Aortic stiffness and aortic dilation in infants and children with tetralogy of Fallot before corrective surgery: evidence for intrinsically abnormal aortic mechanical property

Association between invasively measured central aortic pulse pressure and diameter of ascending aorta

Data on the relationship between arterial pulsatile hemodynamics and aortic root geometry, using invasive hemodynamic measurement, has been scarce. Thus, this study aimed to assess the relationship between invasively measured aortic pulse pressure (aPP) and the diameter of ascending aorta (AoD). We analyzed 665 subjects (64.3 ± 11.0 years; 34.6% female) who underwent elective invasive coronary angiography (ICA) for the evaluation of coronary artery disease. Transthoracic echocardiography was performed on the same day, and AoD was measured at the level of 1 cm above the sinotubular junction at the end-diastole. Body surface area (BSA)-adjusted AoD (AoD/BSA) was used for the analysis. A pig-tail catheter was used to measure aortic pressures at a level approximately 3 cm above the aortic valve just before ICA. aPP was calculated as the difference between systolic and diastolic pressures of the aorta. In multiple linear regression analyses, aPP (β = 0.259; P < 0.001) was found to be significantly correlated with AoD/BSA even after controlling for potential confounders. This correlation power was stronger than aortic systolic pressure (β = 0.189; P < 0.001) and brachial pulse pressure (β = 0.091; P = 0.018) at the same multivariable analyses. In conclusion, our study demonstrated a significant association between invasively measured aPP and AoD/BSA, providing stronger evidence for the link between central aortic pulsatile hemodynamics and aortic root geometry.

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.

Realignment of the ventricular septum in tetralogy of Fallot using (partial) direct closure of the ventricular septal defect: Long-term follow-up and comparison to conventional patch repair

Objectives

Aortic dilatation and regurgitation after surgical repair of tetralogy of Fallot (TOF) is known, and beside other factors, mainly addressed to an intrinsic aortopathy. In 2011, we reported the influence of realingement of the left ventricular outflow tract (LVOT) by (partial) direct closure of the ventricular septal defect (VSD) in TOF on aortic structures and function. We now evaluated the further follow-up of this cohort and compared the results to a matched group of TOF patients with classical VSD patch closure.

Patients and Methods

Forty patients with TOF treated between 2003 and 2008 are included in the study, with 20 patients each in the VSD (a) (partial) direct closure and (b) patch closure group. Follow-up time after surgery was 12.3 years (11.3-13.0).

Results

Patient characteristics, echocardiographic measurements, and surgical and intensive care unit parameters were not significantly different between both groups. After surgery and during long-term follow-up, realignement of the LVOT, shown by the angle between the interventricular septum and the anterior aortic annulus in long axis view in echocardiography, was lower in Group A (34 vs. 45°, P < 0.0001). No differences in LVOT or aortic annulus size, aortic regurgitation, or dilation of the ascending aorta and right ventricular outflow tract gradients were found. Transient rhythm disturbances were found in 3 patients in each group, with only one persistent complete atrioventricular block in Group B.

Conclusion

(Partial) direct closure of the VSD in TOF leads to a better realignement of the LVOT and showed comparable short- and long-term results without higher risk for rhythm disturbances during follow-up.

Vascular aging in adult congenital heart disease-a narrative review

Background and Objective

Many studies about the high prevalence of cardiovascular disease in adults with congenital heart disease (CHD) have been published in response to the growing number of adult patients with CHD. The aging process leads to hypertension and cardiovascular disease, which is caused by a degenerative change in the systemic arterial system characterized by the stiffening of elastic arteries (known as arteriosclerosis) and the enlargement of aorta. In patients with CHD, aortic dilatation (so-called aortopathy) is one of the most frequent complications. It is well known the anatomical and histological changes in aortopathy are similar to those in aging process. The increase of pulse wave velocity (PWV) enhances pressure wave reflection, and it augments left ventricular afterload and impairs the coronary supply-workload balance in aging. This article reviews the aortic function in patients with CHD, aiming to provide a new direction for the management of their cardiovascular aging process.

Methods

Papers on vascular physiology in CHD were retrieved. I searched all original papers and reviews about the vascular physiology in CHD using PubMed, published from January 1, 1973 to June 30, 2022, in English.

Key Content and Findings

Enhancement of pressure wave reflection has been reported in many CHDs. Although PWV in whole aorta is not necessarily elevated, the abnormal arterial stiffness gradient is common in patients with CHD.

