Mitral Valve Pathology

Valvular mitral stenosis in adult cats: knowledge gained from the clinical and pathological workup of 18 cases

INTRODUCTION/OBJECTIVES

Feline valvular mitral stenosis (VMS) is uncommonly reported. The aim of this study was to describe diagnostic and clinicopathological characteristics of VMS in adult cats.

ANIMALS, MATERIALS AND METHODS

Eighteen client-owned cats were included in this study. A retrospective observational study. Clinical records were searched based on echocardiography. Data regarding clinical, laboratory, echocardiographic findings, outcome, and, in four cats, gross postmortem images of the heart were reviewed, and histological examinations performed.

RESULTS

Most cats were non-pedigree (11/18), with a median age of 13.2 years. Congestive heart failure was common (15/18). Three cats had hypertrophic cardiomyopathy phenotype, including one with transient myocardial thickening. Concomitant hyperthyroidism (9/18) was frequent. In one cat, echocardiography performed one year earlier did not show any changes. Upon echocardiography, all 18 cats had characteristic hockey-stick appearance of the anterior leaflet and narrow turbulent diastolic flow across the mitral valve. Twelve cats had fused diastolic transmitral waves, with a median velocity of 0.54 m/s (0.71-3.24 m/s). The remaining six had a median peak velocity of the early and late-diastolic transmitral waves of 1.3 m/s (0.95-2.8 m/s) and 0.99 m/s (0.65-2.05 m/s), respectively. Eleven cats had died, 10 of cardiac death (median survival time: 366 days). Macroscopically, the mitral valve leaflets appeared thickened and distorted, and the surrounded ventricular endocardium thickened. Histology revealed marked endocardial fibrosis of the mitral valve and surrounding ventricular endocardium, dominated by type I collagen.

CONCLUSIONS

The most striking finding is the documented acquirement of VMS in one cat, while the acquired nature of the lesion could not be confirmed in the other cases. The pathological findings are compatible with a chronic remodeling process that results in marked endocardial fibrosis in four cats.

ADAMTS7, a target in atherosclerosis, cooperates with its homolog ADAMTS12 to protect against myxomatous valve degeneration

The physiological roles of the metalloprotease-proteoglycan ADAMTS7, a drug target in atherosclerosis and vascular restenosis, and its homolog ADAMTS12, are undefined in the cardiovascular system. The objective of the present work was to investigate their roles in mice with genetic inactivation of both proteases and in relation to the resulting valve defects, to define their proteolytic activities in the matrisome. Here, we demonstrate that Adamts7 and Adamts12 are co-expressed in heart valves and each buffers inactivation of the other by compensatory upregulation. Leaflets of Adamts7 -/-;Adamts12 -/- aortic valves, but not the respective single mutants, were abnormally shaped at birth, with progressively severe disorganization and enlargement occurring thereafter. Doppler echocardiography showed that Adamts7 -/-;Adamts12 -/- mice had stenotic and regurgitant aortic valves. We investigated ADAMTS7 and ADAMTS12 substrates relevant to the valve matrisome in secretome libraries from Adamts7 -/-;Adamts12 -/- cells using the N-terminomics technique Terminal Amine Isotopic Labeling of Substrates (TAILS). Although ADAMTS7 and ADAMTS12 shared several extracellular matrix (ECM) substrates, cleavage sites and sequence preference for each protease were distinct. Adamts7 -/-;Adamts12 -/- valve leaflets showed accumulation of several of the identified ECM substrates, including periostin, a matricellular protein crucial for cardiac valve homeostasis. We conclude that the myxomatous degeneration in Adamts7 -/-;Adamts12 -/- valve leaflets reflects a complex disturbance of ECM proteostasis with accumulation of multiple ADAMTS7 and ADAMTS12 ECM substrates, and perturbation of regulatory pathways with roots in ECM, such as TGFβ signaling, which was increased in the mutant valves.

Feasibility and Exploration of a Standardized Protocol for Cardiac CT Assessment of Rheumatic Mitral Disease

Rheumatic mitral valve disease often requires surgical interventions, such as percutaneous mitral commissurotomy, surgical mitral valve repair, or replacement, especially in severe cases. This necessitates a precise preoperative assessment of the extent of mitral valve disease. Currently, transthoracic echocardiography, the gold standard for preoperative assessment, has limitations, such as restricted acoustic windows and dependence on the operator, which can affect the evaluation of subvalvular structures and calcification of the mitral valve. Previous studies have shown that cardiac computed tomography (CT), with its high resolution, strong multiplanar reconstruction capabilities, and sensitivity to calcifications, can effectively overcome these limitations. Therefore, this study aims to summarize and evaluate the effectiveness of cardiac CT in examining mitral valve leaflets, annulus, and subvalvular structures. It also reviews the feasibility and guiding significance of using cardiac CT to assess characteristic rheumatic mitral valve lesions.

