Degenerative Mitral Stenosis

Degenerative mitral stenosis by echocardiography: presentation and outcome

AIMS

Degenerative mitral stenosis (DMS) is due to degenerative mitral annular calcification (MAC) and valvular calcification. However, DMS impacts on the outcome, and therefore, potential treatment needs are poorly known. We aimed at evaluating survival after DMS diagnosis by Doppler echocardiography in routine practice.

METHODS AND RESULTS

A cohort of 2937 (75 ± 12 years, 67% women) consecutive patients were diagnosed between 2003 and 2014 with DMS (diastolic mean gradient ≥ 5 mmHg), with analysis of short- and long-term survival. All patients had overt mitral annular/valvular degenerative calcification without rheumatic involvement. Mean gradient was 6.5 ± 2.4 mmHg, and DMS was considered mild in 50%, moderate in 44%, and severe in 6%. DMS was associated with left atrial enlargement (52 ± 23 mL/m2) and elevated pulmonary pressure (49 ± 16 mmHg) despite generally normal ejection fraction (61 ± 13%). DMS was associated with frequent comorbid conditions (74% hypertension, 58% coronary disease, and 52% heart failure) and humoural alterations (haemoglobin 11.3 ± 1.8 g/dL and creatinine 1.5 ± 1.4 mg/dL). One-year mortality was 22%, most strongly related to older age, higher comorbidity, and abnormal haemoglobin/creatinine but only weakly to DMS severity (with anaemia 42% irrespective of DMS severity, P = 0.99; without anaemia 18, 23, and 28% with mild, moderate, and severe DMS, respectively, P < 0.0004). Long-term mortality was high (56% at 5 years) also mostly linked to aging and weakly to DMS severity [with anaemia P = 0.90; without anaemia: adjusted-hazard ratio: 1.30 (1.19-1.42), P < 0.0001, for moderate vs. mild DMS and 1.63 (1.34-1.98), P < 0.0001, for severe vs. mild DMS].

CONCLUSION

DMS is a condition of the elderly potentially resulting in severe mitral obstruction and haemodynamic alterations. However, DMS is frequently associated with severe comorbidities imparting considerable mortality following diagnosis, whereas DMS severity is a weak (albeit independent) determinant of mortality. Hence, patients with DMS should be carefully evaluated and interventional/surgical treatment prudently considered in those with limited comorbidity burden, particularly without anaemia. Keywords: Degenerative Mitral Stenosis; Outcome; Natural history; Ecocardiography; Mitral Stenosis.

Transcatheter aortic valve implantation for combined aortic and mitral stenoses: Insights from the OCEAN-TAVI Registry

AIMS

Mitral stenosis (MS) occasionally coexists with aortic stenosis (AS). Limited data are available regarding the functional class and clinical outcomes of patients who undergo transcatheter aortic valve implantation (TAVI) for combined AS and MS. This study compared the clinical outcomes in patients with and without MS who underwent TAVI for severe AS and assessed the impact of mitral annulus calcification (MAC) severity, transmitral gradient (TMG) and mitral valve area (MVA) on outcomes in patients with combined AS and MS.

METHODS

We investigated patients in the OCEAN-TAVI registry who underwent TAVI. MS was defined as an MVA ≤ 1.5 cm2 or TMG ≥ 5 mmHg. The composite of all-cause death and admission for heart failure was compared between patients with and without MS. The impact of MAC, TMG and MVA on outcomes was assessed in patients with combined AS and MS.

RESULTS

We identified 106 patients with MS (MAC 84%; TMG 6.4 ± 2.6 mmHg; MVA 1.10 ± 0.31 cm2) and 6570 without MS as controls. The MS group was older (85 ± 5 vs. 84 ± 5 years, P = 0.033), more of women (85 vs. 67%, P < 0.01), and had a higher risk of surgery (the Society of Thoracic Surgeons Mortality Score 8.7 ± 5.1 vs. 7.6 ± 5.9, P = 0.047) than the controls. In the MS group, the New York Heart Association Functional Class was 3 or 4 in 56% of the patients at baseline and 6% at 1 year after TAVI. Thirty-day mortality (2.8% vs. 1.3%, P = 0.18) and early composite outcomes (17% vs. 15%, P = 0.56) were comparable between patients with and without MS. During a median follow-up of 2.1 years, the presence of MS was associated with a higher incidence of adverse events compared with controls (adjusted hazard ratio [HR] 1.84; 95% confidence interval [CI] 1.34-2.51, P < 0.01), even on propensity score matched analysis (adjusted HR 1.91; 95% CI 1.14-3.22, P < 0.01). Moderate or severe MAC contributed to increased risk of adverse events in patients with MS (adjusted HR 2.89; 95% CI 1.20-6.99, P = 0.018), but TMG and MVA did not.

