Peripheral resistance vessel dysfunction in Marfan syndrome

Background Patients with Marian syndrome show a hereditary abnormality of elastin metabolism that may cause aortic enlargement and dissection. We have hypothesized that abnormal elastin may alter peripheral vascular structure and function. Methods Forearm blood flow (FBF) (in milliliters per minute per 100 mL) response ta the endothelium-dependent dilator acetylcholine (0.75 to 4.5 mu g/min per 100 mt), the endothelium-independent dilator sodium nitroprusside (0.05 to 0.3 mu g/min per 100 mt), and structure-related maximum dilator response (10-minute occlusion-induced reactive hyperemia) were measured by plethysmograph in 10 patients with Marfan syndrome (mean age 44 years) and 10 healthy age- and sex-matched controls. Patients with the complications of hypercholesterolemia, diabetes mellitus, or heart Failure were excluded from the study. Results Basal FBF (mean +/- SE) did not differ between the 2 groups (2.7 +/- 0.3 vs 2.3 +/- 0.4). Maximum FBF response to acetylcholine in patients with Marfan syndrome was significantly lower than that of healthy controls (8.5 +/- 2.1 vs 15.4 +/- 1.7 mL/min per 100 mi; P < .05). Reactive hyperemia was also lower in patients with Marfan syndrome (at peak 23.0 +/- 2.5 vs 29.5 +/- 2.3 mL/min per 100 mt; P < .05), but sodium nitroprusside-induced FBF changes did not differ between the 2 groups (10.3 +/- 1.1 vs 10.2 +/- 1.5 mL/min per 100 mt; P = not significant). Conclusion These observations suggest that endothelium-dependent dilation and maximum dilator reserve capacity are both abnormal in peripheral resistance vessels of patients with Marfan syndrome. These peripheral vasomotion abnormalities may have a detrimental impact on the cardiovascular system in this disorder.