An Update on Mitral Valve Aging

The aging process can have notable effects on the mitral valve. During life, the mitral valve undergoes various changes that can impact its structure and function. The purpose of this review is to present a comprehensive overview of the literature published up to February 2024 in the Medline database regarding the impact of aging on the mitral valve. The studies were combined with the personal experience of the authors. Until 2024, out of the 12,189 publications that deal with the mitral valve in elderly individuals, 308 refer to mitral valve aging. After reviewing these data, we selected and analyzed the 73 most informative works regarding the age-related transformation of the mitral valve. Understanding the mechanisms driving the aging of the mitral valve is crucial for enhancing diagnostic and therapeutic strategies for reducing age-related valve dysfunction and the subsequent cardiovascular complications.

Predictive nomogram for 28-day mortality risk in mitral valve disorder patients in the intensive care unit: A comprehensive assessment from the MIMIC-III database

BACKGROUND

Mitral valve disorder (MVD) stands as the most prevalent valvular heart disease. Presently, a comprehensive clinical index to predict mortality in MVD remains elusive. The aim of our study is to construct and assess a nomogram for predicting the 28-day mortality risk of MVD patients.

METHODS

Patients diagnosed with MVD were identified via ICD-9 code from the MIMIC-III database. Independent risk factors were identified utilizing the LASSO method and multivariate logistic regression to construct a nomogram model aimed at predicting the 28-day mortality risk. The nomogram's performance was assessed through various metrics including the area under the curve (AUC), calibration curves, Hosmer-Lemeshow test, integrated discriminant improvement (IDI), net reclassification improvement (NRI), and decision curve analysis (DCA).

RESULTS

The study encompassed a total of 2771 patients diagnosed with MVD. Logistic regression analysis identified several independent risk factors: age, anion gap, creatinine, glucose, blood urea nitrogen level (BUN), urine output, systolic blood pressure (SBP), respiratory rate, saturation of peripheral oxygen (SpO2), Glasgow Coma Scale score (GCS), and metastatic cancer. These factors were found to independently influence the 28-day mortality risk among patients with MVD. The calibration curve demonstrated adequate calibration of the nomogram. Furthermore, the nomogram exhibited favorable discrimination in both the training and validation cohorts. The calculations of IDI, NRI, and DCA analyses demonstrate that the nomogram model provides a greater net benefit compared to the Simplified Acute Physiology Score II (SAPSII), Acute Physiology Score III (APSIII), and Sequential Organ Failure Assessment (SOFA) scoring systems.

CONCLUSION

This study successfully identified independent risk factors for 28-day mortality in patients with MVD. Additionally, a nomogram model was developed to predict mortality, offering potential assistance in enhancing the prognosis for MVD patients. It's helpful in persuading patients to receive early interventional catheterization treatment, for example, transcatheter mitral valve replacement (TMVR), transcatheter mitral valve implantation (TMVI).

Wnt Signaling Inhibition Prevents Postnatal Inflammation and Disease Progression in Mouse Congenital Myxomatous Valve Disease

BACKGROUND

Myxomatous valve disease (MVD) is the most common cause of mitral regurgitation, leading to impaired cardiac function and heart failure. MVD in a mouse model of Marfan syndrome includes valve leaflet thickening and progressive valve degeneration. However, the underlying mechanisms by which the disease progresses remain undefined.

METHODS

Mice with Fibrillin 1 gene variant Fbn1C1039G/+ recapitulate histopathologic features of Marfan syndrome, and Wnt (Wingless-related integration site) signaling activity was detected in TCF/Lef-lacZ (T-cell factor/lymphoid enhancer factor-β-galactosidase) reporter mice. Single-cell RNA sequencing was performed from mitral valves of wild-type and Fbn1C1039G/+ mice at 1 month of age. Inhibition of Wnt signaling was achieved by conditional induction of the secreted Wnt inhibitor Dkk1 (Dickkopf-1) expression in periostin-expressing valve interstitial cells of Periostin-Cre; tetO-Dkk1; R26rtTA; TCF/Lef-lacZ; Fbn1C1039G/+ mice. Dietary doxycycline was administered for 1 month beginning with MVD initiation (1-month-old) or MVD progression (2-month-old). Histological evaluation and immunofluorescence for ECM (extracellular matrix) and immune cells were performed.