CONCLUSIONS

In patients undergoing TAVI for severe AS, those with moderate or severe MS experienced worse outcomes after TAVI compared with those without MS. Patients with combined AS and MS sustained symptom improvement at 1-year post-TAVI. MAC severity was a useful predictor of adverse events compared with MS haemodynamics such as TMG and MVA in patients with combined AS and MS.

Optimizing Percutaneous Mitral Valvuloplasty for Rheumatic Mitral Stenosis - Clinical Significance of Changes in Mitral Valve Area

BACKGROUND

Percutaneous mitral valvuloplasty (PMV) is a standard treatment for severe rheumatic mitral stenosis (RMS). However, the prognostic significance of the change in mitral valve area (∆MVA) during PMV is not fully understood.

METHODS AND RESULTS

This study analyzed data from the Multicenter mitrAl STEnosis with Rheumatic etiology (MASTER) registry, which included 3,140 patients with severe RMS. We focused on patients with severe RMS undergoing their first PMV. Changes in echocardiographic parameters, including MVA quantified before and after PMV, and composite outcomes, including mitral valve reintervention, heart failure admission, stroke, and all-cause death, were evaluated. An optimal result was defined as a postprocedural MVA ≥1.5 cm2without mitral regurgitation greater than Grade II. Of the 308 patients included in the study, those with optimal results and ∆MVA >0.5 cm² had a better prognosis (log-rank P<0.001). Patients who achieved optimal results but with ∆MVA ≤0.5 cm² had a greater risk of composite outcomes than those with optimal outcomes and ∆MVA >0.5 cm² (nested Cox regression analysis, hazard ratio 2.27; 95% confidence interval 1.09-4.73; P=0.028).

CONCLUSIONS

Achieving an increase in ∆MVA of >0.5 cm2was found to be correlated with improved outcomes. This suggests that, in addition to achieving traditional optimal results, targeting an increase in ∆MVA of >0.5 cm2could be a beneficial objective in PMV treatment for RMS.

Controlled mitral valvuloplasty using steerable catheter- waist- formed balloon system: A clinical case series

As the general population ages, the incidence of degenerative mitral stenosis (MS) among patients has increased. Percutaneous mitral valvuloplasty (PMV) has emerged as a well-established option for mitral rheumatic stenosis with specific characteristics. However, a blank therapeutic space must be filled with the treatment options for degenerative or rheumatic mitral stenosis in patients with many comorbidities and contraindication for valvuloplasty. We here present a comprehensive overview of the current possibilities, despite their scarce success. That is the reason why we propose a case series to facilitate a better understanding of our innovative technique in this challenging clinical context.

New therapeutic perspectives for vascular and valvular calcifications in chronic kidney disease

PURPOSE OF REVIEW

Vascular and valvular calcification are associated with cardiovascular morbidity and mortality in people with chronic kidney disease (CKD). Uncertainty exists regarding therapeutic strategies to attenuate calcification. This review outlines the pathophysiological mechanisms contributing to vascular and valvular calcification, considers the mechanisms of action of therapeutic interventions, and reports the latest outcomes from interventional studies.

RECENT FINDINGS

Conventional therapies targeted at CKD-mineral and bone disorder (MBD) modulation have yielded conflicting or inconclusive results. Magnesium and vitamin K supplementation appear to offer attenuation of coronary artery calcification but inconsistent findings justify the need for further studies. Strategies targeting hydroxyapatite formation such as sodium thiosulphate and hexasodium fytate show promise and are worthy of further evaluation. The serum calcification propensity assay (T50) correlates with severity and progression; it holds promise as a potential future clinical tool for screening monitoring calcification risk.

SUMMARY

Whilst knowledge of the pathophysiology of vascular calcification has grown and therapeutic approaches appear promising, as yet no medication has been approved to treat vascular or valvular calcification, or calciphylaxis.

Predictors and clinical outcomes of true mitral stenosis in patients undergoing transcatheter aortic valve implantation

Aims

Predictors of true degenerative mitral stenosis (MS) in patients with aortic stenosis who underwent transcatheter aortic valve implantation (TAVI) remain unknown. This study aimed to investigate the predictors and prognostic value of true degenerative MS in this population.

Methods and results

We retrospectively reviewed the records of 760 consecutive patients who underwent TAVI. The mitral valve area (MVA) was assessed using transthoracic echocardiography, and mitral valve calcification was assessed using multi-detector computed tomography. MS was defined as an MVA of ≤2.0 cm², and true MS was defined as moderate or severe MS following TAVI. In our TAVI cohort, we identified 72 (9.5%) patients with degenerative MS. Among these, true MS was observed in 38 (52.7%) patients. Echocardiographic data showed that the true MS group had a significantly lower MVA and higher trans-mitral gradient. The severity of mitral annular calcification was not significantly different between the two groups; however, the true MS group had significantly more posterior mitral leaflet and anterior mitral leaflet (AML) calcification. Multivariable logistic regression analysis showed that AML calcification was the independent predictor of true MS [adjusted odds ratio, 9.23; 95% confidence interval (CI) 2.84-29.9]. True MS was independently associated with poor prognosis (adjusted hazard ratio, 2.76; 95% CI 1.09-6.98).

Conclusion

Approximately half of the patients with concomitant degenerative MS who underwent TAVI had true MS, which was associated with a poor prognosis. Computed tomographic analysis of AML calcification was useful for predicting true MS.

2024 CSANZ Position Statement on Indications, Assessment and Monitoring of Structural and Valvular Heart Disease With Transthoracic Echocardiography in Adults

Transthoracic echocardiography (TTE) is the most widely available and utilised imaging modality for the screening, diagnosis, and serial monitoring of all abnormalities related to cardiac structure or function. The primary objectives of this document are to provide (1) a guiding framework for treating clinicians of the acceptable indications for the initial and serial TTE assessments of the commonly encountered cardiovascular conditions in adults, and (2) the minimum required standard for TTE examinations and reporting for imaging service providers. The main areas covered within this Position Statement pertain to the TTE assessment of the left and right ventricles, valvular heart diseases, pericardial diseases, aortic diseases, infective endocarditis, cardiac masses, pulmonary hypertension, and cardiovascular diseases associated with cancer treatments or cardio-oncology. Facilitating the optimal use and performance of high quality TTEs will prevent the over or under-utilisation of this resource and unnecessary downstream testing due to suboptimal or incomplete studies.

Transcatheter mitral valve implantation versus conventional redo surgery for degenerated mitral valve prostheses and rings in a multicenter registry

OBJECTIVES

Degeneration of mitral prostheses/rings may be treated by redo surgery, and, recently, by transcatheter valve-in-valve/ring implantation. This multicenter registry presents results of transcatheter valve-in-valve and repeat surgery for prostheses/rings degeneration.

METHODS

Data provided by 10 German heart centers underwent propensity score-matched retrospective analysis. The primary endpoint was 30-day/midterm mortality. Perioperative outcome was assessed according to the Mitral Valve Academic Research Consortium criteria. Further, the influence of moderate or greater tricuspid regurgitation (TR) on 30-day/midterm mortality was analyzed.

RESULTS

Between 2014 and 2019, 273 patients (79 transcatheter mitral valve-in-valve [TM-ViV] and 194 redo mitral valve replacement [Re-MVR]) underwent repeat procedure for mitral prosthesis/ring degeneration. Propensity score matching distinguished 79 patient pairs. European System for Cardiac Operative Risk Evaluation (EuroSCORE) II-predicted risk was 15.7 ± 13.7% in the TM-ViV group and 15.0% ± 12.7% in the Re-MVR group (P = .5336). TM-ViV patients were older (74.73 vs 72.2 years; P = .0030) and had higher incidence of atrial fibrillation (54 vs 40 patients; P = .0233). Severe TR incidence was similar (17.95% in TM-ViV vs 14.10%; P = .1741). Sixty-eight TM-ViV patients previously underwent mitral valve replacement, whereas 41 Re-MVR patients underwent valve repair (P < .0001). Stenosis was the leading degeneration mechanism in 42 TM-ViV versus 22 Re-MVR patients (P < .0005). The 30-day/midterm mortality did not differ between groups. Moderate or greater TR was a predictor of total (odds ratio [OR], 4.36; P = .0011), 30-day (OR, 3.76; P = .0180), and midterm mortality (OR, 4.30; P = .0378), irrespective of group.

CONCLUSIONS

In both groups, observed mortality was less than predicted. Redo surgery enabled treatment of concomitant conditions, such as atrial fibrillation or TR. TR was shown to be a predictor of total, 30-day, and midterm mortality in both groups.

Alerting trends in epidemiology for non-rheumatic degenerative mitral valve disease, 1990-2019: An age-period-cohort analysis for the Global Burden of Disease Study 2019

BACKGROUND

The global and national burden of rheumatic mitral valve disease (MVD) has been well studied and estimated before. However, little is known about non-rheumatic degenerative MVD. Therefore, this study aimed to assess the trends in non-rheumatic degenerative MVD (NRDMVD) epidemiology, with an emphasis on NRDMVD mortality, leading risk factors, and their associations with age, period, and birth cohort.

METHODS

Using the data derived from the Global Burden of Disease Study 2019, including prevalence, mortality, and disability-adjusted life years, we analyzed the burden of NRDMVD and the detailed trends of NRDMVD mortality over the past 30 years in 204 countries and territories by implementing the age-period-cohort framework.

