Echocardiographic Assessment of Degenerative Mitral Stenosis: A Diagnostic Challenge of an Emerging Cardiac Disease

A review regarding the article 'clinical and echocardiographic outcomes of patients undergoing transcatheter edge-to-edge repair for functional vs degenerative mitral valve regurgitation'

Echocardiography is widely available in most cardiac centers, plays a key role in both the diagnosis and management of IE, is often the first-hand imaging modality, and should be performed immediately when mitral regurgitation is suspected. In addition, it is helpful during therapy and after surgery to assess valve morphology and function, complications, and heart function. In particular, transthoracic echocardiography is useful to detect new silent complications, monitor vegetation size, assess perivalvular abscess formation, pseudoaneurysm, intracardiac fistula and valvular perforation, as well as examine the embolic risk. In addition, echocardiographic outcomes differences among cardiovascular outcomes assessment of the MitraClip percutaneous therapy for heart failure patients with functional mitral regurgitation (COAPT) like and non COAPT-like patients have shown that non COAPT-like patients had higher left ventricular (LV) dimensions and overall contractility therefore, differences in clinical outcomes have been underestimated. Mitral transcatheter edge-to-edge repair (MTEER) is an established therapeutic approach for mitral regurgitation (MR). Recurrence of MR after TEER with MitraClip is a concern due to increased patients' hospital readmission rate and increasing hospital costs. However, little is known about clinical, valvular, or ventricular parameters that may impact postinterventional course and recurrence of MR after TEER. While individual long-term echocardiographic outcomes of functional vs degenerative MR have been described, there is little data on follow-up echocardiographic outcomes comparing functional vs degenerative MR.

Management of mitral stenosis: a systematic review of clinical practice guidelines and recommendations

A number of guidelines exist with recommendations for diagnosis and management of mitral stenosis (MS). We systematically reviewed existing guidelines for diagnosis and management of MS, highlighting their similarities and differences, in order to guide clinical decision-making. We searched national and international guidelines in MEDLINE and EMBASE (5/4/2011-5/9/2021), the Guidelines International Network, Guideline Library, National Guideline Clearinghouse, National Library for Health Guidelines Finder, Canadian Medical Association Clinical Practice Guidelines Infobase, and websites of relevant organizations. Two independent reviewers screened titles and abstracts, and the full text of potentially relevant articles where needed. Selected guidelines were assessed for rigor of development; only guidelines with Appraisal of Guidelines for Research and Evaluation II instrument score >50% were included in the final analysis. Four guidelines were retained for analysis. There was consensus for percutaneous mitral balloon commissurotomy as first-line treatment of symptomatic severe rheumatic MS with suitable anatomy. In patients with unfavourable anatomy, surgical intervention should be considered. Exercise testing is indicated if discrepancy exists between symptoms and echocardiographic measurements. There was no clear divide between rheumatic MS and degenerative MS for their respective diagnoses and management. Pregnancy in severe MS is discouraged and the stenosis should be treated before conception. Long-term antibiotic prophylaxis is recommended for patients with rheumatic MS. Recommendations for the management of patients with mixed valvular diseases are lacking.

Valvular Heart Disease in Patients with Chronic Kidney Disease

Valvular heart disease (VHD) is highly prevalent in patients with chronic kidney disease (CKD) from the early stages to end-stage renal disease (ESRD). Aortic and mitral valves are the most frequently affected, leading to aortic valve and/or mitral annular calcification, which, in turn, causes either valve stenosis or regurgitation at an accelerated rate compared with the general population. Tricuspid regurgitation is also prevalent in CKD and ESRD, and haemodialysis patients are at an increasingly high risk of infective endocarditis. As for pathophysiology, several mechanisms causing VHD in CKD have been proposed, highlighting the complexity of the process. Echocardiography constitutes the gold standard for the assessment of VHD in CKD/ESRD patients, despite the progress of other imaging modalities. With regard to treatment, the existing 2017 European Society of Cardiology/European Association for Cardio-Thoracic Surgery guidelines on the management of VHD addressing patients with normal kidney function are also applied to patients with CKD/ESRD.

The Relationship Between Primary Knee Osteoarthritis and Aortic Stiffness, Distensibility, and Valve Calcifications: A Case-Control Study

OBJECTIVE

The purpose of our study was to evaluate aortic stiffness and distensibility changes and the presence of aortic and mitral valve calcifications in patients with primary knee osteoarthritis (OA), using 2-dimensional and Doppler transthoracic echocardiography.