Conclusions

Many reports concerning functional abnormalities of the aorta have been reported. The abnormalities can result in cardiovascular disease and organ damage. The practitioners should carefully treat patients with CHD while paying attention to their aging process.

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.

Arterial Stiffness in Congenital Heart Disease

Transposition of the great arteries (TGA), coarctation of the aorta (CoA), single ventricle (SV) and tetralogy of Fallot (ToF) are forms of congenital heart disease (CHD). Despite advances in treatment, cardiovascular and cerebrovascular complications in patients with repaired CHD occur earlier in life compared to healthy subjects. A factor that may contribute to this increased risk is elevated arterial stiffness. This systematic review provides a critical assessment of current evidence on central arterial stiffness in patients with CHD compared to healthy controls. In July 2020, Medline OVID, EMBASE and Scopus were searched using keywords and MeSH terms. Articles were included if they reported indices of aortic or carotid artery stiffness in patients with TGA, CoA, SV or ToF, and compared these to controls. Additional studies were screened from the reference lists of included articles. Of 1,033 studies identified, 43 were included in the final review. Most studies identified at least one index of central arterial stiffness, commonly in the aortic root or ascending aorta, that was higher in patients with CHD compared to controls. The commonly reported surrogate markers of stiffness were pulse wave velocity, aortic distensibility and the β stiffness index. There was a relatively small number of original studies, and synthesis of data was limited by methodological heterogeneity, highlighting the need for further studies with standardised methods. However, there was consistent evidence of early and/or accelerated arterial stiffening in CHD patients, which may contribute to the increased risk of adverse cardiovascular and cerebrovascular events in this population.

Simplified pulse wave velocity measurement in children: Is the pOpmètre valid?

In population exposed to cardiovascular risk, aortic stiffness is an important marker which is assessed by carotid-to-femoral pulse wave velocity (PWV). In childhood, the validated applanation tonometer SphygmoCor® can be used to measure PWV, but is limited in routine practice by the child's cooperation and operator's experience. An alternative device, the pOpmètre® is validated in adults and rapidly measures finger-to-toe PWV using 2 oxymeter-like sensors. The aim of this study is to validate the pOpmètre® device in children aged between 4 and 8 years. We compared simultaneous PWV measurements of the two devices, SphygmoCor® and pOpmètre®, in a training group, using the Bland-Altman method. Then we proposed an algorithm to correct pOpmètre® PWV (PWVpop). Finally, we validated this new algorithm in a validation group of children using the Bland-Altman method. This prospective study enrolled 26 children in the training group. Mean PWVpop was 3.919 ± 0.587 m/s and mean SphygmoCor® PWV was 4.280 ± 0.383 m/s, with a difference of -0.362(CI95%(-0.546;-0.178)) m/s. A new algorithm was defined using transit time (TTpop): corrected PWVpop (m/s) = 0.150/TTpop(s) + 1.381*Height(m) + 1.148. We enrolled 24 children in the validation group. Mean corrected PWVpop was 4.231 ± 0.189 m/s and mean SphygmoCor® PWV was 4.208 ± 0.296 m/s with a corrected difference of 0.023(CI95%(-0.086;0.131)) m/s. With this algorithm correction, we found an agreement between PWV measured by the SphygmoCor® and the pOpmètre®, with a difference of less than 10%. Using this algorithm, the pOpmètre® could be used in clinical or research practice in young children exposed to cardiovascular risk. (This study was registered as NCT02991703).

Gender Related Association between Arterial Stiffness and Aortic Root Geometry

BACKGROUND

The gender-related change in aortic morphology by arterial stiffness has not been well studied. This study was performed to investigate the association between brachial-ankle pulse wave velocity (baPWV) and aortic root size according to gender.

METHODS

A total of 263 consecutive subjects (63.2 ± 10.6 years, 71.1% men) without overt cardiovascular disease who underwent both baPWV measurement and transthoracic echocardiography on the same day were retrospectively analyzed. The diameters of the aortic annulus (AN), sinus of Valsalva (SV), sinotubular junction (STJ), and ascending aorta (AA) were measured using 2-dimensional echocardiography.