RESULTS

Globally, the number of deaths due to NRDMVD increased from 5695.89 (95% uncertainty interval [UI]: 5405.19 to 5895.4) × 1000 in 1990 to 9137.79 (95% UI: 8395.68 to 9743.55) × 1000 in 2019. The all-age mortality rate increased from 106.47 (95% UI: 101.03 to 110.2) per 100,000 to 118.1 (95% UI: 108.51 to 125.93) per 100,000, whereas the age-standardized mortality rate decreased from 170.45 (95% UI: 159.61 to 176.94) per 100,000 to 117.95 (95% UI: 107.83 to 125.92) per 100,000. The estimated net drift of mortality per year was -1.1% (95% confidence interval: -1.17 to -1.04). The risk of death due to NRDMVD increased with age, reaching its peak after 85 years old globally. Despite female patients being associated with lower local drift than male patients, no significant gender differences were observed in the age effect across countries and regions for all sociodemographic index (SDI) levels, except low-SDI regions.

CONCLUSIONS

We estimated the global disease prevalence of and mortality due to NRDMVD over approximately a 30-year period. The health-related burden of NRDMVD has declined worldwide; however, the condition persisted in low-SDI regions. Moreover, higher attention should be paid to female patients.

Risk Factors and Outcomes With Progressive Mitral Annular Calcification

Background Mitral annular calcification (MAC) is a chronic degenerative process that may progress. This study aimed to investigate associating factors and clinical implications of MAC progression. Methods and Results Among 560 patients with MAC identified by transthoracic echocardiography between January 2012 and June 2016, 138 patients (mean±SD age 72.7±10.2 years, 73 women) with mild or moderate MAC who received follow-up examination within 18 to 36 months were retrospectively analyzed. Progressive MAC was defined as hemodynamic or structural profiles that had worsened by more than 1 grade. Hemodynamic features were assessed by the transmitral mean diastolic pressure gradient (MDPG), and structural features were assessed by the MAC angle in the parasternal short-axis view. The clinical outcome was defined as a composite of all-cause mortality, hospitalization for heart failure, and occurrence of ischemic stroke. Forty-three patients (31.2%) showed progressive MAC. Patients with progressive MAC had higher systolic blood pressure, pulse pressure, MAC angle, and MDPG than those with stable MAC. Patients with progressive MAC had smaller left ventricular (LV) end-systolic dimensions and higher LV ejection fractions compared with those with stable MAC. In multivariate analysis, pulse pressure, LV ejection fraction, MAC angle, and MDPG at baseline were significantly associated with MAC progression. During a median of 39.2 months' follow-up, patients with progressive MAC showed poorer clinical outcomes than those with stable MAC (log-rank P=0.015). Conclusions MAC progression is not rare and is associated with structural substrate and hemodynamic loads that result in mechanical stress. Patients with progressive MAC have poor outcomes.

Outcome of Patients With Both Moderate Aortic Stenosis and Moderate Mitral Stenosis

Aims

This study aimed to investigate the symptoms and prognosis of patients with both moderate aortic stenosis (AS) and mitral stenosis (MS).

Methods and Results

We studied 82 patients with moderate AS and MS diagnosed via transthoracic echocardiography. The patients had a mean age of 79 ± 13 years and 95% of patients had degenerative MS. Out of 82 patients, 34 (41%) had heart failure (HF) symptoms (New York Heart Association class ≥ Ⅱ) or a history of HF admission. Left ventricular ejection fraction, stroke volume index, atrial fibrillation, and right ventricular systolic pressure were independent determinants of HF symptoms. The median follow-up duration was 3.2 (interquartile range, 1.0-4.9) years and clinical events occurred in 48 (59%) patients, including death in 11 (13%) patients, aortic or mitral valve interventions in 22 (27%) patients, and HF hospitalization in 15 (18%) patients. The 5-year survival free of the combined endpoint of aortic or mitral valve interventions, HF hospitalization, or death was 19%. A multivariate predictor of clinical events was HF symptoms (hazard ratio [HR], 2.32; 95% confidence interval [CI], 1.30-4.14; p = 0.0045). Kaplan-Meier survival at 5 years was 61% without intervention and HF symptoms were not associated with mortality.

Conclusions

Among patients with both moderate AS and MS, left ventricular ejection fraction, stroke volume index, atrial fibrillation, and right ventricular systolic pressure were strong determinants of HF symptoms. HF symptoms were independently predictive of clinical events.

Myocardial infarction induced by caseous mitral annular calcification: a case report

Background

Caseous mitral annular calcification (CMAC) is a rare variant of mitral annular calcification. Symptoms can be related to mitral valvular dysfunction, arterial embolization, and transient aortic outflow tract obstruction. CMAC usually affects the posterior fibrous mitral annulus and is commonly diagnosed in elderly patients with a history of hypertension, dyslipidaemia, and renal failure.

Case summary

A 68-year-old patient was transferred to our department for late presenting acute myocardial infarction and acute heart failure. Coronary angiography revealed a significant extrinsic compression of the circumflex artery. Transthoracic echocardiography revealed an ovoid calcified mass of 3.6 cm × 2 cm originating from the posterior mitral annulus causing moderate mitral stenosis as well as akinesia of the inferolateral wall, reduced left ventricle ejection fraction (35%), and a low-flow low-gradient severe aortic stenosis. Cardiac computed tomography scan confirmed the presence of a large calcified mass, inserted to the posterior mitral annulus evocating caseous necrosis. The patient underwent a double valve replacement with implantation of both aortic and mitral bioprostheses. Histopathology of the excised mass revealed a chronic mitral valve fibrocalcification with aseptic necrosis, consistent with a caseous calcification of the posterior mitral annulus.

Discussion

Extrinsic coronary artery compression is a rare disease entity. We report a rather peculiar cause of extrinsic artery compression: CMAC inducing significant mitral stenosis and compressing the circumflex artery leading to myocardial infarction. To the best of our knowledge, this is the first case of extrinsic artery compression caused by CMAC.

An Overview of Sport Participation and Exercise Prescription in Mitral Valve Disease

The incidence of heart valve disease (HVD) has been rising over the last few decades, mainly due to the increasing average age of the general population, and mitral valve (MV) disease is the second most prevalent HVD after calcific aortic stenosis, but MV disease is a heterogeneous group of different pathophysiological diseases. It is widely proven that regular physical activity reduces all-cause mortality rates, and exercise prescription is part of the medical recommendations for patients affected by cardiovascular diseases. However, changes in hemodynamic balance during physical exercise (including the increase in heart rate, preload, or afterload) could favor the progression of the MV disease and potentially trigger major cardiac events. In young patients with HVD, it is therefore important to define criteria for allowing competitive sport or exercise prescription, balancing the positive effects as well as the potential risks. This review focuses on mitral valve disease pathophysiology, diagnosis, risk stratification, exercise prescription, and competitive sport participation selection, and offers an overview of the principal mitral valve diseases with the aim of encouraging physicians to embody exercise in their daily practice when appropriate.

Novel 3D Echocardiographic Technique for Mitral Calcium Mapping

Mitral annular calcification (MAC) is a common chronic degenerative process of the mitral valve fibrous support ring. MAC increases the risk of mitral valve dysfunction, all-cause and cardiovascular mortality, and worse outcomes in cardiac interventions. Echocardiography represents the first imaging modality for MAC assessment, but it has low specificity compared to cardiac CT in terms of distinguishing between calcium and dense collagen. Novel three-dimensional transesophageal maximal intensity projection (MIP) mapping allows for the real-time MAC distribution and depth visualization of the cardiac anatomy and represents a useful and promising tool for pre-procedural assessment and intra-procedural guidance of cardiac interventions.

Risk of stroke or systemic embolism in patients with degenerative mitral stenosis with or without atrial fibrillation: A cohort study

Background

Atrial fibrillation (AF) is associated with an increased risk of stroke and the combination of AF and mitral stenosis (MS) is associated with a higher risk. In developed nations, degenerative mitral stenosis (DMS) constitutes a sizeable proportion of patients with MS. Current international guidelines do not offer recommendations regarding anticoagulation in these patients. The objective of this study was to describe the incidence of stroke or systemic embolism in patients with DMS with or without prevalent AF.

Methods

A cohort study of DMS patients from 1997 to 2018, using data from the Danish health registries. The cohort was stratified based on AF prevalence and prior ischemic stroke. The primary outcome was a diagnosis of ischemic stroke or systemic embolism after 1 year of follow-up from time of DMS diagnosis.

Results

The study included 1162 patients with DMS, of which 421 had prevalent AF. The incidence rate of stroke or systemic embolism after 1 year of follow-up was highest in the DMS without AF group (7.58 vs. 6.63 per 100 person-years). In both groups, DMS without AF and DMS with AF, the incidence rate was highest in patients with prior thromboembolic events (29.61 vs. 5.15 and 19.53 vs. 5.15, respectively).

Conclusions

The incidence rate of stroke or systemic embolism was highest in DMS patients without AF. Current Danish guidelines recommend DMS patients should be treated with anticoagulation only with concurrent AF, yet our results call for additional research to establish if DMS patients without AF could benefit from stroke prevention therapy.

