Thoracic Aortic Dissection in Tetralogy of Fallot: A Review of the National Inpatient Sample Database

Adult Congenital Heart Disease in the Emergency Department

While congenital heart disease historically was a pathology primarily restricted to specialized pediatric centers, advances in technology have dramatically increased the number of people living into adulthood, the number of complications faced by these patients, and the number of patients visiting non-specialized emergency departments for these concerns. Clinicians need to be aware of the issues specific to patients' individual congenital defects but also have an understanding of how typical cardiac pathology may manifest in this special group of patients. This manuscript attempts to provide an overview of this diverse but increasingly common group of adult patients with congenital heart diseases, including a review of their anatomical variants, the complications they face at the highest rates, and ways that emergency physicians may need to manage these patients differently to avoid causing harm.

A Severe and Fatal Type A Aortic Dissection in an Adult with a Repaired Tetralogy of Fallot

We report a case of a 44-year-old woman surgically treated for tetralogy of Fallot who experienced an acute and extensive Stanford A type aortic dissection despite the meticulous follow-up. While aortic dilatation is prevalent in individuals with repaired tetralogy of Fallot, aortic dissection represents a rare consequence, that when it appears, is progressive and usually detected during the check-up visits. In the case reported, the dissection was unexpected and severe, and the patient's clinical state worsened suddenly, leading to death after a few days. Constant awareness for aortic aneurysms is essential in the Fallot tetralogy population, nevertheless, several causes may contribute to the acute worsening of the clinical condition until the patient's death.

Natural history of aortic root dilatation and pathologic aortic regurgitation in tetralogy of Fallot and its morphological variants

OBJECTIVE

We sought to characterize the natural history of aortic root dilatation and aortic regurgitation in tetralogy of Fallot (TOF).

METHODS

A single-center review of patients who underwent TOF repair from January 1960 to December 2022 was performed. Morphology was categorized as TOF-pulmonary stenosis or TOF-variant (including TOF-pulmonary atresia and TOF-pulmonary atresia-major aortopulmonary collateral arteries). Echocardiographically determined diameters and derived z scores were measured at the annulus, sinus of Valsalva, and sinotubular junction immediately before TOF repair and throughout follow-up. Linear mixed-effects models assessed trends in dimensions over time.

RESULTS

Of 2205 patients who underwent primary repair of TOF at a median age of 4.9 months (interquartile range, 2.3-20.5 months) and survived to discharge, 1608 (72.9%) patients had TOF-pulmonary stenosis and 597 (27.1%) patients had TOF-variant. At a median postoperative follow-up of 14.4 years (interquartile range, 3.3-27.6 years; range, 0.1-62.6 years), 313 (14.2%) patients had mild or greater aortic regurgitation and 34 (1.5%) patients required an aortic valve or root intervention. The overall mean rates of annular, sinus of Valsalva, and sinotubular junction growth were 0.5 ± 0.2, 0.6 ± 0.3, and 0.7 ± 0.5 mm/year, respectively. Root z scores remained stable with time. At baseline, patients with TOF-variant had larger diameters and z scores at the annulus, sinus of Valsalva, and sinotubular junction, compared with patients with TOF-pulmonary stenosis (all P values < .05). Over time, patients with TOF-variant demonstrated relatively greater annular (P = .020), sinus of Valsalva (P < .001), and sinotubular junction (P < .001) dilatation. Patients with ≥75th percentile root growth rates had a higher incidence of mild or greater aortic regurgitation (P < .001), moderate or greater aortic regurgitation (P < .001), and aortic valve repair or replacement (P = .045).

CONCLUSIONS

Patients with TOF-variant are at comparatively greater risk of pathologic root dilatation over time, warranting closer longitudinal follow-up.

