The transition of pediatric Marfan patients to adult care: a challenge and its risks

Late diagnosis of Marfan syndrome is associated with unplanned aortic surgery and cardiovascular death

BACKGROUND

Marfan syndrome (MFS) guidelines recommend optimal pharmacologic therapy (OPT) and replacement of the ascending aorta (RAA) at 5.0 cm in diameter to prevent acute type A aortic dissection (ATAAD) and death. The effect of early MFS diagnosis and initiation of therapy on outcomes is not known. Therefore, we sought to evaluate the effect of age at MFS diagnosis and therapy initiation on delayed RAA and death.

METHODS

This retrospective observational cohort study with long-term follow-up included consecutive patients with MFS, pathogenic FBN1 variant, and regular visits to a European Reference Network Center. We considered MFS diagnosis at age ≥21 years late and OPT initiation at age <21 years early. Outcomes were delayed RAA with aneurysm diameter >5.0 cm or ATAAD and death from all causes. We used landmark design starting at age 21 years to determine associations with outcomes.

RESULTS

The study group consisted of 288 patients (45.1% male), including 169 patients with late diagnosis of MFS (58.7%) and 63 with early OPT (21.9%). During mean follow-up of 25 ± 14.7 years, 78 patients had delayed RAA, with 42 operations for ATAAD and 36 for aneurysms ≥5.0 cm. There were 33 deaths, including 11 deaths late after ATAAD. All deaths were cardiovascular. Late diagnosis, but not early OPT, showed univariate association with delayed RAA (P < .001) and death (P = .025). Multivariate Cox regression analysis confirmed late diagnosis as predictor of delayed RAA (hazard ratio, 8.01; 95% confidence interval, 2.52-25.45; P < .001) and death (hazard ratio, 4.68; 95% confidence interval, 1.17-18.80; P = .029).

CONCLUSIONS

Late diagnosis of MFS is associated with delayed surgery and death.

Short-term rapamycin treatment increases life span and attenuates aortic aneurysm in a murine model of Marfan-Syndrome

BACKGROUND

Marfan syndrome (MFS) is a genetic disorder leading to medial aortic degeneration and life-limiting dissections. To date, there is no causal prevention or therapy. Rapamycin is a potent and selective inhibitor of the mechanistic target of rapamycin (mTOR) protein kinase, regulating cell growth and metabolism. The mgR/mgR mice represent an accepted MFS model for studying aortic pathologies to understand the underlying molecular pathomechanisms. This study investigated whether rapamycin inhibits the development of thoracic aortic aneurysms and dissections in mgR/mgR mice.

METHODS

Isolated primary aortic smooth muscle cells (mAoSMCs) from mgR/mgR mice were used for in vitro studies. Two mg kg/BW rapamycin was injected intraperitoneally daily for two weeks, beginning at 7-8 weeks of age. Mice were sacrificed 30 days post-treatment. Histopathological and immunofluorescence analyses were performed using adequate tissue specimens and techniques. Animal survival was evaluated accompanied by periodic echocardiographic examinations of the aorta.

RESULTS

The protein level of the phosphorylated ribosomal protein S6 (p-RPS6), a downstream target of mTOR, was significantly increased in the aortic tissue of mgR/mgR mice. In mAoSMCs isolated from these animals, expression of mTOR, p-RPS6, tumour necrosis factor α, matrix metalloproteinase-2 and -9 was significantly suppressed by rapamycin, demonstrating its anti-inflammatory capacity. Short-term rapamycin treatment of Marfan mice was associated with delayed aneurysm formation, medial aortic elastolysis and improved survival.

CONCLUSIONS

Short-term rapamycin-mediated mTOR inhibition significantly reduces aortic aneurysm formation and thus increases survival in mgR/mgR mice. Our results may offer the first causal treatment option to prevent aortic complications in MFS patients.

