Health-Related Quality of Life in Children and Young Adults with Marfan Syndrome.

OBJECTIVE: To assess health-related quality of life (HRQOL) in a large multicenter cohort of children and young adults with Marfan syndrome participating in the Pediatric Heart Network Marfan Trial. STUDY DESIGN: The Pediatric Quality of Life Inventory (PedsQL) 4.0 Generic Core Scales were administered to 321 subjects with Marfan syndrome (5-25 years). PedsQL scores were compared with healthy population norms. The impact of treatment arm (atenolol vs losartan), severity of clinical features, and number of patient-reported symptoms on HRQOL was assessed by general linear models. RESULTS: Mean PedsQL scores in children (5-18 years) with Marfan syndrome were lower than healthy population norms for physical (P ≤ .003) and psychosocial (P < .001) domains; mean psychosocial scores for adults (19-25 years) were greater than healthy norms (P < .001). HRQOL across multiple domains correlated inversely with frequency of patient-reported symptoms (r = 0.30-0.38, P < .0001). Those <18 years of age with neurodevelopmental disorders (mainly learning disability, attention-deficit/hyperactivity disorder) had lower mean PedsQL scores (5.5-7.4 lower, P < .04). A multivariable model found age, sex, patient-reported symptoms, and neurodevelopmental disorder to be independent predictors of HRQOL. There were no differences in HRQOL scores by treatment arm, aortic root z score, number of skeletal features, or presence of ectopia lentis. CONCLUSIONS: Children and adolescents with Marfan syndrome were at high risk for impaired HRQOL. Patient-reported symptoms and neurodevelopmental disorder, but not treatment arm or severity of Marfan syndrome-related physical findings, were associated with lower HRQOL.

Results of a phase I/II multi-center investigation of udenafil in adolescents after fontan palliation.

BACKGROUND: The Fontan operation results in a circulation that is dependent on low pulmonary vascular resistance to maintain an adequate cardiac output. Medical therapies that lower pulmonary vascular resistance may augment cardiac output and improve long-term outcomes. OBJECTIVES: This phase I/II clinical trial conducted by the Pediatric Heart Network was designed to evaluate short-term safety, pharmacokinetics (PK), and preliminary efficacy of udenafil in adolescents following Fontan. METHODS: A 5-day dose-escalation trial was conducted in five study cohorts of six subjects each (37.5, 87.5, and 125 mg daily, 37.5 and 87.5 mg by mouth twice daily). A control cohort with 6 subjects underwent exercise testing only. Adverse events (AEs) were recorded, PK samples were collected on study days six through eight, and clinical testing was performed at baseline and day five. RESULTS: The trial enrolled 36 subjects; mean age 15.8 years (58% male). There were no significant differences in subject characteristics between cohorts. No drug-related serious AEs were reported during the study period; 24 subjects had AEs possibly or probably related to study drug. Headache was the most common AE, occurring in 20 of 30 subjects. The 87.5 mg bid cohort was well tolerated, achieved the highest maximal concentration (506 ng/mL) and the highest average concentration over the dosing interval (279 ng/mL), and was associated with a suggestion of improvement in myocardial performance. Exercise performance did not improve in any of the dosing cohorts. CONCLUSIONS: Udenafil was well-tolerated at all dosing levels. The 87.5 mg bid cohort achieved the highest plasma drug level and was associated with a suggestion of improvement in myocardial performance. These data suggest that the 87.5 mg bid regimen may be the most appropriate for a Phase III clinical trial.

Development and impact of arrhythmias after the Norwood procedure: A report from the Pediatric Heart Network.

