Cardiac magnetic resonance imaging in Turner syndrome

Lifelong cardiovascular care in Turner syndrome: two cases with review of literature

Cardiovascular disease is one of the most important complications in girls and women with Turner syndrome (TS). Although the latest international guideline provides useful suggestions for the management of cardiovascular diseases in TS, some unknown cardiac conditions warrant physicians' attention and awareness. Here, we have reported two adult cases wherein significant cardiovascular diseases were detected during the transition period. The first case patient was diagnosed with aortic crank deformity and left subclavian artery aneurysm at 14 years based on the report of cardiac catheterization, computed tomography angiography, and cardiac magnetic resonance imaging, which had remained undetected by annual evaluations using transthoracic echocardiography (TTE). This case emphasizes the importance of cardiac reevaluation during the transition period. The second case patient was diagnosed with moderate mitral valve regurgitation (MR) due to mitral valve prolapse at 18 years through TTE, although the first evaluation at 7 years by TTE detected slight MR without any clinical concerns. The condition however progressed to severe MR at 28 years, requiring mitral valvuloplasty. MR is the most common valve disease worldwide, which makes it challenging to comprehend whether the condition is a complication. However, the condition requiring surgery at this age is extremely rare, which implies the possibility of early progression. Because almost all literature on cardiovascular complications in TS is cross-sectional, further information about longitudinal cardiovascular conditions is vital for optimal care for girls and women with TS. The two cases reported in this article provide significant information for improving lifelong cardiovascular health issues in TS.

Cardiovascular considerations in management of patients with Turner syndrome

Turner syndrome (TS) is a chromosomal disorder that affects 25-50 per 100,000 live born females. Patients with TS face a heavy burden of cardiovascular disease (congenital and acquired) with an increased risk of mortality and morbidity compared to the general population. Cardiovascular diseases are a major cause of death in females with TS. Approximately 50% of TS patients have a congenital heart abnormality, with a high incidence of bicuspid aortic valve (BAV), coarctation of the aorta (CoA) and generalised arteriopathy. Frequently, females with TS have systemic hypertension, which is also a risk factor for progressive cardiac dysfunction and aortopathy. This paper aims to provide an overview of the cardiovascular assessment, management and follow up strategies in this high-risk population of TS patients.

Hemodynamic Abnormalities in the Aorta of Turner Syndrome Girls

Congenital abnormalities in girls and women with Turner syndrome (TS), alongside an underlying predisposition to obesity and hypertension, contribute to an increased risk of cardiovascular disease and ultimately reduced life expectancy. We observe that children with TS present a greater variance in aortic arch morphology than their healthy counterparts, and hypothesize that their hemodynamics is also different. In this study, computational fluid dynamic (CFD) simulations were performed for four TS girls, and three age-matched healthy girls, using patient-specific inlet boundary conditions, obtained from phase-contrast MRI data. The visualization of multidirectional blood flow revealed an increase in vortical flow in the arch, supra-aortic vessels, and descending aorta, and a correlation between the presence of aortic abnormalities and disturbed flow. Compared to the relatively homogeneous pattern of time-averaged wall shear stress (TAWSS) on the healthy aortae, a highly heterogeneous distribution with elevated TAWSS values was observed in the TS geometries. Visualization of further shear stress parameters, such as oscillatory shear index (OSI), normalized relative residence time (RRTn), and transverse WSS (transWSS), revealed dissimilar heterogeneity in the oscillatory and multidirectional nature of the aortic flow. Taking into account the young age of our TS cohort (average age 13 ± 2 years) and their obesity level (75% were obese or overweight), which is believed to accelerate the initiation and progression of endothelial dysfunction, these findings may be an indication of atherosclerotic disease manifesting earlier in life in TS patients. Age, obesity and aortic morphology may, therefore, play a key role in assessing cardiovascular risk in TS children.

