Estimated pre-dissection aortic diameters and aortic phenotype in the IRAD registry

Background/Introduction Aortic diameters measured at the time of acute aortic dissection (AAD) overestimate true pre-dissection diameters due to acute aortic expansion. Rylski et al. (J Am Coll Cardiol. 2014) quantified diameter increase during dissection, allowing estimation of pre-dissection aortic size. Purpose To report estimated pre-dissection aortic diameters according to aortic phenotype and underlying condition in patients from the IRAD registry: heritable thoracic aortic disease (HTAD), bicuspid aortic valve (BAV), and patients without HTAD or BAV. Methods Patients with AAD enrolled in the IRAD registry were included. Pre-dissection diameters were estimated by applying correction factors proposed by Rylski et al. Patients were categorized into three groups: HTAD, BAV, and others (no HTAD/BAV). Aortic phenotype was defined according to the location of maximal pre-dissection aortic diameter (root, ascending aorta, descending aorta, or sinotubular junction). Results Repartition of the population according to the maximum pre-dissection aortic diameter location:: 71 patients presented a BAV, 81 had an HTAD, and 1970 had none. Root phenotype was present in 41.0% of the patients with BAV, 57.9% of the patients with HTAD, and 42.4% of the patients without BAV or HTAD. The larger diameter was measured at STJ in 8.1% of the patients with BAV, 6.4% of the patients with HTAD, and 5.9% of the patients without BAV or HTAD Ascending phenotype was present in 49.1% of the patients with BAV, 31.4% of the patients with HTAD, and 44.6% of the patients without BAV or HTAD The larger diameter was measured at the descending aorta in 41.0% of the patients with BAV, 57.9% of the patients with HTAD, and 42.4% of the patients without BAV or HTADComparison of root phenotype with ascending phenotype population:: Figure 1Estimated diameter prior to dissection as a function of maximal predissection diameter localisation: Figure 2 Conclusion(s) The root phenotype is predominant before aortic dissection in HTAD and represents approximately 40% of BAV and non-HTAD/non-BAV patients. Estimated pre-dissection diameters are larger in BAV and HTAD patients compared with patients without these conditions whichever phenotype (root or ascending), with HTAD patients demonstrating the greatest estimated pre-dissection aortic dimensions.