Ischaemic mitral regurgitation.
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ABSTRACT:
SUBMITTER: Yadava OP
PROVIDER: S-EPMC7525700 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Ischaemic mitral regurgitation (IMR), a frequent complication following myocardial infarction (MI), leads to higher mortality and poor clinical prognosis if untreated. Accumulating evidence suggests that mitral valve (MV) leaflets actively remodel post MI, and this remodelling increases both the severity of IMR and the occurrence of MV repair failures. However, the mechanisms of extracellular matrix maintenance and modulation by MV interstitial cells (MVICs) and their impact on MV leaflet tissue integrity and repair failure remain largely unknown. Herein, we sought to elucidate the multiscale behaviour of IMR-induced MV remodelling using an established ovine model. Leaflet tissue at eight weeks post MI exhibited significant permanent plastic radial deformation, eliminating mechanical anisotropy, accompanied by altered leaflet composition. Interestingly, no changes in effective collagen fibre modulus were observed, with MVICs slightly rounder, at eight weeks post MI. RNA sequencing indicated that YAP-induced genes were elevated at four weeks post MI, indicating elevated mechanotransduction. Genes related to extracellular matrix organization were downregulated at four weeks post MI when IMR occurred. Transcriptomic changes returned to baseline by eight weeks post MI. This multiscale study suggests that IMR induces plastic deformation of the MV with no functional damage to the collagen fibres, providing crucial information for computational simulations of the MV in IMR.
| S-EPMC7276554 | biostudies-literature
Project description:OBJECTIVES:The Cardiothoracic Surgical Trials Network recently reported no difference in the primary end point of left ventricular end-systolic volume index at 1 year postsurgery in patients randomized to repair (n = 126) or replacement (n = 125) for severe ischemic mitral regurgitation. However, patients undergoing repair experienced significantly more recurrent mitral regurgitation than patients undergoing replacement (32.6% vs 2.3%). We examined whether baseline echocardiographic and clinical characteristics could identify those who will develop moderate/severe recurrent mitral regurgitation or die. METHODS:Our analysis includes 116 patients who were randomized to and received mitral valve repair. Logistic regression was used to estimate a model-based probability of recurrence or death from baseline factors. Receiver operating characteristic curves were constructed from these estimated probabilities to determine classification cut-points maximizing accuracy of prediction based on sensitivity and specificity. RESULTS:Of the 116 patients, 6 received a replacement before leaving the operating room; all other patients had mild or less mitral regurgitation on intraoperative echocardiogram after repair. During the 2-year follow-up period, 76 patients developed moderate/severe mitral regurgitation or died (53 mitral regurgitation recurrences, 13 mitral regurgitation recurrences and death, and 10 deaths). The mechanism for recurrent mitral regurgitation was largely mitral valve leaflet tethering. Our model (including age, body mass index, sex, race, effective regurgitant orifice area, basal aneurysm/dyskinesis, New York Heart Association class, history of coronary artery bypass grafting, percutaneous coronary intervention, or ventricular arrhythmias) yielded an area under the receiver operating characteristic curve of 0.82. CONCLUSIONS:The model demonstrated good discrimination in identifying patients who will survive 2 years without recurrent mitral regurgitation after mitral valve repair. Although our results require validation, they offer a clinically relevant risk score for selection of surgical candidates for this procedure.
| S-EPMC4687890 | biostudies-literature
Project description:ObjectivesThe current guidelines still do not include specific recommendations on the use of subvalvular repair (SV-r) for treatment of ischemic mitral regurgitation (IMR). Therefore, the objective of our study was to evaluate the clinical impact of mitral regurgitation (MR) recurrence and ventricular remodeling on long-term outcomes after SV-r combined with restrictive annuloplasty (RA-r).MethodsWe performed a subanalysis of the papillary muscle approximation trial, studying 96 patients with severe IMR and coronary artery disease undergoing restrictive annuloplasty alongside subvalvular repair (SV-r + RA-r group) or restrictive annuloplasty alone (RA-r group). We analyzed treatment failure differences, the influence of residual MR, left ventricular remodeling, and clinical outcomes. The primary endpoint was treatment failure (composite of death; reoperation; or recurrence of moderate, moderate-to-severe, or severe MR) within 5 years of follow-up after the procedure.ResultsA total of 45 patients showed failure of the treatment within 5 years, of which 16 patients underwent SV-r + RA-r (35.6%) and 29 underwent RA-r (64.4%, p = 0.006). Patients with significant residual MR presented with a higher rate of all-cause mortality at 5 years compared with trivial MR (HR 9.09, 95% CI 2.08-33.33, p = 0.003). MR progression occurred earlier in the RA-r group, as 20 patients in the RA-r group vs. 6 in SV-r + RA-r group had a significant MR 2 years after surgery (p = 0.002).ConclusionsRA-r remains a surgical mitral repair technique with an increased risk of failure and mortality at 5 years compared with SV-r. The rates of recurrent MR are higher, and recurrence occurs earlier, with RA-r alone compared to SV-r. The addition of the subvalvular repair increases the durability of the repair, thus extending all of the benefits of preventing MR recurrence.
