Vasovagal Syncope (VVS)Phase 2POST 11NCT05755737
A Proof of Principle Study of Ondansetron for the Prevention of Vasovagal Syncope: The Eleventh Prevention of Syncope Trial (POST11)
A Phase 2 study testing Ondansetron in people with Vasovagal Syncope (VVS) and Syncope, run by University of Calgary at 1 site in Canada.
Trial summary
About 20% of adults faint recurrently. These patients are often highly symptomatic, have problems with employment and driving, can be injured, and have poor quality of life. There are few therapies that have withstood the test of randomized clinical trials. Read more about this study
- Who is it for?
- Ages 18 to 100 years
- Conditions the study is for
- Vasovagal Syncope (VVS), Syncope
- What is being tested?
- Ondansetron
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 70 participants
- Where
- 1 siteCanada
- Study dates
- 1 Jun 2023to 31 Dec 2026
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
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 100 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- ≥1 syncopal spells in the year preceding enrolment (B) ≥-2 points on the Calgary Syncope Symptom Score( Accurate Calculation for Diagnosis of Vasovagal Syncope) (C) Age ≥18 years with informed consent
Who cannot join
- other causes of syncope, such as ventricular tachycardia, complete heart block, orthostatic hypotension or hypersensitive carotid sinus syndrome
- an inability to give informed consent
- important valvular, coronary, myocardial or conduction abnormality or significant arrhythmia
- hypertrophic cardiomyopathy
- a permanent pacemaker
- a seizure disorder
Show all 13Show fewer
- hypertension defined as >160/90 mm Hg
- pregnancy
- lactating women
- glaucoma
- medications with known effects on BP
- Known hypersensitivity to ondansetron and related medications
- other factors which, in the investigator's opinion, would prevent the subject from completing the protocol.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site, 1 recruiting
- Recruiting
University of Calgary
Calgary, Alberta, T2N 4Z6
Robert S Sheldon, MD, PhD, 403-220-8191, sheldon@ucalgary.ca
Robert Sheldon, MD
About this study
About 20% of adults faint recurrently. These patients are often highly symptomatic, have problems with employment and driving, can be injured, and have poor quality of life. There are few therapies that have withstood the test of randomized clinical trials. the investigators will conduct a prospective, randomized, parallel, double-blind, proof-of-concept study that tests the hypothesis that serotonin 5HT3 receptor inhibition with ondansetron prevents tilt-induced vasovagal syncope (VVS) and pre-syncope in patients with clinical VVS. A total of 70 patients with quantitative clinical diagnostic criteria for VVS and at least 1 syncopal spell in the preceding year will be randomized in a double-blind acute phase 2 study to ondansetron 8 mg PO BID x 2 doses or matching placebo. The endpoint will be presyncope or syncope associated with diagnostic hemodynamic changes. These data should provide useful preliminary data as a foundation on which to conduct a subsequent randomized clinical trial.
Read the detailed description
This will be a randomized, double-blind, parallel-arm study in which the subjects will undergo a tilt table test following 2 doses of ondansetron 8 mg PO (evening before and morning of study) or after 2 doses of matching placebo (on separate days). On the morning of the study, the fasting subject (except for medications) will be instrumented, on an empty bladder. ECG electrodes will be applied to monitor continuous heart rhythm. BP will be monitored continuously using a finger volume clamp method using one or more of several extant devices, and calibrated with intermittent brachial cuff measurements. One intravenous cannula will be placed in the contralateral arm (to the BP cuff) for blood sampling.
3.9. Tilt Table Protocol: Following the insertion of the venous cannulae, a period of at least 20 minutes will be allowed to elapse before a 10-minute basal control (baseline) period. Baseline data will be digitally recorded in this time. In the last 5 minutes of this period, blood will be drawn for fractionated plasma catecholamines. The table will be rapidly raised to 80 degrees for up to 60 minutes. The Investigators are avoiding tilt test methods with provocative medications to avoid the issue of multiple causal factors. At 10 minutes and 30 minutes following onset of tilt (or at the onset of severe presyncope or hypotension [systolic BP <70 mmHg]), venous fractionated catecholamines will be sampled. The study will be terminated if the subject develops syncope or at the completion of the protocol.
