Survival, causes of death, and cardiovascular events in patients with Marfan syndrome

Natural history of the distal aorta following elective root replacement in patients with Marfan syndrome

OBJECTIVE

It is unclear if the addition of a prophylactic arch operation is beneficial at the time of root replacement in patients with Marfan syndrome (MFS). This project aims to understand the fate of the distal aorta following elective root replacement in patients with MFS.

METHODS

Between 2000 and 2019, 124 adult patients with MFS were identified as having undergone elective aortic root replacement with a clamped distal aortic anastomosis during their lifetime. Serial axial imaging was analyzed. The primary outcome was a composite of subsequent type B aortic dissection (TBAD), aneurysmal degeneration (>4 cm), and aortic reintervention. Secondary outcomes included subsequent TBAD and mortality.

RESULTS

Mean age at root replacement was 33.3 years. Median follow-up was 11.3 years. Thirty-one patients (25%) experienced the primary outcome, with no survival difference (P = .9). The crossclamp and aortic cannulation sites were stable (growth rate, 0.33 mm/year), and 2 patients (1.6%) required reintervention there. Twenty-three patients (19.8%) experienced subsequent TBAD. Patients with TBAD had a higher rate of distal degeneration (P < .001), but no significant change in survival (P = .2). Preoperative hypertension (odds ratio, 3.96; P < .05) and younger age at root replacement (odds ratio, 1.05; P < .05) increased the risk of TBAD, based on regression analysis.

CONCLUSIONS

The distal aorta (including the clamp and cannulation site) overall appears stable in patients with MFS following elective root replacement without prophylactic arch operation. Development of TBAD seems to be the primary driver of distal degeneration. Factors associated with TBAD development included hypertension, underscoring the importance of strict blood pressure control in these patients.

The impact of Marfan syndrome and Ehlers-Danlos syndrome on the risk of penile fracture in patients between 18 and 45 years

BACKGROUND

Despite knowledge of the pathophysiology and clinical complications of connective tissue diseases (CTD), little is known regarding their impact on men's sexual health disorders.

AIM

To investigate the prevalence of penile fracture (PF) in patients with Ehlers-Danlos Syndrome (EDS) and Marfan syndrome (MFS) in comparison with disease-free controls between 18 and 45 years of age.

METHODS

A multicenter, international, electronic health record network (TriNetX) was queried to identify adult male patients (between 18 and 45 years) with or without EDS and MFS between 1993 and 2023 using ICD-10 codes. The prevalence of PF was compared between patients with and without the diseases of interest. Prevalence ratios (PR) were generated with 95% confidence intervals.

OUTCOME

Prevalence of PF in patients with EDS and MFS when compared to disease-free controls.

RESULTS

The number of patients with EDS, MFS, and control groups was 8060, 8642, and 20 184 547, respectively, with a mean age of 27.8 ± 7.58, 28.6 ± 7.4, and 31.6 ± 8.04 years. Men with EDS had a higher prevalence of PF (PR 30.18, 95% CI [17.08-53.19]; P < 0.0001). Similarly, men with MFS had a higher prevalence of PF (PR 23.4, 95% CI [12.6-43.7]; P < 0.0001).

CLINICAL IMPLICATIONS

This study demonstrates an association between CTD and men's sexual health disorders. It may be important to counsel such men about the risks of PF.

STRENGTHS AND LIMITATIONS

This is the largest study to date to demonstrate an association between CTD and men's sexual health disorders. While the large sample sizes in this study contribute to the robustness of the findings, the study is limited by the use of a claims-based dataset, which does not provide further details about disease course and complications, and the use of a univariate analysis only.

CONCLUSIONS

Patients with EDS and MFS are possibly at an elevated risk for PF. Due to the limitations of the TriNetX database, the analysis was limited to a univariate one, thus limiting the ability to control for confounders and limiting the generalizability of these findings. Further prospective research is needed to corroborate these findings.

Hereditary Aortopathies as Cause of Sudden Cardiac Death in the Young: State-of-the-Art Review in Molecular Medicine

Hereditary aortopathies are a group of rare genetic diseases affecting the aorta and its major branches, and they represent a cause of sudden cardiac death. These pathologies are classified into syndromic hereditary aortopathies and non-syndromic hereditary aortopathies. The epidemiology of hereditary aortopathies varies according to the specific genetic condition involved; however, these disorders are believed to account for a significant proportion of sudden cardiac death in young individuals with a family history of inherited cardiovascular conditions. The causes of hereditary aortopathies are primarily genetic, with pathogenic variants in various genes encoding structural proteins of the vascular wall, leading to dissection, aneurysms, rupture, and ultimately sudden cardiac death. When the cause of death remains unknown after an autopsy, it is referred to as sudden unexplained death, and post-mortem genetic testing, known as a molecular autopsy, is crucial to confirm hereditary aortopathies and assess the genetic risk in the patient's relatives. This helps to facilitate diagnostic and therapeutic pathways and/or implement monitoring strategies to prevent sudden cardiac death. In this state-of-the-art review, we focus on syndromic and non-syndromic hereditary aortopathies causing sudden cardiac death in the young and explore preventive strategies for affected family members.

Integrated DNA methylation analysis reveals a potential role for PTPRN2 in Marfan syndrome scoliosis

Background

Marfan syndrome (MFS) is a rare genetic disorder caused by mutations in the Fibrillin-1 gene (FBN1) with significant clinical features in the skeletal, cardiopulmonary, and ocular systems. To gain deeper insights into the contribution of epigenetics in the variability of phenotypes observed in MFS, we undertook the first analysis of integrating DNA methylation and gene expression profiles in whole blood from MFS and healthy controls (HCs).

Methods

The Illumina 850K (EPIC) DNA methylation array was used to detect DNA methylation changes on peripheral blood samples of seven patients with MFS and five HCs. Associations between methylation levels and clinical features of MFS were analyzed. Subsequently, we conducted an integrated analysis of the outcomes of the transcriptome data to analyze the correlation between differentially methylated positions (DMPs) and differentially expressed genes (DEGs) and explore the potential role of methylation-regulated DEGs (MeDEGs) in MFS scoliosis. The weighted gene co-expression network analysis was used to find gene modules with the highest correlation coefficient with target MeDEGs to annotate their functions in MFS.