RESULTS

The body surface area (BSA)-corrected diameters of AN, SV, STJ, and AA were significantly higher in women than in men. Univariable analyses showed that baPWV was significantly correlated with SV/BSA and STJ/BSA in men, and with SV/BSA, STJ/BSA, and AA/BSA in women (p < 0.05 for each). In men, however, these associations disappeared in multiple linear regression models after controlling for potential confounders (p > 0.05 for each). In women, the associations of baPWV with diameters of STJ/BSA (β = 0.407, p < 0.001) and AA/BSA (β = 0.391, p = 0.005) remained significant in the same multivariate models. Women-specific correlation between aortic root size and baPWV was also similarly demonstrated in age-matched analyses (n = 61 in each gender).

CONCLUSIONS

Among Korean adult without overt cardiovascular disease, the association between increased arterial stiffness and aortic root dilatation is stronger in women than in men.

Improving medical care and prevention in adults with congenital heart disease-reflections on a global problem-part II: infective endocarditis, pulmonary hypertension, pulmonary arterial hypertension and aortopathy

Despite relevant residua and sequels, follow-up care of adults with congenital heart disease (ACHD) is too often not performed by/in specialized and/or certified physicians or centers although major problems in the long-term course may develop. The most relevant encompass heart failure, cardiac arrhythmias, heart valve disorders, pulmonary vascular disease, infective endocarditis (IE), aortopathy and non-cardiac comorbidities. The present publication emphasizes current data on IE, pulmonary and pulmonary arterial hypertension and aortopathy in ACHD and underlines the deep need of an experienced follow-up care by specialized and/or certified physicians or centers, as treatment regimens from acquired heart disease can not be necessarily transmitted to CHD. Moreover, the need of primary and secondary medical prevention becomes increasingly important in order to reduce the burden of disease as well as the socioeconomic burden and costs in this particular patient group.

Utility of arterial stiffness assessment in children

Atherosclerotic cardiovascular disease is a leading cause of death and disability worldwide, and the atherosclerotic process begins in childhood. Prevention or containment of risk factors that accelerate atherosclerosis can delay the development of atherosclerotic cardiovascular disease. Although current recommendations are to periodically screen for commonly prevailing risk factors for atherosclerosis in children, a single test that could quantify the cumulative effect of all risk factors on the vasculature, thus assessing arterial health, would be helpful in further stratifying risk. Measurement of pulse wave velocity and assessment of augmentation index - measures of arterial stiffness - are easy-to-use, non-invasive methods of examining arterial health. Various studies have assessed pulse wave velocity and augmentation index in children with commonly occurring conditions including obesity, hypertension, insulin resistance, diabetes mellitus, dyslipidaemia, physical inactivity, chronic kidney disease, CHD and acquired heart diseases, and in children who were born premature or small for gestational age. This article summarises pulse wave velocity and augmentation index assessments and the effects of commonly prevailing chronic conditions on arterial health in children. In addition, currently available reference values for pulse wave velocity and augmentation index in healthy children are included. Further research to establish widely applicable normative values and the effect of lifestyle and pharmacological interventions on arterial health in children is needed.

Cross-sectional Areas of the Thoracic Aorta in Children and Adolescents With Repaired Tetralogy of Fallot Obtained by Cardiac Magnetic Resonance Angiography

PURPOSE

Dilatation of the thoracic aorta is a well-known finding in corrected Tetralogy of Fallot. Complications are rare but can be life-threatening. Standard 1-dimensional (1D) measurements have several limitations. We sought to establish contrast-enhanced magnetic resonance angiography cross-sectional areas of the aorta that could serve as reference values and to identify parameters that are associated with aortic dilatation.

MATERIALS AND METHODS

We enrolled 101 children and adolescents. The aortic areas were measured at the level of the aortic sinus (AS), the sinotubular junction (STJ), the ascending aorta (AA), the brachiocephalic trunk (TBC), and the descending aorta (DA). Sex-specific aortic dimensions were presented as percentile curves as well as regression equations. Furthermore volumetric and functional parameters as well as clinical data were analyzed to identify parameters that are associated with aortic dilatation.

RESULTS

Aortic areas (mm) for female subjects were 139+366×body surface area (BSA) for the AS, 134+255×BSA for the STJ, 113+239×BSA for the AA, 88+185×BSA proximal to the TBC, and 2.9+88×BSA for the DA. Aortic areas (mm) for male subjects were 162+403×BSA for the AS, 171+258×BSA for the STJ, 151+233×BSA for the AA, 73+206×BSA proximal to the TBC, and 21+80×BSA for the DA. The postoperative interval and age at examination were parameters associated with aortic size.

