitative means and visualization of complex, three-directional blood flow patterns, various tools have been proposed. This review intends to introduce currently used 4D flow MRI methods, including Cartesian and radial data acquisition, approaches for accelerated data acquisition, cardiac gating, and respiration control. Based on these developments, an overview is provided over the potential this new imaging technique has in different parts of the body from the head to the peripheral arteries.

Diagnosis and management of valvular heart disease in emergency medicine

A popular saying holds that if one can hear a heart murmur in the middle of a loud and busy emergency department, then by definition the murmur is significant. Whether or not this is actually true, it does capture the frustration emergency physicians feel when trying to diagnose or manage valvular pathologic conditions with familiar yet limited tools. This article focuses on the valve-related issues the emergency physician will face, from the trauma patient with a mechanical valve who may need his or her anticoagulation reversed to the febrile patient with a new murmur.

Effects of rosuvastatin on progression of stenosis in adult patients with congenital aortic stenosis (PROCAS Trial)

Recent trials have failed to show that statin therapy halts the progression of calcific aortic stenosis (AS). We hypothesized that statin therapy in younger patients with congenital AS would be more beneficial, because the valve is less calcified. In the present double-blind, placebo-controlled trial, 63 patients with congenital AS (age 18 to 45 years) were randomly assigned to receive either 10 mg of rosuvastatin daily (n = 30) or matched placebo (n = 33). The primary end point was the progression of peak aortic valve velocity. The secondary end points were temporal changes in the left ventricular mass, ascending aortic diameter, and N-terminal pro-brain natriuretic peptide (NT-proBNP). The median follow-up was 2.4 years (interquartile range 1.9 to 3.0). The mean increase in peak velocity was 0.05 ± 0.21 m/s annually in the rosuvastatin group and 0.09 ± 0.24 m/s annually in the placebo group (p = 0.435). The annualized change in the ascending aorta diameter (0.4 ± 1.7 mm with rosuvastatin vs 0.5 ± 1.6 mm with placebo; p = 0.826) and left ventricular mass (1.1 ± 15.8 g with rosuvastatin vs -3.7 ± 30.9 g with placebo; p = 0.476) were not significantly different between the 2 groups. Within the statin group, the NT-proBNP level was 50 pg/ml (range 19 to 98) at baseline and 21 pg/ml (interquartile range 12 to 65) at follow-up (p = 0.638). NT-proBNP increased from 40 pg/ml (interquartile range 20 to 92) to 56 pg/ml (range 26 to 130) within the placebo group (p = 0.008). In conclusion, lipid-lowering therapy with rosuvastatin 10 mg did not reduce the progression of congenital AS in asymptomatic young adult patients. Interestingly, statins halted the increase in NT-proBNP, suggesting a potential positive effect of statins on cardiac function in young patients with congenital AS.

Quantification of hemodynamic wall shear stress in patients with bicuspid aortic valve using phase-contrast MRI

Bicuspid aortic valve (BAV) is often concomitant with aortic dilatation, aneurysm, and dissection. This valve lesion and its complications may affect positional and temporal wall shear stress (WSS), a parameter reported to regulate transcriptional events in vascular remodeling. Thus, this pilot study seeks to determine if the WSS in the ascending aorta (AAo) of BAV patients differs from control patients. Phase-contrast magnetic resonance imaging (PC-MRI) was used to perform flow analysis at the level of the AAo in 15 BAV and 15 control patients. Measurement of the aorta dimensions, flow rates, regurgitant fraction (RF), flow reversal ratio (FRR), temporal and spatial WSS, and shear range indices (SRI) were performed. The BAV and control group showed a significant difference between the circumferentially averaged WSS (p=0.03) and positional WSS at systole (minimum p<0.001). Regressions found that SRI (r=0.77, p<0.001), RF (r=0.68, p<0.001), and WSS at systole (r=0.66, p<0.001) were correlated to AAo size. The spatial distribution and magnitude of systolic WSS in BAV patients (-6.7+/-4.3 dynes/cm2) differed significantly from control patients (-11.5+/-6.6 dynes/cm2, p=0.03). The SRI metric, a measure of shear symmetry along the lumen circumference, was also significantly different (p=0.006) and indicated a heterogenic pattern of dilatation in the BAV patients.