Co-produced evidence-based recommendations for cascade screening and secondary prevention in the relatives of people diagnosed with non-syndromic thoracic aortic disease.

Objective: Over 80% of Thoracic Aortic Disease (TAD) is Non-Syndromic (NS-TAD). However, existing evidence-based guidelines on screening, and secondary prevention are extrapolated from studies in Syndromic-TAD. People with NS-TAD experience unwarranted variation in care. We co-produced evidence-based guidelines for NS-TAD with a view to standardising screening and prevention and identifying gaps in knowledge for future research. Methods: Using a co-production approach, research questions were defined and ranking using a modified Delphi Process. Evidence based treatment guidelines were developed based on systematic literature reviews, evidence synthesis, and consensus, and used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Results: Twelve research questions were selected. Searches screened 7,115 references and identified 121 relevant studies. No studies were identified for 5 questions, so only 7 were subjected to the GRADE synthesis. A strong recommendation was made for routine imaging of all first-degree relatives with NS-TAD. Conditional recommendations with low or very low certainty evidence were made for cascade screening in first- and second-degree relatives, the routine use of combined genetic and imaging for screening, whole exome sequencing over gene panels, and the application of Decision Support Tools to enable shared decision making about cascade screening in families. Research recommendations were made for the comparison of MRI vs. transthoracic echocardiography for cascade screening, and the management of NS-TAD in pregnancy. For secondary prevention, conditional recommendations with low or very low certainty evidence were made for ARBs and Beta Blockers in NS-TAD. Conclusions: Care of people with NS-TAD is guided by Low certainty evidence.