Left ventricular systolic dysfunction in asymptomatic Marfan syndrome patients is related to the severity of gene mutation: insights from the novel three dimensional speckle tracking echocardiography

Intrinsic cardiomyopathy in pediatric Marfan syndrome: predictive factors and risk assessments

BACKGROUND

Marfan syndrome (MFS) is associated with cardiovascular complications, particularly valvulopathies; however, its association with primary cardiomyopathy remains unclear.

METHODS

This retrospective cohort study examined the cardiomyopathy characteristics (CMCs) in pediatric patients with MFS. CMCs were defined as meeting at least one of the following echocardiography or clinical parameters: (1) cardiac index (CI) too low for patient's age, (2) ejection fraction (EF) <50%, and (3) diastolic dysfunction. The predictive factors for CMCs were determined using a multivariable logistic regression model.

RESULTS

Among 83 patients with MFS (age, median [range], 12.5 [0.4-22.3] years), 39.8% exhibited CMCs. Only 4 patients (5%) showed heart failure symptoms (NYHA > 1). Independent predictors for CMCs included a systemic score of ≥7 (revised Ghent criteria) and likely pathogenic or pathogenic variants in FBN1, including variants that introduce a premature stop codon, splice site variants, and missense variants involving cysteine. A multivariable score was constructed with an AUC of 0.733.

CONCLUSION

This study offers valuable insights into the prevalence and predictors of CMC in pediatric patients with MFS and presents potential strategies for risk assessment of cardiomyopathy.

IMPACT

The objective of this study was to elucidate the contentious issue of intrinsic cardiomyopathy in Marfan syndrome and demonstrate its notable occurrence even in pediatric patients who do not exhibit heart failure symptoms or valvular complications. We highlighted the importance of specific FBN1 variants and higher systemic scores in identifying the potential for intrinsic cardiomyopathy in pediatric patients with Marfan syndrome.

Online Personal Training in Patients With Marfan Syndrome: A Randomized Controlled Study of Its Impact on Quality of Life and Physical Capacity

BACKGROUND

Marfan syndrome (MFS) is a genetic disorder affecting the vascular and musculoskeletal systems. Limited knowledge exists regarding the exercise benefits for this population. This study aimed to explore the impact of a structured exercise program on the quality of life (QoL) and physical capabilities of patients with MFS.

METHODS AND RESULTS

This was a randomized, controlled, parallel-group trial. Patients with MFS were randomized in a 1:1 ratio to either a training group or a control group. The trial included a 3-month online supervised training program. Seventy patients with MFS were compared with healthy subjects. They were randomized into a training group (MFS-T) and a control group (MFS-C). The training consisted of 2 supervised online sessions weekly for 3 months. The primary outcome was QoL, assessed using the Medical Outcomes Study Short-Form 36 questionnaire. Baseline QoL in all dimensions was lower in patients with MFS. Their peak oxygen uptake was 25% lower, and muscle elasticity was diminished compared with healthy subjects. Postintervention, significant improvements were observed in the MFS-T group relative to the MFS-C group: QoL (+20.2±14.3 versus +0.7±0.5), peak oxygen uptake (+34% versus +14%), muscle elasticity index (11.5±8.2 versus +1.2±1.7), reduced blood pressures during isometric squats (systolic -19±30 versus 0±6; diastolic -27±39 versus +2±15), and reduced pulse wave velocity at rest (-1.20±1.89 versus -0.40±1.61) and postexercise (-0.42±0.45 versus +0.08±0.48). The aortic diameter remained stable in both groups (MFS-T-0.19±1.1 versus MFS-C+0.11±0.78). After training, QoL remained lower in MFS-T than in healthy subjects, but peak oxygen uptake, pulse wave velocity at rest, and postexercise were similar to those of healthy subjects.

CONCLUSIONS

The 3-month online training program significantly enhanced QoL and cardiovascular/muscular metrics in patients with MFS without affecting aortic root diameter, suggesting its potential as part of a management strategy for MFS.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04553094.

Is Marfan Syndrome Associated with Primary Structural Changes in the Left Atrium?