Results

Our study identified 1253 DMPs annotated to 236 genes that were primarily associated with scoliosis, cardiomyopathy, and vital capacity. These conditions are typically associated with reduced lifespan in untreated MFS. We calculated correlations between DMPs and clinical features, such as cobb angle to evaluate scoliosis and FEV1% to assess pulmonary function. Notably, cg20223687 (PTPRN2) exhibited a positive correlation with cobb angle of scoliosis, potentially playing a role in ERKs inactivation.

Conclusions

Taken together, our systems-level approach sheds light on the contribution of epigenetics to MFS and offers a plausible explanation for the complex phenotypes that are linked to reduced lifespan in untreated MFS patients.

Marfan Syndrome: Enhanced Diagnostic Tools and Follow-up Management Strategies

Marfan syndrome (MFS) is a rare inherited autosomic disorder, which encompasses a variety of systemic manifestations caused by mutations in the Fibrillin-1 encoding gene (FBN1). Cardinal clinical phenotypes of MFS are highly variable in terms of severity, and commonly involve cardiovascular, ocular, and musculoskeletal systems with a wide range of manifestations, such as ascending aorta aneurysms and dissection, mitral valve prolapse, ectopia lentis and long bone overgrowth, respectively. Of note, an accurate and prompt diagnosis is pivotal in order to provide the best treatment to the patients as early as possible. To date, the diagnosis of the syndrome has relied upon a systemic score calculation as well as DNA mutation identification. The aim of this review is to summarize the latest MFS evidence regarding the definition, differences and similarities with other connective tissue pathologies with severe systemic phenotypes (e.g., Autosomal dominant Weill-Marchesani syndrome, Loeys-Dietz syndrome, Ehlers-Danlos syndrome) and clinical assessment. In this regard, the management of MFS requires a multidisciplinary team in order to accurately control the evolution of the most severe and potentially life-threatening complications. Based on recent findings in the literature and our clinical experience, we propose a multidisciplinary approach involving specialists in different clinical fields (i.e., cardiologists, surgeons, ophthalmologists, orthopedics, pneumologists, neurologists, endocrinologists, geneticists, and psychologists) to comprehensively characterize, treat, and manage MFS patients with a personalized medicine approach.

Biology of mitral valve prolapse: from general mechanisms to advanced molecular patterns-a narrative review

Mitral valve prolapse (MVP) represents the most frequent cause of primary mitral regurgitation. For several years, biological mechanisms underlying this condition attracted the attention of investigators, trying to identify the pathways responsible for such a peculiar condition. In the last ten years, cardiovascular research has moved from general biological mechanisms to altered molecular pathways activation. Overexpression of TGF-β signaling, for instance, was shown to play a key role in MVP, while angiotensin-II receptor blockade was found to limit MVP progression by acting on the same signaling pathway. Concerning extracellular matrix organization, the increased valvular interstitial cells density and dysregulated production of catalytic enzymes (matrix metalloproteinases above all) altering the homeostasis between collagen, elastin and proteoglycan components, have been shown to possibly provide a mechanistic basis contributing to the myxomatous MVP phenotype. Moreover, it has been observed that high levels of osteoprotegerin may contribute to the pathogenesis of MVP by increasing collagen deposition in degenerated mitral leaflets. Although MVP is believed to represent the result of multiple genetic pathways alterations, it is important to distinguish between syndromic and non-syndromic conditions. In the first case, such as in Marfan syndrome, the role of specific genes has been clearly identified, while in the latter a progressively increasing number of genetic loci have been thoroughly investigated. Moreover, genomics is gaining more interest as potential disease-causing genes and loci possibly associated with MVP progression and severity have been identified. Animal models could be of help in better understanding the molecular basis of MVP, possibly providing sufficient information to tackle specific mechanisms aimed at slowing down MVP progression, therefore developing non-surgical therapies impacting on the natural history of this condition. Although continuous progress has been made in this field, further translational studies are advocated to improve our knowledge of biological mechanisms underlying MVP development and progression.

Association Between Genetic Diagnosis and Clinical Outcomes in Patients With Heritable Thoracic Aortic Disease

Background Differences in the clinical course of heritable thoracic aortic disease based on the disease-causing gene have not been fully evaluated. To clarify the clinical relevance of causative genes in heritable thoracic aortic disease, we assessed the clinical course of patients categorized based on genetic diagnosis. Methods and Results We investigated cardiovascular events and mortality in 518 genetically diagnosed patients in 4 groups: Group 1, FBN1 (n=344); Group 2, TGFBR1, TGFBR2, SMAD3, or TGFB2 (n=74); Group 3, COL3A1 (n=60); and Group 4, ACTA2 or MYH11 (n=40). The median age at the first cardiovascular event ranged from 30.0 to 35.5 years (P=0.36). Patients with gene variants related to transforming growth factor-β signaling had a significantly higher rate of subsequent events than those with FBN1 variants (adjusted hazard ratio, 2.33 [95% CI, 1.60-3.38]; P<0.001). Regarding the incidence of aortic dissection, there were no significant differences among the 4 groups in male patients (36.3%, 34.3%, 21.4%, and 54.2%, respectively; P=0.06). Female patients with COL3A1 variants had a significantly lower incidence than female patients in the other 3 groups (34.2%, 59.0%, 3.1%, and 43.8%, respectively; P<0.001). Conclusions Gene variants related to transforming growth factor-β signaling are associated with a higher incidence of subsequent cardiovascular events than FBN1 variants. COL3A1 variants might be related to a lower incidence of aortic dissection than other gene variants in women only. Identifying the genetic background of patients with heritable thoracic aortic disease is important for determining appropriate treatment.

National trends in thoracic aortic aneurysms and dissections in patients with Marfans and Ehlers Danlos syndrome

INTRODUCTION

Connective tissue disorders predispose patients to earlier aortic dissections and aneurysms. However, there is limited large cohort data given its low incidence.

METHODS

The National Inpatient Sample was searched for all adults with Marfans (MFS) and Ehlers Danlos (EDS) disease between 2010 and 2017. ICD codes were used to select those with a type A aortic dissection or aneurysm.

