Growth Rate Assessed by Vascular Deformation Mapping Predicts Type B Aortic Dissection in Marfan Syndrome

Patients with Marfan syndrome (MFS) are at a high risk of type B aortic dissection (TBAD). Aortic growth and elongation have been suggested as risk factors for TBAD. Vascular deformation mapping is an image analysis technique for mapping 3-dimensional aortic growth on routine computed tomography angiography (CTA) scans. We aimed to use vascular deformation mapping to examine the value of aortic growth rate in the descending thoracic aorta, among other imaging biomarkers, to identify the factors associated with risk of TBAD in MFS.

Computed tomography angiography scans spanning 2004 to 2023 from adult patients with MFS with native descending thoracic aorta were analyzed by vascular deformation mapping. Other measurements included multilevel thoracoabdominal aortic diameters and the length of the descending thoracic aorta by centerline analysis.

Among the 105 patients with MFS analyzed, 63.8% were men, with median age of 40 (range, 18-73) years and a median surveillance interval of 5.3 (range, 2.0-18.3) years. During surveillance, 12 (11.4%) patients developed TBAD. Patients with TBAD had a higher radial growth rate (0.63 versus 0.23 mm/year; P<0.001) and elongation rate (2.4 versus 0.5 mm/year; P<0.001), on univariate and multivariable analysis, but predissection descending aortic diameter was not significantly different. Predictors of growth rate included younger age, higher baseline maximal diameter of the descending thoracic aorta, smoking history, and warfarin use.

Radial growth and elongation rates of the descending thoracic aorta were independent predictors of TBAD occurrence in MFS. TBAD often occurred at nonaneurysmal diameters (<4.0 cm). These findings emphasize the role of growth over absolute diameter in risk stratification for TBAD in MFS.