3.10. Assessment of Central Volume Changes with Upright Posture: Segmental bioelectrical impedance (BEI) will measure fluid shifts through the study to determine central volume changes with upright posture and in response to changing levels of CO2. The fluid content in the upper torso (chest), the lower torso (abdominal), thigh, and calf will be assessed. BEI is measured by passing a small current between electrodes and measuring the impedance with voltage-sensing electrodes to determine fluid content in four regions of the body . Body segment volume is inversely proportional to electrical resistance (V~1/R), so an increase in resistance reflects a loss of body fluid.
3.11. Questionnaires: A brief online questionnaire will be administered to the patients to get a metric of their health-related quality of life (RAND-36), and anxiety and depression symptoms (HADS). This will be administered through RedCap Survey.
- Conditions
- Vasovagal Syncope (VVS), Syncope
- Being tested
- Ondansetron, Placebo
- Keywords
- Ondansetron
- Medical subject headings
- Syncope, Vasovagal, Syncope
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
OndansetronDrug
Serotonin antagonists (5-HT3 antagonists) (Carbazole Derivative)
PlaceboDrug
Matching placebo identical in appearance.
| Study group | Role | What they receive |
|---|---|---|
| Ondansetron | Active comparator | 2 doses of Ondansetron 8mg PO (evening before and morning of study) Receives: Drug: Ondansetron |
| Placebo | Active comparator | 2 doses of matching placebo 8 mg PO (evening before and morning of study) Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Time to syncope or presyncope
Measured: 1 hour
Secondary outcomes (6)
stroke volume
Measured: 1 hour
cardiac output
Heart Rate * Stroke volume, and it will be measured using Beat -To Beat BP measurement and HR measurement
Measured: 1 hour
catecholamine levels
Measured: 1 hour
Hospital Anxiety and Depression Scale (HADS)
The total score is out of 42, (21 per subscale). Scores are derived by summing responses for each of the two subscales or for the scale as a whole Higher scores indicate greater levels of anxiety or depression. The total HADS score may be regarded as a global measure of psychological distress
Measured: Within 12 months period of the study
RAND-36
The RAND 36-Item Health Survey (Version 1.0) taps eight health concepts: physical functioning, bodily pain, role limitations due to physical health problems, role limitations due to personal or emotional problems, emotional well-being, social functioning, energy/fatigue, and general health perceptions.
All questions are scored on a scale from 0 to 100, with 100 representing the highest level of functioning possible. Aggregate scores are compiled as a percentage of the total points possible, using the RAND scoring table
Measured: Within 12 months period of the study
systemic vascular resistance
it will be measured using Beat -To Beat BP measurement
Measured: 1 hour
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Mar 2023
- Study start1 Jun 2023
- Primary completion31 Dec 2025 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Vasovagal Syncope (VVS)Studies of the same condition, open and under way.
- More trials run by University of CalgaryThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 70 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Calgary
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05755737
- Sponsor's protocol ID
- POST 11
- Acronym
- POST 11
- Status last verified
- May 2024
- First submitted
- 9 Feb 2023
- Last updated
- 10 May 2024
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 10 May 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Proof of Principle Study of Ondansetron for the Prevention of Vasovagal Syncope: The Eleventh Prevention of Syncope Trial (POST11)
- ClinicalTrials.gov ID
- NCT05755737
- Acronym / sponsor ID
- POST 11 / POST 11
- Conditions
- Vasovagal Syncope (VVS), Syncope
- Keywords
- Ondansetron
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 70 participants (estimated)
- Lead sponsor
- University of CalgaryUniversity, hospital or other
- Study start
- 1 Jun 2023 (actual)
- Primary completion
- 31 Dec 2025 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 6 Mar 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
About 20% of adults faint recurrently. These patients are often highly symptomatic, have problems with employment and driving, can be injured, and have poor quality of life. There are few therapies that have withstood the test of randomized clinical trials. the investigators will conduct a prospective, randomized, parallel, double-blind, proof-of-concept study that tests the hypothesis that serotonin 5HT3 receptor inhibition with ondansetron prevents tilt-induced vasovagal syncope (VVS) and pre-syncope in patients with clinical VVS. A total of 70 patients with quantitative clinical diagnostic criteria for VVS and at least 1 syncopal spell in the preceding year will be randomized in a double-blind acute phase 2 study to ondansetron 8 mg PO BID x 2 doses or matching placebo. The endpoint will be presyncope or syncope associated with diagnostic hemodynamic changes. These data should provide useful preliminary data as a foundation on which to conduct a subsequent randomized clinical trial.