Patterns of Aortic Dilation in Tetralogy of Fallot: An Analysis of 100 Fetal Echocardiograms Compared With Matched Controls

Background Although aortic dilation is common in tetralogy of Fallot (TOF), its progression and risk of dissection are not well understood. The mechanism of dilation is primarily attributed to increased flow in utero; an alternative is unequal septation of the truncus arteriosus resulting in a larger aorta and inherently hypoplastic pulmonary artery (PA). If the latter is true, we hypothesize the aorta to PA ratio in TOF is stable throughout gestation, and sums of great artery dimensions are similar to controls. Methods and Results We performed a single-center retrospective study of fetuses with TOF (2014-2020) and matched controls. We compared sums of diameters, circumferences, and cross-sectional areas of the aorta and PA and evaluated the aorta to PA ratio across gestation in 2 TOF subtypes: pulmonary stenosis and atresia (TOF-PA). There were 100 echocardiograms with TOF (36% TOF-PA) with median gestational age of 31 weeks (interquartile range 26.5-34.4) and median maternal age of 34 years (interquartile range 30-37). There were no differences in sums of great artery dimensions between TOF-pulmonary stenosis and controls. In TOF-PA, sums were significantly lower than controls (P values <0.01). The aorta to PA ratio was stable throughout gestation (Pearson's r=0.08 [95% CI, -0.12 to 0.27], -0.06 [95% CI, -0.25 to 0.14]). Conclusions The aorta in fetal TOF is large but grows proportionally throughout gestation, with sums of great artery dimensions similar to controls. TOF-PA appears distinct from TOF-pulmonary stenosis (with smaller sums), warranting further investigation. In conclusion, our findings suggest an intrinsic developmental mechanism contributes to aortic dilation in TOF.

A Comprehensive Review of Management Strategies for Bicuspid Aortic Valve (BAV): Exploring Epidemiology, Aetiology, Aortopathy, and Interventions in Light of Recent Guidelines

OBJECTIVE

bicuspid aortic valve (BAV) stands as the most prevalent congenital heart condition intricately linked to aortic pathologies encompassing aortic regurgitation (AR), aortic stenosis, aortic root dilation, and aortic dissection. The aetiology of BAV is notably intricate, involving a spectrum of genes and polymorphisms. Moreover, BAV lays the groundwork for an array of structural heart and aortic disorders, presenting varying degrees of severity. Establishing a tailored clinical approach amid this diverse range of BAV-related conditions is of utmost significance. In this comprehensive review, we delve into the epidemiology, aetiology, associated ailments, and clinical management of BAV, encompassing imaging to aortic surgery. Our exploration is guided by the perspectives of the aortic team, spanning six distinct guidelines.

METHODS

We conducted an exhaustive search across databases like PubMed, Ovid, Scopus, and Embase to extract relevant studies. Our review incorporates 84 references and integrates insights from six different guidelines to create a comprehensive clinical management section.

RESULTS

BAV presents complexities in its aetiology, with specific polymorphisms and gene disorders observed in groups with elevated BAV prevalence, contributing to increased susceptibility to other cardiovascular conditions. The altered hemodynamics inherent to BAV instigate adverse remodelling of the aorta and heart, thus fostering the development of epigenetically linked aortic and heart diseases. Employing TTE screening for first-degree relatives of BAV patients might be beneficial for disease tracking and enhancing clinical outcomes. While SAVR is the primary recommendation for indicated AVR in BAV, TAVR might be an option for certain patients endorsed by adept aortic teams. In addition, proficient teams can perform aortic valve repair for AR cases. Aortic surgery necessitates personalized evaluation, accounting for genetic makeup and risk factors. While the standard aortic replacement threshold stands at 55 mm, it may be tailored to 50 mm or even 45 mm based on patient-specific considerations.

CONCLUSION

This review reiterates the significance of considering the multifactorial nature of BAV as well as the need for further research to be carried out in the field.

Impaired ascending aortic elasticity in fetuses with tetralogy of Fallot

OBJECTIVES

Aortic wall stiffness has been reported in infants with tetralogy of Fallot (ToF) and may contribute to long-term aortic dilation even after corrective repair surgery. However, little is known about aortic elasticity in fetuses with ToF and the association with neonatal aortic dilation. The objectives of this study were to assess measures of elasticity of the ascending aorta (AAo) in fetuses with ToF and explore the association with neonatal aortic annular dilation in this population.