Cardiovascular disease in women: insights from magnetic resonance imaging

The presentation and identification of cardiovascular disease in women pose unique diagnostic challenges compared to men, and underrecognized conditions in this patient population may lead to clinical mismanagement.This article reviews the sex differences in cardiovascular disease, explores the diagnostic and prognostic role of cardiovascular magnetic resonance (CMR) in the spectrum of cardiovascular disorders in women, and proposes the added value of CMR compared to other imaging modalities. In addition, this article specifically reviews the role of CMR in cardiovascular diseases occurring more frequently or exclusively in female patients, including Takotsubo cardiomyopathy, connective tissue disorders, primary pulmonary arterial hypertension and peripartum cardiomyopathy. Gaps in knowledge and opportunities for further investigation of sex-specific cardiovascular differences by CMR are also highlighted.

Congenital heart defects associated with aneuploidy syndromes: New insights into familiar associations

The frequent occurrence of congenital heart defects (CHDs) in chromosome abnormality syndromes is well-known, and among aneuploidy syndromes, distinctive patterns have been delineated. We update the type and frequency of CHDs in the aneuploidy syndromes involving trisomy 13, 18, 21, and 22, and in several sex chromosome abnormalities (Turner syndrome, trisomy X, Klinefelter syndrome, 47,XYY, and 48,XXYY). We also discuss the impact of noninvasive prenatal screening (mainly, cell-free DNA analysis), critical CHD screening, and the growth of parental advocacy on their surgical management and natural history. We encourage clinicians to view the cardiac diagnosis as a "phenotype" which supplements the external dysmorphology examination. When detected prenatally, severe CHDs may influence decision-making, and postnatally, they are often the major determinants of survival. This review should be useful to geneticists, cardiologists, neonatologists, perinatal specialists, other pediatric specialists, and general pediatricians. As patients survive (and thrive) into adulthood, internists and related adult specialists will also need to be informed about their natural history and management.

Relationship between Echocardiographic and Magnetic Resonance-Derived Measurements of the Thoracic Aorta in Turner Syndrome Patients

INTRODUCTION

Turner syndrome (TS) is assigned to the rare diseases group. Morbidity and mortality of TS patients are high, particularly due to the cardiovascular disorders, so monitoring for cardiovascular complications must be ensured. The data demonstrate a strong correlation between 2-dimensional echocardiographic (2Decho) evaluation and magnetic resonance imaging (MRI); still, according to recent guidelines, MRI remains a gold standard. In this study, we aimed to compare aortic dimensions on MRI and 2Decho in TS patients.

METHODS

50 TS patients (≥18 years) were enrolled into the cross-sectional study. 2Decho and MRI were performed. The measurements of the aorta were assessed in five standard positions on 2Decho and in 9 standard positions on MRI; ASI (aortic size index) of the ascending aorta was calculated since reduced adult height is observed in TS patients.

RESULTS

ASI on echocardiography strongly correlated with ASI on MRI in all positions of the ascending aorta, but significantly larger medians of ASI were found on 2Decho in all positions of the ascending aorta and arch when compared with MRI measurements. Still, the prevalence of aortic sinus dilation was significantly and more frequently (52% vs. 38%, p < 0.001) observed on MRI when compared with 2Decho.

CONCLUSION

The relation of aortic size was significant in all positions when comparing the MRI and 2Decho methods; still, the dilatation of the sinus of aorta was more frequently found on MRI compared with echocardiography.

Elongated transverse aortic arch in subjects without turner syndrome: A preliminary computed tomography study

