Contribution of Angiotensin II to Supine Hypertension in Autonomic Failure
Status:
Terminated
Trial end date:
2017-03-01
Target enrollment:
Participant gender:
Summary
The purpose of this study is to test the hypothesis that angiotensin II plays a role in the
supine hypertension of primary autonomic failure. To determine the contribution of
angiotensin II to renin and blood pressure regulation in autonomic failure, patients with
multiple system atrophy [MSA] or pure autonomic failure [PAF] and supine hypertension will
undergo medication testing with the angiotensin II receptor blocker losartan. The
investigators will compare the biochemical and hemodynamic effects between MSA and PAF
patients. In a subset of patients, the investigators will also give the ACE inhibitor
captopril. Our primary endpoint will be changes in plasma renin activity, and subsequent
components of the circulating renin-angiotensin system, in response to angiotensin II
blockade. Our secondary outcome will be changes in hemodynamic measures during administration
of these drugs.