METHODS

This case-control study included 115 participants with OA and a control group between May 2019 and November 2019. The Kellgren-Lawrence classification was used for the diagnosis and classification of knee OA, based on radiological images. We compared the demographic data, 2-dimensional and Doppler transthoracic echocardiography results, and laboratory findings between the OA patient group and the control group.

RESULTS

There was a significant difference between aortic strain, aortic distensibility, aortic stiffness, and C-reactive protein values between the OA patient group and the control group (p < 0.001 for all). Post hoc analyses revealed that aortic strain and aortic distensibility values were significantly lower, and aortic stiffness values were significantly higher in the grade 4 OA group than those of other groups (p < 0.05 for all). In addition, the C-reactive protein values of the grades 3 and 4 patients were significantly higher than those of other groups (p < 0.05 for all). No significant difference was observed between the groups in terms of aortic and mitral valve calcifications (p > 0.05 for all).

CONCLUSION

Aortic strain and distensibility values were lower in the advanced grades of primary knee OA, whereas aortic stiffness values and the frequency of valve calcifications were higher.

The CirCor DigiScope Dataset: From Murmur Detection to Murmur Classification

Cardiac auscultation is one of the most cost-effective techniques used to detect and identify many heart conditions. Computer-assisted decision systems based on auscultation can support physicians in their decisions. Unfortunately, the application of such systems in clinical trials is still minimal since most of them only aim to detect the presence of extra or abnormal waves in the phonocardiogram signal, i.e., only a binary ground truth variable (normal vs abnormal) is provided. This is mainly due to the lack of large publicly available datasets, where a more detailed description of such abnormal waves (e.g., cardiac murmurs) exists. To pave the way to more effective research on healthcare recommendation systems based on auscultation, our team has prepared the currently largest pediatric heart sound dataset. A total of 5282 recordings have been collected from the four main auscultation locations of 1568 patients, in the process, 215780 heart sounds have been manually annotated. Furthermore, and for the first time, each cardiac murmur has been manually annotated by an expert annotator according to its timing, shape, pitch, grading, and quality. In addition, the auscultation locations where the murmur is present were identified as well as the auscultation location where the murmur is detected more intensively. Such detailed description for a relatively large number of heart sounds may pave the way for new machine learning algorithms with a real-world application for the detection and analysis of murmur waves for diagnostic purposes.

Impact of Mitral Annular Calcium and Mitral Stenosis on Outcomes After Transcatheter Aortic Valve Implantation

Mitral annular calcium (MAC) is a common finding in patients undergoing transcatheter aortic valve implantation (TAVI) and may be associated with mitral stenosis (MAC-MS). Their impact on post-TAVI outcomes remains controversial. We sought to assess the impact of MAC and MAC-MS on clinical outcomes following TAVI. We included 1,177 patients who consecutively underwent TAVI in our institution between January 2008 and May 2018. MAC diagnosis reposed on echocardiogram and computed tomography. The combination of MAC and a mean transmitral gradient ≥ 5 mmHg defined MAC-MS. The study included 1,177 patients, of whom 504 (42.8%) had MAC and 85 (7.2%) had MAC-MS. Patients with and without MAC had similar outcomes except for a higher rate of pacemaker implantation in MAC patients (adjusted HR: 1.32, 95% CI: 1.03-1.69, p = 0.03). The subgroup of patients with severe MAC had similar outcomes. However, MAC-MS was an independent predictor of all-cause mortality at 30 days (adjusted HR: 2.30, 95% CI: 1.08-4.86, p = 0.03) and 1 year (adjusted HR: 1.73, 95% CI: 1.04-2.89, p = 0.04). In conclusion, MAC is present in nearly half of the patients treated with TAVI but MAC-MS is far less frequent. In itself, even severe, MAC does not influence outcomes while MAC-MS is an independent predictor of all-cause 1-year mortality. Measurement of mean transmitral gradient identifies patients with MAC at high risk after TAVI.

Prognostic importance of the transmitral pressure gradient in mitral annular calcification with associated mitral valve dysfunction

AIMS

The aim of this study was to define the natural history of patients with mitral annular calcification (MAC)-related mitral valve dysfunction and to assess the prognostic importance of mean transmitral pressure gradient (MG) and impact of concomitant mitral regurgitation (MR).

