The effect of beta-blockers therapy on progression of thoracic aortic dilatation in the young Marfan syndrome patients: Difference between subtypes of FBN1 gene mutation

Abstract

Mutation in the FBN1 gene was common in the Marfan syndrome (MFS), and caused aortic dilatation that could be delayed by beta-blocker therapy. This study evaluated the effect of beta-blockers therapy on aortic dilatation in the MFS patients with subtypes of FBN1 gene mutation. A single center observational prospective study included 53 MFS patients less than 20-years-old with predicting-happlo insufficiency (PTC) or dominant-negative (DN) mutation of FBN1 gene. Among 41 patients used beta-blockers therapy, aortic diameter and aortic dilatation rate were evaluated by echocardiography. At the baseline, dimension of aortic sinus of Valsalva of PTC-MFS patients and DN-MFS patients were in the upper bound of normal range (Z-score: 1.76 ± 1.25 vs. 1.69 ± 0.87, P = 0.621, respectively). While, dimension of ascending aorta was in the normal range. After a mean follow-up 1.5 ± 0.71 years with beta-blockers therapy, the dilatation rate at aortic sinus of Valsalva decreased [PTC-MFS: −0.28 ± 0.85 mm/m 2 .year (95% CI: −0.82; 0.26) vs. DN-MFS: −0.32 ± 1.34 mm/m 2 .year (95% CI: −0.91; 1.34), P = 0.069]. The dilatation rate at ascending aorta decreased in PTC-MFS patients [−0.18 ± 1.19 mm/m 2 .year (95% CI: −0.96; 0.61)] and increased in DN-MFS patients [0.4 ± 1.82 mm/m 2 .year (95% CI: −0.43; 1.23)], P = 0.554. Among the FBN1-MFS patients, beta-blockers therapy was effective to reduce the aortic dilatation rate, of which difference between PTC-MFS patients and DN-MFS patients was not significant.