Increased aortic root stiffness associated with osteogenesis imperfecta

M-mode echocardiograms obtained from 31 patients with types I and IV osteogenesis imperfecta (OI) were evaluated for increased aortic root dilatation and wall stiffness. Four patients were observed to have dilated aortic roots. The pressure-strain elastic moduli (Ep) of the majority of OI patients studied were significantly different from those of age-matched controls; the observed values of Ep were both greater and less than that of controls. At high strain in the circumferential direction, nine of 31 OI patients had aortic roots that were significantly stiffer than those of controls. Increased stiffness in the circumferential direction was associated with decreased aortic pumping efficiency. The increased stiffness observed in the circumferential direction is consistent with increased accumulation and crosslinking of collagen within the aortic wall and may reflect premature aging of OI patients.