METHODS AND RESULTS

The institutional echocardiography database was examined from 2001 to 2019 for all patients with MAC and MG ≥3 mmHg. A total of 5754 patients were stratified by MG in low (3-5 mmHg, n = 3927), mid (5-10 mmHg, n = 1476), and high (≥10 mmHg, n = 351) gradient. The mean age was 78 ± 11 years, and 67% were female. MR was none/trace in 32%, mild in 42%, moderate in 23%, and severe in 3%. Primary outcome was all-cause mortality, and outcome models were adjusted for age, sex, and MAC-related risk factors (hypertension, diabetes, coronary artery disease, chronic kidney disease). Survival at 1, 5, and 10 years was 77%, 42%, and 18% in the low-gradient group; 73%, 38%, and 17% in the mid-gradient group; and 67%, 25%, and 11% in the high-gradient group, respectively (log-rank P < 0.001 between groups). MG was independently associated with mortality (adjusted HR 1.064 per 1 mmHg increase, 95% CI 1.049-1.080). MR severity was associated with mortality at low gradients (P < 0.001) but not at higher gradients (P = 0.166 and 0.372 in the mid- and high-gradient groups, respectively).

CONCLUSION

In MAC-related mitral valve dysfunction, mean transmitral gradient is associated with increased mortality after adjustment for age, sex, and MAC-related risk factors. Concomitant MR is associated with excess mortality in low-gradient ranges (3-5 mmHg) but gradually loses prognostic importance at higher gradients, indicating prognostic utility of transmitral gradient in MAC regardless of MR severity.

Energy loss associated with in-vitro modeling of mitral annular calcification

Introduction

Study aims were to compare hemodynamics and viscous energy dissipation (VED) in 3D printed mitral valves–one replicating a normal valve and the other a valve with severe mitral annular calcification (MAC). Patients with severe MAC develop transmitral gradients, without the commissural fusion typifying rheumatic mitral stenosis (MS), and may have symptoms similar to classical MS. A proposed mechanism relates to VED due to disturbed blood flow through the diseased valve into the ventricle.

Methods

A silicone model of a normal mitral valve (MV) was created using a transesophageal echocardiography dataset. 3D printed calcium phantoms were incorporated into a second valve model to replicate severe MAC. The synthetic MVs were tested in a left heart duplicator under rest and exercise conditions. Fine particles were suspended in a water/glycerol blood analogue for particle image velocimetry calculation of VED.

Results

Catheter mean transmitral gradients were slightly higher in the MAC valve compared to the normal MV, both at rest (3.2 vs. 1.3 mm Hg) and with exercise (5.9 vs. 5.0 mm Hg); Doppler gradients were 2.7 vs. 2.1 mm Hg at rest and 9.9 vs 8.2 mm Hg with exercise. VED was similar between the two valves at rest. During exercise, VED increased to a greater extent for the MAC valve (240%) versus the normal valve (127%).

Conclusion

MAC MS is associated with slightly increased transmitral gradients but markedly increased VED during exercise. These energy losses may contribute to the exercise intolerance and exertional dyspnea present in MAC patients.

Dimensionless index of the mitral valve for evaluation of degenerative mitral stenosis

PURPOSE

Degenerative mitral stenosis (DMS) is an increasingly recognized cause of mitral stenosis. The goal of this study was to compare echocardiographic differences between DMS and rheumatic mitral stenosis (RMS), identify echocardiographic variables reflective of DMS severity, and propose a dimensionless mitral stenosis index (DMSI) for assessment of DMS severity.

METHODS

This is a single-center, retrospective cohort study. We included patients with at least mild MS and a mean transmitral pressure gradient (TMPG) ≥4 mm Hg. Mitral valve area by the continuity equation (MVA_CEQ ) was used as an independent reference. The DMSI was calculated as follows: DMSI = VTI_LVOT / VTI_MV. All-cause mortality data were collected retrospectively.

