Trial Information

An Investigation of Endothelium-Derived Vasodilation in Patients With Fabry's Disease

Fabry disease is a systematic genetic disease in which patients have abnormal blood vessels,
and leads to numerous complications including cerebrovascular strokes. The objective of
this study is to test the hypothesis that patients with Fabry disease have abnormal
endothelial-derived vasodilation. If found to be abnormal, endothelial-derived vasodilation
will serve as a useful clinical outcome measure in the evaluation of the efficacy of
specific treatment of Fabry disease, and possibly of other causes of cerebrovascular stroke.
The endothelium modulates vascular tone by the release of contracting and relaxing
substances that act on the underlying smooth muscle. It has been previously demonstrated
that patients with essential hypertension have a blunted vascular response to acetylcholine
(an endothelium-dependent vasodilator). In the present study, we shall analyze the regional
vascular responses to acetylcholine and sodium nitroprusside alone, and in the presence of
L-NMMA (an inhibitor of the synthesis of EDRF by endothelial cells) in 12 patients with
Fabry disease and 12 normal age matched control subjects. We will infuse drugs into the
brachial artery and will measure the responses of the forearm vasculature by means of strain
gauge plethysmography. Forearm blood flow and vascular resistance at baseline and after
infusion of vasoactive drugs, in Fabry patients, will be compared to the responses obtained
in the healthy control population. This study will be performed with collaboration of Dr.
Julio A. Panza, Senior Clinical Investigator from the Cardiology Branch, NHLBI.