Detailed description
This will be a randomized, double-blind, parallel-arm study in which the subjects will undergo a tilt table test following 2 doses of ondansetron 8 mg PO (evening before and morning of study) or after 2 doses of matching placebo (on separate days). On the morning of the study, the fasting subject (except for medications) will be instrumented, on an empty bladder. ECG electrodes will be applied to monitor continuous heart rhythm. BP will be monitored continuously using a finger volume clamp method using one or more of several extant devices, and calibrated with intermittent brachial cuff measurements. One intravenous cannula will be placed in the contralateral arm (to the BP cuff) for blood sampling.
3.9. Tilt Table Protocol: Following the insertion of the venous cannulae, a period of at least 20 minutes will be allowed to elapse before a 10-minute basal control (baseline) period. Baseline data will be digitally recorded in this time. In the last 5 minutes of this period, blood will be drawn for fractionated plasma catecholamines. The table will be rapidly raised to 80 degrees for up to 60 minutes. The Investigators are avoiding tilt test methods with provocative medications to avoid the issue of multiple causal factors. At 10 minutes and 30 minutes following onset of tilt (or at the onset of severe presyncope or hypotension [systolic BP <70 mmHg]), venous fractionated catecholamines will be sampled. The study will be terminated if the subject develops syncope or at the completion of the protocol.
3.10. Assessment of Central Volume Changes with Upright Posture: Segmental bioelectrical impedance (BEI) will measure fluid shifts through the study to determine central volume changes with upright posture and in response to changing levels of CO2. The fluid content in the upper torso (chest), the lower torso (abdominal), thigh, and calf will be assessed. BEI is measured by passing a small current between electrodes and measuring the impedance with voltage-sensing electrodes to determine fluid content in four regions of the body . Body segment volume is inversely proportional to electrical resistance (V~1/R), so an increase in resistance reflects a loss of body fluid.
3.11. Questionnaires: A brief online questionnaire will be administered to the patients to get a metric of their health-related quality of life (RAND-36), and anxiety and depression symptoms (HADS). This will be administered through RedCap Survey.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Ondansetron | Active comparator | Drug: Ondansetron2 doses of Ondansetron 8mg PO (evening before and morning of study) |
| Placebo | Active comparator | Drug: Placebo2 doses of matching placebo 8 mg PO (evening before and morning of study) |
Who may qualify
- Ages
- 18 to 100 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- ≥1 syncopal spells in the year preceding enrolment (B) ≥-2 points on the Calgary Syncope Symptom Score( Accurate Calculation for Diagnosis of Vasovagal Syncope) (C) Age ≥18 years with informed consent
Key exclusion criteria (13 listed)
- other causes of syncope, such as ventricular tachycardia, complete heart block, orthostatic hypotension or hypersensitive carotid sinus syndrome
- an inability to give informed consent
- important valvular, coronary, myocardial or conduction abnormality or significant arrhythmia
- hypertrophic cardiomyopathy
- a permanent pacemaker
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| OndansetronSerotonin antagonists (5-HT3 antagonists) (Carbazole Derivative) | Drug | Ondansetron |
| PlaceboMatching placebo identical in appearance. | Drug | Placebo |
Primary outcome
Time to syncope or presyncope
Time frame: 1 hour
6 secondary outcomes
stroke volume
Time frame: 1 hour
cardiac output
Time frame: 1 hour
catecholamine levels
Time frame: 1 hour
Hospital Anxiety and Depression Scale (HADS)
Time frame: Within 12 months period of the study
RAND-36
Time frame: Within 12 months period of the study
systemic vascular resistance
Time frame: 1 hour
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 May 2024.
- Individual participant dataSharing planned: No
Related trials for Vasovagal Syncope (VVS)
Active, not recruitingObservational study
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Recruiting
Assesment of the Clinical Benefit of Provocation on Tilt-table in SYNCope Patients, TiltSYNC-trial
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RecruitingObservational study
POLish Registry of CArdioneuroablation and CArdioneuromodulation
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Ondansetron in people with Vasovagal Syncope (VVS) and Syncope, run by University of Calgary at 1 site in Canada.
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 1 inclusion and 13 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: looking for participants now, as of the sponsor's last update on 10 May 2024. 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 Canada. 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. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Time to syncope or presyncope (time frame: 1 hour). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 May 2024.