Evaluation of aortic wall mechanics in Marfan syndrome by transesophageal tissue Doppler echocardiography

Background: It has been described that the presence of aortic dilation is associated with an increased risk of aortic dissection in patients with Marfan disease. The aim of our study was to investigate the value of combined thoracic aorta dilation and decreased aortic elastic properties in assessing the severity of aortic disease in patients with Marfan syndrome. Methods: Sixteen patients (pts) with Marfan syndrome (Beighton criteria) aged 13 to 45 years were studied with multiplane transesophageal echocardiography (TEE). 6/16 pts had surgery for aortic dissection. Tissue Doppler imaging (TDI, Toshiba corp.) during TEE was used for the quantification of aortic elastic properties. Eleven age-matched healthy subjects who had normal findings at TEE served as controls. The descending aorta was visualized in a TEE short axis view at the level of the left atrium. TDI tracing displayed accelerated expansion of the aortic wall followed by a slow deceleration, a plateau and then a rapid deceleration into diastole. Acceleration time (AT, msec), maximum wall expansion velocity (Vmax, cm/sec), and wall contraction velocities (cm/sec) were determined. Results: Descending thoracic aorta dilation (>30mm) was present in 12/16 pts. Vmax values were significantly decreased compared to controls (p<.001). Vmax was 4.1±1.6 in pts without surgery and 2.3±1.2 in pts with surgery (p<.005). Aortic dilation ³ 40 mm was detected in 5/6 pts with surgery and 3/10 pts without surgery. Vmax < 3.0 cm/sec combined with descending thoracic aortic dilation > 40 mm had a sensitivity of 92%, specificity of 80% and positive predictive value of 77% for predicting aortic dissection. Conclusion: Our results show that this combined 2D/TDI method is highly predictive for the development of aortic dissection in Marfan syndrome and should suggest aggressive treatment.