(375) The Genetic Contribution to Peripartum Thoracic Aortic Dissection in a Retrospective Cohort

67 peripartum aortic dissection cases with a median age of 33 years (IQR 29-35.5) at time of diagnosis were included in this study. Forty-three presented with type A dissections (64%; median 33 years [IQR 29-36.5]), 20 with type B dissections (30%; median 32.5 years [IQR 29.8-34.3]), and the classification could not be determined in 4 cases. Nineteen individuals died as a result of dissection complications (28%; median 32 years). The majority of dissections occurred during pregnancy (n=40) in the third trimester (n=38) and only 2 in the second trimester. Of the 27 confirmed postpartum cases, all presented within 6 weeks of delivery, except one type A dissection at 10 months. 43% of the total 67 peripartum cases (n=29) had had family history of thoracic aortic disease, and 7 reported a family history of premature sudden death. 55% of the all peripartum cases were found to have a pathogenic or likely pathogenic variant in an HTAD gene (n=34) or had a family member with confirmed variant (n=3), and 19% had a rare variant of uncertain significance (n=10) or family history of VUS (n=3) in an HTAD gene.

Conclusion:

Our data indicates the majority of individuals with peripartum aortic dissections have a family history of thoracic aortic disease or molecular genetic diagnosis. Early identification of this high-risk population allows for increased surveillance to prevent dissection-related deaths, particularly in the third trimester and postpartum period.