OBJECTIVES: The study objective was to determine the predictors of new-onset arrhythmia among infants with single-ventricle anomalies during the post-Norwood hospitalization and the association of those arrhythmias with postoperative outcomes (ventilator time and length of stay) and interstage mortality. METHODS: After excluding patients with preoperative arrhythmias, we used data from the Pediatric Heart Network Single Ventricle Reconstruction Trial to identify risk factors for tachyarrhythmias (atrial fibrillation, atrial flutter, supraventricular tachycardia, junctional ectopic tachycardia, and ventricular tachycardia) and atrioventricular block (second or third degree) among 544 eligible patients. We then determined the association of arrhythmia with outcomes during the post-Norwood hospitalization and interstage period, adjusting for identified risk factors and previously published factors. RESULTS: Tachyarrhythmias were noted in 20% of subjects, and atrioventricular block was noted in 4% of subjects. Potentially significant risk factors for tachyarrhythmia included the presence of modified Blalock-Taussig shunt (P = .08) and age at Norwood (P = .07, with risk decreasing each day at age 8-20 days); the only significant risk factor for atrioventricular block was undergoing a concomitant procedure at the time of the Norwood (P = .001), with the greatest risk being in those undergoing a tricuspid valve procedure. Both tachyarrhythmias and atrioventricular block were associated with longer ventilation time and length of stay (P < .001 for all analyses). Tachyarrhythmias were not associated with interstage mortality; atrioventricular block was associated with mortality among those without a pacemaker in the unadjusted analysis (hazard ratio, 2.3; P = .02), but not after adding covariates. CONCLUSIONS: Tachyarrhythmias are common after the Norwood procedure, but atrioventricular block may portend a greater risk for interstage mortality.

Assessment of Quality of Life in Young Patients with Single Ventricle after the Fontan Operation.

OBJECTIVES: To assess self-reported quality of life (QOL) in a large multicenter cohort of adolescent and young adults surviving Fontan. STUDY DESIGN: Cross-sectional. The Pediatric Quality of Life Inventory (PedsQL) was administered to 408 survivors of Fontan ages 13-25 years enrolled in the Pediatric Heart Network Fontan Follow-up Study. Subjects also completed either the Child Health Questionnaire (age <19 years) or Short Form Health Survey (age ≥ 19 years). PedsQL data were compared with matched controls without a chronic health condition. Correlations between the measures were examined. RESULTS: Mean PedsQL scores for subjects receiving Fontan were significantly lower than those for the control group for physical and psychosocial QOL (P < .001). Overall, 45% of subjects receiving Fontan had scores in the clinically significant impaired range for physical QOL with 30% in the impaired range for psychosocial QOL. For each 1 year increase in age, the physical functioning score decreased by an average of 0.76 points (P = .004) and the emotional functioning score decreased by an average of 0.64 points (P = .03). Among subjects ≥19 years of age, the physical functioning score decreased by an average of 2 points for each year increase in age (P = .02). PedsQL scale scores were significantly correlated with conceptually related Child Health Questionnaire (P < .001) and Short Form Health Survey scores (P < .001). CONCLUSIONS: Survivors of Fontan are at risk for significantly impaired QOL which may decline with advancing age. Routine assessment of QOL is essential to inform interventions to improve health outcomes. The PedsQL allowed QOL assessment from pediatrics to young adulthood. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00132782.

The reproducibility and absolute values of echocardiographic measurements of left ventricular size and function in children are algorithm dependent.

BACKGROUND: Several quantification algorithms for measuring left ventricular (LV) size and function are used in clinical and research settings. The aims of this study were to investigate the effects of measurement algorithm and beat averaging on the reproducibility of measurements of the left ventricle and to assess the magnitude of agreement among the algorithms in children with dilated cardiomyopathy. METHODS: Echocardiograms were obtained in 169 children from eight clinical centers. Inter- and intrareader reproducibility was assessed on measurements of LV volumes using the biplane Simpson, modified Simpson, and 5/6 × area × length (5/6AL) algorithms. Percentage error was calculated as inter- or intrareader difference/mean × 100. Single-beat measurements and the three-beat average (3BA) were compared. Intraclass correlation coefficients were calculated to assess agreement. RESULTS: Single-beat interreader reproducibility was lowest (percentage error was highest) using biplane Simpson; 5/6AL and modified Simpson were similar but significantly better than biplane Simpson (P < .05). Single-beat intrareader reproducibility was highest using 5/6AL (P < .05). The 3BA improved reproducibility for almost all measures (P < .05). Reproducibility in both single-beat and 3BA values fell with greater LV dilation and systolic dysfunction (P < .05). Intraclass correlation coefficients were >0.95 across measures, although absolute volume and mass values were systematically lower for biplane Simpson compared with modified Simpson and 5/6AL. CONCLUSIONS: The reproducibility of LV size and functional measurements in children with dilated cardiomyopathy is highest using the 5/6AL algorithm and can be further improved by using the 3BA. However, values derived from different algorithms are not interchangeable.

Atenolol versus losartan in children and young adults with Marfan's syndrome.

BACKGROUND: Aortic-root dissection is the leading cause of death in Marfan's syndrome. Studies suggest that with regard to slowing aortic-root enlargement, losartan may be more effective than beta-blockers, the current standard therapy in most centers. METHODS: We conducted a randomized trial comparing losartan with atenolol in children and young adults with Marfan's syndrome. The primary outcome was the rate of aortic-root enlargement, expressed as the change in the maximum aortic-root-diameter z score indexed to body-surface area (hereafter, aortic-root z score) over a 3-year period. Secondary outcomes included the rate of change in the absolute diameter of the aortic root; the rate of change in aortic regurgitation; the time to aortic dissection, aortic-root surgery, or death; somatic growth; and the incidence of adverse events. RESULTS: From January 2007 through February 2011, a total of 21 clinical centers enrolled 608 participants, 6 months to 25 years of age (mean [±SD] age, 11.5±6.5 years in the atenolol group and 11.0±6.2 years in the losartan group), who had an aortic-root z score greater than 3.0. The baseline-adjusted rate of change in the mean (±SE) aortic-root z score did not differ significantly between the atenolol group and the losartan group (-0.139±0.013 and -0.107±0.013 standard-deviation units per year, respectively; P=0.08). Both slopes were significantly less than zero, indicating a decrease in the aortic-root diameter relative to body-surface area with either treatment. The 3-year rates of aortic-root surgery, aortic dissection, death, and a composite of these events did not differ significantly between the two treatment groups. CONCLUSIONS: Among children and young adults with Marfan's syndrome who were randomly assigned to losartan or atenolol, we found no significant difference in the rate of aortic-root dilatation between the two treatment groups over a 3-year period. (Funded by the National Heart, Lung, and Blood Institute and others; ClinicalTrials.gov number, NCT00429364.).

Predictors of disease progression in pediatric dilated cardiomyopathy.

BACKGROUND: Despite medical advances, children with dilated cardiomyopathy (DCM) remain at high risk of death or need for cardiac transplantation. We sought to identify predictors of disease progression in pediatric DCM. METHODS AND RESULTS: The Pediatric Heart Network evaluated chronic DCM patients with prospective echocardiographic and clinical data collection during an 18-month follow-up. Inclusion criteria were age <22 years and DCM disease duration >2 months. Patients requiring intravenous inotropic/mechanical support or listed status 1A/1B for transplant were excluded. Disease progression was defined as an increase in transplant listing status, hospitalization for heart failure, intravenous inotropes, mechanical support, or death. Predictors of disease progression were identified using Cox proportional hazards modeling and classification and regression tree analysis. Of the 127 patients, 28 (22%) had disease progression during the 18-month follow-up. Multivariable analysis identified older age at diagnosis (hazard ratio=1.14 per year; P<0.001), larger left ventricular (LV) end-diastolic M-mode dimension z-score (hazard ratio=1.49; P<0.001), and lower septal peak systolic tissue Doppler velocity z-score (hazard ratio=0.81; P=0.01) as independent predictors of disease progression. Classification and regression tree analysis stratified patients at risk of disease progression with 89% sensitivity and 94% specificity based on LV end-diastolic M-mode dimension z-score ≥7.7, LV ejection fraction <39%, LV inflow propagation velocity (color M-mode) z-score <-0.28, and age at diagnosis ≥8.5 months. CONCLUSIONS: In children with chronic stable DCM, a combination of diagnosis after late infancy and echocardiographic parameters of larger LV size and systolic and diastolic function predicted disease progression. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00123071.

Characteristics of children and young adults with Marfan syndrome and aortic root dilation in a randomized trial comparing atenolol and losartan therapy.