Mitral valve stenosis in the current era: a changing landscape

Mitral stenosis results from haemodynamic obstruction at the mitral valve level because of structural abnormalities of the valve apparatus, leading to increased resistance to the transmitral flow. Although rheumatic fever remains the predominant cause of mitral stenosis worldwide, other causes are increasingly relevant in the developed countries with degenerative mitral stenosis (DMS) because of mitral annulus calcification (MAC) becoming growingly prevalent in industrialized countries with higher life expectancy. Rheumatic mitral stenosis (RMS) and DMS display dramatic differences in pathophysiology, prognosis, and disease progression. Furthermore, to date, robust evidence regarding the management of DMS because of MAC is lacking. Nevertheless, new diagnostic techniques and catheter-based interventions are changing this landscape and paving the way to a significant reduction in DMS-related morbidity and mortality. Here we briefly review the current knowledge on the pathophysiology, diagnosis and treatment of DMS and RMS, underscoring the current diagnostic and therapeutic pathways, as well as persisting uncertainties and perspectives.

The Evolution of Transcatheter Therapies for Mitral Valve Disease: From Mitral Valvuloplasty to Transcatheter Mitral Valve Replacement

The prevalence of mitral valve disease has evolved over the past 5 decades from primarily a disease of rheumatic origin to a disease affecting the aging population that encompasses a range of phenotypes from rheumatic mitral stenosis, degenerative mitral regurgitation, and degenerative mitral valve calcification to secondary mitral regurgitation. A reflection on the history of therapy for mitral valve disease is an expedition that follows the birth and development of structural heart intervention from the first percutaneous balloon mitral valvuloplasty to innovative technologies for transcatheter mitral valve repair and replacement. This review will lead you along this journey, pause to acknowledge the feats accomplished, and reflect on the road that lies ahead.

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.

Mitral Valve Dysfunction in Patients With Annular Calcification: JACC Review Topic of the Week

Mitral annular calcification (MAC) is a common clinical finding and is associated with adverse clinical outcomes, but the clinical impact of MAC-related mitral valve (MV) dysfunction remains underappreciated. Patients with MAC frequently have stenotic, regurgitant, or mixed valvular disease, and this valvular dysfunction is increasingly recognized to be independently associated with worse prognosis. MAC-related MV dysfunction is a distinct pathophysiologic entity, and importantly much of the diagnostic and therapeutic paradigm from published rheumatic MV disease research cannot be applied in this context, leaving important gaps in our knowledge. This review summarizes the current epidemiology, pathophysiology, diagnosis, and classification of MAC-related MV dysfunction and proposes both an integrative definition and an overarching approach to this important and increasingly recognized clinical condition.

Natural History of Mitral Annulus Calcification and Calcific Mitral Valve Disease

BACKGROUND

The natural history of mitral annular calcification (MAC) and risk for developing calcific mitral valve disease (CMVD) has been poorly defined. We sought to evaluate the progression rate of MAC and of the development of CMVD.

METHODS

Patients with MAC and paired echocardiograms at least one year apart between 2005 and 2019 were included. Progression rates from mild/moderate to severe MAC and to CMVD (defined as severe MAC and significant mitral stenosis and/or regurgitation) were assessed, along with potential association with sex.

RESULTS

A total of 11,605 patients (73±10years, 51%male) with MAC (78% mild, 17% moderate, 5% severe) were included and had a follow up echocardiogram at 4.2±2.7years. In patients with mild/moderate MAC, 33% presented with severe MAC at 10 years. The rate of severe MAC was higher in females than in males (41% vs. 24%, P<0.001, HR=1.3, P<0.001) and in patients with moderate vs. mild MAC (71% vs. 22%, P<0.001, HR=6.1, P<0.001). At 10 years 10% presented with CMVD (4%, 23% and 60% in patients with mild, moderate, and severe MAC respectively) and was predicted by female sex (15% vs. 5%, P<0.0001), even after adjustment for MAC severity (HR=1.9, P<0.001).

CONCLUSION

In this large cohort of patients with MAC, progression to severe MAC was common and frequently results in CMVD. Female sex was associated with higher progression rates. MAC and CMVD are expected to dramatically increase as the population ages highlighting the importance of a better understanding of the pathophysiology of MAC in order to develop effective preventive medical therapies.

Sex Differences in Mitral Annular Calcification and the Clinical Implications

Background: Heterogeneous mechanisms may contribute to the occurrence of mitral annular calcification (MAC), however, little is known about the sex differences in MAC and the clinical implications of these differences. This study aimed to investigate clinical and imaging differences of MAC according to sex.

Methods: In total, 537 patients (221 men) with MAC were identified by transthoracic echocardiography at a single center from January 2012 to June 2016. Moderate-to-severe MAC was defined as calcification extent ≥120° of the mitral annulus. Significant functional mitral stenosis (MS) was defined as a transmitral mean diastolic pressure gradient ≥5 mmHg.