RESULTS

There was a total of 19,567 cases, giving the estimated incidence of MFS and EDS of 18 and 22.4 per 100k people, respectively. After inclusion criteria, there were 2553 MF and 180 EDS patients. There was no statistical difference in mortality between the MFS and EDS cohorts (4.6% vs. 2.8%, p = .26). EDS patients were more likely to undergo a TEVAR procedure (2.8% vs. 1.0%, p = .03). MF patients were more likely to have a complication of acute kidney injury (p = .02). EDS patients were more likely older (50 vs. 42, p < .001) and female (47% vs. 33%, p < .001). MFS patients were more likely to have a type A aortic dissection (44% vs. 31%, p < .001). The majority (89%) of patients were treated at urban teaching hospitals. On univariable logistic regression, aortic dissection was a predictor for mortality (odds ratio 7.31, p < .001). The type of connective tissue disease was not a significant predictor.

CONCLUSIONS

National level estimates show low mortality for patients with MF or ED presenting to the hospital with aortic dissection or aneurysm. The differences in age and gender can guide surveillance for these patient populations, leading to more elective admissions and reduced hospital mortality.

Functional Analysis of an Intronic FBN1 Pathogenic Gene Variant in a Family With Marfan Syndrome

Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder that canonically affects the ocular, skeletal, and cardiovascular system, in which aortic tear and rupture is the leading cause of death for MFS patients. Genetically, MFS is primarily associated with fibrillin-1 (FBN1) pathogenic variants. However, the disease-causing variant in approximately 10% of patients cannot be identified, partly due to some cryptic mutations that may be missed using routine exonic sequencing, such as non-coding intronic variants that affects the RNA splicing process. We present a 32-year female with typical MFS systemic presentation that reached to a clinical diagnosis according to the revised Ghent nosology. We performed whole-exome sequencing (WES) but the report failed to identify known causal variants when analyzing the exonic sequence. However, further investigation on the exon/intron boundaries of the WES report revealed a candidate intronic variant of the fibrillin 1 (FBN1) gene (c.248-3 C>G) that predicted to affect the RNA splicing process. We conducted minigene splicing analyses and demonstrated that the c.248-3 C>G variant abolished the canonical splicing site of intron 3, leading to activation of two cryptic splicing sites and causing insertion (c.248-1_248-2insAG and c.248-1_248-282ins). Our study not only characterizes an intronic variant to the mutational spectrum of the FBN1 gene in MFS and its aberrant effect on splicing, but highlights the importance to not neglect the exon/intron boundaries when reporting and assessing WES results. We point out the need of conducting functional analysis to verify the pathogenicity of intronic mutation, and the opportunity to re-consider the standard diagnostic approaches in cases of clinically diagnosed MFS with normal or variant of unknown significance genetic results.

Fibroblast-Secreted Phosphoprotein 1 Mediates Extracellular Matrix Deposition and Inhibits Smooth Muscle Cell Contractility in Marfan Syndrome Aortic Aneurysm

Fibrillin 1 (Fbn1) mutation causes Marfan syndrome (MFS) with thoracic aortic aneurysm (TAA) as the main complication. The mechanisms for extracellular matrix (ECM) homeostasis disruption in MFS TAA are unclear. Here, we found ECM-related gene secreted phosphoprotein 1 (Spp1) increased in Fbn1^C1041G/+ mice using transcriptome sequencing and a distinct fibroblast subcluster with Spp1 as the strongest marker was identified with analysis of the MFS mouse aortic single-cell sequencing dataset. Immunostaining confirmed elevated Spp1 in adventitial fibroblasts, and Spp1 might regulate fibroblast and smooth muscle cell (SMC) communication primarily through Itga8/Itgb1. Then, we observed Spp1 reduced contractile genes Acta2 and Tagln expression in SMCs and increased collagen expression in fibroblasts, which might contribute to TAA development. Finally, we also found elevated SPP1 plasma level was associated with an increased risk of TAA in patients. Therefore, SPP1 may serve as a biomarker and therapeutic target for TAA.

A previously undescribed pathogenic variant in FBN1 gene causing Marfan syndrome: a case report

Background

Marfan syndrome (MFS) is an autosomal dominant multisystem connective tissue disorder with increased risk of aortopathy with a high risk of subsequent life-threatening aortic dissection. Diagnosing this condition is reliant on recognizing clinical features and genetic testing for confirming diagnosis, using the revised Ghent criteria.

Case summary

We identified a 49-year-old patient who presented with dyspnoea, with Marfan syndrome (MFS) and a previously unreported variant in the fibrillin-1 gene (FBN1), designated c.7016G>C. Prior to identifying the new gene variant, this patient did not meet the revised Ghent criteria for MFS diagnosis. We present clinical and molecular evidence supporting the likely pathogenic nature of this variant, leading to earlier therapy and intervention.

Discussion

The discovery of a new pathogenic gene will expand the current aortopathy and MFS database and may lead to more informed clinical management decisions for the timing and nature of interventions.

Determine Cumulative Radiation Dose and Lifetime Cancer Risk in Marfan Syndrome Patients Who Underwent Computed Tomography Angiography of the Aorta in Northeast Thailand: A 5-Year Retrospective Cohort Study

Objective: To evaluate computed tomography angiography (CTA) data focusing on radiation dose parameters in Thais with Marfan syndrome (MFS) and estimate the distribution of cumulative radiation exposure from CTA surveillance and the risk of cancers. Methods: Between 1st January 2015 and 31st December 2020, we retrospectively evaluated the cumulative CTA radiation doses of MFS patients who underwent CTA at Khon Kaen University Hospital, a leading teaching hospital and advanced tertiary care institution in northeastern Thailand. We utilized the Radiation Risk Assessment Tool (RadRAT) established at the National Cancer Institute in Bethesda, Maryland, to evaluate the risk of cancer-related CTA radiation. Results: The study recruited 29 adult MFS patients who had CTA of the aorta during a 5-year study period with 89 CTA studies. The mean cumulative CTDI vol is 21.5 ± 14.68 mGy, mean cumulative DLP is 682.2 ± 466.7 mGy.cm, the mean baseline future risk for all cancer is 26,134 ± 7601 per 100,000, and the excess lifetime risk for all cancer is 2080.3 ± 1330 per 100,000. The excess lifetime risk of radiation-induced cancer associated with the CTA surveillance study is significantly lower than the risk of aortic dissection or rupture and lower than the baseline future cancer risk. Conclusions: We attempted to quantify the radiation-induced cancer risk from CTA surveillance imaging performed for MFS patients in this study, with all patients receiving a low-risk cumulative radiation dose (less than 1 Gy) and all patients having a low excessive lifetime risk of cancer as a result of CTA. The risk–benefit decision must be made at the point of care, and it entails balancing the benefits of surveillance imaging in anticipating rupture and providing practical, safe treatment, therefore avoiding morbidity and mortality.