CONCLUSIONS

We provide aortic areas in children and adolescents after correction of Tetralogy of Fallot measured by contrast-enhanced magnetic resonance angiography. Our 2D data may better depict the geometry of enlarged aortae than standard 1D diameters and serve as reference values for evaluating aortic disease in these patients.

Landmark lecture: Perloff lecture: Tribute to Professor Joseph Kayle Perloff and lessons learned from him: aortopathy in adults with CHD

Marfan syndrome, bicuspid aortic valve, and/or coarctation of the aorta are associated with medial abnormalities of the ascending aortic or para-coarctation aorta. Medial abnormalities in the ascending aorta are prevalent in other type of patients with a variety of CHDs such as single ventricle, persistent truncus arteriosus, transposition of the great arteries, hypoplastic left heart syndrome, and tetralogy of Fallot, encompassing a wide age range and may predispose to dilatation, aneurysm, and rapture necessitating aortic valve and root surgery. These CHDs exhibit ongoing dilatation of the aortic root and reduced aortic elasticity and increased aortic stiffness that may relate to intrinsic properties of the aortic root. These aortic dilatation and increased stiffness can induce aortic aneurysm, rapture of the aorta, and aortic regurgitation, but also provoke left ventricular hypertrophy, reduced coronary artery flow, and left ventricular failure. Therefore, a new clinical entity can be used to call this association of aortic pathophysiological abnormality, aortic dilation, and aorto-left ventricular interaction - "aortopathy".

Vascular and Endothelial Function in Youth with Type 2 Diabetes Mellitus

PURPOSE OF REVIEW

This review aims to discuss the burden of type 2 diabetes in youth and summarize the studies that have utilized noninvasive techniques to assess early vascular disease in youth with type 2 diabetes.

RECENT FINDINGS

Noninvasive imaging modalities provide researchers with tools to investigate the vasculature in adolescents with type 2 diabetes. The data published to date consistently show adolescents with type 2 diabetes have greater vascular thickness and stiffness and worse endothelial function compared to their obese and lean peers. As the prevalence of type 2 diabetes continues to increase adolescent youth, there is concern adolescents with type 2 diabetes are at risk to develop early onset cardiovascular disease and complications. Future studies need to address treatments that have the potential to improve or reverse vascular dysfunction and decrease the rate of cardiovascular disease and complications.

Developmental Changes in Aortic Mechanical Properties in Normal Fetuses and Fetuses with Cardiovascular Disease

BACKGROUND

We hypothesized that fetal aortic mechanical properties assessed by aortic diameter (AoD) and flow show maturational changes during the gestational period, and that these properties are different in fetuses with congenital heart diseases and fetuses with normal development.

METHODS

Phasic changes in ascending AoD along with Doppler flow profile were measured in 84 consecutive normal fetuses (gestational age, 18-36 weeks) and in 30 consecutive fetuses with cardiovascular diseases (gestational age, 22-39 weeks).

RESULTS

AoD and cardiac output significantly increased with gestational age. Fetal aortic compliance (AC), assessed as (maximum AoD - minimum AoD)/stroke volume, significantly decreased with gestational age in normal fetuses, indicating maturational changes in aortic wall properties. Importantly, fetuses with Marfan syndrome and tetralogy of Fallot that exhibit "aortopathy" showed significantly lower AC than normal fetuses of the same gestational age, suggesting intrinsic abnormalities in aortic wall properties in these diseases. Fetuses with trisomy 18 and Noonan syndrome also had AC values below the normal ranges.

CONCLUSION

Measurements of phasic changes in fetal AoD and flow measurements can provide useful information about aortic mechanical properties and may help clarify abnormal arterial hemodynamics in pathologic conditions.