METHODS

Seventy-six singleton fetuses with ToF and 76 control fetuses of singleton low-risk pregnancies were enroled into this prospective study. Fetal measures of AAo elasticity, including mean longitudinal strain (MLS), global circumferential strain (GCS) and fractional area change (FAC), were assessed by velocity vector imaging. The z-score of the aortic valve (AV) diameter at the level of the annulus, as a measure of aortic annular dilation, was determined in newborns. Logistic regression analysis was used to investigate the association between fetal measures of AAo elasticity and neonatal aortic annular dilation (defined as an AV annular z-score > 2) in cases with ToF identified prenatally.

RESULTS

Median MLS, GCS and FAC in fetuses with ToF were lower than those in normal fetuses (7.52% vs 12.15% for MLS, 22.05% vs 29.73% for GCS and 34.2% vs 48.3% for FAC, all P < 0.001). Aortic annular dilation was present in 53/76 (69.7%) newborns with ToF. After adjustment for gestational age at fetal echocardiography and birth weight, fetal MLS, GCS and FAC were independently associated with aortic annular dilation neonatally, with odds ratios of 0.66, 0.78 and 0.82, respectively (P < 0.05). The best cut-off values of these prenatal measures of AAo elasticity for predicting neonatal aortic annular dilation in fetuses with ToF were 9.02% for MLS, 23.56% for GCS and 37.2% for FAC (P < 0.001), with areas under the receiver-operating-characteristics curves of 0.94, 0.91 and 0.93, respectively.

CONCLUSION

Measures of AAo elasticity are decreased in fetuses with ToF. Impaired AAo elasticity in the fetal period is associated with aortic annular dilation postnatally. Additional research is needed to evaluate the relationship between the AAo elasticity injury pattern and degeneration of AAo elasticity under stress as well as the long-term outcome in this population. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Serial Magnetic Resonance Imaging for Aortic Dilation in Tetralogy of Fallot With Pulmonary Stenosis

Aortic dilation occurs in patients with repaired tetralogy of Fallot (TOF), but the rate of growth is incompletely characterized. The aim of this study was to assess the rates of growth of the aortic root and ascending aorta in a cohort of pediatric and adult patients with sequential magnetic resonance angiography Magnetic Resonance Imaging (MRI) data. Using serial MRI data from pediatric and adult patients with repaired TOF, we performed a retrospective analysis of the rates of growth and associations with growth of the aortic root and ascending aorta. Patients with pulmonary atresia or absent pulmonary valve were excluded. Between years 2005 to 2021, a total of 99 patients were enrolled. A follow-up MRI was performed an average of 5.9 ± 3.7 years from the initial study. For the cohort aged ≥16 years, the mean rate of change in diameter was 0.2 ± 0.5 mm/year at the ascending aorta and 0.2 ± 0.6 mm/year at the sinus of Valsalva. For the entire cohort, the mean change in cross-sectional area indexed to height at the ascending aorta was 7 ± 12 mm2/m/year and at the sinus of Valsalva was 10 ± 16 mm2/m/year. Younger age was associated with higher rates of growth of the sinus of Valsalva while the use of β blockers or angiotensin-converting enzyme inhibitors was associated with a slower rate of growth. There were no cases of aortic dissection in this cohort. We conclude that serial MRI demonstrates a slow rate of growth of the aorta in the TOF.

Computed tomography for aortic assessment in children

Because the aorta is the major vessel of the body, basic knowledge of aortic pathology is essential to the pediatric imager. This review divides aortic pathology into anatomical (e.g., congenital abnormalities) and acquired (e.g., vasculitis, trauma) entities, providing a brief description of pathology, technical considerations in CT acquisition and processing, and some pearls and pitfalls of interpretation. The objective of this paper is to familiarize general pediatric imagers with imaging features of common as well as high-impact aortic pathology on CT and prepare them for acquisition and reporting.