| S-EPMC10053850 | biostudies-literature
Project description:Dr. O.P. Yadava, Editor-in-Chief, IJTC, and Dr. J.L. Pomar, Former President, EACTS, discuss issues related to secondary mitral regurgitation (MR). Though it is considered a ventricular disease, mitral valve leaflets are not entirely normal. Alignment of subvalvular apparatus plays a more dominant role than annular dilatation. Early repair is preferred.
| S-EPMC7525855 | biostudies-literature
Project description:BackgroundLeft ventricular pseudoaneurysm (LVPA) is an infrequent but highly lethal complication of myocardial infarction. Early surgical repair with a resection of pseudoaneurysm is often performed, given that medical therapy alone is associated with a high risk of mortality. This report describes a case of a giant LVPA on the lateral wall post-infarction and mitral valve regurgitation that was successfully treated by surgical transatrial closure and mitral valve replacement.Case summaryA 77-year-old man with chronic kidney disease and a history of percutaneous coronary interventions for acute myocardial infarction was referred to the cardiac surgeons because of a spontaneous finding of an abnormal mass adjacent to the heart on imaging studies, which was missed on a chest radiograph obtained 3 months earlier. Cardiac studies revealed LVPA and severe mitral regurgitation with poor ejection fraction. Early repair of LVPA and concurrent mitral valve surgery were recommended. Transatrial patch closure and mitral valve replacement were performed using an interatrial approach via median sternotomy. Although the patient's post-operative course was complicated by congestive heart failure and irreversible renal failure, he was discharged with good functional status after 1 month of intermittent renal replacement therapy with haemodialysis.DiscussionTransatrial repair of LVPA and concurrent mitral valve replacement can be a treatment of choice for reducing surgical trauma to the left ventricle and protecting the sealing structure from rupture.
| S-EPMC11328527 | biostudies-literature
Project description:Rationale: Ischemic mitral regurgitation (IMR) is frequently observed following myocardial infarction (MI) and is associated with higher mortality and poor clinical prognosis if left untreated. Accumulating evidence suggests that mitral valve (MV) leaflets actively remodel post-MI, yet the cellular mechanisms underlying these responses and how this affects tissue function remain largely unknown. Objective: We sought to elucidate MV remodeling post-MI at the tissue, cellular, and transcriptomic levels. Methods and Results: The mechanical behavior of ovine MV leaflets pre-MI and 8 weeks post-MI reveal a significant decrease in radial direction extensibility, which essentially eliminated the mechanical anisotropy typically observed in healthy MVs. Quantitative histology and ultrastructural assessment by transmission electron microscopy revealed altered leaflet composition and architecture at 8 weeks post-MI. Assessment of the MV interstitial cell (MVIC) nuclear aspect ratio, a metric of cellular deformation, revealed that MVICs were on average rounder following MI. RNA sequencing (RNA-seq) indicated that YAP-induced genes were elevated at 4 weeks post-MI and genes related to extracellular matrix organization were some of the most downregulated in sheep with IMR compared to sheep without IMR at 4 weeks post-MI. Additionally, RNA-seq revealed the possible recruitment of immune cells in this remodeling process due to the drastic elevation of CXCL9 and CLEC10A. Conclusions: This multiscale assessment revealed significant mechanical and microstructural changes due to MI. RNA-seq provided a baseline for global gene expression changes in response to MI with and without IMR and suggests YAP-induced mechanotransduction, altered expression of ECM-related genes, and recruitment of immune cells as mechanisms contributing to altered MV biomechanics post-MI. Conclusions: This multiscale assessment revealed significant mechanical and microstructural changes due to MI. RNA-seq provided a baseline for global gene expression changes in response to MI with and without IMR and suggests YAP-induced mechanotransduction, altered expression of ECM-related genes, and recruitment of immune cells as mechanisms contributing to altered MV biomechanics post-MI.