The purpose of the present study was to investigate the presence of an elongated transverse aortic arch (ETA), which has been reported to be specific for Turner syndrome, in a population without Turner syndrome. A set of 1,012 patients (713 men, 299 women) under 40 years old, who underwent thoracic CT examination in our radiology department between July 2016 and December 2016, were included in the study. CT scans were performed by 16-slice scanners. CT images were retrieved from the picture archiving and communication system and retrospectively re-assessed by two radiologists. Diagnostic criteria for ETA, which are late take-off of the left subclavian artery (LSA), convex kinking of the inferior aortic arch along the lesser curvature and flattening of the transverse aortic arch, were searched in each case. The mean age of the study population was 25.5 ± 10.0 years. Late take-off of the LSA was detected in 17 (1.7%) subjects (10 men, 7 women). In six of these, the other criteria for ETA were not met. However, in the other 11 (1.1% of the study population) cases, in addition to late take-off of the LSA, aortic morphology was compatible with ETA. The dimensions of the aortic root and the ascending and descending aorta were within normal limits in all 17 cases. Our results supported the presence of ETA in subjects without Turner syndrome with ∼1.1% frequency. This is the first preliminary report regarding the frequency of ETA in non-Turner subjects. Clin. Anat. 31:887-890, 2018. © 2018 Wiley Periodicals, Inc.

Clinical practice guidelines for the care of girls and women with Turner syndrome: proceedings from the 2016 Cincinnati International Turner Syndrome Meeting

Turner syndrome affects 25-50 per 100,000 females and can involve multiple organs through all stages of life, necessitating multidisciplinary approach to care. Previous guidelines have highlighted this, but numerous important advances have been noted recently. These advances cover all specialty fields involved in the care of girls and women with TS. This paper is based on an international effort that started with exploratory meetings in 2014 in both Europe and the USA, and culminated with a Consensus Meeting held in Cincinnati, Ohio, USA in July 2016. Prior to this meeting, five groups each addressed important areas in TS care: 1) diagnostic and genetic issues, 2) growth and development during childhood and adolescence, 3) congenital and acquired cardiovascular disease, 4) transition and adult care, and 5) other comorbidities and neurocognitive issues. These groups produced proposals for the present guidelines. Additionally, four pertinent questions were submitted for formal GRADE (Grading of Recommendations, Assessment, Development and Evaluation) evaluation with a separate systematic review of the literature. These four questions related to the efficacy and most optimal treatment of short stature, infertility, hypertension, and hormonal replacement therapy. The guidelines project was initiated by the European Society for Endocrinology and the Pediatric Endocrine Society, in collaboration with The European Society for Pediatric Endocrinology, The Endocrine Society, European Society of Human Reproduction and Embryology, The American Heart Association, The Society for Endocrinology, and the European Society of Cardiology. The guideline has been formally endorsed by the European Society for Endocrinology, the Pediatric Endocrine Society, the European Society for Pediatric Endocrinology, the European Society of Human Reproduction and Embryology and the Endocrine Society. Advocacy groups appointed representatives who participated in pre-meeting discussions and in the consensus meeting.

Effects of human recombinant growth hormone on exercise capacity, cardiac structure, and cardiac function in patients with adult-onset growth hormone deficiency

Objective

Epidemiological studies suggest that adult-onset growth hormone deficiency (AGHD) might increase the risk of death from cardiovascular causes.

Methods

This was a 6-month double-blind, placebo-controlled, randomised, cross-over trial followed by a 6-month open-label phase. Seventeen patients with AGHD received either recombinant human growth hormone (rGH) (0.4 mg injection daily) or placebo for 12 weeks, underwent washout for 2 weeks, and were then crossed over to the alternative treatment for a further 12 weeks. Cardiac magnetic resonance imaging, echocardiography, and cardiopulmonary exercise testing were performed at baseline, 12 weeks, 26 weeks, and the end of the open phase (12 months). The results were compared with those of 16 age- and sex-matched control subjects.

Results

At baseline, patients with AGHD had a significantly higher systolic blood pressure, ejection fraction, and left ventricular mass than the control group, even when corrected for body surface area. Treatment with rGH normalised the insulin-like growth factor 1 concentration without an effect on exercise capacity, cardiac structure, or cardiac function.

Conclusion

Administration of rGH therapy for 6 to 9 months failed to normalise the functional and structural cardiac differences observed in patients with AGHD when compared with a control group.

Magnetic resonance imaging 4-D flow-based analysis of aortic hemodynamics in Turner syndrome

BACKGROUND

Cardiovascular surveillance is important in Turner syndrome because of the increased risk of aortic dilation and dissection with consecutively increased mortality.