Results: Women more frequently had moderate-to-severe MAC and concomitant mitral regurgitation than men; however, significant functional MS was comparable between sexes. In the logistic regression analysis, old age, uncontrolled hypertension, end-stage renal disease (ESRD), and obstructive hypertrophic cardiomyopathy were significantly associated with moderate-to-severe MAC in women, whereas ESRD and moderate-to-severe aortic stenosis were in men. In the Cox regression analysis, significant functional MS was associated with all-cause death in both sexes, although an independent association was found in only women.

Conclusion: Women had more extended MAC than men. Significant functional MS was independently associated with unfavorable clinical outcomes in patients with MAC, which was more pronounced in women than in men.

Prevalence of mitral annular calcification and its association with mitral valvular disease

BACKGROUND

Mitral annular calcification (MAC) is increasingly observed in elderly population. The purpose of this study was to investigate incidence of MAC and its association with mitral valvular disease (MVD).

METHODS

A total of 13,483 consecutive patients who underwent echocardiography were enrolled. MAC was defined as an echo-dense, shelf-like structure with an irregular, lumpy appearance involving the mitral valve annulus, with acoustic shadowing. Prevalence of MAC and its association with significant mitral stenosis (MS) or mitral regurgitation (MR) were studied. Significant (≥moderate) MS was defined as mean transmitral valvular pressure gradient > 5 mm Hg and significant MR was defined as ≥moderate MR based on quantitative or semi-quantitative Doppler methods.

RESULTS

MAC was present in 1881 of 13,483 patients (14%). Patients with MAC (MAC group) was older and more female gender than those without MAC (non-MAC group). Significant MS was present in 2.2% of MAC and in .6% of the non-MAC group (p < 0.0001). Significant MR was present in 11.9% of MAC and in 5.0% of the non-MAC group (p < 0.0001). Co-existence of MAC and aortic valve replacement (AVR) was associated with increased prevalence of MVD (MS:11.4%, MR:17.2%, respectively).

CONCLUSION

MAC was present in 14% of the patients and was associated with significant MVD. Co-existence of MAC and AVR may increase the risk of MVD.

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.

Current methods to assess mitral annular calcification and its risk factors

INTRODUCTION

Mitral annulus calcification (MAC) is a chronic, non-inflammatory, degenerative mechanism of the fibrous base of the mitral valve. While MAC was originally thought to be an age-related degenerative process, there is evidence that other mechanisms, such as atherosclerosis and abnormal calcium phosphorus metabolism, also contribute to the development of MAC.

AREAS COVERED

This paper summarizes, existing perception of clinically valid definition of MAC and the pathophysiological processes that lead to the development of MAC and the diagnostic implications of this disease entity.

EXPERT OPINION

Minimal evidence exists on the natural history and progression of MAC. Characterization of MAC progression and identification of predisposing risk factors can help to validate hypotheses. MAC is most commonly asymptomatic and incidental finding. Echocardiography is the primary imaging modality for identification and characterization of MAC and associated mitral valve (MV) disease. For patients with an indication for MV surgery, computed tomography (CT) is a complementary imaging modality for MAC. MAC is generally recognized by its characteristic density, location, and shape on echocardiography and CT, unusual variants are sometimes confused with other lesions.

The 2020 ACC/AHA Guidelines for Management of Patients With Valvular Heart Disease: Highlights and Perioperative Implications

Valvular heart disease contributes to a large burden of morbidity and mortality in the United States. During the last decade there has been a paradigm shift in the management of valve disease, primarily driven by the emergence of novel transcatheter technologies. In this article, the latest update of the American College of Cardiology/American Heart Association valve heart disease guidelines is reviewed.

Mitral Annular Calcification and Calcific Mitral Stenosis: Role of Echocardiography in Hemodynamic Assessment and Management

As the life expectancy of the population continues to increase, mitral annular calcification has emerged as an important cause of mitral stenosis (MS), commonly referred to as calcific or degenerative MS. Mitral annular calcification results in valvular stenosis when calcification extends into the base of the mitral leaflet(s) and displaces the mitral valve hinge point(s) into the left ventricular inlet. Echocardiographic determination of mitral vale area is fraught with difficulties and often precludes using planimetry or the Hatle formula. Given the numerous confounders that affect transmitral flow in calcific MS, evaluation of lesion severity should incorporate flow-independent methods such as the continuity equation and the mitral valve dimensionless index. In light of the significant risks entailed, there is little enthusiasm for mitral valve replacement in patients with calcific MS. Transcatheter mitral valve replacement is generally offered on a compassionate use basis to patients deemed to be at high surgical risk.