RESULTS

A total of 64 patients with DMS and 24 patients with RMS were identified. MVA_CEQ was larger in patients with DMS (1.43 ± 0.4 cm² ) than RMS (0.9 ± 0.3 cm² ) by ~0.5 cm² (P = <.001), and mean TMPG was lower in the DMS group (6.0 ± 2 vs 7.9 ± 3 mm Hg, P = .003). A DMSI of ≤0.50 and ≤0.351 was associated with MVA_CEQ ≤1.5 and MVA_CEQ ≤1.0 cm² (P < .001), respectively. With the progression of DMS from severe to very severe, there was a significant drop in DMSI. There was a nonsignificant trend toward worse survival in patients with MVA_CEQ ≤1.0 cm² and DMSI ≤0.35, suggesting severe stenosis severity.

CONCLUSION

Our results show that TMPG correlates poorly with MVA in patients with DMS. Proposed DMSI may serve as a simple echocardiographic indicator of hemodynamically significant DMS.

Degenerative mitral valve stenosis: Diagnosis and management

Mitral stenosis (MS) is a common valvular disease characterized by narrowing of the mitral valve orifice and a reduction in mitral valve area (MVA). While rheumatic MS (RMS) is frequently encountered in young individuals in developing countries, degenerative MS (DMS) is seen in the elderly in developed countries and its prevalence is increasing. DMS is usually a late presentation of mitral annular calcification (MAC). Accurate assessment of MVA in patients with MAC is challenging due to the alterations in the atrial and valvular structures as well as the presence of other comorbidities in this aging population. We will review the epidemiology, etiology, pathophysiology, diagnostic assessment, and management of DMS and compare the findings with RMS. The latest therapeutic approaches, including medical, surgical, and transcatheter valvular interventions, will be discussed.

Mitral annulus calcification: current management and future challenges

Mitral annulus calcification is a chronic degenerative process in the fibrous base of the mitral valve. Assessment and treatment of mitral valve disease in patients with severe mitral annulus calcification is challenging, and a multimodal approach is helpful to delineate its severity and anatomic features, and to guide the therapeutic strategy. This article reviews the current literature to provide a clinically relevant description of mitral annulus calcification, analyze the diagnostic pathway of a patient with mitral annulus calcification, and summarize the therapeutic options.

Mitral Annular Calcification and Calcific Mitral Stenosis: Therapeutic Challenges and Considerations

PURPOSE OF REVIEW

Mitral annular calcification (MAC) and associated calcific mitral stenosis (MS) are frequent in the aging population, although optimal management remains debated and outcomes are poor. This article summarizes challenges in the diagnosis and therapy of calcific MS, the indications for valve intervention, procedural concerns, and emerging treatment options.

RECENT FINDINGS

Surgical mitral valve replacement is the procedure of choice in symptomatic patients at acceptable surgical risk, with transcatheter mitral valve replacement (TMVR) being evaluated in clinical trials as an alternative for patients at prohibitive surgical risk. Significant challenges exist with the currently available technology and outcomes have been suboptimal. Optimizing the patient-selection process by using multimodality imaging tools has proven to be essential. MAC and calcific MS is an increasingly prevalent, challenging issue with poor outcomes. While surgical valve replacement can be performed in patients with acceptable surgical risk, TMVR can be considered for patients at higher risk. Clinical trials are underway to optimize outcomes. Dedicated device designs and techniques to minimize risk of left ventricular outflow tract obstruction, paravalvular leakage, and device embolization are to be awaited.

Degenerative Mitral Stenosis: From Pathophysiology to Challenging Interventional Treatment

Mitral stenosis (MS) is characterized by obstruction of left ventricular inflow as a result of narrowing of the mitral valve orifice. Although its prevalence has declined over the last decade, especially in developed countries, it remains an important cause of morbidity and mortality.  The most often cause of MS worldwide is still postrheumatic mitral valve disease. However, in developed countries, degenerative or calcific changes cause MS in a siginificant proportion of patients. Although the range of treatment for mitral valve disease has grown over the years in parallel with transcatheter therapies for aortic valve disease, these improvements in mitral valve disease therapy have experienced slower development. This is mainly due to the more complex anatomy of the mitral valve and entire mitral apparatus, and the interplay of the mitral valve with the left ventricle which hinders the development of effective implantable mitral valve devices. This is especially the case with degenerative MS where percutaneous or surgical comissurotomy is rarely employed due to the presence of extensive annular calcification and at the base of leaflets, without associated commissural fusion. However, the last few years have witnessed innovations in transcatheter interventional procedures for degenerative MS which consequently hinted that in the future, transcatheter mitral valve replacement could be the treatment of choice for these patients.