THE NATURAL-HISTORY OF AORTIC DILATATION IN MARFAN-SYNDROME

Objectives: To determine the relationship between age and aortic dilat ation in patients with Marfan syndrome and to define the rate of progr ession of aortic dilatation in these patients. Design: All patients we re evaluated in a multidisciplinary clinic to establish a firm diagnos is of Marfan syndrome. Aortic dimensions were measured by echocardiogr aphy and patients with Marfan syndrome were followed up with annual ph ysical and echocardiographic examinations to detect any change in aort ic diameter over the subsequent four years. Patients: One hundred and fifty-seven patients were referred to the clinic for assessment, of wh om 40 exhibited diagnostic features of Marfan syndrome. Only 24 of the se patients had previously been diagnosed with Marfan syndrome, while 17 other patients, previously diagnosed with Marfan syndrome, had insu fficient clinical features to justify the diagnosis. Results: Among th e 40 patients (19 male, 21 female) with Marfan syndrome (mean age, 28 +/- 15 years), the prevalence of cardiovascular abnormalities was 90%. Aortic root dilatation was present in 78% of patients, aortic regurgi tation in 28%, mitral valve prolapse in 65% and mitral regurgitation i n 35%. Mean aortic root diameter in the Marfan patients (21.4 +/- 4.0 mm/m2 body surface area) markedly exceeded that of age and sex matched controls without Marfan syndrome (14.9 +/- 2.2 mm/m2) and that of fir st-degree relatives without Marfan syndrome (15.3 +/- 2.9 mm/m2). The occurrence of aortic dilatation in Marfan syndrome was variable, with patients as young as 20 years exhibiting severe dilatation. All patien ts with Marfan syndrome exhibiting aortic dilatation were advised to t ake beta-adrenergic blocking drugs, unless contraindicated, in an effo rt to retard the rate of aortic dilatation. Among 33 patients followed up for at least one year, 14 (42%) exhibited an increase in aortic di ameter of at least 2 mm, while 16 of 23 patients (70%) followed up for at least three years exhibited similar progression of aortic dilatati on. The overall mean rate of dilatation in the Marfan patients was 1.9 mm per year. Nine patients developed aortic dilatation of more than 5 0 mm diameter during four years' follow-up and required surgical repai r of the aorta. Each of these patients is well at between three months ' and four years' follow-up. Conclusions: Aneurysmal dilatation of the aorta is a common complication of Marfan syndrome and may become mani fest at an early age. Furthermore, aortic dilatation can progress rapi dly, even in the absence of symptoms. Individuals with Marfan syndrome should have annual echocardiographic examinations to monitor aortic r oot dimensions, and those exhibiting rapid progression of aortic dilat ation or an aortic root diameter in excess of 60 mm, should be conside red for elective composite graft repair of the aorta.