OBJECTIVE

To compare 4-D flow MRI for the characterization of aortic 3-D flow patterns, dimensions and vessel wall parameters in pediatric patients with Turner syndrome and age-matched controls.

MATERIALS AND METHODS

We performed 4-D flow MRI measuring in vivo 3-D blood flow with coverage of the thoracic aorta in 25 patients with Turner syndrome and in 16 female healthy controls (age mean ± standard deviation were 16 ± 5 years and 17 ± 4 years, respectively). Blood flow was visualized by time-resolved 3-D path lines. Visual grading of aortic flow in terms of helices and vortices was performed by two independent observers. Quantitative analysis included measurement of aortic diameters, quantification of peak systolic wall shear stress, pulsatility index and oscillatory shear index at eight defined sites.

RESULTS

Patients with Turner syndrome had significantly larger aortic diameters normalized to BSA, increased vortices in the ascending aorta and elevated helix flow in the ascending and descending aorta compared to controls (all P<0.03). Patients with abnormal helical or vortical flow in the ascending aorta had significantly larger diameters of the ascending aorta (P<0.03). Peak systolic wall shear stress, pulsatility index and oscillatory shear index were significantly lower in Turner patients compared to controls (p=0.02, p=0.002 and p=0.01 respectively).

CONCLUSION

Four-dimensional flow MRI provides new insights into the altered aortic hemodynamics and wall shear stress that could have an impact on the development of aortic dissections.

Cardiac MRI and 3D contrast-enhanced MR angiography in pediatric and young adult patients with Turner syndrome

BACKGROUND/AIM

This study aimed to describe the spectrum and frequency of cardiovascular abnormalities in pediatric and young adult patients with Turner syndrome (TS) using cardiac MRI and MR angiography.

MATERIALS AND METHODS

This prospective study consisted of 47 female patients of pediatric age and young adults with a karyotypically confirmed diagnosis of TS. All patients underwent cardiac MRI and contrast-enhanced MR angiography. A second examination after 9-26 months was performed for 28 of these patients.

RESULTS

Elongation of the transverse aortic arch (ETA) was the most frequent abnormality with a rate of 37%. The rate of partial anomalous pulmonary venous connection (PAPVC) was 21.7%, bicuspid aortic valve (BAV) was 19.6%, coarctation was 6.5%, ascending aorta dilatation was 28.3%, and descending aorta dilatation was 15.2%. The diameters of the aorta and the rate of aortic dilatation per unit of time was greater in the patients with BAV (P < 0.05). ETA was less observed in the patients who were receiving growth hormone therapy (P < 0.05).

CONCLUSION

The most common cardiovascular abnormalities in TS patients are aortic arch anomalies such as ETA and coarctation, aortic dilatation, PAPVCs, and BAV. The presence of BAV is an important risk factor for the aortic dilatation.

Continuous measurement of aortic dimensions in Turner syndrome: a cardiovascular magnetic resonance study

BACKGROUND

Severity of thoracic aortic disease in Turner syndrome (TS) patients is currently described through measures of aorta size and geometry at discrete locations. The objective of this study is to develop an improved measurement tool that quantifies changes in size and geometry over time, continuously along the length of the thoracic aorta.

METHODS

Cardiovascular magnetic resonance (CMR) scans for 15 TS patients [41 ± 9 years (mean age ± standard deviation (SD))] were acquired over a 10-year period and compared with ten healthy gender and age-matched controls. Three-dimensional aortic geometries were reconstructed, smoothed and clipped, which was followed by identification of centerlines and planes normal to the centerlines. Geometric variables, including maximum diameter and cross-sectional area, were evaluated continuously along the thoracic aorta. Distance maps were computed for TS and compared to the corresponding maps for controls, to highlight any asymmetry and dimensional differences between diseased and normal aortae. Furthermore, a registration scheme was proposed to estimate localized changes in aorta geometry between visits. The estimated maximum diameter from the continuous method was then compared with corresponding manual measurements at 7 discrete locations for each visit and for changes between visits.

