Abnormal Cardiac Magnetic Resonance-Derived Ascending Aortic Area Strain Demonstrates Altered Ventriculo-Vascular Function in Marfan Syndrome.

PURPOSE: There remains a need for improved imaging markers for risk stratification and treatment guidance in Marfan syndrome (MFS). After aortic root replacement (ARR), vascular remodeling and progressive aneurysm formation can occur due to alterations in up- and downstream wall biomechanics and hemodynamics. We aim to compare the ventriculo-vascular properties of patients with MFS with controls, and investigate the correlation between ascending aortic area strain and descending aortic area strain (DAAS) with other clinical variables. PATIENTS AND METHODS: Nineteen patients with MFS (47% males), including 6 with ARR were studied. In 26 studies, aortic area strain was measured using cross-sectional cardiac magnetic resonance images at the ascending and proximal descending aortic levels. Left atrial, left ventricular longitudinal, and left ventricle circumferential strain (left atrial longitudinal strain, left ventricular longitudinal strain, and left ventricular circumferential strain, respectively) were measured using cardiac magnetic resonance-feature tracking. RESULTS: Compared with healthy controls, patients with MFS had significantly impaired left ventricular longitudinal strain and left ventricular circumferential strain (-15.8 ± 4.7 vs -19.7 ± 4.8, P = 0.005, and -17.7 ± 4.0 vs -27.0 ± 4.1, P < 0.001). Left atrial longitudinal strain was comparable between patients with MFS and controls. AAAS was significantly reduced (19.0 [11.9, 23.7] vs 46.1 ± 11.3, P < 0.001), whereas DAAS was not significantly decreased. AAAS and DAAS were negatively correlated with age, whereas no significant associations were identified with left ventricle function indices. No significant differences were observed between the ventriculo-vascular properties of patients with MFS who underwent ARR and those who did not. CONCLUSION: Patients with MFS demonstrated impaired ventricular and vascular function compared with healthy controls. Further investigations are warranted to determine clinical utility of aortic stiffness indices for predicting primary and repeat aortic events.

Angiotensin receptor blockers and ß blockers in Marfan syndrome: an individual patient data meta-analysis of randomised trials.

BACKGROUND: Angiotensin receptor blockers (ARBs) and ß blockers are widely used in the treatment of Marfan syndrome to try to reduce the rate of progressive aortic root enlargement characteristic of this condition, but their separate and joint effects are uncertain. We aimed to determine these effects in a collaborative individual patient data meta-analysis of randomised trials of these treatments. METHODS: In this meta-analysis, we identified relevant trials of patients with Marfan syndrome by systematically searching MEDLINE, Embase, and CENTRAL from database inception to Nov 2, 2021. Trials were eligible if they involved a randomised comparison of an ARB versus control or an ARB versus ß blocker. We used individual patient data from patients with no prior aortic surgery to estimate the effects of: ARB versus control (placebo or open control); ARB versus ß blocker; and indirectly, ß blocker versus control. The primary endpoint was the annual rate of change of body surface area-adjusted aortic root dimension Z score, measured at the sinuses of Valsalva. FINDINGS: We identified ten potentially eligible trials including 1836 patients from our search, from which seven trials and 1442 patients were eligible for inclusion in our main analyses. Four trials involving 676 eligible participants compared ARB with control. During a median follow-up of 3 years, allocation to ARB approximately halved the annual rate of change in the aortic root Z score (mean annual increase 0·07 [SE 0·02] ARB vs 0·13 [SE 0·02] control; absolute difference -0·07 [95% CI -0·12 to -0·01]; p=0·012). Prespecified secondary subgroup analyses showed that the effects of ARB were particularly large in those with pathogenic variants in fibrillin-1, compared with those without such variants (heterogeneity p=0·0050), and there was no evidence to suggest that the effect of ARB varied with ß-blocker use (heterogeneity p=0·54). Three trials involving 766 eligible participants compared ARBs with ß blockers. During a median follow-up of 3 years, the annual change in the aortic root Z score was similar in the two groups (annual increase -0·08 [SE 0·03] in ARB groups vs -0·11 [SE 0·02] in ß-blocker groups; absolute difference 0·03 [95% CI -0·05 to 0·10]; p=0·48). Thus, indirectly, the difference in the annual change in the aortic root Z score between ß blockers and control was -0·09 (95% CI -0·18 to 0·00; p=0·042). INTERPRETATION: In people with Marfan syndrome and no previous aortic surgery, ARBs reduced the rate of increase of the aortic root Z score by about one half, including among those taking a ß blocker. The effects of ß blockers were similar to those of ARBs. Assuming additivity, combination therapy with both ARBs and ß blockers from the time of diagnosis would provide even greater reductions in the rate of aortic enlargement than either treatment alone, which, if maintained over a number of years, would be expected to lead to a delay in the need for aortic surgery. FUNDING: Marfan Foundation, the Oxford British Heart Foundation Centre for Research Excellence, and the UK Medical Research Council.

