Cardiovascular surgery in Loeys-Dietz syndrome types 1-4

Validating a Curvature-Based Marker of Cervical Carotid Tortuosity for Risk Assessment in Heritable Aortopathies

BACKGROUND

Cervical arterial tortuosity is associated with adverse outcomes in Loeys-Dietz syndrome and other heritable aortopathies.

METHODS AND RESULTS

A method to assess tortuosity based on curvature of the vessel centerline in 3-dimensional space was developed. We measured cervical carotid tortuosity in 65 patients with Loeys-Dietz syndrome from baseline computed tomography angiogram/magnetic resonance angiogram and all serial images during follow-up. Relations between baseline carotid tortuosity, age, aortic root diameter, and its change over time were compared. Patients with unoperated aortic roots were assessed for clinical end point (type A aortic dissection or aortic root surgery during 4 years of follow-up). Logistic regression was performed to assess the likelihood of clinical end point according to baseline carotid tortuosity. Total absolute curvature at baseline was 11.13±5.76 and was relatively unchanged at 8 to 10 years (fold change: 0.026±0.298, P=1.00), whereas tortuosity index at baseline was 0.262±0.131, with greater variability at 8 to 10 years (fold change: 0.302±0.656, P=0.818). Baseline total absolute curvature correlated with aortic root diameter (r=0.456, P=0.004) and was independently associated with aortic events during the 4-year follow-up (adjusted odds ratio [OR], 2.64 [95% CI, 1.02-6.85]). Baseline tortuosity index correlated with age (r=0.532, P<0.001) and was not associated with events (adjusted OR, 1.88 [95% CI, 0.79-4.51]). Finally, baseline total absolute curvature had good discrimination of 4-year outcomes (area under the curve=0.724, P=0.014), which may be prognostic or predictive.

CONCLUSIONS

Here we introduce cervical carotid tortuosity as a promising quantitative biomarker with validated, standardized characteristics. Specifically, we recommend the adoption of a curvature-based measure, total absolute curvature, for early detection or monitoring of disease progression in Loeys-Dietz syndrome.

Clinical features and complications of Loeys-Dietz syndrome: A systematic review

INTRODUCTION

Loeys-Dietz syndrome (LDS) is a connective tissue disorder that arises from mutations altering the transforming growth factor β signalling pathway. Due to the recent discovery of the underlying genetic mutations leading to LDS, the spectrum of characteristics and complications is not fully understood.

METHODS

Our search included five databases (Pubmed, SCOPUS, Web of Science, EMBASE and google scholar) and included variations of "Loeys-Dietz Syndrome" as search terms, using all available data until February 2021. All study types were included. Three reviewers screened 1394 abstracts, of which 418 underwent full-text review and 392 were included in the final analysis.

RESULTS

We identified 3896 reported cases of LDS with the most commonly reported features and complications being: aortic aneurysms and dissections, arterial tortuosity, high arched palate, abnormal uvula and hypertelorism. LDS Types 1 and 2 share many clinical features, LDS Type 2 appears to have a more aggressive aortic disease. LDS Type 3 demonstrated an increased prevalence of mitral valve prolapse and arthritis. LDS Type 4 and 5 demonstrated a lower prevalence of musculoskeletal and cardiovascular involvement. Amongst 222 women who underwent 522 pregnancies, 4% experienced an aortic dissection and the peripartum mortality rate was 1%.

CONCLUSION

We observed that LDS is a multisystem connective tissue disorder that is associated with a high burden of complications, requiring a multidisciplinary approach. Ongoing attempts to better characterise these features will allow clinicians to appropriately screen and manage these complications.

Connective tissue disease type mediates branch patency of grafts in open thoracoabdominal aortic reconstruction

OBJECTIVE

Despite a shared degenerative vascular phenotype, Marfan syndrome (MFS), Loeys-Dietz syndrome (LDS), and other genetically distinct connective tissue diseases (CTDs) have unique extravascular pathologies that impact the outcomes of aortic replacement. The aim of our study was to investigate the association of CTD genotype with postoperative outcomes and branch patency following open thoracoabdominal aortic replacement in a large institutional cohort.

METHODS

All patients undergoing open branched thoracoabdominal aortic replacement at a single academic center from 2006 to 2020 were included and classified as CTD or non-CTD based on the presence of genotypic documentation. Outcomes were compared using analysis of variance and χ² testing for continuous and discrete variables, respectively. Kaplan-Meier curves were utilized to examine patency of graft branches over time.