Age and sex dependency of thoracic aortopathy in a mouse model of Marfan syndrome

Thoracic aortic aneurysm is one of the manifestations of Marfan syndrome (MFS) that is known to affect men more severely than women. However, the incidence of MFS is similar between men and women. The aim of this study is to show that during pathological aortic dilation, sex-dependent severity of thoracic aortopathy in a mouse model of MFS translates into sex-dependent alterations in cells and matrix of the ascending aorta, consequently affecting aortic biomechanics. Fibrillin-1 C1041G/+ (Het) mice were used as a mouse model of MFS. Ultrasound measurements from 3 to 12 mo showed increased aortic diameter in Het aorta, with larger percentage increase in diameter for males compared with females. Immunohistochemistry showed decreased contractile smooth muscle cells in Het aortic wall compared with healthy aorta, which was accompanied by decreased contractility measured by wire myography. Elastin autofluorescence, second-harmonic generation microscopy of collagen fibers, and passive biomechanical assessments using myography showed more severe damage to elastin fibers, increased medial fibrosis, and increased stiffness of the aortic wall in MFS males but not females. Male and female Het mice showed increased expression of Sca-1-positive adventitial progenitor cells versus controls at young ages. In agreement with clinical data, Het mice demonstrate sex-dependent severity of thoracic aortopathy. It was also shown that aging exacerbates the disease state especially for males. Our findings suggest that female mice are protected from progression of aortic dilation at early ages, leading to a lag in aneurysm growth.NEW & NOTEWORTHY Male Fbn1^C1041G/+ mice show more severe thoracic aortic changes compared with females, especially at 12 mo of age. Up to 6 mo of age, Sca-1⁺ smooth muscle progenitor cells are more abundant in the adventitia of both male and female Fbn1 Het mice compared with wild types (WTs). Male and female Het mice show similar patterns of expression of Sca-1⁺ cells at early ages.

Pupillary response in adults with Marfan syndrome and its effect on straylight

PURPOSE

The main objective of this study was to examine the pupillary response in patients with Marfan syndrome (MFS) and secondarily to determine whether changes in the pupillary response are associated with the increased disability glare previously shown in the same patient population.

METHODS

This study included 60 eyes of 34 patients with MFS diagnosed in accordance with the Ghent-2 criteria and 81 eyes of 44 controls. Pupillary response was measured with a pupillograph and disability glare with a straylight meter.

RESULTS

The patients with MFS had a significantly smaller maximum pupil size than the control group, 4.87 (4.50-5.23) mm versus 5.58 (5.25-5.90) mm (p = 0.01). In addition, they exhibited slower contraction velocities (p = 0.03) and longer re-dilation times (p = 0.01) compared with the control group. The mean straylight value was higher in patients with MFS than controls, even when including pupillary parameters together with lens surgery, cataract, iris colour, axial length and corneal curvature as possible explanatory variables in the analysis. However, when including data from both groups, a significant negative correlation was seen between maximum pupillary diameter and straylight value (p = 0.01). The other pupillary parameters did not correlate with straylight.

CONCLUSION

Patients with MFS had a smaller maximum pupil diameter, slower pupillary contraction and longer re-dilation time than the controls. Despite the correlation between pupil size and straylight value, the pupillary response demonstrated in MFS eyes could not explain the increased straylight in these patients.

Association of sleep apnoea risk and aortic enlargement in Marfan syndrome

Background

Marfan syndrome (MFS) is a connective tissue disorder characterised by complex aortic pathology and a high prevalence of obstructive sleep apnoea (OSA). OSA produces intrathoracic transmural stresses that may accelerate aortic injury. The current study was designed to examine the associations between OSA risk and markers of aortic enlargement in MFS.

Method

Consecutive patients with MFS were recruited at Johns Hopkins if they completed a STOP-BANG survey. Composite survey scores were categorised into those with low OSA risk (STOP-BANG <3) and high OSA risk (STOP-BANG ≥3). Participants’ aortic data were collated to ascertain aortic root diameter, dilatation and prior aortic root replacement. Regression analyses were used to examine associations between OSA risk strata and these aortic parameters.

Results

Of the 89 participants studied, 28% had a high OSA risk and 32% had aortic grafts. Persons with high OSA risk had greater aortic root diameter (mm) (ß=4.13, SE=1.81, p=0.027) and aortic root dilatation (ß=2.80, SE=1.34, p=0.046) compared with those with low OSA risk. In addition, the odds of prior aortic root replacement was three times greater in those with high OSA risk compared with those with low OSA risk.

Conclusion

In MFS, high OSA risk is associated with aortic enlargement and a threefold increased risk of having had prior aortic root replacement. These findings invite further exploration of the relationship between OSA and aortic disease in MFS, and studies to clarify whether targeted interventions for OSA might mitigate aortic disease progression in MFS.

Registration number

IRB00157483.

