Transient Mitral Regurgitation Following Septal Myectomy: A Retrospective Echocardiographic Study
Trial Snapshot
- Phase
- Not Applicable
- Status
- Not yet recruiting
- Enrollment
- 150
- Primary Endpoint
- ≥ moderate MR on intraoperative post-bypass TEE that improves to ≤ mild MR on predischarge transthoracic echocardiography (TTE)
Study Overview
Brief Summary
Mitral regurgitation (MR) following septal myectomy for hypertrophic obstructive cardiomyopathy may persist despite relief of systolic anterior motion and left ventricular outflow tract obstruction. Clinical observations suggest that a subset of postoperative MR may be transient and related to posterior leaflet restriction rather than structural mitral valve abnormality.
We will perform a retrospective single-centre cohort study of patients undergoing septal myectomy between 2022 and 2025. Intraoperative post-bypass transesophageal echocardiograms and predischarge transthoracic echocardiograms will be independently reviewed to assess MR severity and mechanism.
We hypothesize that a substantial proportion of moderate-or-greater postoperative MR resolves before discharge, supporting a conservative approach to mitral valve intervention and improving intraoperative echocardiographic decision-making.
Detailed Description
Hypertrophic obstructive cardiomyopathy (HOCM) is characterized by asymmetric septal hypertrophy and dynamic LVOT obstruction. Septal myectomy is the standard surgical therapy for symptomatic patients refractory to medical management.
Mitral regurgitation (MR) in HOCM is classically related to systolic anterior motion (SAM) of the anterior leaflet. Following myectomy, relief of LVOT obstruction typically reduces SAM-associated MR. However; intraoperative transesophageal echocardiography (TEE) frequently demonstrates persistent or new MR following separation from cardiopulmonary bypass.
Clinical observation suggests that a subset of this MR may be due to transient posterior leaflet restriction, potentially related to incomplete myocardial protection in hypertrophied myocardium. This may result in MR that resolves prior to discharge without requiring mitral valve intervention. Misinterpretation of this transient phenomenon may lead to unnecessary surgical procedures.
There is currently limited systematic evaluation of the mechanism and natural history of MR observed immediately following myectomy. This study aims to address this knowledge gap using retrospective echocardiographic review.
Study Design
- Study Type
- Observational
- Observational Model
- Cohort
- Time Perspective
- Retrospective
Eligibility Criteria
- Ages
- 18 Years to — (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Adult patients (≥18 years)
- •Undergoing septal myectomy for HOCM
- •Availability of intraoperative post-cardiopulmonary bypass TEE images
- •Availability of predischarge TTE
Exclusion Criteria
- •Concomitant primary mitral valve disease due to structural abnormalities, prior ischemic MR or previous MV intervention (repair or replacement)
- •Inadequate echocardiographic image quality precluding MR assessment
- •Patients without paired TEE and TTE studies
Arms & Interventions
Patients who underwent septal myectomy at Toronto General Hospital between 2022 and 2025
We enroll into the study all patients who underwent septal myectomy at Toronto General Hospital between January 1, 2022 and December 31, 2025.
Outcomes
Primary Outcomes
≥ moderate MR on intraoperative post-bypass TEE that improves to ≤ mild MR on predischarge transthoracic echocardiography (TTE)
Time Frame: From January 1, 2022 to December 31, 2025
To determine the proportion of patients with ≥ moderate MR on intraoperative post-bypass TEE that improves to ≤ mild MR on predischarge transthoracic echocardiography (TTE).
Secondary Outcomes
No secondary outcomes reported
Investigators
Marcus Salvatori
Staff Anesthesiologist
University Health Network, Toronto