RESULTS

Overall, 172 patients were included, with a mean follow-up of 30.5 ± 34.9 months. CTD was present in 45 patients (26%); specifically, 32 had MFS, five had LDS, and eight had another CTD. Patients with CTDs had more extent II thoracoabdominal aneurysms (40% vs 15%), more reconstructed branches (3.5 vs 1.8), more frequently reconstructed visceral branches (86.7% vs 22.7%), and higher intraoperative blood loss (13.3 vs 6.8 L; all P < .05) compared with non-CTD patients. Patients with MFS were more frequently systemically anticoagulated preoperatively (50% vs 5%) and demonstrated higher rates of postoperative deep vein thrombosis/pulmonary embolism compared with non-CTD patients (9% vs 2%; both P < .05). Five-year renal branch patency was decreased among all patients compared with visceral branches (87.3% vs 95.6%; P = .05), but there were no individual branch patency differences between patients with and without CTDs (P = .086). Overall branch patency at 1 and 5 years was significantly higher in patients with MFS than in non-CTD patients (98.9% vs 89.1% at 5 years); there were no significant patency differences between non-CTD patients and any other CTD subgroup, mostly due to early patency loss.

CONCLUSIONS

Open thoracoabdominal reconstruction in patients with CTD is technically challenging and associated with increased transfusion and postoperative thromboembolic events when compared with non-CTD patients. Technical outcomes of the procedure are excellent and are differentially associated with genotype, with patients with MFS experiencing significantly improved branch patency over both non-CTD patients and patients with other CTDs, a finding which has multifactorial drivers.

Loeys-Dietz syndrome and isolated severe ostial left main coronary stenosis presenting as ventricular fibrillation arrest and biventricular takotsubo syndrome in a 25-year-old patient

We present the case of a previously healthy 25-year-old woman who presented with an out-of-hospital ventricular fibrillation arrest. Postresuscitation ECG did not show any evidence of ST segment elevation. Echocardiogram showed regional wall abnormalities in keeping with takotsubo syndrome (TTS). Urgent coronary angiogram to rule out malignant congenital coronary artery anomaly revealed an isolated severe ostial left main coronary artery (LMCA) stenosis, a rare disease, approximately 0.2% in previous case series. The LMCA was aneurysmal. Genetic studies revealed a novel frameshift pathogenic variant in the transforming growth factor B two ligand gene (TGFB2) gene, suggestive of Loeys-Dietz syndrome (LDS) type 4, an aggressive vascular disease. Ostial LMCA stenosis has not been previously reported in LDS, and we outline the management of this unique disease combination. We also reflect on its presentation as TTS and infer that TTS and acute coronary syndromes are not mutually exclusive.

Cardiomyopathy in Genetic Aortic Diseases

Genetic aortic diseases are a group of illnesses characterized by aortic aneurysms or dissection in the presence of an underlying genetic defect. They are part of the broader spectrum of heritable thoracic aortic disease, which also includes those cases of aortic aneurysm or dissection with a positive family history but in whom no genetic cause is identified. Aortic disease in these conditions is a major cause of mortality, justifying clinical and scientific emphasis on the aorta. Aortic valve disease and atrioventricular valve abnormalities are known as important additional manifestations that require careful follow-up and management. The archetype of genetic aortic disease is Marfan syndrome, caused by pathogenic variants in the Fibrillin-1 gene. Given the presence of fibrillin-1 microfibers in the myocardium, myocardial dysfunction and associated arrhythmia are conceivable and have been shown to contribute to morbidity and mortality in patients with Marfan syndrome. In this review, we will discuss data on myocardial disease from human studies as well as insights obtained from the study of mouse models of Marfan syndrome. We will elaborate on the various phenotypic presentations in childhood and in adults and on the topic of arrhythmia. We will also briefly discuss the limited data available on other genetic forms of aortic disease.