MED12 Regulates Smooth Muscle Cell Functions and Participates in the Development of Aortic Dissection

Aortic dissection (AD) is a life-threatening disease with high morbidity and mortality, and effective pharmacotherapeutic remedies for it are lacking. Therefore, AD’s molecular pathogenesis and etiology must be elucidated. The aim of this study was to investigate the possible mechanism of mediator complex subunit 12 (human: MED12, mouse: Med12)involvement in AD. Firstly, we examined the expression of MED12 protein (human: MED12, mouse: Med12) in the aortic tissues of AD patients and AD mice. Subsequently, Med12 gene silencing was accomplished with RNA interference (siRNA). The effects of Med12 on AD and the possible biological mechanisms were investigated based on the proliferation, senescence, phenotypic transformation, and its involved signal pathway of mouse aortic smooth muscle cells (MOVAS), s. The results show that the expression of MED12 in the aortae of AD patients and AD mice was decreased. Moreover, the downregulation of Med12 inhibited the proliferation of MOVAS and promoted senescence. Further research found that Med12, as an inhibitor of the TGFβ1 signaling pathway, reduced the expression of Med12 and enhanced the activity of the TGFβ1 nonclassical signaling pathway, while TGFβ1 inhibited the phenotype transformation and proliferation of MOVAS by inhibiting Med12 synthesis. In conclusion, Med12 affected the phenotype, proliferation, and senescence of MOVAS through the TGFβ signaling pathway. This study provides a potential new target for the prevention and treatment of AD.

Prevalence and risk of progressive aortic aneurysm and dissection in adults with conotruncal anomalies

AIMS

Conotruncal anomalies share common embryogenic defects of the outflow tracts and great arteries, which result in a predisposition to aortic aneurysms. The purpose of this study was to describe the prevalence and risk of progressive aortic aneurysms in adults with conotruncal anomalies.

METHODS AND RESULTS

Retrospective study of adults with conotruncal anomalies that underwent cross-sectional imaging 2003-20. Aneurysm was defined as aortic root/mid-ascending aorta >2.1 mm/m2/>1.9 mm/m2, progressive aneurysm as increase by >2 mm, and severe aneurysm as dimension >50 mm. Of 2261 patients (38 ± 12 years; male 58%), 1167 (52%) had an aortic aneurysm, and 205 (14%) had a severe aortic aneurysm. Mean annual increase in aortic root/mid-ascending aorta was 0.3 ± 0.1 mm/0.2 ± 0.1 mm. The 3-, 5-, and 7-year cumulative incidence of the progressive aortic aneurysm was 4%, 7%, and 9%, respectively. The rate of aneurysm growth decreased with age, with no significant growth after age 40 years. There was an excellent correlation between aortic indices from cross-sectional imaging and echocardiography. Of 950 females, 184 had ≥1 pregnancy, and 81 (44%) of the 184 patients had aortic aneurysm prior to pregnancy. There was no aortic dissection or progression of the aortic aneurysm during pregnancy. Overall, there was no aortic dissection during 7984 patient-years of follow-up.

CONCLUSIONS

Aortic aneurysm was common in patients with conotruncal anomalies. However, the risk of progressive aneurysm or dissection was low. Collectively, these data suggest a benign natural history and perhaps a less frequent need for cross-sectional imaging. Further studies are required to determine the optimal timing for surgical intervention in this population.

Proximal Aortic Dilatation and Pulmonary Valve Replacement in Patients with Repaired Tetralogy of Fallot: Is There a Relationship? A Cardiac Magnetic Resonance Imaging Study

