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Hypertrophic Obstructive CardiomyopathyPhase 4NCT05025644

Quantitative Assessment of Hypertrophic Obstructive Cardiomyopathy With Intraoperative Three-dimensional Transesophageal Echocardiography Under Provocative Dobutamine Stress Test

A Phase 4 study testing Pre and post-CPB Drug: Dobutamine Hydrochloride and Post-CPB Drug: Dobutamine Hydrochloride in people with Hypertrophic Obstructive Cardiomyopathy, run by University Health Network, Toronto.

Unknown status

Status not confirmed. The sponsor has not verified this record for over two years, so it may be out of date.

Official record
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Trial summary

The objectives of this study are to determine if the left ventricle outflow tract (LVOT) gradients may be reproduced with dobutamine (DBT) provocation test in obstructive HCM patients under general anesthesia and to analyze the change in anatomic LVOT area and pressure gradients (PG) before and after septal myectomy. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Hypertrophic Obstructive Cardiomyopathy
What is being tested?
Pre and post-CPB Drug: Dobutamine Hydrochloride and Post-CPB Drug: Dobutamine Hydrochloride
Could I receive a placebo?
No, everyone receives an active treatment
How many people
60 participants
Where
No sites listed yet
Study dates
Mar 2023to Nov 2024
Phase
Phase 4
Are there results?
None posted in the registry

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 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • HOCM refractory to medical treatment with symptoms like syncope, angina or NYHA functional classes III and IV, with a resting gradient or provocable gradient equal or greater than 50 mmHg, requiring surgical intervention.
  • Absence of other cardiac or systemic diseases capable of producing hypertrophy.
  • Sinus rhythm.

Who cannot join

  • Patient refusal.
  • Patient unable to give consent.
  • TEE contraindication.
  • Different rhythm than sinus.
  • Other systemic diseases capable of producing hypertrophy.
  • Severe Aortic or coronary artery pathology.

Trial locations and contacts

No sites are listed yet.

About this study

The objectives of this study are to determine if the left ventricle outflow tract (LVOT) gradients may be reproduced with dobutamine (DBT) provocation test in obstructive HCM patients under general anesthesia and to analyze the change in anatomic LVOT area and pressure gradients (PG) before and after septal myectomy.

If the DBT stress test can reproduce preoperative gradients in HCM patients during septal myectomy surgery, surgeons will have the opportunity to assess the quality of the surgical procedure depending on the obtained gradients with DBT stress test after surgery when gradients can't be reproduced during general anesthesia after myectomy, and decide if further myectomy is required, saving a re-operation on the patient in the future.

Read the detailed description

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiomyopathy. Echocardiography is the noninvasive method of choice for the evaluation of morphologic and functional abnormalities in HCM. It is of paramount importance to distinguish between obstructive or non-obstructive HCM, based on the presence or absence of left ventricle outflow tract (LVOT) gradient using continuous wave Doppler (CWD), under resting and/or provocable conditions. HCM can then be divided into three different subgroups. When the gradient at rest is ≥ 30 mmHg the HCM is considered obstructive (HOCM); when the gradient is <30 mmHg at rest but ≥ 30 mmHg with provocation, the HCM is considered latent obstructive, and finally, non-obstructive occurs when the gradient is < 30mmHg at rest or with provocation.

The gold standard technique to treat symptomatic HOCM is the surgical transaortic septal myectomy, when the resting gradient or the provocable gradient is ≥50 mmHg. Hemodynamic conditions may change and lead to worsening or improvement in LVOT obstruction during general anesthesia. LVOT gradients during surgery should be measured under reproducible conditions possibly mimicking preoperative hemodynamics.

Dobutamine is a well-known inotropic agent, capable to induce sub-aortic gradients in HOCM. The development of a dynamic LVOT gradient during this test is a pharmacological phenomenon with no clinical significance, not been associated with increased frequency of chest pain, shortness of breath or ischemic wall motion abnormalities, because obstruction resolves after termination of dobutamine (DBT) infusion.

Being tested
Pre and post-CPB Drug: Dobutamine Hydrochloride, Post-CPB Drug: Dobutamine Hydrochloride
Keywords
Transesophageal Echocardiography, Dobutamine Stress test
Medical subject headings
Cardiomyopathy, Hypertrophic

What participants receive

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

  • Pre and post-CPB Drug: Dobutamine HydrochlorideDrug

    Also called Transthoracic or 2D Echocardiogram, Transesophageal Echocardiogram (TEE)

    • Pre-CPB provocation test with DBT stress test will be started (starting at 5 mcg/kg/min, increasing every 3 min, to 10, 15 and 20 mcg/kg/min) until a PG ≥ 50mmHg is achieved (DBT peak dose). The DBT peak dose (DBT-pd) will be recorded.
    • Post-CPB provocation test at the DBT-pd achieved preoperatively.
  • Post-CPB Drug: Dobutamine HydrochlorideDrug