Marfan syndrome (MFS) is an autosomal-dominant multisystem connective tissue disorder that is based on mutations in the FBN1 gene and variably affects different organs, including the heart. In this study, we investigated cardiac function with a focus on the left atrium (LA) in a relatively large cohort of patients with MFS. After screening of 1165 patients that had been examined in our center between 2016 and 2020, 231 adult MFS patients with and without aortic operation were included in our study and compared to a healthy control group (n = 106). Cardiac function was assessed by transthoracic echocardiography and NT-proBNP was used as a secretory marker. Most (94.8%) of the patients received genetic testing. Left ventricular function was within normal ranges and not impaired. Interestingly, we found that LA size and secretory activity were increased in MFS patients, despite normal left ventricular filling pressures. This finding was even more pronounced in MFS patients with prior aortic surgery. A correlation between LA size or NT-proBNP levels and the type of pathogenic FBN1 variant could not be identified. Right ventricular function and right atrial size were increased only in MFS patients that had undergone aortic surgery. In conclusion, these findings suggest that MFS leads to structural changes in the LA that are not solely resulting from left ventricular dysfunction, but probably can be considered a primary pathology of MFS.

Cardiac function in adolescents and young adults with 22q11.2 deletion syndrome without congenital heart disease

BACKGROUND

Diagnosis and treatment of 22q11.2 deletion syndrome (22q11.2DS) have led to improved life expectancy and achievement of adulthood. Limited data on long-term outcomes reported an increased risk of premature death for cardiovascular causes, even without congenital heart disease (CHD). The aim of this study was to assess the cardiac function in adolescents and young adults with 22q11.2DS without CHDs.

METHODS

A total of 32 patients (20M, 12F; mean age 26.00 ± 8.08 years) and a healthy control group underwent transthoracic echocardiography, including Tissue Doppler Imaging (TDI) and 2-dimensional Speckle Tracking Echocardiography (2D-STE).

RESULTS

Compared to controls, 22q11.2DS patients showed a significant increase of the left ventricle (LV) diastolic and systolic diameters (p = 0.029 and p = 0.035 respectively), interventricular septum thickness (p = 0.005), LV mass index (p < 0.001) and aortic root size (p < 0.001). 2D-STE analysis revealed a significant reduction of LV global longitudinal strain (p < 0.001) in 22q11.2DS than controls. Moreover, several LV diastolic parameters were significantly different between groups.

CONCLUSIONS

Our results suggest that an echocardiographic follow-up in 22q11.2DS patients without CHDs can help to identify subclinical impairment of the LV and evaluate a potential progression of aortic root dilation over time, improving outcomes, reducing long-term complications and allowing for a better prognosis.

Prevalence and Outcomes of Primary Left Ventricular Dysfunction in Marfan Syndrome

Even in the absence of significant valvular disease, patients with Marfan syndrome (MFS) have evidence of impaired left ventricular (LV) performance, suggestive of a primary cardiomyopathy. However, the true prevalence and long-term outcomes of this disease process remain largely unknown. We performed a retrospective analysis of all adult patients with confirmed MFS followed at Stanford Health Care. Those with significant valvular regurgitation, coronary artery disease, or previous cardiac surgery were excluded. LV systolic dysfunction was defined as a LV ejection fraction (LVEF) <55% on transthoracic echocardiography. A total of 753 patients with confirmed MFS were followed up over a median duration of 8 years (interquartile range 4 to 13). Of those, 241 patients (53% women, 71% White) met inclusion criteria and comprised the study cohort. LV systolic dysfunction was present in 30 patients (12%), with a median age of onset of 25 years (interquartile range 19 to 37), median EF of 52% (interquartile range 48 to 54), and evidence of clinical heart failure (New York Heart Association functional class ≥II) in 10% of patients. LV systolic dysfunction was more common in patients with larger aortic root diameters (≥4.0 cm: Odds ratio = 4.5, 95% confidence interval = 1.2 to 17.1) but was not associated with other cardiovascular manifestations of MFS or traditional atherosclerotic risk factors. In conclusion, apart from significant valvular pathology, LV systolic dysfunction was prevalent in MFS from a young age, suggestive of a primary cardiomyopathy. LV dysfunction was typically mild and subclinical and occurred more commonly in patients with more pronounced aortopathies.