Cardio-Ankle Vascular Index (CAVI) and Plasma Transforming Growth Factor-β1 (TGF-β1) Level Correlate with Aortopathy in Adults with Repaired Tetralogy of Fallot

It is challenging to evaluate aortopathy in congenital heart disease using conventional investigations such as brachial-ankle pulse wave velocity (baPWV). Therefore, we evaluated the cardio-ankle vascular index (CAVI), a dimension of the ascending aorta and plasma transforming growth factor-β1 (TGF-β1) level, in order to find novel noninvasive parameters of aortopathy in adults with repaired tetralogy of Fallot (TOF). Prospectively, we enrolled 42 consecutive adults with TOF (28 patients with repaired TOF were not on ARB, 8 patients with repaired TOF on ARB, 6 patients with no repair or only palliative repair) and 20 age-matched healthy controls. We measured CAVI, baPWV, plasma TGF-β1 level and a diameter of the ascending aorta using echocardiography. The mean age of repaired TOF without ARB were 31.9 ± 9.1 years. An aortic diameter of the ascending aorta, CAVI, and plasma TGF-β1 level were significantly higher in repaired TOF without ARB than those in controls, whereas baPWV did not differ. On a univariate analysis, CAVI, plasma TGF-β1 level and Rastelli procedure were important factors for an aortic diameter of the ascending aorta (r = 0.56, P < 0.01, r = 0.59, P < 0.01, r = 0.39, P < 0.05, respectively) in this population. There was no significant correlation with age, baPWV, NT-pro brain natriuretic peptide (BNP), repair age, shunt duration, aortic regurgitation or right aortic arch. On the other hand, patients with unrepaired or palliative TOF, who had obvious volume overload, showed no significant correlation with CAVI, baPWV or plasma TGF-β1 level. CAVI and plasma TGF-β1 level, not baPWV, correlate to aortopathy in adults with repaired TOF.

Holodiastolic Flow Reversal at the Descending Aorta on Cardiac Magnetic Resonance is Neither Sensitive Nor Specific for Significant Aortic Regurgitation in Patients with Congenital Heart Disease

Holodiastolic flow reversal in the descending aorta on echocardiogram suggests significant aortic regurgitation. The study aim was to determine whether the presence of holodiastolic flow reversal on cardiac magnetic resonance imaging (MRI) correlates with aortic valve regurgitant fraction. We retrospectively reviewed 166 cardiac MRIs (64 % male, age 14.1 ± 9.5 years) from January 2011 to May 2012 where velocity mapping was acquired at both the aortic valve and the descending aorta at the level of the diaphragm. Descending aorta velocity maps were checked for baseline offset using a static reference region. Holodiastolic flow reversal was defined as flow reversal throughout diastole both before and after baseline correction. Significant aortic regurgitation was defined as regurgitant fraction >10 %. Aortic valve regurgitant fraction was <10 % in 144 patients (Group A), 10-20 % inclusive in 7 patients (Group B), and >20 % in 15 patients (Group C). Though the aortic valve regurgitant fraction was significantly higher for patients with holodiastolic flow reversal versus those without (8.5 ± 14.2 vs. 3.8 ± 6.6 %, p = 0.02), holodiastolic flow reversal was present in 32 Group A patients (22 %). In comparison, 4 Group B patients (57 %) and 7 Group C patients (47 %) had holodiastolic flow reversal. The sensitivity (Groups B and C) was 0.5, and the specificity (Group A) was 0.78. Holodiastolic flow reversal in the descending aorta on cardiac MRI was neither sensitive nor specific for predicting significant aortic regurgitation in this study population. Holodiastolic flow reversal in the absence of significant aortic regurgitation may be a relatively common finding in patients with congenital heart disease.

Mechanism of aortic root dilation and cardiovascular function in tetralogy of Fallot

The aortic root dilation in tetralogy of Fallot (TOF) is a long-term clinical problem, because a severely dilated aorta can lead to aortic regurgitation, dissection, or rupture, which can be fatal, necessitating surgical intervention. The details of the mechanism of aortic root dilation, however, are unclear. We have shown that aortic stiffness is increased in patients with repaired TOF, and may mirror the histological abnormality of elastic fiber disruption and matrix expansion. This aortic stiffness is related closely to the aortic dilation, indicating that aortic stiffness may be a predictor of outcome of aortic dilation. Furthermore, the aortic volume overload is a very important determinant of aortic diameter in TOF patients before corrective surgery. In addition, a chromosomal abnormality and the transforming growth factor-β signaling pathway, a major contributor to aortic dilation in Marfan syndrome, also affect this mechanism. In this way, aortic dilation in TOF patients is suggested to be a multifactorial disorder. The aim of this review was therefore to clarify the mechanism of aortic dilation in TOF, focusing on recent research findings. Studies linking histopathology, mechanical properties, molecular/cellular physiology, and clinical manifestations of aortic dilation facilitate appropriate treatment intervention and improvement of long-term prognosis of TOF.