RESULTS

Wnt signaling is activated early in mitral valve disease progression, before immune cell infiltration in Fbn1C1039G/+ mice. Single-cell transcriptomics revealed similar mitral valve cell heterogeneity between wild-type and Fbn1C1039G/+ mice at 1 month of age. Wnt pathway genes were predominantly expressed in valve interstitial cells and valve endothelial cells of Fbn1C1039G/+ mice. Inhibition of Wnt signaling in Fbn1C1039G/+ mice at 1 month of age prevented the initiation of MVD as indicated by improved ECM remodeling and reduced valve leaflet thickness with decreased infiltrating macrophages. However, later, Wnt inhibition starting at 2 months did not prevent the progression of MVD.

CONCLUSIONS

Wnt signaling is involved in the initiation of mitral valve abnormalities and inflammation but is not responsible for later-stage valve disease progression once it has been initiated. Thus, Wnt signaling contributes to MVD progression in a time-dependent manner and provides a promising therapeutic target for the early treatment of congenital MVD in Marfan syndrome.

Proof of Concept: Development of a Mitral Annuloplasty Ring With Crosshatch Net

OBJECTIVE

Here we report our preclinical, proof-of-concept testing to assess the ability of a novel device to correct mitral regurgitation. The Milwaukee Heart device aims to enable any cardiac surgeon to perform high-quality mitral valve repair using a standard annuloplasty ring with a crosshatch of microporous, monofilament suture.

METHODS

Hemodynamic, echocardiographic, and videographic data were collected at baseline, following induction of mitral regurgitation, and after repair using porcine hearts in an ex vivo biosimulator model. A commercially available cardiac prosthesis assessment platform was then used to assess the hydrodynamic characteristics of the study device.

RESULTS

Porcine biosimulator pressure and flow metrics exhibited successful correction of mitral regurgitation following device implantation with similar values to baseline. Hydrodynamic results yielded pressure gradients and an effective orifice area comparable to currently approved prostheses.

CONCLUSIONS

The study device effectively reduced mitral valve regurgitation and improved hemodynamics in our preclinical model with similar biophysical metrics to currently approved devices. Future in vivo trials are needed to evaluate the efficacy, biocompatibility, and freedom from the most likely adverse events, such as device thrombosis, embolic events, and hemolysis.

A simulation-based phantom model for generating synthetic mitral valve image data-application to MRI acquisition planning

PURPOSE

Numerical phantom methods are widely used in the development of medical imaging methods. They enable quantitative evaluation and direct comparison with controlled and known ground truth information. Cardiac magnetic resonance has the potential for a comprehensive evaluation of the mitral valve (MV). The goal of this work is the development of a numerical simulation framework that supports the investigation of MRI imaging strategies for the mitral valve.

METHODS

We present a pipeline for synthetic image generation based on the combination of individual anatomical 3D models with a position-based dynamics simulation of the mitral valve closure. The corresponding images are generated using modality-specific intensity models and spatiotemporal sampling concepts. We test the applicability in the context of MRI imaging strategies for the assessment of the mitral valve. Synthetic images are generated with different strategies regarding image orientation (SAX and rLAX) and spatial sampling density.

RESULTS

The suitability of the imaging strategy is evaluated by comparing MV segmentations against ground truth annotations. The generated synthetic images were compared to ones acquired with similar parameters, and the result is promising. The quantitative analysis of annotation results suggests that the rLAX sampling strategy is preferable for MV assessment, reaching accuracy values that are comparable to or even outperform literature values.

CONCLUSION

The proposed approach provides a valuable tool for the evaluation and optimization of cardiac valve image acquisition. Its application to the use case identifies the radial image sampling strategy as the most suitable for MV assessment through MRI.

Prognostic Implication of Pulmonary Arterial Pressure in Surgical Repair of Predominantly Congenital Mitral Valve Regurgitation-Based Intracardiac Abnormalities

INTRODUCTION

Knowledge is limited regarding the significance of pulmonary arterial pressure (PAP) in predominantly congenital mitral valve regurgitation (MR)-based intracardiac abnormalities.