Marfan syndrome

Marfan syndrome (MFS) is an autosomal dominant, age-related but highly penetrant condition with substantial intrafamilial and interfamilial variability. MFS is caused by pathogenetic variants in FBN1, which encodes fibrillin-1, a major structural component of the extracellular matrix that provides support to connective tissues, particularly in arteries, the pericondrium and structures in the eye. Up to 25% of individuals with MFS have de novo variants. The most prominent manifestations of MFS are asymptomatic aortic root aneurysms, aortic dissections, dislocation of the ocular lens (ectopia lentis) and skeletal abnormalities that are characterized by overgrowth of the long bones. MFS is diagnosed based on the Ghent II nosology; genetic testing confirming the presence of a FBN1 pathogenetic variant is not always required for diagnosis but can help distinguish MFS from other heritable thoracic aortic disease syndromes that can present with skeletal features similar to those in MFS. Untreated aortic root aneurysms can progress to life-threatening acute aortic dissections. Management of MFS requires medical therapy to slow the rate of growth of aneurysms and decrease the risk of dissection. Routine surveillance with imaging techniques such as transthoracic echocardiography, CT or MRI is necessary to monitor aneurysm growth and determine when to perform prophylactic repair surgery to prevent an acute aortic dissection.

An Overview of Investigational and Experimental Drug Treatment Strategies for Marfan Syndrome

Marfan syndrome (MFS) is a heritable connective tissue disorder caused by pathogenic variants in the gene coding for the extracellular matrix protein fibrillin-1. While the disease affects multiple organ systems, the most life-threatening manifestations are aortic aneurysms leading to dissection and rupture. Other cardiovascular complications, including mitral valve prolapse, primary cardiomyopathy, and arrhythmia, also occur more frequently in patients with MFS. The standard medical care relies on cardiovascular imaging at regular intervals, along with pharmacological treatment with β-adrenergic receptor blockers aimed at reducing the aortic growth rate. When aortic dilatation reaches a threshold associated with increased risk of dissection, prophylactic surgical aortic replacement is performed. Although current clinical management has significantly improved the life expectancy of patients with MFS, no cure is available and fatal complications still occur, underscoring the need for new treatment options. In recent years, preclinical studies have identified a number of potentially promising therapeutic targets. Nevertheless, the translation of these results into clinical practice has remained challenging. In this review, we present an overview of the currently available knowledge regarding the underlying pathophysiological processes associated with MFS cardiovascular pathology. We then summarize the treatment options that have been developed based on this knowledge and are currently in different stages of preclinical or clinical development, provide a critical review of the limitations of current studies and highlight potential opportunities for future research.

Mitral Valve Prolapse and Its Motley Crew-Syndromic Prevalence, Pathophysiology, and Progression of a Common Heart Condition

Mitral valve prolapse (MVP) is a commonly occurring heart condition defined by enlargement and superior displacement of the mitral valve leaflet(s) during systole. Although commonly seen as a standalone disorder, MVP has also been described in case reports and small studies of patients with various genetic syndromes. In this review, we analyzed the prevalence of MVP within syndromes where an association to MVP has previously been reported. We further discussed the shared biological pathways that cause MVP in these syndromes, as well as how MVP in turn causes a diverse array of cardiac and noncardiac complications. We found 105 studies that identified patients with mitral valve anomalies within 18 different genetic, developmental, and connective tissue diseases. We show that some disorders previously believed to have an increased prevalence of MVP, including osteogenesis imperfecta, fragile X syndrome, Down syndrome, and Pseudoxanthoma elasticum, have few to no studies that use up-to-date diagnostic criteria for the disease and therefore may be overestimating the prevalence of MVP within the syndrome. Additionally, we highlight that in contrast to early studies describing MVP as a benign entity, the clinical course experienced by patients can be heterogeneous and may cause significant cardiovascular morbidity and mortality. Currently only surgical correction of MVP is curative, but it is reserved for severe cases in which irreversible complications of MVP may already be established; therefore, a review of clinical guidelines to allow for earlier surgical intervention may be warranted to lower cardiovascular risk in patients with MVP.

Is SF-12 a valid and reliable measurement of health-related quality of life among adults with Marfan syndrome? A confirmatory study

Introduction

The structural validity and reliability of the Short-Form Health Survey 12 (SF-12) has not yet been tested in adults with the Marfan syndrome (MFS). This gap could undermine an evidence-grounded practice and research, especially considering that the need to assess health-related quality of life in patients with MFS has increased due to the improved life expectancy of these patients and the need to identify their determinants of quality of life. For this reason, this study aimed to confirm the dimensionality (structural validity) of the SF-12, its concurrent validity, and its reliability (internal consistency).

Methods

We performed a cross-sectional study in a convenience sample of 111 Italian adults with MFS, collecting anamnestic and socio-demographic information, the SF-12, and short-form Health Survey 36 (SF-36). A confirmatory factor analysis was performed to verify whether the items of SF-12 related to physical restrictions, physical functioning, and bodily pain were retained by the physical summary component of the SF-12. The items referred to the role limitations due to emotional issues, social functioning, and mental health were retained by the mental summary component (MCS12). SF-36 was used to assess the concurrent validity of SF-12, hypothesizing positive correlations among the equivalent summary scores.

Results

The two-factor structural solution resulted in fitting the sample statistics adequately. The internal consistency was adequate for the two factors. Furthermore, the physical and mental summary scores of the SF-36 were positively correlated with their equivalent summary scores derived from the SF-12.

Conclusions

This study confirmed the factor structure of the SF-12. Therefore, the use of SF-12 in clinical practice and research for assessing the health-related quality of life among adults with MFS is evidence-grounded. Future research is recommended to determine whether the SF-12 shows measurement invariance in different national contexts and determine eventual demographic variation in the SF-12 scores among patients with MFS.

3D Printed Personalized External Aortic Root Model in Marfan Syndrome with Isolated Sinus of Valsalva Aneurysm Caused by a Novel Pathogenic FBN1 p.Gly1127Cys Variant

The major cause of death in Marfan syndrome (MFS) is cardiovascular complications, particularly progressive dilatation of the proximal aorta, rendering these patients at risk of aortic dissection or fatal rupture. We report a 3D printed personalized external aortic root model for MFS with an isolated sinus of Valsalva aneurysm caused by a novel pathogenic FBN1 variant. A 67-year-old female with a history of lens dislocation and retinal detachment in the left eye was admitted for the evaluation of resting dyspnea several months prior. Transesophageal and transthoracic echocardiography revealed severe aortic valve regurgitation and a large left coronary sinus of Valsalva aneurysm in the proband. Sanger sequencing identified a heterozygous p.Gly1127Cys variant in the FBN1 gene; previously, a mutation at this amino acid position was described as pathogenic (p.Gly1127Ser; rs137854468). A 3D printed personalized external aortic root model based on a multidetector computed tomography scan was constructed to illustrate the location of the ostium of the left main coronary artery on the aneurysm of the left coronary artery cusp. Aortic root replacement with the Bentall procedure matched the exact shape of the 3D printed model. Creation of a 3D printed patient-specific model could be useful in facilitating the development of next-generation medical devices and resolving the risks of postoperative complications and aortic root disease.