Dimensions of the ascending aorta in children and adolescents with repaired Tetralogy of Fallot obtained by cardiac magnetic resonance angiography

Introduction

Dilatation of the ascending aorta is a common finding in Tetralogy of fallot (TOF). We sought to provide aortic dimensions in children and adolescents after corrected TOF obtained by contrast-enhanced cardiac-magnetic-resonance angiography (CE-CMRA) that could serve as reference values.

Materials and methods

We enrolled 101 children and adolescents (56 male) with a median age of 10.9 years. All patients underwent CE-CMRA imaging using a 3-dimensional spoiled gradient-echo-sequence. Aortic diameters were measured at the level of the aortic valve (AV), aortic sinus (AS), sino-tubular junction (STJ) and the ascending aorta (AA) and compared with normal values obtained from literature. Sex-specific aortic dimensions are given as percentile curves as well as z scores. Furthermore CMR volumetric and functional parameters as well as clinical and anamnestic data were analyzed to identify parameters that are associated with aortic dilatation.

Results

Diameters for aortic size for males were 3.6 + 16.6*BSA^0.5 at the AV level, 7.0 + 19.5*BSA^0.5 at the AS level, 7.0 + 14.4*BSA^0.5 at the STJ level and 7.3 + 15.5*BSA^0.5 at the AA level. Diameters for females were 5.8 + 14.1*BSA^0.5 at the AV level, 7.2 + 17.6*BSA^0.5 at the AS level, 5.2 + 15.4*BSA^0.5 at the STJ level and 2.0 + 17.8*BSA^0.5 at the AA level. All diameters in TOF patients were larger compared with normal values. The postoperative interval and age at examination were the only parameters associated with aortic size at all measured levels.

Conclusion

We provide CE-CMRA data of aortic dimensions in children and adolescents after correction of TOF. Our data might be useful for an estimation of the “normal” aortic size in this patient cohort and can serve as a basis for future longitudinal studies adding prognostic data.

Relation of aortic stiffness and strain by cardiovascular magnetic resonance imaging to age in repaired tetralogy of fallot

Patients with tetralogy of Fallot (TOF) have abnormal aortic properties. It is not known if this increases the risk for aneurysm formation. We sought to identify clinical and cardiovascular magnetic resonance (CMR) imaging patient characteristics associated with worsened aortic pulse wave velocity (PWV) and aortic strain in patients with repaired TOF. In 124 patients with TOF undergoing CMR (median age 24.6 years, interquartile range 17.8 to 34.2), left and right ventricular volumetric data, aortic PWV, and aortic strain were evaluated. Increased PWV positively correlated with age at repair (r = 0.3, p = 0.001) and cross-sectional ascending aortic area (r = 0.34, p <0.001) and was associated with a history of shunt placement (p = 0.01). Decreased aortic strain also correlated with age at TOF repair (r = -0.5, p <0.001), cross-sectional ascending aortic area (r = -0.43, p <0.001), aortic regurgitation (r = -0.46, p ≤0.001), and history of shunt placement (p <0.001). In a multivariate regression model controlling for history of shunt placement, use of cardiac medication, and aortic regurgitation, age at CMR was significantly associated with PWV (p = 0.005), whereas age at repair trended toward significance (p = 0.06). In conclusion, patients with TOF have abnormal aortic properties correlated with greater age, which may be associated with later repair. Longitudinal data are necessary to assess the risk of aortic aneurysm and dissection as the TOF population grows older. Functional imaging of the aorta by CMR may be useful in predicting risk and assessing vascular health.

Central-radial artery pressure gradient after cardiopulmonary bypass is associated with cardiac function and may affect therapeutic direction

Objective

To investigate the risk factors involved in radial-femoral artery pressure gradient after cardiac surgery.

Methods

In this retrospective study, we reviewed 412 cardiac surgeries with both femoral artery pressure and radial artery pressure monitoring before cardiopulmonary bypass. 138 patients had radial-femoral artery pressure gradient after cardiopulmonary bypass (group P) but 263 were not (group N). Their hemodynamic data and other demographic data were analyzed.