METHODS

From a prospective cohort, we included 200 patients with congenital MR regardless of other associated intracardiac abnormalities (mean age 60.4 months, 67% female, systolic PAP (sPAP) 54.2 mm Hg) surgically repaired in 2012-2019 and followed up to 2020 (median 30.0 months). Significant pulmonary hypertension (PH) was defined as sPAP >50 mm Hg at rest or mean PAP >25 mm Hg on right heart catheterization. By perioperative sPAP changes, patients were stratified as group I (pre-normotension to post-normotension), group II (pre-hypertension to post-normotension), or group III (pre-hypertension to post-hypertension). Primary outcomes were the recurrence of MR (defined as the regurgitation grade of moderate or greater) and the progression of MR (defined as any increase in the magnitude of regurgitation grade after surgery). Cox proportional hazard and Kaplan-Meier curve were performed.

RESULTS

There was no association between preoperative PH and the recurrent MR (adjusted hazard ratios [aHR]: 1.146 [95% CI: 0.453-2.899]) and progressive MR (aHR: 1.753 [95% CI: 0.807-3.804]), respectively. There were no significant differences among group I, group II, and group III in the recurrent MR but in the progressive MR. A dose dependency was identified for preoperative sPAP with recurrent MR (aHR: 1.050 [95% CI: 1.029-1.071]) and progressive MR risks (aHR: 1.037 [95% CI: 1.019-1.055]), respectively.

CONCLUSIONS

Preoperative higher sPAP is associated with worse outcomes, warranting heightened attention to the identification of perioperative sPAP.

Prediction of Surgical Approach in Mitral Valve Disease by XGBoost Algorithm Based on Echocardiographic Features

In this study, we aimed to develop a prediction model to assist surgeons in choosing an appropriate surgical approach for mitral valve disease patients. We retrospectively analyzed a total of 143 patients who underwent surgery for mitral valve disease. The XGBoost algorithm was used to establish a predictive model to decide a surgical approach (mitral valve repair or replacement) based on the echocardiographic features of the mitral valve apparatus, such as leaflets, the annulus, and sub-valvular structures. The results showed that the accuracy of the predictive model was 81.09% in predicting the appropriate surgical approach based on the patient's preoperative echocardiography. The result of the predictive model was superior to the traditional complexity score (81.09% vs. 75%). Additionally, the predictive model showed that the three main factors affecting the choice of surgical approach were leaflet restriction, calcification of the leaflet, and perforation or cleft of the leaflet. We developed a novel predictive model using the XGBoost algorithm based on echocardiographic features to assist surgeons in choosing an appropriate surgical approach for patients with mitral valve disease.

A new perspective: Fat tissue and adipokines in rheumatic heart valves

OBJECTIVE

To observe fat tissue and the expression of adipokines in rheumatic heart valves and explore the possible role of fat tissue and adipokines in the pathology of rheumatic heart disease (RHD).

METHODS

In this retrospective study, a total of 29 patients who received mitral valve replacement surgery were included. The study group consisted of 25 patients with RHD while the control group consisted of 4 patients with secondary mitral insufficiency caused by coronary heart disease (CAD). The clinical data of the patients including medical history, age, body mass index (BMI), fasting blood glucose (FBG), total triglycerides (TG), total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), apolipoprotein(a) [apo(a)], apolipoprotein(b) [apo(b)] were collected and compared. Cardiac ultrasonography was used to assess valve conditions before surgery. The removed valves were collected. The hematoxylin-eosin (HE) staining, oil-red O staining, and Masson's trichrome staining were adopted to evaluate the histological changes in the mitral valve. Immunohistochemical (IMC) staining was performed to evaluate the expression of adiponectin, leptin, and chemerin.

RESULTS

There was no significant difference in general information and blood lipid levels between the two groups (all p > .05). Preoperative ultrasonography showed adipose tissue in the mitral valve of RHD patients. In the study group, rheumatic mitral valve samples showed thickening, adherence at the junction of the leaflets, calcification, and yellowish or fat mass by naked observation. The HE staining showed that there was calcification, inflammatory cell infiltration, fibrous tissue arranged disorder, and neovascularization. The oil-red O staining suggested fatty infiltration. Masson's trichrome staining suggested disorderly arrangement of collagen fiber and elastic fiber in rheumatic lesions, and the lesions were dominated by collagen fiber hyperplasia and less elastic fiber hyperplasia. The results of IMC indicated that chemerin was not expressed in valves of the control group. Most of the valve samples from the study group also did not show leptin and the leptin was seen in only a few rheumatic mitral valves with vascular hyperplasia. Adiponectin was not found in the valves of the study group and the control group.

