Intrinsic biventricular dysfunction in Marfan syndrome

Background Marfan syndrome (MFS) is an autosomal, dominantly inherited, connective tissue disorder usually caused by a mutation in the fibrillin-1 gene (FBN1). As fibrillin-1 is a component of the extracellular matrix of the myocardium, mutations in FBN1 may cause impairment of ventricular function. Furthermore, aortic elasticity is decreased in patients with MFS, which might also impair ventricular function. We assessed biventricular function and the influence of aortic elasticity in patients with MFS by means of cardiac MRI. Methods and results Cardiac magnetic resonance was performed in 144 patients with MFS without significant valvular dysfunction, previous cardiac surgery or previous aortic surgery. Biventricular diastolic and systolic volumes were measured, and ejection fractions were calculated. Flow wave velocity, a measurable derivative of aortic elasticity, was measured between the ascending aorta and the bifurcation. When compared to healthy controls (n = 19), left ventricular ejection fraction (LVEF) was impaired in patients with MFS (53% +/- 7% vs 57% +/- 4%, p<0.005), as was right ventricular ejection fraction (RVEF) (51% +/- 7% vs 56% +/- 4%, p<0.005). LVEF and RVEF were strongly correlated. (r = 0.7, p<0.001). No significant differences were found between patients with beta-blocker treatment and those without. There was no correlation between aortic elasticity as measured by flow wave velocity and LVEF. Conclusions Biventricular ejection fraction was impaired in patients with MFS, and the impairment was independent of aortic elasticity and b-blocker usage. There was also a strong correlation between LVEF and RVEF. Our findings suggest intrinsic myocardial dysfunction in patients with MFS.