Impaired central pulsatile hemodynamics in children and adolescents with Marfan syndrome

Background--Marfan syndrome is characterized by aortic root dilation, beginning in childhood. Data about aortic pulsatile hemodynamics and stiffness in pediatric age are currently lacking. Methods and Results--In 51 young patients with Marfan syndrome (12.0 ± 3.3 years), carotid tonometry was performed for the measurement of central pulse pressure, pulse pressure amplification, and aortic stiffness (carotid-femoral pulse wave velocity). Patients underwent an echocardiogram at baseline and at 1 year follow-up and a genetic evaluation. Pathogenetic fibrillin-1 mutations were classified between "dominant negative" and "haploinsufficient." The hemodynamic parameters of patients were compared with those of 80 sex, age, blood pressure, and heart-rate matched controls. Central pulse pressure was significantly higher (38.3 ± 12.3 versus 33.6 ± 7.8 mm Hg; P=0.009), and pulse pressure amplification was significantly reduced in Marfan than controls (17.9 ± 15.3% versus 32.3 ± 17.4%; P < 0.0001). Pulse wave velocity was not significantly different between Marfan and controls (4.98 ± 1.00 versus 4.75 ± 0.67 m/s). In the Marfan group, central pulse pressure and pulse pressure amplification were independently associated with aortic diameter at the sinuses of Valsalva (respectively, β=0.371, P=0.010; β=-0.271, P=0.026). No significant difference in hemodynamic parameters was found according to fibrillin-1 genotype. Patients who increased aortic Zscores at 1-year follow-up presented a higher central pulse pressure than the remaining (42.7 ± 14.2 versus 32.3 ± 5.9 mm Hg; P=0.004). Conclusions--Central pulse pressure and pulse pressure amplification were impaired in pediatric Marfan syndrome, and associated with aortic root diameters, whereas aortic pulse wave velocity was similar to that of a general pediatric population. An increased central pulse pressure was present among patients whose aortic dilatation worsened at 1-year follow-up.