Effects of a personalized home-based training program among patients suffering from Marfan syndrome: a pilot randomized and controlled study

Marfan syndrome (MFS) is an autosomal hereditary pathology affecting 1:5000 peoples. Alteration of the fibrillin 1 gene (FBN1) results in haplo-insufficiency of the FBN1 protein mainly altering the vascular system. International recommendations have gradually allowed MFS patients to perform training programs because of its potential benefits. However, to date, there are no data on the effect of a long training period in these patients. The aim of the present study is to investigate the effect of a 3-month personalized home-based training on quality of life (QoL) of patients suffering from MFS. At least 50 MFS patients were included in the study. They were randomly placed into 4 groups: control group; endurance; resistance and endurance + resistance training groups. The training program lasted 3 months and is performed at patients' home. There were 2 training sessions per week telemonitored by a specialist of physical activity and cardiology. Pre and post-training evaluations were performed at the Bichat-Paris Hospital, France. They consisted of assessing psychometrics based on self-administered questionnaires (FiRST, GPAQ, ISP-25, MOS SF-36) and physiological parameters such as the peak oxygen consumption, aorta diameter, cardiac ventricle function and skeletal muscle power at rest and during exercise. Our preliminary results showed an improvement of 50% in QoL, cardiorespiratory fitness and skeletal muscle power in a patient who completed the combined training program. This experimental approach might be a new alternative way for MFS patients' care that may improve their QoL, cardiorespiratory fitness and skeletal muscle power.

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.

Cardiovascular Magnetic Resonance Provides Evidence of Abnormal Myocardial Strain and Primary Cardiomyopathy in Marfan syndrome

OBJECTIVE

Marfan syndrome is an autosomal-dominant genetic disorder caused by mutations in the fibrillin-1 gene. The condition is a connective tissue disease that frequently involves the cardiovascular system. The existence of a primary cardiomyopathy in Marfan syndrome, however, is controversial. The aims of this study were to investigate the prevalence of left ventricular dysfunction with both transthoracic echocardiography and cardiovascular magnetic resonance (CMR) in a cohort of Marfan syndrome patients and to investigate patterns of myocardial strain across the cohort.

METHODS

We used an institutional database to identify all patients with a firm diagnosis of Marfan syndrome based on Ghent criteria. Inclusion required left ventricular ejection fraction (LVEF) to have been measured by both CMR and transthoracic echocardiography within 12 months of each other. Normal LVEF was defined as a value of >55% when measured by CMR. Velocity vector imaging was used to measure left ventricular longitudinal strain patterns by application of feature tracking to cine magnetic resonance images. Results were compared with data from 20 age-matched control subjects.

RESULTS

Sixty-nine Marfan syndrome patients met the inclusion criteria. The mean age was 35.4 ± 15.0 years, and 56.5% were male. The mean LVEF was 59.0% ± 7.0% by CMR and 59.1% ± 5.8% by echo. One-fifth of Marfan syndrome patients (15/69; 21.7%) had reduced function with LVEF ≤55% by CMR, but only 5 of these were identified by echo. Furthermore, echo identified 5 Marfan syndrome patients as having reduced LVEF in the presence of a normal LVEF by CMR. Some Marfan syndrome patients had abnormal longitudinal strain patterns even with LVEF within the reference range.

CONCLUSIONS

These data provide support for a primary cardiomyopathy in some Marfan syndrome patients. Cardiovascular magnetic resonance is more sensitive than echo for identifying cases with mild systolic dysfunction. Strain analysis may be more sensitive than simple LVEF assessment for identifying at-risk individuals.

A Novel Murine Model of Marfan Syndrome Accelerates Aortopathy and Cardiomyopathy

BACKGROUND

Marfan syndrome (MFS) represents a genetic disorder with variable phenotypic expression. The main cardiovascular sequelae of MFS include aortic aneurysm/dissection and cardiomyopathy. Although significant advances in the understanding of transforming growth factor beta signaling have led to promising therapeutic targets for the treatment of aortopathy, clinical studies have tempered this optimism. In particular, these studies suggest additional signaling pathways that play a significant role in disease progression. To date, studies aimed at elucidating molecular mechanisms involved in MFS-induced disease progression have been hampered by the lack of an accelerated disease model.

METHODS

Wild-type B6.129 mice and MFS Fbn1^C1039G/+ mice underwent subcutaneous, cervical osmotic minipump installation with sodium chloride (wild-type mice, n = 39; MFS mice, n = 12) or angiotensin II, 4.5 mg/kg daily (wild-type mice, n = 11; MFS mice; n = 35) for as long as 28 days. Hemodynamic measurements were obtained throughout the experiment. Aortas and hearts were analyzed by transthoracic echocardiography and histopathology study.

