Abstract

Objective: To investigate the heterogeneous response to β blockade in patients with Marfan syndrome by non-invasive assessment of the aortic pressure–area curve.

Design and patients: 25 patients with the Marfan syndrome who used β blocking agents (mean (SD) age, 29 (10) years; 20 men, five women), seven without β blockade (34 (14) years; five men, two women), and 10 controls (29 (5) years; seven men, three women) underwent magnetic resonance imaging and non-invasive continuous blood pressure measurement. Pressure–area curves were constructed at the level of the descending thoracic aorta. A transition point was defined as the pressure at which the pressure–area relation deviated from its elastic (linear) to the collagen (exponential) course.

Setting: Tertiary referral centre for adult congenital heart disease.

Results: In six patients (five with and one without β blockade), a transition point in the pressure–area curve was observed, indicating that the load bearing component was not only elastin but also collagen. In the remaining 26 Marfan patients and in the control subjects a linear pressure–area relation was observed.

Conclusions: This new non-invasive method to derive aortic pressure–area curves showed that most patients with Marfan syndrome have a similar pressure–area curve to controls with similar blood pressures. Five patients on β blockade showed a transition point in the pressure–area curve which could play a crucial role in the heterogeneous response to β blocker treatment in Marfan patients. Patients with a transition at low blood pressures may not benefit from β blocking agents.