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HypertensionNCT02417415

Local Heat Stress in Autonomic Failure Patients With Supine Hypertension

A study testing Passive heat stress in people with Hypertension and Pure Autonomic Failure, run by Vanderbilt University at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Patients with autonomic failure are characterized by disabling orthostatic hypotension (low blood pressure on standing), and at least half of them also have high blood pressure while lying down (supine hypertension). Exposure to heat, such as in hot environments, often worsens their orthostatic hypotension. Read more about this study

Who is it for?
Ages 18 to 80 years
What is being tested?
Passive heat stress
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
22 participants
Where
1 siteUnited States
Study dates
Apr 2015to Feb 2021
Phase
Interventional
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 80 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Male and female patients, between 18-80 yrs., with primary autonomic failure (Parkinson Disease, Multiple System Atrophy, and Pure Autonomic Failure) and supine hypertension. Supine hypertension will be defined as SBP≥150 mmHg.
  • Patients able and willing to provide informed consent.

Who cannot join

  • Pregnancy
  • Significant cardiac, renal or hepatic illness, or with contraindications to administration of pressor agents or with 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.

Trial locations and contacts

1 site in 1 country.

United States1 site
  • Vanderbilt University

    Nashville, Tennessee, 37232

Other trials in United States

About this study

Patients with autonomic failure are characterized by disabling orthostatic hypotension (low blood pressure on standing), and at least half of them also have high blood pressure while lying down (supine hypertension). Exposure to heat, such as in hot environments, often worsens their orthostatic hypotension. The causes of this are not fully understood. The purpose of this study is to evaluate whether applying local heat over the abdomen of patients with autonomic failure and supine hypertension would decrease their high blood pressure while lying down. This will help us better understand the mechanisms underlying this phenomenon, and may be of use in the treatment of supine hypertension.

Read the detailed description

Primary autonomic failure is a neurodegenerative condition characterized by severe impairment of the autonomic nervous system. The clinical hallmark of autonomic failure is disabling orthostatic hypotension, but at least half of patients are also hypertensive while lying down. This supine hypertension can be severe and associated with end-organ damage and worsening of orthostatic hypotension due to increased pressure natriuresis. It also complicates the management of these patients by limiting the use of daytime pressor agents for the treatment of orthostatic hypotension.

It is well known that heat exposure (e.g. hot weather or a hot bath or shower) produces an acute and temporary worsening of orthostatic hypotension in autonomic failure patients. However, the mechanisms underlying this phenomenon are completely unexplored. Factors that may predispose autonomic failure patients to the acute lowering blood pressure effects of heat stress include 1) impaired heat dissipation due to inability to sweat, 2) preserved heat-mediated skin vasodilation, and 3) blunted sympathetic hemodynamic responses to maintain blood pressure. In this study, we test the hypothesis that moderate levels of local (abdominal) passive heat stress will lower blood pressure in autonomic failure patients with supine hypertension.

To test this hypothesis, we propose this pilot study with the following specific aims:

  1. To evaluate the acute blood pressure effects of local passive heat stress in autonomic failure patients with supine hypertension, we will compare changes in BP between controlled local heat stress (~44ºC) using a commercial heating pad that covers the abdomen and part of the torso, and a control (non-heating) study day using the same heating pad but turned off.
  2. To evaluate the mechanisms underlying BP changes during local heat stress, we will compare changes in hemodynamic parameters (cardiac output, stroke volume and peripheral vascular resistance), segmental fluid shifts (measured by segmental bioimpedance), skin blood flow and skin temperature between the heat and non-heating study days.
Being tested
Passive heat stress, Control (non-heating)
Keywords
Supine hypertension, Autonomic failure, Heat intolerance, Orthostatic hypotension, Heat stress
Medical subject headings
Hypertension, Pure Autonomic Failure, Multiple System Atrophy, Hypotension, Orthostatic, Heat Stress Disorders

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Passive heat stressOther

    Also called Heating pad

    Passive heat stress will be applied with a commercial heating pad that covers all the abdomen and part of the torso to provide local heating at ~44ºC continuously for 2 hr.

  • Control (non-heating)Other

    Also called sham

    Heating pad will be applied over the abdomen and part of the torso but it will be turned off.

Study groups in NCT02417415
Study groupRoleWhat they receive
Local Heat StressExperimentalPassive heat-stress using a commercial heating pad applied over the abdomen and part of the torso
Receives: Other: Passive heat stress
Control (Non-heating)Sham comparatorCommercial heating pad applied over the abdomen and part of the torso but turned off
Receives: Other: Control (non-heating)

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in Systolic Blood Pressure

    Change from baseline in systolic blood pressure at 2 hr post-intervention

    Measured: 2 hours of heat stress or sham

Secondary outcomes (1)
  1. Percent Change in Hemodynamic Parameters (Cardiac Output, Stroke Volume and Systemic Vascular Resistance)

    Percent change from baseline ([post-intervention - baseline]/baseline X 100) in cardiac output, stroke volume and systemic vascular resistance at 2 hours post-intervention

    Measured: 2 hours of heat stress or sham

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted15 Apr 2015 (estimated)
  2. Study startApr 2015
  3. Primary completionFeb 2021
  4. Study completionFeb 2021

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Other
Allocation
Randomised
Intervention model
Crossover
Model description
randomized, 2-arm crossover study (heat vs. sham)
Masking
Single blind
Who is masked
Participant
Enrolment
22 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT02417415
Sponsor's protocol ID
141523
Status last verified
Dec 2021
First submitted
10 Apr 2015
Last updated
10 Mar 2022
Data monitoring committee
No

Publications

  • Okamoto LE, Celedonio JE, Smith EC, Gamboa A, Shibao CA, Diedrich A, Paranjape SY, Black BK, Muldowney JAS 3rd, Peltier AC, Habermann R, Crandall CG, Biaggioni I. Local Passive Heat for the Treatment of Hypertension in Autonomic Failure. J Am Heart Assoc. 2021 Apr 6;10(7):e018979. doi: 10.1161/JAHA.120.018979. Epub 2021 Mar 19.

    PubMed 33739123

Questions about this trial

What is this clinical trial studying?

A study testing Passive heat stress in people with Hypertension and Pure Autonomic Failure, run by Vanderbilt University at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 2 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 10 Mar 2022. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Yes. Results are posted in the registry (first posted 10 Mar 2022). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in Systolic Blood Pressure (time frame: 2 hours of heat stress or sham). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT02417415, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Mar 2022.

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