2020-05-06 | GSE139921 | GEO
Project description:This review outlines the first trial experience with transcatheter therapy for mitral regurgitation (MR), developed from the EVEREST II MitraClip trial in a trial population comprised predominantly of patients with degenerative mitral regurgitation (DMR). Subsequent experience with MitraClip and several other devices has been mostly in functional MR patients. At the same time, there has been ongoing experience with MitraClip in DMR, and a variety of other devices have been developed for catheter-based treatment of MR. Annuloplasty devices have been indicated for DMR, and the potential for transcatheter annuloplasty to be used, in conjunction with other catheter techniques, such as chordal replacement, as it is in standard mitral repair, is developing. Transcatheter mitral valve replacement will clearly have some role for MR of both functional and degenerative etiologies, when repair is not feasible or fails. This review will discuss the evidence base and future development of these mitral repair and replacement approaches for DMR.
| S-EPMC6288224 | biostudies-other
Project description:AimsSecondary mitral regurgitation (MR) drives adverse remodelling towards late heart failure stages. Little is known about the evolution of MR under guideline-directed therapy (GDT) and its relation to cardiac remodelling and outcome. We therefore aimed to assess incidence, impact, and predictors of progressive secondary MR in patients under GDT.Methods and resultsWe prospectively enrolled 249 patients with chronic heart failure and reduced ejection fraction receiving GDT in this long-term observational study. Of patients with non-severe MR at baseline 81% remained stable whereas 19% had progressive MR. Those patients were more symptomatic (P < 0.001), had higher neurohumoral activation (encompassing various neurohumoral pathways in heart failure, all P < 0.05), larger left atrial size (P = 0.004) and more tricuspid regurgitation (TR, P = 0.02). During a median follow-up of 61 months (IQR 50-72), 61 patients died. Progression of MR conveyed an increased risk of mortality-univariately (HR 2.33; 95% CI 1.34-4.08; P = 0.003), that persisted after multivariate adjustment using a bootstrap-selected confounder model (adjusted HR 2.48; 95% CI 1.40-4.39; P = 0.002). In contrast, regression of MR was not associated with a beneficiary effect on outcome (crude HR 0.84; 95% CI 0.30-2.30; P = 0.73).ConclusionsEvery fifth patient with chronic heart failure suffers from MR progression. This entity is associated with a more than two-fold increased risk of death even after careful multivariable adjustment. Symptomatic status, left atrial size, TR, and neurohumoral pathways help to identify patients at risk for progressive secondary MR in an early disease process and open the possibility for closer follow-up and timely intervention.
| S-EPMC6458899 | biostudies-literature
Project description:AimThe objective of this study was to investigate the prognostic importance of right ventricular dysfunction (RVD) and tricuspid regurgitation (TR) in patients with moderate-severe functional mitral regurgitation (FMR) receiving MitraClip procedure. RVD and TR grade are associated with cardiovascular mortality in the general population and other cardiovascular diseases. However, there are limited data from observational studies on the prognostic significance of RVD and TR in FMR receiving MitraClip procedure.Methods and resultsA systemic review and meta-analysis were performed using MEDLINE, Scopus, and Embase to assess the prognostic value of RVD and TR grade for mortality in patients with functional mitral regurgitation (FMR) receiving MitraClip procedure. Hazard ratios were extracted from multivariate models reporting on the association of RVD and TR with mortality and described as pooled estimates with 95% confidence intervals. A total of eight non-randomized studies met the inclusion criteria with seven studies having at least 12 months follow-up with a mean follow-up of 20.9 months. Among the aforementioned studies, a total of 1112 patients (71.5% being male) were eligible for being included in our meta-analysis with an overall mortality rate of 28.4% (n = 316). Of the enrolled patients, RVD was present in 46.1% and moderate-severe TR in 29.2%. RVD was significantly associated with mortality compared to normal RV function (HR, 1.79, 95% CI, 1.39-2.31, P < 0.001, I2 = 0). Patients with moderate-severe TR showed increased risk of mortality compared with those in the none-mild TR group (HR, 1.61. 95% CI, 1.11-2.33, P = 0.01, I2 = 14).ConclusionsThis meta-analysis demonstrates the prognostic importance of RVD and TR grade in predicting all-cause mortality in patients with significant FMR. RV function and TR parameters may therefore be useful in the risk stratification of patients with significant FMR undergoing MitraClip procedure.
| S-EPMC8712790 | biostudies-literature
Project description:Ischemic mitral regurgitation is an important consequence of LV remodeling after myocardial infarction. Echocardiographic diagnosis and assessment of ischemic mitral regurgitation are critical to gauge its adverse effects on prognosis and to attempt to tailor rational treatment strategy. There is no single approach to the echocardiographic assessment of ischemic mitral regurgitation: standard echocardiographic measures of mitral regurgitation severity and of LV dysfunction are complemented by assessments of displacement of the papillary muscles and quantitative indices of mitral valve deformation. Development of novel approaches to understand mitral valve geometry by echocardiography may improve understanding of the mechanism, clinical trajectory, and reparability of ischemic mitral regurgitation.
| S-EPMC4277822 | biostudies-other