Determinants of inferolateral basal hypertrophy in patients with Marfan syndrome

Introduction Marfan syndrome (MFS) is responsible for cardiovascular disease such as aortic aneurysm and mitral valve prolapse (MVP). A recent study found an enlargement of the inferolateral basal segment (ILBH) in more than 20% of MFS FBN1 patients. Objective The aim of this study is to describe the clinical, electrical and morphological cardiac abnormalities in a cohort of MFS patients carrying FBN1 mutations in connection with the presence of an absolute hypertrophy (AH) (> 11 mm thick) or relative hypertrophy (RH) (Basal/average segment > 1.5). Methods All patients who came for a multidisciplinary consultation at the National Reference Centre for Marfan Syndrome were evaluated prospectively by a clinical examination, a 12-lead electrocardiogram, a standard transthoracic echocardiography and molecular genetic screening. Results In total, 250 consecutive patients were included from April 2015 to October 2016. AH was found in 54 patients (22.31%) and RH in 30 patients (12%). Patients with AH had more MVP [67.4% of HA + SV 32.62% AH− (P = 0.001)] as did patients with RH [60% of RH + vs. 35.78% RH− (P = 0.0111)]. Patients with AH had fewer positive T waves in lower territory and a significant QTc prolongation (P = 0.0221) compared to patients without AH. Patients with RH had more often abnormal mitral ring kinetics evidenced by a delta of the diastole-systole negative mitral ring (P = 0.0286) compared to patients without RH. Conclusion AH and RH are frequent anomalies in MFS. AH being linked to repolarisation disorders as well as a tendency to abnormal kinetics of the mitral ring and RH being linked to abnormal kinetics of the mitral ring. The combination of the two criteria seems to allow the isolation of patients who present with a disease of the entire posterior wall (abnormal kinetics of the mitral ring, bivalvular MVP and ILBH).