Background: There is a paucity of evidence on people with thoracic aortic aneurysm and dissection. We aimed to determine the prevalence of genetic variants and associations with phenotypes. Methods: In the current cross-sectional single centre cohort study of consecutive patients who underwent endovascular or open-surgical repair of thoracic aortic aneurysm and dissection, we applied genetic analysis using four-stage Next Generation Sequencing and confirmed findings with Sanger sequencing. We collected personal and family history on comorbidities, clinical examination, anthropometrics, skeletal deformities, joint function ophthalmological measures. Cardiovascular risk- and phenotype scores were calculated. Results: 95 patients were eligible (mean age 54±9 years, 70% males, 56% aortic dissection). One-fifth had a family history of aortic disease, 95% and 54% had a phenotype score of ≤5 and ≤2, respectively. There weren’t significant differences in the distribution of phenotype characteristics according to age, sex, aortic pathology, or performed invasive procedure. Genetic variants were detected in 40% of patients; classic variants comprised 18% of all variants. We observed no significant association with cardiovascular and phenotype score but with higher joint function scores (p=.015). Conclusion: Genetic variants are highly present in clinically-relevant aortic pathologies. Variants appear to play a larger role than previously described. The different variants don’t correlate with specific phenotypes, nor with age, pathology, sex, or family history.

Pathogenesis of aortic aneurysm and dissection continues to be under discussion. Extracellular matrix (ECM) remodeling processes in the aortic wall are hypothesized to be involved in the development of the disorders. Therefore, in a histological study, we investigated the expression of metalloproteases 1 and 9 (MMP1 and MMP9) and their inhibitors (TIMP 1 and TIMP 2) in cardiac surgery patients. In parallel, we studied the aortic roots by echocardiography. Clinical reports of 111 patients (30 women and 81 men) who suffered from aortic aneurysms and an aortic dissection were evaluated and studied by transesophageal echocardiography. Seven patients, who had coronary heart disease served as „healthy controls“ All patients were surgically operated in the period from 2007 to 2015. A tissue sample of the aortic biopsies was collected from each patient during surgery. Immunohistochemical staining was performed for MMP1, MMP9 and TIMP1, TIMP2 as well. Vascularization was monitored by an CD 31 antibody. In direct comparison, the expressions are not homogeneous. We found smallest changes in the intima area at all. An increase in MMP 1 and MMP 9 expression was detected in both media and adventitia in case of dissections. TIMP 1 and TIMP 2 distribution increases from the lumen of the vessel outward in the wall layers of the aorta. In case of arteriosclerotic changes, intima had a capillarization, but not in the media. Opposite pattern was found in the dissected aortas. Whereas the intima appears empty, vascularization was found in the media and adventitia layers, as well. There are differences in the vascularization between between the aneurysm and dissection and the different layers as well, respectively. A different remodeling process of the ECM in comparison of the vascular layers must be hypothesized. Reading the patterns of staining and with regard to the known inhibitory effect of MMP9 on ECM remodeling, but especially TIMP 2 on neoangiogenesis, a disturbed nutrition and a dysfunctional vasa vasorum remodeling must be assumed as cause of dissection.