BACKGROUND: The Pediatric Heart Network designed a clinical trial to compare aortic root growth and other short-term cardiovascular outcomes in children and young adults with Marfan syndrome randomized to receive atenolol or losartan. We report here the characteristics of the screened population and enrolled subjects. METHODS AND RESULTS: Between 2007 and 2011, 21 clinical sites randomized 608 subjects, aged 6 months to 25 years who met the original Ghent criteria and had a body surface area-adjusted aortic root diameter z-score >3.0. The mean age at study entry was 11.2 years, 60% were male, and 25% were older teenagers and young adults. The median aortic root diameter z-score was 4.0. Aortic root diameter z-score did not vary with age. Mitral valve prolapse and mitral regurgitation were more common in females. Among those with a positive family history, 56% had a family member with aortic surgery, and 32% had a family member with a history of aortic dissection. CONCLUSIONS: Baseline demographic, clinical, and anthropometric characteristics of the randomized cohort are representative of patients in this population with moderate to severe aortic root dilation. The high percentage of young subjects with relatives who have had aortic dissection or surgery illustrates the need for more definitive therapy; we expect that the results of the study and the wealth of systematic data collected will make an important contribution to the management of individuals with Marfan syndrome.

The ventricular volume variability study of the Pediatric Heart Network: study design and impact of beat averaging and variable type on the reproducibility of echocardiographic measurements in children with chronic dilated cardiomyopathy.

BACKGROUND: Clinical trials often rely on echocardiographic measures of left ventricular size and function as surrogate end points. However, the quantitative impact of factors that affect the reproducibility of these measures is unknown. To address this issue, the National Heart, Lung, and Blood Institute-funded Pediatric Heart Network designed a longitudinal observational study of children with known or suspected dilated cardiomyopathy aged 0 to 22 years from eight pediatric clinical centers. METHODS: Clinical data were collected together with 150 echocardiographic indices of left ventricular size and function. Separate observers performed duplicate echocardiographic imaging. Multiple observers performed measurements from three cardiac cycles to enable assessment of intraobserver and interobserver variability. The impacts of beat averaging (BA), observer type (local vs core), and variable type (areas, calculations, dimensions, slopes, time intervals, and velocities) on measurement reproducibility were studied. The outcome measure was percentage error (100 × difference/mean). RESULTS: Of 173 enrolled subjects, 131 met criteria for dilated cardiomyopathy. BA, variable type and observer type all influenced percentage error (P < .0001). Core interobserver percentage error (medians, 11.4%, 10.2%, and 9.3% for BA using one, two, and three beats, respectively) was approximately twice the intraobserver percentage error (medians, 6.3%, 4.9%, and 4.2% for BA using one, two, and three beats, respectively). Slopes and calculated variables exhibited high percentage error despite BA. Chamber dimensions, areas, velocities, and time intervals exhibited low percentage error. CONCLUSIONS: This comprehensive evaluation of quantitative echocardiographic methods will provide a valuable resource for the design of future pediatric studies. BA and a single core lab observer improve the reproducibility of echocardiographic measurements in children with dilated cardiomyopathy. Certain measurements are highly reproducible, while others, despite BA, are poorly reproducible.

Late status of Fontan patients with persistent surgical fenestration.

OBJECTIVES: This study was undertaken to determine the effects of creating a systemic-to-pulmonary venous atrial-level communication (fenestration) at the time of the Fontan procedure on late outcomes. BACKGROUND: Fenestrations are frequently performed during Fontan procedures, but late consequences are not well described. METHODS: Patient characteristics were compared between those with and without surgical fenestration among 536 subjects (mean age 11.9 years) enrolled in the Pediatric Heart Network Fontan Cross-Sectional Study. The status of the fenestration and the association of a currently patent fenestration with health status and measures of ventricular performance were investigated. RESULTS: Fenestration was performed in 361 patients (67%), and frequency differed by year and center (p < 0.001 for each). After adjustment for center, age at Fontan, year of Fontan, and prior superior cavopulmonary surgery, the fenestrated group had shorter length of Fontan hospital stay. At the time of cross-sectional testing 8 ± 3 years after Fontan, the fenestration remained open in 19% of subjects. Among those with confirmed fenestration closure, 59% were by catheter intervention and 1% by surgical intervention, and 40% had apparent spontaneous closure. Compared with those without evidence of a fenestration, subjects with a current fenestration were taking more medications (p = 0.02) and had lower resting oxygen saturation (median 89% vs. 95%, p < 0.001). Functional health status, exercise performance, echocardiographic variables, prevalence of post-Fontan stroke or thrombosis, and growth did not differ by current fenestration status. CONCLUSIONS: Surgical fenestration is associated with well-demonstrated early post-operative benefits. This cross-sectional study found few associations between a persistent fenestration and deleterious later outcomes.

