Autonomic Determinants of POTS - Pilot1
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ClinicalTrials.gov Identifier: NCT04050410 |
Recruitment Status :
Recruiting
First Posted : August 8, 2019
Last Update Posted : January 13, 2021
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Condition or disease | Intervention/treatment | Phase |
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Postural Tachycardia Syndrome | Drug: Moxonidine Drug: Placebo | Early Phase 1 |
Postural tachycardia syndrome (POTS) is a relatively common condition affecting mostly otherwise healthy young women. It is the cause of significant disability and an impairment in quality of life of a magnitude comparable to patients with chronic obstructive pulmonary disease or congestive heart failure. It is characterized by sympathetic activation with an exaggerated orthostatic tachycardia that responds to low doses of beta-blockers. The underlying pathophysiology of this disorder and the nature of this sympathetic activation is not clear and is likely heterogeneous. In many patients this sympathetic activation could be an appropriate compensatory response to hypovolemia, deconditioning or partial neuropathy.
The investigators have identified a subset of patients in whom sympathetic activation appears to be a primary phenomenon. These patients are characterized by high central sympathetic outflow, as determined by muscle sympathetic nerve activity (MSNA) above the upper 95% confidence interval for the group. This "hyperadrenergic" phenotype is associated with a paradoxical increase in blood pressure on standing and exaggerated pressor response to the vasoconstrictive phase of the Valsalva maneuver, and clinical observations suggest they improve clinically when treated with central sympatholytics.
The investigators propose to test the hypothesis that there is a subset of POTS patients with a central sympathetic activation as the primary pathophysiology. In an acute double blind, placebo-controlled, randomized study, the investigators propose that administration of the central sympatholytic moxonidine will improve orthostatic symptoms and abnormalities in orthostatic hemodynamics, as well as sympathetic outflow.
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 48 participants |
Allocation: | Randomized |
Intervention Model: | Crossover Assignment |
Intervention Model Description: | Randomized, double-blind, placebo-controlled crossover |
Masking: | Double (Participant, Investigator) |
Masking Description: | Subject and investigator will be blinded. The randomization will be generated by the pharmacy. A staff member of the Autonomic Dysfunction Center who is not involved in the study will keep secretly the randomization blinding table for emergencies. Blinding will be broken for intermediate data analysis and in case of emergencies if necessary. The blinding will be broken at the end of statistical analysis for interpretation of results. |
Primary Purpose: | Other |
Official Title: | Autonomic Determinants of Postural Tachycardia Syndrome (Acute Pilot Study 1) |
Actual Study Start Date : | August 27, 2019 |
Estimated Primary Completion Date : | July 31, 2024 |
Estimated Study Completion Date : | December 31, 2025 |
Arm | Intervention/treatment |
---|---|
Experimental: Moxonidine
Patients will receive a single oral dose of moxonidine 0.4 mg.
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Drug: Moxonidine
active drug given as 1 dose
Other Name: Physiotens |
Placebo Comparator: Placebo
Patients will receive a single oral dose of placebo.
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Drug: Placebo
placebo pill given as 1 dose
Other Name: inactive pill |
- Change in Orthostatic Symptom Burden [delta (delta VOSS)] [ Time Frame: after 30 min supine to after 15 min upright (delta VOSS), 2-3 hours after placebo or moxonidine intake [delta (delta VOSS)]. ]VOSS is a validated questionnaire that consists of 9 items: mental clouding, blurred vision, shortness of breath, rapid heartbeat, tremulousness, chest discomfort, headache, lightheadedness, and nausea. Each item is scored on a 0 to 10 scale (with 0 reflecting absence of symptoms), and the change of the total scores (range: 0-90) from supine to upright postures (delta VOSS) will be used as a measure of orthostatic symptom burden. The primary outcome measure will be the difference in orthostatic symptom burden [delta (delta VOSS)] following placebo vs. moxonidine administration.
- Change in Orthostatic Change in Heart Rate [delta (delta HR)] [ Time Frame: after 30 min supine to after 15 min upright (delta HR), 2-3 hours after placebo or moxonidine intake [delta (delta HR)]. ]Difference in heart rate change from supine to upright postures (delta HR) following placebo vs. moxonidine administration.

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Ages Eligible for Study: | 18 Years to 55 Years (Adult) |
Sexes Eligible for Study: | Female |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
- female/male subjects, age 18-55 years,
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criteria for postural tachycardia syndrome (POTS):
- a heart rate increase of ≥30 beats/min within 10 minutes of upright posture;
- lack of orthostatic hypotension (blood pressure fall ≥ 20/10 mmHg within 10 minutes of standing); and
- chronic symptoms during upright posture over at least 6 months, in the absence of any other acute cause.
- in the follicular phase of the menstrual cycle (day 5-13 of a 28-day cycle)
- POTS with primary central sympathetic activation (psPOTS) as defined as having resting muscle sympathetic nerve activity (MSNA) greater than or equal to 25 bursts/min
- able and willing to provide informed consent.
Exclusion Criteria:
- pregnancy,
- smoker,
- BMI>30 kg/m2,
- deconditioned status (if available VO2max<80% of predicted)
- unable to withdraw from medications known to affect autonomic function, blood pressure or blood volume
- systemic illnesses known to produce autonomic neuropathy, including but not limited to diabetes mellitus, amyloidosis, monoclonal gammopathies, and autoimmune neuropathies.
- Arteriosclerotic disease of carotid artery. History of neck surgery.
- conditions associated with inflammatory processes, such as coronary artery disease, hypertension, smoking, hypercholesterolemia (or on statin therapy), rheumatoid arthritis, diabetes
- treatment with oral corticosteroids, current infections (e.g., urinary tract infection), or use of non-steroidal anti-inflammatory drugs
- 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.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04050410
Contact: Emily C Smith, RN | 615 875-1516 | autonomics@vumc.org |
United States, Tennessee | |
Vanderbilt University Medical Center | Recruiting |
Nashville, Tennessee, United States, 37232 | |
Contact: Emily C Smith, RN 615-875-1516 autonomics@vumc.org | |
Principal Investigator: Andre Diedrich, MD |
Principal Investigator: | André Diedrich, MD | Vanderbilt University Medical Center |
Responsible Party: | Andre' Diedrich, Research Professor of Medicine, Vanderbilt University Medical Center |
ClinicalTrials.gov Identifier: | NCT04050410 |
Other Study ID Numbers: |
VANDERBILT_IRB_190703 R56HL142583 ( U.S. NIH Grant/Contract ) |
First Posted: | August 8, 2019 Key Record Dates |
Last Update Posted: | January 13, 2021 |
Last Verified: | January 2021 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
postural tachycardia syndrome hyperadrenergic moxonidine |
sympatholytic orthostatic symptoms POTS |
Postural Orthostatic Tachycardia Syndrome Tachycardia Syndrome Disease Pathologic Processes Arrhythmias, Cardiac Heart Diseases Cardiovascular Diseases |
Cardiac Conduction System Disease Orthostatic Intolerance Primary Dysautonomias Autonomic Nervous System Diseases Nervous System Diseases Moxonidine Antihypertensive Agents |