BackgroundCongenital mitral rings represent a rare subset of congenital mitral stenosis often associated with complex cardiac anomalies. Comprehensive literature on congenital mitral rings, particularly from large single-institution experiences, remains sparse. Methods: This retrospective study, conducted at All India Institute of Medical Sciences, New Delhi, analyzed data from 52 patients who underwent surgical correction for congenital mitral rings between 2014 and 2024. Data on demographics, clinical presentation, preoperative echocardiographic and cardiac catheterization parameters, associated cardiac anomalies, intraoperative findings, and postoperative outcomes were collected. Patients had a mean follow-up of 72 months.ResultsThe cohort had a mean age of 6 years. An isolated vestibular mitral ring was noted in only 1 patient, with 51 cases showing associated cardiac anomalies. The mean preoperative diastolic gradient was 13 mm Hg, significantly reduced to 2.69 mm Hg in the immediate postoperative period and 3.35 mm Hg at follow-up. Two distinct morphological types were identified: "distinct vestibular supramitral ring" (43 patients) and "adherent intramitral ring" (9 patients), with the latter demonstrating a higher association with subvalvular apparatus abnormalities. Preoperative transesophageal echocardiography proved crucial in detecting these rings in 4 cases where the diagnosis was doubtful on transthoracic echocardiography. Surgical outcomes were favorable, with 1 early postoperative mortality and 3 late mortalities. Four patients required reinterventions for residual lesions, achieving successful resolution.ConclusionThis large single institution series provides valuable insights into associated anomalies, morphological variants, and long-term surgical outcomes of congenital mitral rings. Accurate diagnosis and timely surgical intervention led to favorable outcomes, reinforcing the need for thorough preoperative evaluation.

Hypertrophic cardiomyopathy (HCM) is a genetic cardiac disorder characterized predominantly by left ventricular (LV) hypertrophy, frequently leading to dynamic obstruction of the left ventricular outflow tract (LVOT). Obstructive HCM is driven by structural abnormalities including asymmetric septal hypertrophy, systolic anterior motion of often elongated mitral valve leaflets, and alterations in the mitral sub-valvular apparatus such as displaced or hypertrophied papillary muscles. Pathophysiological mechanisms underlying HCM include hypercontractility due to increased actin-myosin cross bridges, myocyte hypertrophy and disarray, interstitial fibrosis, and coronary microvascular dysfunction-which contribute variably to disease expression, impaired myocardial relaxation, ischemia, fibrosis, and arrhythmogenesis. Diagnosis relies on integrating clinical presentation, physical examination, electrocardiographic features, genetic testing, and advanced imaging techniques. Transthoracic echocardiography remains the primary diagnostic and monitoring tool, accurately assessing patterns of hypertrophy, dynamic LVOT gradients, mitral valve abnormalities, and ventricular function, including strain imaging for early functional impairment. Cardiac magnetic resonance imaging complements echocardiography, providing superior anatomical delineation, precise quantification of LV mass, detection of apical and distal-dominant forms, identification of fibrosis via late gadolinium enhancement, and detailed tissue characterization. This review emphasizes the complex interplay of genetic, structural, and functional elements in obstructive HCM, underscoring the importance of comprehensive evaluation to facilitate individualized and effective therapeutic decisions.

This study examines whether anterior mitral valve leaflet (AMVL) length is associated with response to mavacamten in patients with obstructive hypertrophic cardiomyopathy (HCM). Obstruction of the left-ventricular outflow tract (LVOT) in HCM has been associated with asymmetric septal hypertrophy and abnormalities of the mitral valve and sub-valvular apparatus. Mavacamten is a myosin-inhibitor shown to decrease LVOT gradient and improve functional status in patients with obstructive HCM. Measurements of cardiac structural elements were obtained from magnetic resonance imaging and echocardiography data among patients with obstructive HCM treated with mavacamten. Endpoints were effective mavacamten dose, defined as the dose required to achieve a Valsalva LVOT gradient <30 mmHg, and rapid response to mavacamten therapy, defined as achieved Valsalva LVOT gradient <20 mmHg within 8 weeks of initiation. Among 33 patients, patients with an effective dose of 5 mg (n = 13) had a shorter AMVL length [20.00 (18.50, 20.80) mm] compared with patients with a dose of 10 mg (n = 12) [23.30 (22.45, 26.10) mm] and 15 mg (n = 8) [25.45 (24.20, 26.85) mm] (P < 0.001). After adjusting for age and sex, the 5 mg dose was associated with a shorter AMVL length (P = 0.003). AMVL length was shorter in rapid responders [20.9 (19.9, 22.5) mm] compared with patients without a rapid response [24.9 (23.3, 26.5) mm] (P = 0.006). Shorter AMVL length is associated with a lower effective dose and a rapid response to mavacamten. If confirmed in larger studies, AMVL length may inform optimal dosing of myosin inhibitors in obstructive HCM.

Mitral regurgitation (MR) in hypertrophic cardiomyopathy (HCM) patients is mainly due to systolic anterior motion (SAM) of the mitral valve (MV). However, other mechanisms contributing to mitral regurgitation may coexist as a result of further structural abnormalities. SAM might occur because of the increased septal thickness alone or due to simultaneous MV or subvalvular apparatus anomalies, such as mitral leaflet elongation, papillary muscle body anomalies, accessory papillary muscles or additional papillary muscle heads. Additionally, anomalous mitral chordae or the recently described mitral-aortic discontinuity (leading to a longer anterior mitral leaflet (AML)) can contribute to abnormal physiology. A closed aortomitral angle may also contribute. During intraoperative echocardiographic assessment, it is important to thoroughly evaluate the MV and the regurgitant jet to understand the mechanism(s) that cause MR in HCM patients. Although myectomy alone is frequently enough to correct SAM, concomitant MV procedures may be needed, especially when the septum is thin (<16-18 mm) and/or there is intrinsic MV disease. Detection of concomitant regurgitation mechanisms beyond SAM can eventually be identified preoperatively, either by direct structural detection (valve prolapse), by pharmacological palliation of SAM with vasopressors and negative inotropic agents or suspected by identification of anteriorly and centrally directed regurgitant mitral jets. Surgical techniques that can be employed to contribute to SAM elimination include plication/extension/retention plasty of the AML, resection/release/reorientation of papillary muscles, division of anomalous chordae, edge-to-edge repair, or, at times, prosthetic MV replacement. If there is structural MV disease concomitant to HCM, appropriately tailored techniques to address the MV may be used. Transoesophageal echocardiography at the end of the procedure should demonstrate elimination of SAM, resolution of LVOT obstruction, and appropriate coaptation of the MV leaflets and nearly resolution of MR. Provocation with inotropes can be used to ensure no latent obstruction persists.

The arcade-like mitral apparatus is a rare congenital anomaly characterized by complex subvalvular pathology, often resulting in mitral dysfunction. These anatomical complexities make conventional surgical interventions particularly challenging, especially for elderly high-risk patients. For these patients, less invasive options like Transcatheter Edge-to-Edge Repair (TEER) present a promising alternative, addressing both anatomical challenges and procedural risks. To assess the feasibility, procedural success, safety, and clinical outcomes of TEER in patients with isolated severe MR due to arcade-like mitral apparatus. This case series involved four high-risk patients with isolated severe mitral regurgitation (MR) secondary to arcade-like mitral apparatus treated with TEER between August 2022 and August 2023. Each patient was evaluated by a multidisciplinary Heart Team to ensure optimal selection and procedural planning. Detailed anatomical assessment using advanced imaging techniques, was performed to customize the approach and ensure procedural success. The MitraClip XTR device was employed in all cases, with careful attention to patient-specific anatomical challenges. TEER was successfully performed in all patients, with immediate and sustained reductions in MR severity. At the one-year follow-up, all patients demonstrated improved cardiac function, an increase in New York Heart Association (NYHA) functional class, and a reduction in Borg dyspnea scores. Significant improvements in myocardial mechanics and work parameters were observed. Global Longitudinal Strain (GLS) improved significantly compared to baseline. The Global Work Index (GWI), Global Constructive Work (GCW), Global Pressure-Volume Work (GPW), Global Systolic Constructive Work (GSCW) and Global Work Efficiency (GWE) also showed a marked increase. TEER represents a promising, minimally invasive option for managing severe MR due to arcade-like mitral apparatus in high-risk patients. This case series underscores TEER's potential to offer significant symptom relief and improved hemodynamics, presenting a new therapeutic perspective for treating isolated MR in this anatomically challenging condition. Further large-scale studies are warranted to validate these findings and establish TEER's role in broader clinical practice.