Echo-Doppler Assessment of the Biophysical Properties of the Aorta in Patients with Marfan Syndrome-A simple Non-Invasive Method

$12,000 funded by TFF & CMA

Dr. George Sandor

Department of Pediatrics, BC Children’s Hospital, British Columbia, Canada

Echo-Doppler Assessment of Aortic Stiffness and Impedance in Pediatric Patients with Marfan syndrome
Timothy J. Bradley, MBChB, James E. Potts, PhD; Mary T. Potts, RDCS; Astrid DeSouza, BSc; George G.S. Sandor, MB, ChB

Aortic root dilatation has been reported to be positively related to aortic stiffness in adult patients with Marfan syndrome (MFS), but not consistently. We sought to determine the presence and correlates of early changes in aortic stiffness and impedance indices in pediatric patients with MFS.

Methods and Results
Twenty-six young MFS (14 males; age 13.4 ± 4.2 years) and 69 healthy controls (29 males; age 13.4 ± 3.9 years) were included in this cross-sectional study. Pulse wave velocity (PWV), aortic stiffness and vascular impedance indices were derived using an Echo-Doppler method. In pediatric MFS compared with controls, the stiffness indices were all greater; PWV (481 ± 70 versus 357 ± 61 cm/s, p<0.0001), arterial pressure-strain elastic modulus (Ep; 283 ± 99 versus 238 ± 56 mmHg, p<0.006) and arterial wall stiffness index (βindex; 3.55 ± 1.28 versus 2.80 ± 0.68, p<0.0004); input impedance (Zi; 149 ± 42 versus 186 ± 39 dyne•s/cm5, p<0.0002) was less; and characteristic impedance (Zc; 139 ± 37 versus 138 ± 38 dyne•s/cm5, p=NS) was similar. After adjustment for sex, age and height, only PWV and βindex remained significantly increased in MFS. Abnormal aortic stiffness and impedance indices were not consistently associated with aortic root dilatation, as a surrogate measure of aortic root disease in pediatric MFS.

Abnormal aortic stiffness indices are present in pediatric MFS, independent of age, sex and height. This Echo-Doppler method has potential for monitoring the effect of therapy on aortic stiffness in the long-term follow-up of MFS.

Echocardiographic Doppler Assessment of the Biophysical Properties of the Aorta in Pediatric Patients With the Marfan Syndrome

Timothy J. Bradley MBChB, James E. Potts PhD, Mary T. Potts RDCS, Astrid M. DeSouza BSc and George G.S. Sandor MB, ChB

The American Journal of Cardiology, Volume 96, Issue 9 1 November 2005 Pages 1317-1321

In the Marfan syndrome (MS), aortic root involvement is usually clinically monitored according to the aortic sinus of Valsalva dilation. Using an echocardiographic Doppler method in this cross-sectional study, abnormal biophysical properties of the ascending aorta were found in pediatric patients with MS compared with healthy controls but not consistently in association with the aortic sinus of Valsalva dilation.