Results

Phenylephrine usage was 1.7±1.1 mg in group N and 2.9±1.2 mg in group P (P<0.001). Total adrenaline usage was 229.2±116.9 µg in group N and 400.6±145.1 µg in group P (P<0.001). SBP gradient was -4±3, 14±9, 10±4, 0±11 mmHg in group P and -3±3, 0±1, -1±9, -6±4 mmHg in group N after induction, during discontinuation of CPB, at the end of surgery and 1 postoperative day respectively. DBP gradient was 3±3, -1±9, 4±5, 0±8 mmHg in group P and 3±3, 5±2, 7±5, 0±8 mmHg in group N after induction, during discontinuation of CPB, at the end of surgery and 1 postoperative day respectively. MAP gradient was 1±2, 4±6, 6±4, 0±8 mmHg in group P and 1±2, 3±1, 1±4, -2±5 mmHg in group N after induction, during discontinuation of CPB, at the end of surgery and 1 postoperative day respectively. Significant arterial pressure gradient emerged during discontinuation of CPB and at the end of surgery, which was more obvious in group P(P<0.01). CI was 2.0±0.3, 2.3±0.4,2.3±0.4, 2.2±0.4 L/min/m² in group P and 2.1±0.3, 2.8±0.5,2.8±0.5, 2.8±0.5 L/min/m² in group N at baseline, after discontinuation of CPB, at the end of surgery and the first postoperative day (P<0.001).

Conclusion

Detecting the exact central artery pressure is most important when patients have artery pressure gradients after cardiac surgery. Use inotropic agents to improve cardiac output, avoiding excessive vasoconstriction might reduce artery pressure gradient.

Aortopathy in Congenital Heart Disease in Adults: Aortic Dilatation with Decreased Aortic Elasticity that Impacts Negatively on Left Ventricular Function

Bicuspid aortic valve and/or coarctation of the aorta are consistently associated with ascending aortic and para-coarctation medial abnormalities. Medial abnormalities in the ascending aorta are prevalent in other types of patients with a variety of forms congenital heart disease (CHD), such as single ventricle, persistent truncus arteriosus, transposition of the great arteries, hypoplastic left heart syndrome, tetralogy of Fallot. These abnormalities encompass a wide age range, and may predispose to dilatation, aneurysm, and rupture that necessitates aortic valve and root surgery. This dilatation can develop in CHD patients without stenotic region. These CHDs exhibit ongoing dilatation of the aortic root and reduced aortic elasticity and increased aortic stiffness that may relate to intrinsic properties of the aortic root. The concept of aortic dilatation is shifting a paradigm of aortic dilatation, as so called post stenotic dilatation, to primary intrinsic aortopahy. These aortic dilatation and increased stiffness can induce aortic aneurysm, rupture of the aorta and aortic regurgitation, but also provoke left ventricular hypertrophy, reduced coronary artery flow and left ventricular failure. We can recognize this association of aortic pathophysiological abnormality, aortic dilation and aorto-left ventricular interaction as a new clinical entity: "aortopathy".

Progressive aortic dilation and aortic stiffness in children with repaired tetralogy of Fallot

Progressive aortic dilation occurs in patients with tetralogy of Fallot (TOF), possibly due to abnormal histopathology of the aortic media that weakens the aortic wall. This medial histopathology may be reflected as aortic stiffness, which in turn may predict progressive aortic dilation. To test this theory, we studied the relationship between aortic wall stiffness, measured by pulse wave velocity (PWV), and subsequent aortic dilation in 32 consecutive patients with repaired TOF. The ascending aortic diameter (AOD) was obtained by two-dimensional transthoracic echocardiography performed at baseline and at the follow-up examination, 7.6 ± 2.0 years after baseline. TOF patients exhibited significantly greater AODs than normal reference values, at baseline (19.8 ± 5.0 vs 14.3 ± 3.1 mm; P = 0.0001) and at the follow-up examination (25.9 ± 3.8 vs 18.1 ± 2.4 mm; P = 0.0001). The observed change in AOD during the follow-up period (0.83 ± 0.43 mm/year) was significantly larger than the change that would be expected by the patient's growth (0.50 ± 0.25 mm/year; P = 0.0001). The PWV at baseline correlated positively with both AOD at follow-up (P = 0.0018) and the annual rate of aortic dilation (P = 0.0007). On multivariate regression analysis, PWV remained a significant and independent predictor of subsequent aortic dilation. These results suggest a causative role for aortic stiffening in the progressive aortic dilation noted in TOF, indicating that incorporating aortic stiffness as well as aortic diameter in the assessment of TOF aortopathy may help better define the need for, and the timing of, medical intervention.