A mutation update on the LDS-associated genes TGFB2/3 and SMAD2/3.

The Loeys-Dietz syndrome (LDS) is a connective tissue disorder affecting the cardiovascular, skeletal, and ocular system. Most typically, LDS patients present with aortic aneurysms and arterial tortuosity, hypertelorism, and bifid/broad uvula or cleft palate. Initially, mutations in transforming growth factor-ß (TGF-ß) receptors (TGFBR1 and TGFBR2) were described to cause LDS, hereby leading to impaired TGF-ß signaling. More recently, TGF-ß ligands, TGFB2 and TGFB3, as well as intracellular downstream effectors of the TGF-ß pathway, SMAD2 and SMAD3, were shown to be involved in LDS. This emphasizes the role of disturbed TGF-ß signaling in LDS pathogenesis. Since most literature so far has focused on TGFBR1/2, we provide a comprehensive review on the known and some novel TGFB2/3 and SMAD2/3 mutations. For TGFB2 and SMAD3, the clinical manifestations, both of the patients previously described in the literature and our newly reported patients, are summarized in detail. This clearly indicates that LDS concerns a disorder with a broad phenotypical spectrum that is still emerging as more patients will be identified. All mutations described here are present in the corresponding Leiden Open Variant Database.

Utility of Genetic Testing in Elite Volleyball Players with Aortic Root Dilation.

Basketball and volleyball attract individuals with a characteristic biophysical profile, mimicking features of Marfan syndrome. Consequently, identification of these abnormalities can be lifesaving. PURPOSE: To determine how physical examination, echocardiography, and genetic screening can identify elite volleyball players with a previously undiagnosed aortopathy. METHODS: We have performed cardiac screening on 90 US Volleyball National Team members and identified four individuals with dilated sinuses of Valsalva. This case series reports on three individuals who underwent a comprehensive genetics evaluation, including gene sequencing. RESULTS: Cardiac screening combined with genetic testing can identify previously undiagnosed tall athletes with an aortopathy, in the absence of noncardiac findings of a connective tissue disorder. Subject 1 had a revised Ghent systems (RGS) score of 2 and a normal aortopathy gene panel. Subject 2 had a RGS score of 1 and genetic testing revealed a de novo disease causing mutation in the gene encoding fibrillin-1 (FBN1). Subject 3 had an RGS score of 4.0 and had a normal aortopathy gene panel. CONCLUSIONS: Despite variable clinical features of Marfan syndrome, dilated sinuses of Valsalva were found in 4.9% of the athletes. A disease-causing mutation in the FBN1 gene was identified in subject 2, who had the lowest RGS but the largest aortic root measurement. Subjects 1 and 3, with the highest RGS, had a normal aortopathy gene panel. Our findings provide further evidence suggesting that a cardiac evaluation, including a screening echocardiogram, should be performed on all elite tall adult athletes independent of other physical findings. Genetic testing should be considered for athletes with dilated sinuses of Valsalva (male, >4.2 cm; female, >3.4 cm), regardless of other extracardiac findings.

Aortic Complications Associated With Pregnancy in Marfan Syndrome: The NHLBI National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions (GenTAC).

BACKGROUND: The risk of aortic complications associated with pregnancy in women with Marfan syndrome (MFS) is not fully understood. METHODS AND RESULTS: MFS women participating in the large National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions (GenTAC) were evaluated. Among 184 women with MFS in whom pregnancy information was available, 94 (51%) had a total of 227 pregnancies. Among the women with pregnancies, 10 (10.6%) experienced a pregnancy-related aortic complication (4 type A and 3 type B dissections, 1 coronary artery dissection, and 2 with significant [≥3 mm] aortic growth). Five of 7 aortic dissections, including all 3 type B, and the coronary dissection (75% of all dissections) occurred in the postpartum period. Only 5 of 8 women with pregnancy-associated dissection were aware of their MFS diagnosis. The rate of aortic dissection was higher during the pregnancy and postpartum period (5.4 per 100 person-years vs 0.6 per 100 person-years of nonpregnancy; rate ratio, 8.4 [95% CI=3.9, 18.4]; P<0.0001). CONCLUSIONS: Pregnancy in MFS is associated with an increased risk of aortic dissection, both types A and B, particularly in the immediate postpartum period. Lack of knowledge of underlying MFS diagnosis before aortic dissection is a major contributing factor. These findings underscore the need for early diagnosis, prepregnancy risk counseling, and multidisciplinary peripartum management.

A Decade of Discovery in the Genetic Understanding of Thoracic Aortic Disease.