Loeys-Dietz syndrome associated with a heterozygous mutation in TGFBR2 in a female infant: A case report

Loeys-Dietz syndrome (LDS) is an unusual hereditary connective tissue disease with no clear standard clinical diagnosis. The present report describes a case of an infant diagnosed with LDS at the age of 2 months and 23 days. To the best of our knowledge, this case represents the youngest reported case of LDS in China. Whole exome sequencing revealed a heterozygous variation, c.1441(exon 6)G>A [p.E481k(p.Glu481Lys) (NM_001024847)], located at chr3:30715708 in the transforming growth factor β receptor 2 gene. The patient underwent systematic rehabilitation and standard high-risk infant follow-up. Currently, the overall development of the patient continues to improve. The patient can walk with assistance, stand up on her feet unaided, exhibits improved optical line of sight and both eyes can move up and down, side to side (left and right) and track moving objects. The parents have been advised that a further echocardiogram should be performed as soon as possible and regular follow-up sessions with a cardiovascular specialist are ongoing. LDS diagnosis was confirmed in the patient based on collective findings of skeletal system changes, ocular hypertelorism, ocular exotropia, micrognathia and high-vaulted palate, in combination with a specific pathogenic gene mutation.

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.

Disorders of the Aorta and Aortic Valve in Connective Tissue Diseases

PURPOSE OF REVIEW

The incidence of aortic valve disease in inherited connective tissue disorders is well documented; however, recent studies have only begun to unravel the pathology behind this association. In this review, we aim to describe the etiology, clinical manifestations, management, and prognosis of aortic and aortic valvular disorders that co-exist in a variety of connective tissue diseases. An extensive literature review was performed in PubMed. Articles from 2008 to 2018 were included for review. Predetermined search terms used in PubMed include "aortic manifestation of connective tissue diseases" and "aortic valve disorders in rheumatologic disease."

RECENT FINDINGS

Manifestations of aortic valve disease in the context of connective tissue disorders include valvular stenosis, regurgitation, and/or thoracic aortic aneurysms. Both inherited and inflammatory connective tissue disorders contribute to aortic valve damage with increased susceptibility associated with specific gene variants. Anti-inflammatory and immunosuppressive therapies have demonstrated beneficial results in Marfan's syndrome, Behcet disease, rheumatoid arthritis, ankylosing spondylitis, and systemic sclerosis, often leading to remission. Yet, such therapy is less effective in other disorders compared to alternative treatments such as surgical intervention. Additionally, regular echocardiographic studies should be recommended to those suffering from these disorders, especially those at higher risk for cardiovascular involvement. Given the rates of relapse with immunosuppressants, even following aortic valve replacement, further studies are needed to determine if certain dosing and/or combinations of immunosuppressants could be given to those diagnosed with connective tissue diseases to prevent progression of aortic valve involvement.

Case-matched Comparison of Cardiovascular Outcome in Loeys-Dietz Syndrome versus Marfan Syndrome

Background: Pathogenic variants in TGFBR1, TGFBR2 and SMAD3 genes cause Loeys-Dietz syndrome, and pathogenic variants in FBN1 cause Marfan syndrome. Despite their similar phenotypes, both syndromes may have different cardiovascular outcomes. Methods: Three expert centers performed a case-matched comparison of cardiovascular outcomes. The Loeys-Dietz group comprised 43 men and 40 women with a mean age of 34 ± 18 years. Twenty-six individuals had pathogenic variants in TGFBR1, 40 in TGFBR2, and 17 in SMAD3. For case-matched comparison we used 83 age and sex-frequency matched individuals with Marfan syndrome. Results: In Loeys-Dietz compared to Marfan syndrome, a patent ductus arteriosus (p = 0.014) was more prevalent, the craniofacial score was higher (p < 0.001), the systemic score lower (p < 0.001), and mitral valve prolapse less frequent (p = 0.003). Mean survival for Loeys-Dietz and Marfan syndrome was similar (75 ± 3 versus 73 ± 2 years; p = 0.811). Cardiovascular outcome was comparable between Loeys-Dietz and Marfan syndrome, including mean freedom from proximal aortic surgery (53 ± 4 versus 48 ± 3 years; p = 0.589), distal aortic repair (72 ± 3 versus 67 ± 2 years; p = 0.777), mitral valve surgery (75 ± 4 versus 65 ± 3 years; p = 0.108), and reintervention (20 ± 3 versus 14 ± 2 years; p = 0.112). In Loeys-Dietz syndrome, lower age at initial presentation predicted proximal aortic surgery (HR = 0.748; p < 0.001), where receiver operating characteristic analysis identified ≤33.5 years with increased risk. In addition, increased aortic sinus diameters (HR = 6.502; p = 0.001), and higher systemic score points at least marginally (HR = 1.175; p = 0.065) related to proximal aortic surgery in Loeys-Dietz syndrome. Conclusions: Cardiovascular outcome of Loeys-Dietz syndrome was comparable to Marfan syndrome, but the severity of systemic manifestations was a predictor of proximal aortic surgery.