Reporting adverse events in a surgical trial for complex congenital heart disease: the Pediatric Heart Network experience.

OBJECTIVE: The purpose of this analysis was to evaluate a novel strategy for reporting adverse events in the Pediatric Heart Network's randomized surgical trial of systemic-pulmonary artery shunt versus right ventricle-pulmonary artery conduit in infants with hypoplastic left heart syndrome. The strategy was developed to align the reporting process with the needs of a surgical trial while maintaining participant safety. METHODS: Adverse event reporting was analyzed for 2 groups of study subjects: those randomized to a trial arm during a period in which a standard adverse event reporting system was used (period 1) and those randomized after institution of a system that focused serious adverse event reporting on 6 sentinel events (period 2). The analysis encompassed the period from randomization (Norwood surgery) to hospital discharge from stage II surgery. Adverse event rates were compared using a Poisson regression model for the number of events per subject. RESULTS: From period 1 to period 2, the rate of serious adverse events requiring expedited reporting decreased as expected (0.42 vs 0.14/subject/month of follow-up; P < .001). Subjects with a serious (sentinel) adverse event in period 2 had a significantly higher rate of death and cardiac transplantation. CONCLUSIONS: The new adverse event reporting system successfully targeted subjects at highest risk, while decreasing the administrative burden associated with adverse event reports. This methodology may be of benefit in trials evaluating surgical or device-based interventions and in critically ill populations where many common clinical events would qualify as serious adverse events in the context of a drug trial.

Lessons learned from a pediatric clinical trial: the Pediatric Heart Network angiotensin-converting enzyme inhibition in mitral regurgitation study.

BACKGROUND: Mitral regurgitation is the most common indication for reoperation in children following repair of atrioventricular septal defect (AVSD). We hypothesized that angiotensin-converting enzyme inhibitor therapy would decrease the severity of mitral regurgitation and limit left ventricular volume overload in children following AVSD repair. METHODS: The Pediatric Heart Network designed a placebo-controlled randomized trial of enalapril in this population. The primary aim was to test the effect of enalapril on the change in left ventricular end-diastolic dimension body surface area-adjusted z score. Before the launch of the trial, a feasibility study was performed to estimate the number of patients with at least moderate mitral regurgitation following AVSD repair. TRIAL EXPERIENCE: Seventeen months after the start of the study, 349 patients were screened, 8 were trial eligible, and only 5 were enrolled. The study was subsequently terminated because of low patient accrual. Several factors led to the problems with patient accrual, including (1) the use of criteria to assess disease severity in the feasibility study that were not identical to those used in the trial, (2) failure to achieve equipoise for the study among clinicians and referring physicians, (3) reliance on methodology developed in adult populations with different disease mechanisms, and (4) absence of adequate data to define the natural history of the disease process under study. Progress in the treatment of children with cardiovascular disease will depend on the future of multicenter collaborative clinical trials. The lessons learned from this study may contribute to improvements in this research.

Parent- versus child-reported functional health status after the Fontan procedure.

OBJECTIVE: We sought to compare perceptions of functional health status between children who had undergone a Fontan procedure and their parents. METHODS: Fontan procedure survivors 10 to 18 years of age were included in the study if the child completed the Child Health Questionnaire (CHQ) and the parent completed the parent form to assess the child's functional health status. Comparisons were made between raw domain scores for the parent- and child-completed CHQs. RESULTS: Between March 2003 and April 2004, 1078 Fontan survivors were screened. Of the 546 eligible and consented patients, 354 were 10-18 years of age and 328 parent/child pairs completed the CHQs. Parents reported significantly lower scores (worse functioning) for their children than the children reported for themselves in the domains of physical functioning (P < .01), impact on school or activities from emotional and behavioral problems (P < .01), impact on school or activities from physical health issues (P < .01), general behavior (P < .01), mental health (P < .01), self-esteem (P < .01), and general health perceptions (P < .01). No significant differences were noted for the domains of bodily pain, family cohesiveness, or family activities. For the physical functioning domain, factors contributing to lower scores for parent versus child reports included pulmonary artery anomalies and fenestration at the time of the Fontan operation. Lower parent-reported scores also were associated with more noncardiac health problems in the child. CONCLUSIONS: Parents' perceptions of the functional health status of their children after the Fontan procedure were worse than the children's perceptions.