    Also called Transthoracic or 2D Echocardiogram, Transesophageal Echocardiogram (TEE)

    • Pre-CPB no intervention will be required.
    • Post-CPB provocation test with DBT stress test will be started (starting at 5 mcg/kg/min, increasing every 3 min, to 10, 15 and 20 mcg/kg/min) or until postoperative provocable PG is >16 mmHg.
Study groups in NCT05025644
Study groupRoleWhat they receive
Preoperative Transesophageal Echocardiogram (TEE) PG under anesthesia <50mmHg (Group A)Experimental* Pre-cardiopulmonary bypass (CPB) (pre-myectomy) echocardiographic parameters: PG under DBT stress test at 5, 10, 15 and 20 mcg/kg/min or until a PG ≥ 50mmHg is achieved, will be recorded. * Post-CPB (post-myectomy) echocardiographic parameters: PG at DBT peak dose (DBT-pd) will be recorded. If LVOT PG post myectomy are >16 mmHg, the surgeon will be advised, for surgical management considerations.
Receives: Drug: Pre and post-CPB Drug: Dobutamine Hydrochloride
Preoperative PG under anesthesia ≥ 50mmHg (Group B)Experimental* Pre-cardiopulmonary bypass (CPB) (pre-myectomy) echocardiographic parameters: PG without DBT stress test will be recorded. * Post-CPB (post-myectomy) echocardiographic parameters: PG at 5, 10, 15, 20 mcg/kg/min DBT stress test or until the postoperative provocable PG is >16 mmHg will be recorded.
Receives: Drug: Post-CPB Drug: Dobutamine Hydrochloride

What is being measured

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

  1. Analyze if TEE immediate post-myectomy LVOT gradients, may be reproduced with provocation dobutamine test in HOCM patients, when compared to TTE LVOT gradients performed within 6 months post-myectomy, to prove septal myectomy efficacy.

    The preoperative gradients obtained by TTE, with and without stress test, within 6 months pre-myectomy, will be compared with the intraoperative TEE pre-myectomy gradients at baseline (before and after DBT stress test).

    The post-myectomy TEE gradients (before and after DBT stress test), will be compared with the follow up TTE gradients with and without stress test, performed within 6 months post-myectomy, to assess short term outcomes.

    Measured: Pre-operative up to 6 months, Immediate Intra-operative Pre-myectomy, Immediate Intra-operative Post-myectomy and Post-operative up to 6 months

Timeline

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

  1. First posted27 Aug 2021
  2. Study startMar 2023 (estimated)
  3. Primary completionAug 2024 (estimated)
  4. Study completionNov 2024 (estimated)

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 4
Primary purpose
Diagnosis
Allocation
Non-randomised
Intervention model
Parallel groups
Model description
This is a monocentric Phase IV prospective study that will be conducted on patients undergoing surgical myectomy treatment for HOCM, at Toronto General Hospital, to assess if LVOT gradients may be reproduced with dobutamine provocation test in HOCM patients under general anesthesia. The participants in the study will require a standard 2D echocardiography within 6 months pre and post-surgery. Intraoperatively, the patients will be divided into two groups, one with preoperative PG under anesthesia \<50mmHg (Group A), and one with preoperative PG under anesthesia ≥ 50mmHg (Group B).
Masking
None (open label)
Enrolment
60 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05025644
Sponsor's protocol ID
16-5412
Status last verified
Nov 2022
First submitted
11 Aug 2021
Last updated
8 Nov 2022
Results posted
No
FDA-regulated drug
No
FDA-regulated device
No

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing Pre and post-CPB Drug: Dobutamine Hydrochloride and Post-CPB Drug: Dobutamine Hydrochloride in people with Hypertrophic Obstructive Cardiomyopathy, run by University Health Network, Toronto.

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 3 inclusion and 6 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: status not confirmed, as of the sponsor's last update on 8 Nov 2022. Status can change between updates, so confirm with the study contact before making plans.

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 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Results are not available in the source record.

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

Contact Azad Mashari, MD ((416) 340-4800 ext. 5164, azad.mashari@uhn.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Analyze if TEE immediate post-myectomy LVOT gradients, may be reproduced with provocation dobutamine test in HOCM patients, when compared to TTE LVOT gradients performed within 6 months post-myectomy, to prove septal myectomy efficacy. (time frame: Pre-operative up to 6 months, Immediate Intra-operative Pre-myectomy, Immediate Intra-operative Post-myectomy and Post-operative up to 6 months). 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 8 Nov 2022.

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