CONCLUSION

Adipose tissue in the rheumatic mitral valve could be observed by ultrasound. The fat mass and adipokines existed in rheumatic mitral valves, the adipocytokine chemerin is involved in the progression of the pathology in RHD.

Characterization of the spontaneous degenerative mitral valve disease in FVB mice

BACKGROUND

The development of new non-surgical treatments dedicated to mitral valve degeneration is limited by the absence of relevant spontaneous and rapidly progressing animal experimental models.

ANIMALS

We characterized the spontaneous mitral valve degeneration in two inbred FVB mouse strains compared to C57BL/6J and investigated a contribution of the serotonergic system.

METHODS

Males and females FVB/NJ and FVB/NRj were compared to the putative C57BL/6J control at 12, 16, 20 and 24 weeks of age. Body weight, systolic blood pressure, heart rate, urinary 5-hydroxyindoleacetic acid (5-HIAA), whole blood and plasma serotonin, tail bleeding time, blood cell count, plasma TGF-β1 and plasma natriuretic peptide concentrations were measured. Myocardium and mitral valves were characterized by histology. mRNA mitral expression of 5-HT2A and 5-HT2B receptors was measured in the anterior leaflet. Cardiac anatomy and function were assessed by echocardiography.

RESULTS

Compared to C57BL/6J, FVB mice strains did not significantly differ regarding body weight increase, arterial blood pressure and heart rate. A progressive augmentation of plasma pro-ANP was observed in FVB mice. Nevertheless, no cardiac hypertrophy or left-ventricular fibrosis were observed. Accordingly, plasma TGF-β1 was not different among the three strains. Conversely, FVB mice demonstrated a high prevalence of fibromyxoid highly cellularized and enriched in glycosaminoglycans lesions, inducing major mitral leaflets thickening without increase in length. The increased thickness was correlated with urinary 5-HIAA and blood platelet count. Whole blood serotonin concentration was similar in the two strains but, in FVB, a reduction of plasma serotonin was observed together with an increase of the bleeding time. Finally, echocardiography identified left atrial and left ventricular remodeling associated with thickening of both mitral leaflets and mitral insufficient in 30% of FVB mice but no systolic protrusion of mitral leaflets towards the atrium.

CONCLUSION

The FVB mouse strain is highly prone to spontaneous mitral myxomatous degeneration. A contribution of the peripheral serotonergic system is suggested.

Preoperative mitral annulus size - Can we get it right?

Objective

We looked for a correlation between the surgically measured mitral valve size and the cardiac dimensions (left ventricle internal diameter, left atrial size, aorta size, and body surface area) measured by preoperative and intraoperative echocardiography. We also assessed to see if we could predict the mitral prosthesis size based on the correlation data obtained.

Methods

The hospital records of 180 patients who underwent mitral valve replacement (MVR) with TTK Chitra valve between January 2008 and December 2012 at our hospital, were studied. The correlation between surgically measured mitral annulus size to left ventricular internal diameter systolic (LVIDS) and diastolic (LVIDD), left atrial size (linear measurement), and aorta size on echocardiography and body surface area was calculated using Pearson correlation coefficient. Mean LVIDS was calculated for each valve prosthesis size separately and the correlation was studied.

Results

The correlation between mitral valve prosthesis size and left ventricular internal diameter (systolic) showed a Pearson coefficient of 3.3 with significance at the level 0.01. Mitral valve size and left atrial size showed a correlation coefficient of 2.7 with significance at the level 0.01. The correlation coefficient for mitral valve size with left ventricular internal diameter diastolic, aorta and body surface area were 2.5, 1.9, and 1.8, respectively. There was a gradual increase in the mean LVIDS with increase in the prosthetic valve size. Box plot and scatter plot showed linear correlation between valve size and mean LVIDS.