Aortopathy is a known complication whose incidence is growing within the population of tetralogy of Fallot (TOF) patients. Its pathology and relationship with other comorbidities remain unclear. This study was designed to determine the prevalence and predictors of proximal aortic dilatation after TOF repair. We retrospectively investigated all patients who underwent follow-up cardiac magnetic resonance imaging (CMR; at least 4 years after TOF repair) between March 2004 and December 2019. The dimensions at the ascending aorta (AAo) and sinus of Valsalva (SoV) levels were measured. Aortic dilatation was defined as an internal aortic diameter that was >2 standard deviation of the previously published normal values. We included 77 patients (mean age 28.9 ± 10.5 years, 41.5% female, mean follow-up of 24.5 ± 8.1 years). AAo and SoV were dilated in 19 (24.6%) and 43 (55.8%) patients, respectively. Patients with dilated AAo and SoV were older during the corrective surgery (p < 0.001 and p = 0.004, respectively) and during CMR (p = 0.002 and 0.024, respectively) than patients without AAo and SoV dilatation. Patients of the dilated AAo group were more likely to have prior palliative shunt (p = 0.008), longer shunt duration (p = 0.005), and a higher degree of aortic valve regurgitation (AR) fraction (p < 0.001) and to undergo pulmonary (PVR) and/or aortic valve replacement (p < 0.001 and p = 0.013, respectively). PVR (p = 0.048, odds ratio = 6.413, and 95% CI = 1.013-40.619) and higher AR fraction (p = 0.031, odds ratio = 1.194, and 95% CI = 1.017-1.403) were independent predictors for AAo dilatation. Aortopathy is a common progressive complication that may require reintervention and lifelong follow-up. Our study shows that proximal aortic dilatation may be attributed to factors that increase the volume overload across the proximal aorta, including late corrective surgery and palliative shunt. We also found that PVR and higher AR fraction are independent predictors of AAo dilatation.

The challenges of an aging tetralogy of Fallot population

Introduction: Advancements in surgery and management have resulted in a growing population of aging adults with tetralogy of Fallot (TOF). As a result, there has been a parallel growth in late complications associated with the sequelae from the underlying cardiac anomalies as well as the surgical and other interventional treatments.Areas covered: Here, we review challenges related to an aging population of patients with TOF, particularly late complications, and highlight advances in management and key areas for future research. Pulmonary regurgitation, heart failure, arrhythmias, and aortic complications are some of these late complications. There is also a growing incidence of acquired cardiovascular disease, obesity, and diabetes associated with aging. Management of these late complications and acquired comorbidities continues to evolve as research provides insights into long-term outcomes from medical therapies and surgical interventions.Expert opinion: The management of an aging TOF population will continue to transform with advances in imaging technologies to identify subclinical disease and valve replacement technologies that will prevent and mitigate disease progression. In the coming years, we speculate that there will be more data to support the use of novel heart failure therapies in TOF and consensus guidelines on the management of refractory arrhythmias and aortic complications.

[The adult with tetralogy of fallot: what the clinical cardiologist needs to know]

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease. After more than seven decades of the first palliative surgery, TOF prognosis has changed dramatically. The prevalence of TOF is approximately 3 per 10 000 births, representing 7 to 10% of congenital heart disease. With a higher survival into adulthood, the clinical cardiologist faces challenges in the management of this population, from severe pulmonary regurgitation to heart failure and ventricular arrhythmias. Its prevalence is approximately 3 per 10 000 live births, representing 7 to 10% of congenital heart disease. This review will describe the most relevant aspects of the care of adult patients with this disease.

Heart failure in adult congenital heart disease: tetralogy of Fallot

The number of rTOF patients who survive into adulthood is steadily rising, with currently more than 90% reaching the third decade of life. However, rTOF patients are not cured, but rather have a lifelong increased risk for cardiac and non-cardiac complications. Heart failure is recognized as a significant complication. Its occurrence is strongly associated with adverse outcome. Unfortunately, conventional concepts of heart failure may not be directly applicable in this patient group. This article presents a review of the current knowledge on HF in rTOF patients, including incidence and prevalence, the most common mechanisms of heart failure, i.e., valvular pathologies, shunt lesions, left atrial hypertension, primary left heart and right heart failure, arrhythmias, and coronary artery disease. In addition, we will review information regarding extracardiac complications, risk factors for the development of heart failure, clinical impact and prognosis, and assessment possibilities, particularly of the right ventricle, as well as management strategies. We explore potential future concepts that may stimulate further research into this field.

The aortic root in repaired tetralogy of Fallot: Serial measurements and impact of losartan treatment

BACKGROUND

Aortic root dilatation is common in adults with repaired tetralogy of Fallot (rTOF) and might lead to aortic dissection. However, little is known on progression of aortic dilatation and the effect of pharmaceutical treatment. This study aims to determine factors associated with aortic growth and investigate effects of losartan.