RESULTS

Manual measures at the seven positions and the corresponding continuous measurements of maximum diameter for all visits considered, correlated highly (R-value = 0.77, P < 0.01). There was good agreement between manual and continuous measurement methods for visit-to-visit changes in maximum diameter. The continuous method was less sensitive to inter-user variability [0.2 ± 2.3 mm (mean difference in diameters ± SD)] and choice of smoothing software [0.3 ± 1.3 mm]. Aortic diameters were larger in TS than controls in the ascending [TS: 13.4 ± 2.1 mm (mean distance ± SD), Controls: 12.6 ± 1 mm] and descending [TS: 10.2 ± 1.3 mm (mean distance ± SD), Controls: 9.5 ± 0.9 mm] thoracic aorta as observed from the distance maps.

CONCLUSIONS

An automated methodology is presented that enables rapid and precise three-dimensional measurement of thoracic aortic geometry, which can serve as an improved tool to define disease severity and monitor disease progression.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier - NCT01678274 . Registered - 08.30.2012.

Cardiovascular alterations in adult GH deficiency

There is a growing body of evidence indicating that patients with adult GH deficiency (GHD) are characterized by a cluster of traditional and emerging cardiovascular risk factors and markers, which can significantly increase their cardiovascular morbidity and mortality possibly linked to aberrations in GH status. Patients with adult GHD present multiple different cardiovascular abnormalities. In addition, cardiovascular risk in adult GHD is increased due to altered body composition, abnormal lipid profile, insulin resistance and impaired glucose metabolism. Cardiovascular risk factors can be reversed, at least partially, after GH replacement. However, evidence on the effects of GH replacement on cardiovascular events and mortality is too limited in adult GHD patients. Aim of this review is to provide an at-a-glance overview of the role of the GH/IGF-I on the cardiovascular system and the state of art of the effects of GH replacement on cardiovascular system.

Characterisation of myocardial structure and function in adult-onset growth hormone deficiency using cardiac magnetic resonance

Growth hormone (GH) can profoundly influence cardiac function. While GH excess causes well-defined cardiac pathology, fewer data are available regarding the more subtle cardiac changes seen in GH deficiency (GHD). This preliminary study uses cardiac magnetic resonance imaging (CMR) to assess myocardial structure and function in GHD. Ten adult-onset GHD patients underwent CMR, before and after 6 and 12 months of GH replacement. They were compared to 10 age-matched healthy controls and sex-matched healthy controls. Left ventricular (LV) mass index (LVMi) increased with 1 year of GH replacement (53.8 vs. 57.0 vs. 57.3 g/m², analysis of variance p = 0.0229). Compared to controls, patients showed a trend towards reduced LVMi at baseline (51.4 vs. 60.0 g/m², p = 0.0615); this difference was lost by 1 year of GH treatment (57.3 vs. 59.9 g/m², p = 0.666). Significantly reduced aortic area was observed in GHD (13.2 vs. 19.0 cm²/m², p = 0.001). This did not change with GH treatment. There were no differences in other LV parameters including end-diastolic volume index (EDVi), end-systolic volume index, stroke volume index (SVi), cardiac index and ejection fraction. There was a trend towards reduced baseline right ventricular (RV)SVi (44.1 vs. 49.1 ml/m², p = 0.0793) and increased RVEDVi over 1 year (70.3 vs. 74.3 vs. 73.8 ml/m², p = 0.062). Two patients demonstrated interstitial expansion, for example with fibrosis, and three myocardial ischaemia as assessed by late gadolinium enhancement and stress perfusion. The increased sensitivity of CMR to subtle cardiac changes demonstrates that adult-onset GHD patients have reduced aortic area and LVMi increases after 1 year of GH treatment. These early data should be studied in larger studies in the future.

Cardiac Magnetic Resonance Imaging in Pediatric Turner Syndrome

OBJECTIVE

To compare the detection of cardiac lesions with the use of cardiac magnetic resonance imaging (CMR) and conventional echocardiography in children with Turner syndrome.

