Quantitative Assessment of Hypertrophic Obstructive Cardiomyopathy With Intraoperative Three-dimensional Transesophageal Echocardiography Under Provocative Dobutamine Stress Test
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|ClinicalTrials.gov Identifier: NCT05025644|
Recruitment Status : Not yet recruiting
First Posted : August 27, 2021
Last Update Posted : November 8, 2022
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.
|Condition or disease||Intervention/treatment||Phase|
|Hypertrophic Obstructive Cardiomyopathy||Drug: Pre and post-CPB Drug: Dobutamine Hydrochloride Drug: Post-CPB Drug: Dobutamine Hydrochloride||Phase 4|
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.
|Study Type :||Interventional (Clinical Trial)|
|Estimated Enrollment :||60 participants|
|Intervention Model:||Parallel Assignment|
|Intervention 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)|
|Official Title:||Quantitative Assessment of Hypertrophic Obstructive Cardiomyopathy With Intraoperative Three-dimensional Transesophageal Echocardiography Under Provocative Dobutamine Stress Test|
|Estimated Study Start Date :||March 2023|
|Estimated Primary Completion Date :||August 2024|
|Estimated Study Completion Date :||November 2024|
Experimental: Preoperative Transesophageal Echocardiogram (TEE) PG under anesthesia <50mmHg (Group A)
If LVOT PG post myectomy are >16 mmHg, the surgeon will be advised, for surgical management considerations.
Drug: Pre and post-CPB Drug: Dobutamine Hydrochloride
Experimental: Preoperative PG under anesthesia ≥ 50mmHg (Group B)
Drug: Post-CPB Drug: Dobutamine Hydrochloride
- 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 ]
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.
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): NCT05025644
|Contact: Azad Mashari, MD||(416) 340-4800 ext email@example.com|
|Contact: Jo Carroll||416 340-4800 ext firstname.lastname@example.org|
|Principal Investigator:||Jacobo Moreno Garijo, MD||Sunnybrook Health Science Centre|
|Principal Investigator:||Azad Mashari, MD||University Health Network, Toronto|