METHODS AND RESULTS

We performed a prespecified analysis from the 1:1 randomized, double-blind REDEFINE trial. Aortic root diameters were measured at baseline and after 2.0 ± 0.3 years of follow-up using cardiovascular magnetic resonance (CMR) imaging. A total of 66 patients were included (68% men, age 40 ± 12 years, baseline aortic root 37 ± 6 mm, 32% aortic dilatation (>40 mm)). There was a trend towards slow aortic root growth (+0.6 ± 2.3 mm after two years, p = 0.06) (n = 60). LV stroke volume was the only factor associated with both a larger baseline aortic root (β: 0.09 mm/ml (95% C.I.:0.02, 0.15), p = 0.010) and with aortic growth during follow-up (β: 0.04 mm/ml (95% C.I.:0.005, 0.066), p = 0.024), after correction for age, sex, and body surface area using linear regression analysis. No treatment effect of losartan was found (p = 0.17).

CONCLUSIONS

Aortic root dilatation was present in about one-third of rTOF patients. A larger LV stroke volume was associated with both a larger baseline aortic root and ongoing growth. Our findings provide no arguments for lower aortic diameter thresholds for prophylactic surgery compared to the general population.

Aortic dissection in a Chinese patient 31 years after surgical repair of tetralogy of Fallot

Aortic dilation has been increasingly recognized in congenital heart diseases, and aortic dissection is one of the important complications. We report a case of aortic dissection in a patient 31 years after repair of tetralogy of Fallot (TOF) and review reported cases. While aortic dissection is uncommon, aortic dilation is common among patients with repaired TOF and it appeared progressive in some patients. Based on the reported cases, progressive aortic dilation appeared as the pre-requisite for aortic dissection, although other factors might be involved. Regular surveillance and monitoring for aortic complications should be incorporated into clinical practice. <Learning objective: Aortic dilation is common but aortic dissection is uncommon in patients with tetralogy of Fallot, and threshold for prophylactic surgery is lacking. Recognition of progressive aortic dilation is important to identify patients at risk of aortic dissection in tetralogy of Fallot.>.

Thoracic Aortic Dissection in Tetralogy of Fallot: A Review of the National Inpatient Sample Database

Background

Thoracic aortic aneurysm is common in patients with tetralogy of Fallot (TOF); the incidence of thoracic aortic dissection (TAD) is unknown, but generally considered to be uncommon. The purpose of this study was to determine incidence and risk factors for TAD in TOF patients.

Methods and Results

This work is a retrospective review of the National Inpatient Sample (NIS) database for cases of ascending TAD among all hospital admissions in adults with TOF, 2000–2014. Of 18 353 admissions in TOF patients, 11 (0.06%; 6 per 10 000 admissions) of these were TAD‐related admissions. For the TAD‐related admissions, mean age was 49.8±7.2 years; aortic surgical interventions were performed during 8 of the admissions, and overall in‐hospital mortality was 45% (5 of 11). Risk factors associated with TAD‐related admission were age >60 years (odds ratio, 2.41; 95% CI, 1.23–3.25; P=0.013), male sex (odds ratio, 6.91; 95% CI, 4.85–8.54; P<0.001), and hypertension (odds ratio, 1.74; 95% CI, 1.06–3.19; P=0.037).

Conclusions

This is the first population‐based study of TAD outcomes in patients with TOF, and it showed a low risk of TAD in this population. This has important clinical implication with regard to surveillance and surgical intervention. Given that prevalence of thoracic aortic aneurysm is higher in TOF patients compared with the general population; therefore, making clinical decisions based on outcomes data and practice guidelines derived from patients with degenerative and bicuspid aortic valve–related aortopathies may lead to overtreatment. Further studies are required to better understand the pathobiology of this disease in order to make evidence‐based recommendations for surveillance and treatment.

Significant delayed aortic dilatation after tetralogy of Fallot repair: a case report

Background

Aortic dilatation may occur in some patients even after complete repair of tetralogy of Fallot (TOF). The progression rate of the aortic diameter is so slow, and the incidence of aortic dissection is so low that it is suspected that frequent imaging of the aorta may not be necessary.