RESULTS

This accelerated murine MFS model replicates increased mortality from MFS-related maladies (20.0%, 39.3%, and 52.9% at 10, 14, and 28 days, respectively). Aortic diameters in accelerated MFS mice were significantly enlarged at 10 days after minipump implantation and correlated with a higher degree of elastin fragmentation. Accelerated MFS mice also demonstrated dilated cardiomyopathy at 14 days, even without aortic insufficiency, suggesting an intrinsic etiology.

CONCLUSIONS

A novel in vivo model consisting of subcutaneously delivered angiotensin II in MFS mice reproducibly causes accelerated aortic aneurysm formation and cardiomyopathy. This model allows for better investigation of MFS sequelae by rapid experimental processes.

Ventricular-Vascular Coupling in Marfan and Non-Marfan Aortopathies

Background

Marfan syndrome (MFS) and familial non–syndromal thoracic aortic aneurysm and dissection (ns‐TAAD) are genetic aortopathies causing aortic dilatation with increased aortic stiffness. Left ventricular (LV) contractility and ventricular‐vascular coupling index (VVI) were compared between MFS and ns‐TAAD and determinants of VVI were investigated.

Methods and Results

Patients with MFS (M 57, F 47) and ns‐TAAD (M 72, F 39) were studied by echocardiography and compared with controls (M 77, F 71). Aortic geometry, hemodynamics, LV work, LV contractility (end‐systolic elastance [E_es]), and VVI were documented. Aortic sinuses were equally dilated in MFS (19.7±2.4) and ns‐TAAD (19.8±1.8) compared to controls (16.2±1.4 mm·m⁻², P<0.001). Aortic stiffness index was increased in MFS (9.7±5.1) and ns‐TAAD (10.8±4.7) versus controls (5.4±2.0, P<0.01); LV stroke work was unchanged in MFS (436±74) compared to controls (435±60) but increased in ns‐TAAD (492±109 mJ·m⁻²P<0.01). The LV E_es was reduced in MFS (1.32±0.19) compared to controls (1.65±0.29 mm Hg·mL⁻¹, P<0.01) but increased in ns‐TAAD (1.83±0.30, P<0.01) and VVI was abnormal in MFS (0.71±0.11) compared to controls (0.62±0.07, P<0.01) and ns‐TAAD (0.62±0.09). Treatment with β‐blockers was associated with partial normalization of VVI in MFS. A VVI ≥0.8 was associated with increased risk of death and heart failure in MFS.

Conclusions

Left ventricular contractility and ventricular‐vascular coupling are abnormal in MFS but preserved in ns‐TAAD, and are independent of aortic stiffness, consistent with intrinsic impairment of myocardial contractility in MFS.

Marfan syndrome: current perspectives

Marfan syndrome (MFS) is a pleiotropic connective tissue disease inherited as an autosomal dominant trait, due to mutations in the FBN1 gene encoding fibrillin 1. It is an important protein of the extracellular matrix that contributes to the final structure of a microfibril. Few cases displaying an autosomal recessive transmission are reported in the world. The FBN1 gene, which is made of 66 exons, is located on chromosome 15q21.1. This review, after an introduction on the clinical manifestations that leads to the diagnosis of MFS, focuses on cardiovascular manifestations, pharmacological and surgical therapies of thoracic aortic aneurysm and/or dissection (TAAD), mechanisms underlying the progression of aneurysm or of acute dissection, and biomarkers associated with progression of TAADs. A Dutch group compared treatment with losartan, an angiotensin II receptor-1 blocker, vs no other additional treatment (COMPARE clinical trial). They observed that losartan reduces the aortic dilatation rate in patients with Marfan syndrome. Later on, they also reported that losartan exerts a beneficial effect on patients with Marfan syndrome carrying an FBN1 mutation that causes haploinsufficiency (quantitative mutation), while it has no significant effect on patients displaying dominant negative (qualitative) mutations. Moreover, a French group in a 3-year trial compared the administration of losartan vs placebo in patients with Marfan syndrome under treatment with beta-receptor blockers. They observed that losartan decreases blood pressure but has no effect on aortic diameter progression. Thus, beta-receptor blockers remain the gold standard therapy in patients with Marfan syndrome. Three potential biochemical markers are mentioned in this review: total homocysteine, serum transforming growth factor beta, and lysyl oxidase. Moreover, markers of oxidative stress measured in plasma, previously correlated with clinical features of Marfan syndrome, may be explored as potential biomarkers of clinical severity.