Functional health status of adolescents after the Fontan procedure -- comparison with their siblings.

BACKGROUND: Studies have suggested that patients who have undergone the Fontan procedure experience lower functional health status and diminished exercise capacity compared with other children. OBJECTIVES: To compare the functional health status of Fontan patients with and without siblings, assess whether there are any differences between Fontan patients and their siblings, and determine associated factors. METHODS: A cross-sectional, single-centre, observational study was performed on Fontan patients 10 to 20 years of age, and their sibling closest in age, followed in a tertiary pediatric hospital. Functional health status was measured by the Child Health Questionnaire Child Form and the Pediatric Quality of Life Inventory. RESULTS: A total of 68 patients and 38 siblings were enrolled. Patients with siblings scored significantly lower on numerous domains of physical functional status than those without siblings. Compared with their matched siblings, Fontan patients reported significantly lower scores in all domains of the Pediatric Quality of Life Inventory and on physical (but not psychosocial) domains of the Child Health Questionnaire Child Form. Factors associated with increased patient-sibling differences included younger patient age, female sex, intracardiac lateral tunnel Fontan connection and lower ejection fraction at the time of study enrollment. CONCLUSIONS: Adolescents with Fontan physiology reported a lower functional health status in physical domains than their siblings, but had similar status in psychosocial domains. Having a sibling was associated with lower reported functional health status, suggesting an important effect of self-perceived physical limitations over true limitations.

Associated symptoms in the ten days before diagnosis of Kawasaki disease.

OBJECTIVE: To describe common associated symptoms within the 10 days before diagnosis in subjects enrolled in the Pediatric Heart Network's trial of steroid therapy in Kawasaki disease (KD). STUDY DESIGN: Patients with acute KD were enrolled between days 4 and 10 of illness at 8 centers between 2002 and 2004. We defined common associated symptoms as those occurring in >or=10% of patients. Principal clinical criteria for KD were not included in this analysis. RESULTS: Among 198 patients, irritability was reported in 98 (50%), vomiting in 88 (44%), decreased food/fluid intake in 73 (37%), cough in 55 (28%), diarrhea in 52 (26%), rhinorrhea in 37 (19%), weakness in 37 (19%), abdominal pain in 35 (18%), and joint pain (arthralgia or arthritis) in 29 (15%). One or more gastrointestinal symptom (vomiting, diarrhea, or abdominal pain) was present in 120 patients (61%) and 69 patients (35%) had >or= 1 respiratory symptom (rhinorrhea or cough). CONCLUSIONS: Nonspecific symptoms occur commonly in children with KD. To reduce delays in diagnosis, clinicians should be educated that such symptoms may comprise a significant component in the chief complaint.

Rationale and design of a randomized clinical trial of beta-blocker therapy (atenolol) versus angiotensin II receptor blocker therapy (losartan) in individuals with Marfan syndrome.

BACKGROUND: Cardiovascular disease, including aortic root dilation, dissection, and rupture, is the leading cause of mortality in patients with Marfan syndrome (MFS). The maximal aortic root diameter at the sinuses of Valsalva is considered the best predictor of adverse cardiovascular outcome. Although advances in therapy have improved life expectancy, affected individuals continue to suffer cardiovascular morbidity and mortality. Recent studies in an FBN1-targeted mouse model of MFS with aortic disease similar to that seen in humans showed that treatment with losartan normalized aortic root growth and aortic wall architecture. METHODS: The Pediatric Heart Network designed a randomized clinical trial to compare aortic root growth and other short-term cardiovascular outcomes in subjects with MFS receiving atenolol or losartan. Individuals 6 months to 25 years of age with a body surface area-adjusted aortic root z score >3.0 will be eligible for inclusion. The primary aim is to compare the effect of atenolol therapy with that of losartan therapy on the rate of aortic root growth over 3 years. Secondary end points include progression of aortic regurgitation; incidence of aortic dissection, aortic root surgery, and death; progression of mitral regurgitation; left ventricular size and function; echocardiographically derived measures of central aortic stiffness; skeletal and somatic growth; and incidence of adverse drug reactions. CONCLUSION: This randomized trial should make a substantial contribution to the management of individuals with MFS and expand our understanding of the mechanisms responsible for the aortic manifestations of this disorder.