Case presentation

We describe an asymptomatic 41-year-old man with hypertension in whom aortic dilatation was accidentally discovered 39 years after TOF repair. He underwent ambulatory follow-up without any difficulty for 21 years after the repair. Contrast-enhanced computed tomography revealed significant aortic dilatation (maximum diameter of 88 mm at the sinus of Valsalva), and echocardiography revealed severe aortic regurgitation, which seemed to progress during the last 18 years without any evaluation or follow-up. The Bentall procedure was successfully performed using a valved graft, under deep hypothermic circulatory arrest with antegrade cerebral perfusion, and his postoperative course was uneventful. Histopathological examination of ascending aorta specimens revealed severe cystic medial degeneration.

Conclusions

Keeping in mind that a patient with rapid progression of the aortic dilatation after TOF repair exist, periodic follow-up for evaluation of the aorta is essential in patients with TOF.

Downregulation of HDAC1 suppresses media degeneration by inhibiting the migration and phenotypic switch of aortic vascular smooth muscle cells in aortic dissection

Although much progress has been made in the diagnosis and treatment of thoracic aortic dissection (TAD), the overall morbidity and mortality rates of TAD are still high. Therefore, the molecular pathogenesis and etiology of TAD need to be elucidated. In this study, we found that histone deacetylase 1 (HDAC1) expression is dramatically higher in the aortic wall of patients with TAD (than that in a normal group) and negatively correlates with the levels of the vascular smooth muscle cell (SMC) contractile-phenotype markers. Knockdown of HDAC1 upregulated both smooth muscle 22 α (SM22α) and α-smooth muscle actin (α-SMA) in platelet-derived growth factor (PDGF)-BB-treated and -untreated SMCs. In addition, the knockdown of HDAC1 markedly decreased SMC viability and migration in contrast to the control group under the conditions of quiescence and PDGF-BB treatment. We also showed that the expression of polycystic kidney disease 1 (PKD1) is decreased in the aortic wall of patients with TAD and negatively correlates with HDAC1 expression. Overexpressed PKD1 obviously increased SM22α and α-SMA expression and reduced the viability and migration of SMCs, but these effects were attenuated by HDAC1. Furthermore, we demonstrated that HDAC1 serves as an important modulator of the migration and phenotypic switch of SMCs by suppressing the PKD1- mammalian target of the rapamycin signaling pathway. HDAC1 downregulation inhibited media degeneration and attenuated the loss of elastic-fiber integrity in a mouse model of TAD. Our results suggest that HDAC1 might be a new target for the treatment of a macrovascular disease such as TAD.

Is there any association between aortic root rotation angle and aortic dissection?

Introduction

Thoracic aortic dissection is a probable fatal condition that requires early diagnosis and management. The underlying etiology of this disorder is an important issue that has not been completely responded yet. In the current study, the association between aortic root rotation and ascending aortic dissection has been assessed.

Methods

This is a non-randomized retrospective case-control study conducted on twenty-five cases referring with ascending aortic dissection and seventy-five controls that underwent computed tomography (CT) angiography for reasons other than aortic dissection. Aortic root rotation angle and aortic diameter for both cases and controls were measured and then compared.

Results

There was no significant difference regarding age and gender distribution (P value = 0.22 and 0.38 respectively) between patients in case and control groups. The mean values of aortic root rotation angle and aortic diameter in cases were 22.5 ± 10.5° and 43.1 ± 12.5 mm versus 15.7 ± 10.7° and 30.7 ± 5.3 mm in controls (P value = 0.007 and 0.001 respectively). Direct relation was found between aortic root rotation angle and aortic diameter (P value = 0.007, r = 0.276). Mean of aortic root rotation angle was significantly higher in females (P value = 0.02). No association between cases' age with either aortic root rotation angle or aortic diameter was found (P value = 0.33, r = 0.098, and P value = 0.085, r = 0.173 respectively).

Conclusion

Based on the findings of the current study, aortic root rotation angle was independently in direct association with thoracic aortic dissection. In addition, females had higher aortic root rotation angles.