RELATION BETWEEN AGE, ARTERIAL DISTENSIBILITY, AND AORTIC DILATATION IN THE MARFAN-SYNDROME

This study examined the relations between age, arterial distensibility, and systemic hemodynamics in patients with the Marfan syndrome. The study group included 170 patients referred to a specialist clinic, of whom 55 (age 26 +/- 12 years) were diagnosed as having Marfan syndrome. The remaining 115 patients (age 25 +/- 14 years) formed a control group. Each patient underwent echocardiographic examination, with measurement of ascending aorta diameter at end-diastole and end-systole, and aortic now velocities. The elastic properties of the aorta were indexed by calculation of aortic distensibility, wall stiffness, and systemic pulse wave velocity. Mean end-diastolic aortic diameter in the Marfan group (38 +/- 9 mm) was greater than that in the controls (26 +/- 4 mm, p <0.01). Resting heart rate and aortic now velocities were similar in the 2 groups, but systemic arterial pulse pressure was greater in the Marfan group (50 +/- 12 mm Hg) than in the controls (41 +/- 8 mm Hand p <0.01). Aortic diameter increased with age in both age groups, but at all ages the Marfan group exhibited greater aortic diameters (p <0.05). Aortic distensibility was less in the Marfan group (2.6 +/- 1.3 cm(2) . dynes(-1) . 10(-6)) than in the controls (6.2 +/- 2.1 cm(2) . dynes(-1) . 10(-6), p <0.01), and the aortic wall stiffness index was greater in the Marfan group (7.9 +/- 3.4) than in the controls (2.8 +/- 0.6, p <0.01). Aortic wall stiffness increased with age and aortic diameter, but at all ages the Marfan group exhibited a stiffer aorta for a given diameter than did the controls. Systemic pulse wave velocity was greater in the Marfan group (621 +/- 139 cm . s(-1)) than in the controls (394 +/- 62 cm . s(-1), p <0.01). In patients with the Marfan syndrome, the aorta exhibits markedly abnormal elastic properties from an early age, including increased stiffness and increased systemic pulse wave velocities.