Tricuspid valve prolapse as an early predictor for severe phenotype in children with Marfan syndrome

AIM

In Marfan syndrome, various cardiovascular pathologies, such as aortic dilatation and mitral valve pathologies, already occur in childhood and determine course of the disease. This study aimed to establish additional cardiovascular risk markers for severe Marfan phenotypes. We investigated tricuspid valve prolapse (TVP) and its predictive value for outcome of paediatric Marfan disease.

METHODS

In this retrospective, observational cohort study, we identified 130 paediatric Marfan patients (10.7 ± 4.8 years) with FBN1 variants. We divided patients into two groups based on TVP presence and performed a cross-sectional analysis to investigate the association of TVP with other cardiovascular, ocular and systemic pathologies, at first and last visit. A longitudinal analysis was performed with follow-up data.

RESULTS

At baseline, patients with TVP had higher incidence of aortic root dilatation (p = 0.013), mitral valve prolapse (p = 0.0001) and systemic manifestations (p = 0.025) than patients without TVP. At follow-up, previous presence of TVP predicted higher probability of aortic root dilatation (p = 0.002), mitral valve prolapse (p = 0.0001) and systemic manifestations (p = 0.002).

CONCLUSION

This shows that TVP is linked to both cardiac and extracardiac Marfan manifestations and TVP is an important marker for a disease severity in these children. Therefore, TVP should be assessed routinely using echocardiography in paediatric Marfan patients.

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.

The pattern and progression of hearing loss in Marfan Syndrome: A study of children and young adults

OBJECTIVE

(s): To describe the prevalence, type, severity, and progression of hearing loss (HL) in children and young adults with Marfan Syndrome (MFS), and to evaluate the influence of comorbidities on HL.

STUDY DESIGN

Retrospective database analysis.

RESULTS

Of 70 patients with MFS, 52.8% (N = 37) had HL. Within the HL group, 75.7% (N = 28) had bilateral HL, while 24.3% (N = 9) had unilateral HL. 21.4% (N = 15) had moderate or more severe HL. The overall prevalence of CHL was 40.5% (N = 15), SNHL 13.5% (N = 5), and mixed HL 37.8% (N = 14). The mean initial age of HL was 8.4 years (range 0.8-24.0). HL was more prevalent in patients with MFS who also experienced chronic otitis media (ES 1.00, 95% CI, 0.32-1.68) and skull anomalies (ES 0.75, 95% CI, 0.07-1.44) as well as for patients with hypertension (ES 2.17, 95% CI, -1.29-5.64).

CONCLUSIONS

Children and young adults with Marfan syndrome have a high likelihood of hearing loss, with high rates of CHL, chronic otitis media, and Eustachian tube dysfunction. SNHL is also prevalent in this syndrome; hypertension increased the likelihood of SNHL. Early audiologic screening is needed to ascertain type of HL and to efficiently direct patient care in this population.

A scoping review presenting a wide variety of research on paediatric and adolescent patients with Marfan syndrome

Aim

The present study aimed to map and summarise the research on children, aged 0‐18 years, with Marfan syndrome, identify research gaps and point to research agendas.

Methods

A scoping review was systematically performed by searching multiple databases from January 1996 to April 2019. Primary studies presenting results on at least six individuals aged 0‐18 years with Marfan syndrome, diagnosed according to the Ghent nosology, were selected.

Results

From 2341 de‐duplicated records, 92 papers were included, mapped and described. Their topics were diagnostics (12%), cardiovascular matters (50%), skeletal matters (22%), ocular matters (9%), other medical aspects (5%) and psychosocial perspectives (2%). Most studies were from Europe and North America and published between 1999 and 2019 in subject‐specific or paediatric journals, while a few were published in genetics journals. All studies had quantitative designs, and very few were multicentre studies. Each study had six to 608 subjects for a total of approximately 5809.

Conclusion

A wide range of research topics on adolescent and paediatric Marfan syndrome was found, but qualitative studies and a focus on psychosocial matters were lacking. Future investigations addressing noncardiovascular consequences and patient experiences are needed, as well as studies reaffirming or replicating existing intervention study results.