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.
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 Type
OBSERVATIONAL
Enrollment
150
≥ moderate MR on intraoperative post-bypass TEE that improves to ≤ mild MR on predischarge transthoracic echocardiography (TTE)
To determine the proportion of patients with ≥ 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
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