The Molecular Genetics of Marfan Syndrome

Marfan syndrome (MFS) is a complex connective tissue disease that is primarily characterized by cardiovascular, ocular and skeletal systems disorders. Despite its rarity, MFS severely impacts the quality of life of the patients. It has been shown that molecular genetic factors serve critical roles in the pathogenesis of MFS. FBN1 is associated with MFS and the other genes such as FBN2, transforming growth factor beta (TGF-β) receptors (TGFBR1 and TGFBR2), latent TGF-β-binding protein 2 (LTBP2) and SKI, amongst others also have their associated syndromes, however high overlap may exist between these syndromes and MFS. Abnormalities in the TGF-β signaling pathway also contribute to the development of aneurysms in patients with MFS, although the detailed molecular mechanism remains unclear. Mutant FBN1 protein may cause unstableness in elastic structures, thereby perturbing the TGF-β signaling pathway, which regulates several processes in cells. Additionally, DNA methylation of FBN1 and histone acetylation in an MFS mouse model demonstrated that epigenetic factors play a regulatory role in MFS. The purpose of the present review is to provide an up-to-date understanding of MFS-related genes and relevant assessment technologies, with the aim of laying a foundation for the early diagnosis, consultation and treatment of MFS.

Health-related quality of life in Marfan syndrome: a 10-year follow-up

Background

Marfan syndrome, a rare hereditary connective tissue disorder caused by mutations in fibrillin-1, can affect many organ systems, especially the cardiovascular system. Previous research has paid less attention to health-related quality of life and prospective studies on this topic are needed. The aim of this study was to assess changes in health-related quality of life after 10 years in a Norwegian Marfan syndrome cohort.

Methods

Forty-seven Marfan syndrome patients ≥ 18 years were investigated for all organ manifestations in the 1996 Ghent nosology and completed the self-reported questionnaire, Short-Form-36 Health Survey, at baseline in 2003–2004 and at follow-up in 2014–2015. Paired sample t tests were performed to compare means and multiple regression analyses were performed with age, sex, new cardiovascular and new non-cardiovascular pathology as predictors.

Results

At 10-year follow-up: a significant decline was found in the physical domain. The mental domain was unchanged. Older age predicted a larger decline in physical health-related quality of life. None of the chosen Marfan-related variables predicted changes in any of the subscales of the Short-Form 36 Health Survey or in the physical or the mental domain.

Conclusion

Knowledge of decline in the physical domain, not related to organ affections, may be important in the follow-up of Marfan syndrome patients.

Genotype FBN1/phenotype relationship in a cohort of patients with Marfan syndrome

Marfan syndrome (MFS) is a systemic connective tissue disorder caused by mutations in the fibrillin-1 (FBN1) gene, and cardiovascular involvement is the leading cause of mortality. We sought to examine the genotype/phenotype realtionship in 61 consecutive patients with a phenotype and genotype compatible with MFS. The FBN1 gene was analyzed by massive sequencing using a hybridization capture-based target enrichment custom panel. Forty-three different variants of FBN1 were identified, of which 17 have not been previously reported. The causal variants of MFS were grouped into mutations resulting in haploinsufficiency (HI group; 23 patients) and mutations producing a dominant-negative effect (DN group; 38 patients). Patient information was collected from electronic medical records and clinical evaluation. While no significant differences were found between the two groups, the HI group included more cases with aortic dissection and occurring at a younger age that the DN group (34.7% vs. 15.8%; p = 0.160). Irrespective of the mutation group, males presented with a higher probability of aortic involvement (4-fold higher risk than females) and aortic dissections events occurred at younger ages. Patients with DN variants carrying a cysteine substitution had a higher incidence of ectopia lentis.

Steered molecular dynamic simulations reveal Marfan syndrome mutations disrupt fibrillin-1 cbEGF domain mechanosensitive calcium binding

Marfan syndrome (MFS) is a highly variable genetic connective tissue disorder caused by mutations in the calcium binding extracellular matrix glycoprotein fibrillin-1. Patients with the most severe form of MFS (neonatal MFS; nMFS) tend to have mutations that cluster in an internal region of fibrillin-1 called the neonatal region. This region is predominantly composed of eight calcium-binding epidermal growth factor-like (cbEGF) domains, each of which binds one calcium ion and is stabilized by three highly conserved disulfide bonds. Crucially, calcium plays a fundamental role in stabilizing cbEGF domains. Perturbed calcium binding caused by cbEGF domain mutations is thus thought to be a central driver of MFS pathophysiology. Using steered molecular dynamics (SMD) simulations, we demonstrate that cbEGF domain calcium binding decreases under mechanical stress (i.e. cbEGF domains are mechanosensitive). We further demonstrate the disulfide bonds in cbEGF domains uniquely orchestrate protein unfolding by showing that MFS disulfide bond mutations markedly disrupt normal mechanosensitive calcium binding dynamics. These results point to a potential mechanosensitive mechanism for fibrillin-1 in regulating extracellular transforming growth factor beta (TGFB) bioavailability and microfibril integrity. Such mechanosensitive “smart” features may represent novel mechanisms for mechanical hemostasis regulation in extracellular matrix that are pathologically activated in MFS.

Myocardial Function, Heart Failure and Arrhythmia in Marfan Syndrome: A Systematic Literature Review

Marfan syndrome (MFS) is a heritable systemic connective tissue disease with important cardiovascular involvement, including aortic root dilatation and mitral valve prolapse. Life expectancy in patients with MFS is mainly determined by cardiovascular complications, among which aortic dissection or rupture are most dreaded. In recent years, heart failure and ventricular arrhythmia have drawn attention as extra-aortic cardiovascular manifestations and as additional reported causes of death. Imaging studies have provided data supporting a primary myocardial impairment in the absence of valvular disease or cardiovascular surgery, while studies using ambulatory ECG have demonstrated an increased susceptibility to ventricular arrhythmia. In this paper, current literature was reviewed in order to provide insights in characteristics, pathophysiology and evolution of myocardial function, heart failure and ventricular arrhythmia in MFS.

