Aortic Dissection in Patients With Genetically Mediated Aneurysms: Incidence and Predictors in the GenTAC Registry

Abstract Background Aortic dissection (AoD) is a serious complication of thoracic aortic aneurysm (TAA). Relative risk for AoD in relation to TAA etiology, incidence, and pattern after prophylactic TAA surgery are poorly understood. Objectives This study sought to determine the incidence, pattern, and relative risk for AoD among patients with genetically associated TAA. Methods The population included adult GenTAC participants without AoD at baseline. Standardized core laboratory tests classified TAA etiology and measured aortic size. Follow-up was performed for AoD. Results Bicuspid aortic valve (BAV) (39%) and Marfan syndrome (MFS) (22%) were the leading diagnoses in the studied GenTAC participants (n = 1,991). AoD occurred in 1.6% over 3.6 ± 2.0 years; 61% of AoD occurred in patients with MFS. Cumulative AoD incidence was 6-fold higher among patients with MFS (4.5%) versus others (0.7%; p  Conclusions Among patients with genetically associated TAA, MFS augments risk for AoD even after TAA grafting. Although increased aortic size is a risk factor for subsequent AoD, events typically occur below established thresholds for prophylactic TAA repair.