STUDY DESIGN

Twenty-four girls with Turner syndrome, 8-18 years of age, were recruited through the Pediatric Endocrinology Program. Participants underwent CMR and echocardiography within a 2-year period, and discrepancies between the results of each modality were identified.

RESULTS

Fifteen of 24 (63%) girls had a cardiac lesion identified on CMR or echocardiography. Both modalities identified the same lesion in 10 of 15 (67%); however, 6 of 15 (40%) participants had a lesion identified on CMR but not echocardiography. Participants with a missed lesion had a trend towards greater body mass index. Aortic dilation and bicuspid aortic valve were the most commonly missed lesions by echocardiography.

CONCLUSIONS

CMR identifies significant cardiac lesions missed by echocardiography in pediatric patients with Turner syndrome, particularly along the aorta. These findings support the current guidelines that recommend screening CMR in addition to echocardiogram. Early identification of cardiac abnormalities in patients with Turner syndrome will allow for a greater understanding of the natural history in these patients and potentially identify candidates for earlier intervention.

Effects of aortic irregularities on blood flow

Anatomic aortic anomalies are seen in many medical conditions and are known to cause disturbances in blood flow. Turner syndrome (TS) is a genetic disorder occurring only in females where cardiovascular anomalies, particularly of the aorta, are frequently encountered. In this study, numerical simulations are applied to investigate the flow characteristics in four TS patient- related aortic arches (a normal geometry, dilatation, coarctation and elongation of the transverse aorta). The Quemada viscosity model was applied to account for the non-Newtonian behavior of blood. The blood is treated as a mixture consisting of water and red blood cells (RBC) where the RBCs are modeled as a convected scalar. The results show clear geometry effects where the flow structures and RBC distribution are significantly different between the aortas. Transitional flow is observed as a jet is formed due to a constriction in the descending aorta for the coarctation case. RBC dilution is found to vary between the aortas, influencing the WSS. Moreover, the local variations in RBC volume fraction may induce large viscosity variations, stressing the importance of accounting for the non-Newtonian effects.

Imaging of cardiovascular risk in patients with Turner's syndrome

Turner's syndrome is a disorder defined by an absent or structurally abnormal second X chromosome and affects around 1 in 2000 newborn females. The standardised mortality ratio in Turner's syndrome is around three-times higher than in the general female population, mainly as a result of cardiovascular disorders. Most striking is the early age at which Turner's syndrome patients develop the life-threatening complications of cardiovascular disorders compared to the general population. The cardiovascular risk stratification in Turner's syndrome is challenging and imaging is not systematically used. The aim of this article is to review cardiovascular risks in this group of patients and discuss a systematic imaging approach for early identification of cardiovascular disorders in these patients.

Current controversies in turner syndrome: Genetic testing, assisted reproduction, and cardiovascular risks

Patients with Turner syndrome (TS) require close medical follow-up and management for cardiac abnormalities, growth and reproductive issues. This review summarizes current controversies in this condition, including: 1) the optimal genetic testing for Turner syndrome patients, particularly with respect to identification of Y chromosome material that may increase the patient's risk of gonadoblastoma and dysgerminoma, 2) which patients should be referred for bilateral gonadectomy and the recommended timing of such referral, 3) options for assisted reproduction in these patients and associated risks, 4) the increased risk of mortality associated with pregnancy in this population, and 5) how best to assess and monitor cardiovascular risks.

Unreliability of aortic size index to predict risk of aortic dissection in a patient with Turner syndrome

Aortic size index (ASI) has been proposed as a reliable criterion to predict risk for aortic dissection in Turner syndrome with significant thresholds of 20-25 mm/m². We report a case of aortic arch dissection in a patient with Turner syndrome who, from the ASI thresholds proposed, was deemed to be at low risk of aortic dissection or rupture and was not eligible for prophylactic surgery. This case report strongly supports careful monitoring and surgical evaluation even when the ASI is < 20 mm/m² if other significant risk factors are present.