Multidisciplinary aortopathy clinics: A systematic scoping review of the literature and evaluation of patient experiences from a newly started clinic in Norway

Background

International guidelines recommend hereditary thoracic aortic diseases (HTADs) to be managed in multidisciplinary aorta clinics.

Aim

To study HTAD patient's experiences with a aortopathy clinic in Norway and to review the literature on aortopathy clinics.

Methods

(a) A systematic scoping review of research on multidisciplinary clinics for HTADs. (b) A cross‐sectional postal questionnaire study to investigate patient experiences with the health‐services. Fifty consecutive patients from the aortopathy clinic and 50 controls in usual care were invited to participate.

Results

The review identified eight publications on aortopathy clinics. Although the papers were not judged for quality, these showed promising results from such clinics in terms of diagnostics and increased adherence to guideline‐directed therapy. The survey constituted thirty‐seven (74%) patients and 22 (44%) controls who responded to postal questionnaires. Both groups reported delays in diagnostics and follow‐up appointments prior to the start of the clinic. Patients indicated high satisfaction with the aortopathy clinic, whereas controls reported poor coordination of medical follow‐up. Individuals in both groups struggled with disease self‐management.

Conclusion

Norwegian patient experiences found the aortopathy clinic beneficial. According to studies included in the review, disease management in aortopathy clinics may improve patient satisfaction, diagnostics and follow‐up. Effect studies may further document the benefits of clinic organization, treatment, cost‐efficiency and patient experiences.

Increased frequency of FBN1 frameshift and nonsense mutations in Marfan syndrome patients with aortic dissection

Background

Marfan syndrome (MFS) is an inherited connective tissue disease that mainly involves Fibrillin‐1 (FBN1) mutations and aortic manifestations. In this study, we investigated the correlations between the FBN1 genotype–phenotype and aortic events (aortic dissection and aortic aneurysm) in patients with Marfan syndrome.

Methods

Genotype and phenotype information was evaluated in 180 patients with MFS. DNA sequencing was performed on each patient. According to the clinical manifestation, these patients were split into two groups: the aortic dissection group and the aortic aneurysm group. Aortic wall tissue was obtained from Marfan patients who underwent surgery and was used for staining.

Results

A total of 180 patients with FBN1 mutations were grouped into four categories: 90 with missense mutations, 32 with splicing mutations, 29 with frameshift mutations, and 29 with nonsense mutations. There was a significantly higher frequency of frameshift and nonsense mutations observed in aortic dissection than in aortic aneurysm (25.58% vs. 4.35%, p = .005; 25.58% vs. 8.70%, p = .033, respectively;), while missense mutations showed a higher frequency in aortic aneurysm than in aortic dissection (69.57% vs. 32.56%, respectively; p < .001) and a higher rate of lens dislocation (34.78% vs. 13.95%, respectively; p = .008). Pathological staining showed that elastic fibers were sparser in patients with a frameshift and nonsense mutations, and the smooth muscle cells were sparser and more disorganized than those observed in patients with missense mutations.

Conclusion

This study showed that FBN1 gene frameshift and nonsense mutations are more common in patients with aortic dissection and may have meaningful guidance for the treatment of Marfan syndrome patients.

Dural ectasia in Marfan syndrome and other hereditary connective tissue disorders: a 10-year follow-up study

BACKGROUND CONTEXT

Dural ectasia is widening of the dural sac often seen in patients with Marfan syndrome and other hereditary connective tissue disorders. Dural ectasia can cause specific symptoms and is associated with surgical complications. The knowledge on how and at which age dural ectasia develops is incomplete. There is no established gold standard for diagnosing dural ectasia, making it difficult to compare results from different studies.

PURPOSE

Our primary aim was to explore whether the radiological findings of dural ectasia changed after 10 years in an adult cohort with suspected Marfan syndrome. Our secondary aim was to re-evaluate the radiological criteria of dural ectasia.

STUDY DESIGN

Prospective cohort study.

PATIENT SAMPLE

Sixty-two persons from a cross-sectional study of 105 persons with suspected Marfan syndrome were included in a 10-year follow-up of dural ectasia. Forty-six were diagnosed with Marfan syndrome, 7 with Loeys-Dietz syndrome, and 5 with other hereditary connective tissue disorders. For comparison 64 matched hospital controls were evaluated.

OUTCOME MEASURES

Previously used radiological criteria for dural ectasia based on quantitative measurements of the lumbosacral spine.

METHODS

MRI of the lumbosacral spine was performed if not contraindicated, and if so then CT was performed. Differences in the study group between baseline and follow-up were assessed with paired Student t test, Wilcoxon rank signed test, and McNemar test. Receiver operating characteristic curves were constructed to assess the ability of radiological measurement to differentiate between the study and control group.

RESULTS

Fifty-two of 58 patients with hereditary connective tissue disorders and 11 controls had dural ectasia at follow-up. Forty-five Marfan patients had dural ectasia at follow-up vs. 41 at baseline. Five Loeys-Dietz patients had dural ectasia at follow-up vs. four at baseline. Twenty-four Marfan and 2 Loeys-Dietz patients had anterior sacral meningocele at follow-up, compared with 21 and 1, respectively, at baseline. Three Marfan patients developed herniation of a nerve root sleeve during follow-up. This was not seen in other individuals. The dural sac ended significantly lower at follow-up, and the dural sac ratio at level L5 was significantly increased from baseline in the Marfan patients.

CONCLUSIONS

In Marfan and Loeys-Dietz syndrome, dural ectasia may present or worsen during adulthood. The cut-off value of dural sac ratio at level S1 is suggested elevated to 0.64. The results from the present study may help as guidance for appropriate follow-up of patients with dural ectasia.

