Bicuspid aortic valve syndrome and fibrillinopathies: potential impact on clinical approach

Bicuspid aortic valve (BAV) is a common heterogeneous disorder whose natural history is determined by hemodynamic valvular impairment and/or increased prevalence of aortic abnormalities ranging from dilatation to aneurysm and dissection. BAV-related aortopathy is frequently associated with relevant aortic pathologic changes leading to structural alterations, characteristic degenerative lesions and histological changes of the aorta very similar to those identified and described in patients with Marfan syndrome (MFS), an inherited connective tissue disorder associated with mutations in fibrillin 1 (FBN1) gene in more than 90% of patients. Recently, a 4-fold increase in the prevalence of BAV in MFS patients has been reported. Subsequently, pathogenetic FBN1 mutations in patients with BAV and aortic dilatation/aneurysm in whom MFS and other more severe type 1 fibrillinopathies were clinically excluded have been identified. In this review we discuss how this evidence, together with that of the wide heterogeneity in pathogenetic mechanisms of BAV-related aortopathy, may impact the clinical management of BAV.