Clinical trial NCT02429557: Hemodynamic Mechanisms of Abdominal Compression in the Treatment of Orthostatic Hypotension in Autonomic Failure
Official title: Hemodynamic Mechanisms of Abdominal Compression in the Treatment of Orthostatic Hypotension in Autonomic Failure
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: PHASE1
Conditions: Orthostatic Hypotension
Pure Autonomic Failure
Multiple System Atrophy
Autonomic Failure
Keywords: autonomic failure
orthostatic hypotension
compression garments
treatment
Lead sponsor: Vanderbilt University Medical Center
Sponsor class: OTHER
Collaborators: name: National Heart, Lung, and Blood Institute (NHLBI)
First posted: 2015-04-29
Enrollment: 29
Sex: ALL
Minimum age (years): 18
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: OTHER

Brief summary: Compression garments have been shown to be effective in the treatment of orthostatic hypotension in autonomic failure patients. The purpose of this study is to determine the hemodynamic mechanisms by which abdominal compression (up to 40 mm Hg) improve the standing blood pressure and orthostatic tolerance in these patients, and to compare them with those of the standard of care midodrine. The investigators will test the hypothesis that abdominal compression will blunt the exaggerated fall in stroke volume and the increase in abdominal vascular volume during head up tilt.

Detailed description: Patients with autonomic failure are characterized by disabling orthostatic hypotension (low blood pressure on standing) due to severe impairment of the autonomic nervous system. Compression garments such as waist-high stockings and abdominal binders have been shown to improve orthostatic hypotension in these patients. The purpose of this study is to determine the hemodynamic mechanisms by which abdominal compression (up to 40 mm Hg) improve the standing blood pressure and orthostatic tolerance in these patients, and to compare them with those of the standard of care midodrine. The investigators will test the hypothesis that abdominal compression will blunt the exaggerated fall in stroke volume and the increase in abdominal vascular volume during head up tilt. This study will help us better understand the contribution of the abdominal veins to orthostatic hypotension and the mechanisms underlying this non-pharmacological therapeutic approach.

Participants will be studied in a tilt table in two separate days in a randomized, crossover fashion with sham abdominal compression (\~5 mmHg) and active compression (\~40 mmHg).

Eligibility criteria: Inclusion Criteria:

* Male and female patients,
* between 18-80 yrs.,
* with neurogenic orthostatic hypotension associated with primary autonomic failure (Parkinson Disease, Multiple System Atrophy and Pure Autonomic Failure). Orthostatic hypotension will be defined as ≥20 mmHg decrease in systolic BP or ≥10 mmHg of diastolic BP within 3 minutes on standing associated with impaired autonomic reflexes determined by autonomic testing in the absence of other identifiable causes (Freeman et al., 2011).
* Patients able and willing to provide informed consent.

Exclusion Criteria:

* Pregnancy.
* Significant cardiac, renal or hepatic illness, or with contraindications to administration of pressor agents or external abdominal compression will be excluded.
* Clinically unstable coronary artery disease, or major cardiovascular or neurological event in the past 6 months, and; other factors which in the investigator's opinion would prevent the subject from completing the protocol including clinically significant abnormalities in clinical, mental or laboratory testing

Primary outcomes:
measure: Stroke volume
timeFrame: an average of 15 minutes of head up tilt
Secondary outcomes:
measure: Systolic blood pressure
timeFrame: an average of 15 minutes of head up tilt
measure: Splanchnic vascular volume
timeFrame: an average of 15 minutes of head up tilt
Other outcomes:
Locations:
city: Nashville
country: United States
facility: Vanderbilt University
state: Tennessee
Study officials:
affiliation: Vanderbilt University
name: Italo Biaggioni, MD
role: PRINCIPAL_INVESTIGATOR
affiliation: Vanderbilt University Medical Center
name: Luis E Okamoto, MD
role: PRINCIPAL_INVESTIGATOR
References: