No abstract

Background Thoracic aortic aneurysm / dissection (TAAD) is a common phenotype that may occur as an isolated manifestation or within the constellation of a defined syndrome. In contrast to syndromic TAAD, the elucidation of the genetic basis of isolated TAAD has only recently started. To date, defects have been found in genes encoding extracellular matrix proteins (fibrillin-1, FBN1; collagen type III alpha 1, COL3A1), proteins involved in transforming growth factor beta (TGFβ) signaling (TGFβ receptor 1 and 2, TGFBR1/2; and SMAD3) or proteins that build up the contractile apparatus of aortic smooth muscle cells (myosin heavy chain 11, MYH11; smooth muscle actin alpha 2, ACTA2; and MYLK). Methods and results In 110 non-syndromic TAAD patients that previously tested negative for FBN1 or TGFBR1/2 mutations, we identified 7 ACTA2 mutations in a cohort of 43 familial TAAD patients, including 2 premature truncating mutations. Sequencing of MYH11 revealed an in frame splice-site alteration in one out of two probands with TAA(D) associated with PDA but none in the series of 22 probands from the cohort of 110 patients with non-syndromic TAAD. Interestingly, immunohistochemical staining of aortic biopsies of a patient and a family member with MYH11 and patients with ACTA2 missense mutations showed upregulation of the TGFβ signaling pathway. Conclusions MYH11 mutations are rare and typically identified in patients with TAAD associated with PDA. ACTA2 mutations were identified in 16% of a cohort presenting familial TAAD. Different molecular defects in TAAD may account for a different pathogenic mechanism of enhanced TGFβ signaling.

Objective-Pseudoxanthoma elasticum (PXE) is an autosomal recessive connective tissue disorder with involvement of the skin, the retina, and the cardiovascular system. Cardiovascular involvement is mainly characterized by mineralization and fragmentation of elastic fibers of blood vessels and premature atherosclerosis. We conducted an ultrasound study to investigate the cardiovascular phenotype and to propose recommendations for the management of patients with PXE and heterozygous ABCC6 mutation carriers. Approach and Results-Thirty-two patients, 23 carriers, and 28 healthy volunteers underwent cardiac and vascular ultrasound studies. Cardiac imaging revealed left ventricular diastolic dysfunction in patients with PXE with a significantly prolonged deceleration time and lower septal early diastolic velocities of the mitral annulus compared with controls. Carriers also demonstrated significantly prolonged deceleration time. Carotid-to-femoral pulse wave velocity was significantly increased in patients with PXE when compared with carriers and controls. Vascular imaging revealed a high prevalence of peripheral artery disease in both patients and carriers and a significantly higher carotid intima-media thickness compared with controls. Conclusions-The results of this study clearly demonstrate impaired left ventricular diastolic function, impairment of the elastic properties of the aorta, and a high prevalence of peripheral artery disease in patients with PXE. Carriers also seem to exhibit a cardiovascular phenotype with mainly mild diastolic dysfunction and accelerated atherosclerosis. Increased awareness for cardiovascular events in both patients and heterozygous carriers is warranted. The ABCC6 gene (chrom. 16p13.1) codes for an ATPdependent transmembrane transporter, which is most abundant in the liver and kidney. Remarkably, the expression of the ABCC6 transporter in tissues clinically affected by PXE is very low. 19 This observation led to the hypothesis that PXE is primarily a metabolic disorder in which circulating serum factor(s) plays a role. 17 Another, and probably complimentary, pathogenetic mechanism is the so-called cellular hypothesis in which fibroblast perturbation may evoke local mineralization and elastic fiber alterations. This hypothesis is based on the observation that elastic fiber alterations are not present homogeneously throughout the skin and blood vessels of patients with PXE, but only in peculiar regions. Moreover, PXE skin fibroblasts exhibit a distinct behavior with altered biosynthetic expression profile and cell-cell and cell-matrix interactions compared with fibroblasts from normal subjects. [20][21][22] This study focuses on the cardiovascular phenotype of patients with PXE and carriers. Cardiovascular changes in patients with PXE are characterized by (1) mineralization and fragmentation of elastic fibers of the internal elastic lamina, medial and adventitial layers of medium-sized arteries and aorta, as well as of the endocardium, pericardium, connective tissue around vessels in t...

AimsPatients with adult congenital heart disease (ACHD) are a potentially vulnerable patient cohort in case of COVID-19. Some cardiac defects may be associated with a poor COVID-19 outcome. Risk estimation in ACHD is currently based on expert opinion. The aim of this study was to collect clinical outcome data and to identify risk factors for a complicated course of COVID-19 in patients with ACHD.MethodsTwenty-five ACHD centres in nine European countries participated in the study. Consecutive patients with ACHD diagnosed with COVID-19 presenting to one of the participating centres between 27 March and 6 June 2020 were included. A complicated disease course was defined as hospitalisation for COVID-19 requiring non-invasive or invasive ventilation and/or inotropic support, or a fatal outcome.ResultsOf 105 patients with a mean age of 38±13 years (58% women), 13 had a complicated disease course, of whom 5 died. In univariable analysis, age (OR 1.3, 95% CI 1.1 to 1.7, per 5 years), ≥2 comorbidities (OR 7.1, 95% CI 2.1 to 24.5), body mass index of >25 kg/m2 (OR 7.2, 95% CI 1.9 to 28.3) and cyanotic heart disease (OR 13.2, 95% CI 2.5 to 68.4) were associated with a complicated disease course. In a multivariable logistic regression model, cyanotic heart disease was the most important predictor (OR 60.0, 95% CI 7.6 to 474.0).ConclusionsAmong patients with ACHD, general risk factors (age, obesity and multiple comorbidities) are associated with an increased risk of complicated COVID-19 course. Congenital cardiac defects at particularly high risk were cyanotic lesions, including unrepaired cyanotic defects or Eisenmenger syndrome.

No abstract