Aortic aneurysms are responsible for a significant number of all deaths in Western countries. In this review we provide a perspective on the important progress made over the past decade in the understanding of the genetics of this condition, with an emphasis on the more frequent forms of vascular smooth muscle and transforming growth factor ß (TGF-ß) signalling alterations. For several nonsyndromic and syndromic forms of thoracic aortic disease, a genetic basis has now been identified, with 3 main pathomechanisms that have emerged: perturbation of the TGF-ß signalling pathway, disruption of the vascular smooth muscle cell (VSMC) contractile apparatus, and impairment of extracellular matrix synthesis. Because smooth muscle cells and proteins of the extracellular matrix directly regulate TGF-ß signalling, this latter pathway emerges as a key component of thoracic aortic disease initiation and progression. These discoveries have revolutionized our understanding of thoracic aortic disease and provided inroads toward gene-specific stratification of treatment. Last, we outline how these genetic findings are translated into novel pharmaceutical approaches for thoracic aortic disease.

Anesthesia considerations for cesarean delivery in a patient with Loeys-Dietz syndrome.

A 28-year-old primigravida female with Loeys-Dietz syndrome presented at 36 weeks' gestation for scheduled primary elective cesarean delivery. The patient had clinical findings consistent with this diagnosis, including mild aortic root dilation, chronic right vertebral artery dissection with 2 intracerebral aneurysms, and small ectasias of the thecal sac in the lumbar region. Pregnant patients with Loeys-Dietz syndrome have significant risks, including aneurysm rupture, new aneurysm formation, and uterine rupture. After a thorough preoperative evaluation, the patient underwent successful general anesthesia focused on maintenance of intraoperative hemodynamic stability and minimal intraoperative blood loss.

Applying massive parallel sequencing to molecular diagnosis of Marfan and Loeys-Dietz syndromes.

The Marfan (MFS) and Loeys-Dietz (LDS) syndromes are caused by mutations in the fibrillin-1 (FBN1) and Transforming Growth Factor Beta Receptor 1 and 2 (TGFBR1 and TGFBR2) genes, respectively. With the current conventional mutation screening technologies, analysis of this set of genes is time consuming and expensive. We have tailored a cost-effective and reliable mutation discovery strategy using multiplex PCR followed by Next Generation Sequencing (NGS). In a first stage, genomic DNA from five MFS or LDS patient samples with previously identified mutations and/or polymorphisms in FBN1 and TGFBR1 and 2 were analyzed and revealed all expected variants. In a second stage, we validated the technique on 87 samples from MFS patients fulfilling the Ghent criteria. This resulted in the identification of 75 FBN1 mutations, of which 67 were unique. Subsequent Multiplex Ligation-dependent Probe Amplification (MLPA) analysis of the remaining negative samples identified four large deletions/insertions. Finally, Sanger sequencing identified a missense mutation in FBN1 exon 1 that was not included in the NGS workflow. In total, there was an overall mutation identification rate of 92%, which is in agreement with data published previously. We conclude that multiplex PCR of all coding exons of FBN1 and TGFBR1/2 followed by NGS analysis and MLPA is a robust strategy for time- and cost-effective identification of mutations.

Surgical treatment of patients enrolled in the national registry of genetically triggered thoracic aortic conditions.

BACKGROUND: Genetic disorders are an important cause of thoracic aortic aneurysms (TAAs) in young patients. Despite advances in the treatment of genetically triggered TAAs, the optimal syndrome-specific treatment approach remains undefined. We used data from the National Institutes of Health-funded, multicenter National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions (GenTAC) to characterize the contemporary surgical treatment of patients with genetically triggered TAAs. METHODS: GenTAC's aim is to collect longitudinal clinical data and banked biospecimens from 2800 patients with genetically triggered TAAs. We analyzed data from the 606 patients (mean age, 37.5 years) enrolled in GenTAC to date whose clinical data were available. RESULTS: The patients' primary diagnoses included Marfan syndrome (35.8%), bicuspid aortic valve with aneurysm (29.2%), and familial TAAs and dissections (10.7%). Of these, 56.4% had undergone at least one operation; the most common indications were aneurysm (85.7%), valve dysfunction (65.8%), and dissection (25.4%). Surgical procedures included replacement of the aortic root (50.6%), ascending aorta (64.8%), aortic arch (27.9%), and descending or thoracoabdominal aorta (12.4%). Syndrome-specific differences in age, indications for operation, and procedure type were identified. CONCLUSIONS: Patients with genetically transmitted TAAs evaluated in tertiary care centers frequently undergo surgical repair. Aneurysm repairs most commonly involve the aortic root and ascending aorta; distal repairs are less common. Like TAAs themselves, complications of TAAs, including dissection and aortic valve dysfunction, are important indications for intervention. Future studies will focus on syndrome- and gene-specific phenotypes, biomarkers, treatments, and outcomes to improve the treatment of patients with TAAs.