Activation of the Interleukin-33/ST2 Pathway Exerts Deleterious Effects in Myxomatous Mitral Valve Disease

Mitral valve disease (MVD) is a frequent cause of heart failure and death worldwide, but its etiopathogenesis is not fully understood. Interleukin (IL)-33 regulates inflammation and thrombosis in the vascular endothelium and may play a role in the atherosclerotic process, but its role in mitral valve has not been investigated. We aim to explore IL-33 as a possible inductor of myxomatous degeneration in human mitral valves. We enrolled 103 patients suffering from severe mitral regurgitation due to myxomatous degeneration undergoing mitral valve replacement. Immunohistochemistry of the resected leaflets showed IL-33 and ST2 expression in both valve interstitial cells (VICs) and valve endothelial cells (VECs). Positive correlations were found between the levels of IL-33 and molecules implicated in the development of myxomatous MVD, such as proteoglycans, extracellular matrix remodeling enzymes (matrix metalloproteinases and their tissue inhibitors), inflammatory and fibrotic markers. Stimulation of single cell cultures of VICs and VECs with recombinant human IL-33 induced the expression of activated VIC markers, endothelial–mesenchymal transition of VECs, proteoglycan synthesis, inflammatory molecules and extracellular matrix turnover. Our findings suggest that the IL-33/ST2 system may be involved in the development of myxomatous MVD by enhancing extracellular matrix remodeling.

Surgical repair of mitral valve bileaflet prolapse in pediatric patients

BACKGROUND

Pediatric mitral regurgitation (MR), especially with bileaflet prolapse, is relatively rare, of high complexity, and frequently associated with other congenital cardiac abnormalities. It remains a major therapeutic challenge for surgeons. This study reports our experience of surgical treatment of this mitral disease and midterm follow-up results.

METHODS

Between January 2016 and April 2020, nine pediatric patients, six females and three males, age ranged from 3 to 12 years (median age was 6 years) with a weight range of 12-36 kg (median weight was 25 kg), who all had over moderate regurgitation caused by bileaflet prolapse with mean distance of leaflet coaptation beyond annular plane 5.89 ± 1.66 mm (4-9 mm), received mitral valve (MV) repair. Various surgical techniques were used to repair MV.

RESULTS

The median follow-up period was 23(6-51) months, only one patient had moderately severe recurrent of MR, no patient developed systolic anterior motion (SAM) or mitral stenosis. Freedom from reoperation was 100% during the follow-up period. Compared to preoperation, the left atrial (LA) diameter and left ventricular end-diastolic diameter (LVEDD) decreased significantly from 2.94 ± 0.49 cm to 2.37 ± 0.38 cm (LA, p < .01) and from 4.13 ± 0.73 cm to 3.62 ± 0.49 cm (LVEDD, p < .01) respectively, ejection fraction (EF) decreased significantly (p < .05) from 68.56 ± 3.98% to 62.89 ± 4.48% before discharged.

CONCLUSION

We share our experience of surgical repair of mitral valve bileaflet prolapse in pediatric patients. Several surgical methods are considered to be used to repair the MV due to the high complexity of lesions. Anatomic correction or functional correction in our reports almost reaches the same result, while functional correction means simpler operation.

Outcomes of mitral valve repair compared with replacement for patients with rheumatic heart disease

OBJECTIVE

Whether mitral valve repair is superior to replacement in the population with rheumatic heart disease has been debated. This study aims to compare outcomes of repair with replacement by the propensity score method.

METHODS

This observational, prospective study enrolled patients with rheumatic heart disease who underwent mitral valve repair and replacement from January 2011 to April 2019. The propensity score method was used to select 2 groups with similar baseline characteristics. Baseline, clinical, and follow-up data were collected. Clinical outcomes included death from any cause, reoperation, and valve-related complications.

RESULTS

The overall population before matching (N = 1644) included 612 patients who underwent repair and 1032 patients who underwent replacement. The propensity score analysis generated matches for 1058 patients (529 pairs). The median follow-up time was 4.12 years. Early mortality and death from any cause during follow-up were significantly lower in the repair group compared with the replacement group (hazard ratio, 0.19; 95% confidence interval [CI], 0.05-0.64; P = .003; hazard ratio, 0.38; 95% CI, 0.19-0.74; P = .003, respectively). Patients in the repair group had a lower risk of valve-related complications compared with patients in the replacement group (subhazard ratio, 0.44; 95% CI, 0.21-0.90; P = .025). In terms of reoperation, no significant difference was observed between the repair and replacement groups (subhazard ratio, 2.54; 95% CI, 0.89-7.22; P = .081).

CONCLUSIONS

The results suggest that rheumatic mitral valve repair in select patients is superior to mitral valve replacement with regard to lower mortality and fewer valve-related complications; meanwhile, it has a comparable risk of reoperation compared with replacement.