Marfan and Loeys-Dietz aortic phenotype: a potential tool for diagnosis and management

Objective In heritable aortic diseases, different vascular involvement may occur with potential variable implications in aortic dilation/dissection risk. This study aimed to analyse the aortic anatomy of individuals with Marfan syndrome and Loeys-Dietz Syndrome, to identify possible morphological differences. Methods Computed Tomography and Magnetic Resonance imaging of the thoraco-abdominal aorta from the proximal supraortic vessels to the femoral bifurcation level of 114 Marfan and Loeys-Dietz patients and 20 matched control subjects were examined. Aortic diameters, areas, length, tortuosity were measured in different aortic segments using specific vessel analysis software. Results Marfan patients showed higher prevalence of ascending aorta and aortic root dilation (p=0.005), larger and longer aortic root (p=0.013) with pear-shaped phenotype, larger isthmus/descending aorta diameter ratio (p=0.006), larger suprarenal aorta and iliac arteries. Loeys-Dietz patients showed longer indexed segments, significantly longer arch (p=0.006) with type 2/3 arch prevalence (p=0.097). Measurement ratios analysis provided cut-off values (aortic root-to-ascending aorta length/aortic root diameter, aortic root/sino-tubular junction, aortic root/ascending aorta diameter) differentiating Marfan from Loeys-Dietz patients, even in early stage of the disease. Conclusions Both syndromes show peculiar anatomical patterns at different aortic levels irrespective of aortic dilation and disease severity. These features may represent the expression of different genetic mutations on aortic development, with potential impact on prognosis and possibly contributing to better management of the diseases The systematic adoption of whole body imaging with Magnetic Resonance or Computed Tomography should always be considered, as they allow a complete vascular assessment with practical indicators of differential diagnosis.