Aortic Valve-Sparing Root Replacement (David I Procedure) in Adolescents: Long-Term Outcome

INTRODUCTION

Aortic valve-sparing root replacement (David's procedure) is an especially appealing treatment option for young patients. Here, we present the short-, mid, and long-term outcomes of this operation in adolescent patients.

METHODS

Between September 1994 and March 2014, 29 patients aged 6 to 21 years underwent the David-I procedure at our center. We conducted a retrospective study with follow-up.

RESULTS

The mean age was 16.8 ± 3.4 years and 90% (n = 26) were male. Marfan's syndrome was present in 86% (n = 25) of cases. Ninety-seven percent (n = 28) of cases were performed electively, and one case (3%) was performed emergently for acute aortic dissection type A. There were no early perioperative deaths (0%). Follow-up, which was completed on 100% of patients, comprised a total of 394 patient years and a mean follow-up time of 13.6 ± 5.4 years. The estimates for survival at 1, 5, and 10 years after initial surgery were 100, 97, and 93%, respectively. During follow-up, there were four (14%) late deaths and five (17%) aortic valve-related reoperations. The 1-, 5-, and 10-year estimates for freedom from valve-related reoperation were 100, 86, and 83%, respectively. The perioperative mortality for these five reoperations was 0%.

DISCUSSION

Aortic valve-sparing root replacement can be performed in adolescents with a very low perioperative risk. Long-term survival seems to be affected by connective tissue diseases.

Detection of ten novel FBN1 mutations in Chinese patients with typical or incomplete Marfan syndrome and an overview of the genotype-phenotype correlations

OBJECTIVE

The aim of this study is to identify the mutation spectrum of FBN1 in patients with Marfan syndrome (MFS) or Marfan-Like Phenotypes and to analyze the genotype-phenotype correlations of existing literature.

METHODS AND RESULTS

A total of 21 unrelated patients with a definite or suspected clinical diagnosis of MFS were recruited for research. Eleven FBN1 mutations were identified in 12 patients who strictly fulfilled the Ghent criteria for MFS, and 1 FBN1 mutations were detected in 9 patients with suspected MFS by screening the mutations of FBN1. These FBN1 mutations include 10 novel mutations (c.357 C>A, c.493 C>T, c.1374 T>A, c.4143 delG, c. 6987 C>G, c.7238 G>A, c. 7765 A>G, c.8200 A>G, c. 8431 G>A, c.8547 T>G,) and 2 previously reported mutations (c.4567 C>T, c.4615 C>T). By searching PubMed and Embase (from 1990 up to December 2018), twenty nine studies (including the present study) with 890 subjects with MFS or Marfan-like phenotypes were included to analyze the genotype-phenotype correlations. Several genotype-phenotype correlations were founded. Firstly, mutations of premature termination codons (PTC) were associated with an increased risk of major cardiovascular involvements. Secondly, the frequency of patients with major cardiovascular involvement in exons 43-65 group was as high as that in exons 24-32 group (71.4% vs. 77.0%; p = 0.238). Finally, cysteine missense mutations might be associated with major cardiovascular involvements.

CONCLUSIONS

These results extended the FBN1 mutation spectrum of this rare disease and revealed the genotype-phenotype correlations in MFS by analyzing existing literature.

Marfan syndrome: A therapeutic challenge for long-term care

Marfan syndrome (MFS) is an autosomal dominant genetic disorder caused by mutations in the fibrillin-1 gene. Acute aortic dissection is the leading cause of death in patients suffering from MFS and consequence of medial degeneration and aneurysm formation. In addition to its structural function in the formation of elastic fibers, fibrillin has a major role in keeping maintaining transforming growth factor β (TGF-β) in an inactive form. Dysfunctional fibrillin increases TGF-β bioavailability and concentration in the extracellular matrix, leading to activation of proinflammatory transcription factors. In turn, these events cause increased expression of matrix metalloproteinases and cytokines that control the migration and infiltration of inflammatory cells into the aorta. Moreover, TGF-β causes accumulation of reactive oxygen species leading to further degradation of elastin fibers. All these processes result in medial elastolysis, which increases the risk of vascular complications. Although MFS is a hereditary disease, symptoms and traits are usually not noticeable at birth. During childhood or adolescence affected individuals present with severe tissue weaknesses, especially in the aorta, heart, eyes, and skeleton. Considering this, even young patients should avoid activities that exert additional stress and pressure on the aorta and the cardiovascular system. Thus, if the diagnosis is made and prophylactic treatment is initiated in a timely fashion, MFS and its preliminary pathophysiologic vascular remodeling can be successfully ameliorated reducing the risk of life-threatening complications. This commentary focuses on new research opportunities and molecular findings on MFS, discusses future challenges and possible long-term therapies.

Survival, causes of death, and cardiovascular events in patients with Marfan syndrome

BACKGROUND

To explore survival, causes of death, and the prevalence of cardiovascular events in a Norwegian Marfan syndrome (MFS) cohort. MFS is a heritable connective tissue disorder associated with reduced life expectancy-primarily due to aortic pathology.

METHODS

A follow-up study of 84 MFS adults, initially investigated in 2003-2004. In 2014-2015, 16 were deceased, 47 of 68 survivors consented to new clinical investigations. Analyses of events were performed for 47 survivors and 16 deceased at follow-up. Standardized mortality ratios (SMR), using the mortality rate of the Norwegian population as reference, were calculated for all 84 and calculated for men and women separately. Causes of death and information on cardiovascular events were retrieved from death certificates and medical records.

RESULTS

Standardized mortality ratios (95% confidence interval): for the whole cohort: 5.24 (3.00-8.51); for men: 8.20 (3.54-16.16); for women: 3.85 (1.66-7.58). Cardiovascular causes were found in 11 of 16 deceased, eight of these related to aortic pathology. Cancer was the cause of death in three patients. At follow-up, 51% had new cardiovascular events; 59% had undergone aortic surgery. Men experienced aortic events at younger age than women. 32% of the survivors were not followed-up as recommended.

CONCLUSION

Life expectancy is reduced in this MFS cohort compared to the Norwegian population. Cardiovascular complications develop throughout life, particularly aortic pathology, the major cause of death in MFS. Death and aortic pathology seem to occur earlier in men. There is a need to improve follow-up according to guidelines.