Surgical and Transcatheter Mitral Valve Replacement in Mitral Annular Calcification: A Systematic Review

Mitral annular calcification with mitral valve disease is a challenging problem that could necessitate surgical mitral valve replacement (SMVR). Transcatheter mitral valve replacement (TMVR) is emerging as a feasible alternative in high-risk patients with appropriate anatomy. PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched from inception to December 25, 2019 for studies discussing SMVR or TMVR in patients with mitral annular calcification; 27 of 1539 articles were selected for final review. TMVR was used in 15 studies. Relevant data were available on 82 patients who underwent hybrid transatrial TMVR, and 354 patients who underwent transapical or transseptal TMVR. Outcomes on SMVR were generally reported as small case series (447 patients from 11 studies); however, 1 large study recently reported outcomes in 9551 patients. Patients who underwent TMVR had a shorter median follow-up of 9 to 12 months (range, in-hospital‒19 months) compared with patients with SMVR (54 months; range, in-hospital‒120 months). Overall, those undergoing TMVR were older and had higher Society of Thoracic Surgeons risk scores. SMVR showed a wide range of early (0%-27%; median 6.3%) and long-term mortality (0%-65%; median at 1 year, 15.8%; 5 years, 38.8%, 10 years, 62.4%). The median in-hospital, 30-day, and 1-year mortality rates were 16.7%, 22.7%, and 43%, respectively, for transseptal/transapical TMVR, and 9.5%, 20.0%, and 40%, respectively, for transatrial TMVR. Mitral annular calcification is a complex disease and TMVR, with a versatile option of transatrial approach in patients with challenging anatomy, offers a promising alternative to SMVR in high-risk patients. However, further studies are needed to improve technology, patient selection, operative expertise, and long-term outcomes.

Comparison of Clinical Characteristics, Natural History and Predictors of Disease Progression in Patients With Degenerative Mitral Stenosis Versus Rheumatic Mitral Stenosis

Mitral annular calcification (MAC) is a common echocardiographic finding and an increasingly recognized cause of degenerative mitral stenosis (DMS). However, little is known about the clinical characteristics and disease progression in DMS, particularly in comparison with rheumatic mitral stenosis (RMS). We retrospectively reviewed 203 consecutive patients with mitral stenosis (113 with DMS and 90 with RMS) who underwent echocardiography at our institution between January 2014 and December 2017. We compared the clinical characteristics and disease progression between the 2 groups. In addition, we analyzed the predictors of disease progression (defined as annual progression rate of a mean gradient >0 mm Hg/year) among patients with DMS. Patients with DMS were significantly older and had higher prevalence of atherosclerotic comorbidities than those with RMS. During the median follow-up period of 2.2 years, the annual progression rates were comparable (0.8 ± 0.8 mm Hg/year in DMS vs 1.0 ± 1.2 mm Hg/year in RMS; p = 0.32) and were highly variable (0.0 to 3.5 mm Hg/year in DMS and 0.0 to 5.5 mm Hg/year in RMS) within both groups among disease progression. In DMS patients, atherosclerotic comorbidities and lower initial mean gradient were significantly associated with disease progression even after adjustment by age and sex. There was no significant difference in the disease progression according to the circumferential MAC severity determined by echocardiography among DMS. In conclusion, DMS disease progression was slow but highly variable, similar to that of RMS. In patients with DMS, the baseline MAC severity did not correlate with disease progression, suggesting the importance of follow-up echocardiography regardless of the MAC 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.

A Novel Assessment Using Projected Transmitral Gradient Improves Diagnostic Yield of Doppler Hemodynamics in Rheumatic and Calcific Mitral Stenosis

OBJECTIVES

The aims of this study were to: 1) develop a formula for projected transmitral gradient (TMG), expected gradient under normal heart rate (HR), and stroke volume (SV); and 2) assess the prognostic value of projected TMG.

BACKGROUND

In mitral stenosis (MS), TMG is highly dependent on hemodynamics, often leading to discordance between TMG and mitral valve area.

METHODS

All patients with suspected MS based on echocardiography from 2001 to 2017 were analyzed. Data were randomly split (2:1); projected TMG was modeled in the derivation cohort, then tested in the validation cohort. The composite endpoint was death or mitral valve intervention.

RESULTS

Of 4,973 patients with suspected MS, severe and moderate MS, defined as mitral valve area ≤1.5 and >1.5 to 2.0 cm², were present in 437 (9%) and 936 (19%), respectively. In the derivation cohort (n = 3,315; age 73 ± 12 years; 34% male), corresponding gradients were TMG ≥6 and 4 to <6 mm Hg, respectively, under normal hemodynamics. Based on the impact of hemodynamics on TMG, the formula was projected TMG = TMG - 0.07 (HR - 70) - 0.03 (SV - 97) in men and projected TMG = TMG - 0.08 (HR - 72) - 0.04 (SV - 84) in women. In the validation cohort (n = 1,658), projected TMG had better agreement with MS severity than TMG (kappa 0.61 vs. 0.28). Among 281 patients with TMG ≥6 mm Hg, projected TMG ≥6 mm Hg, present in 171 patients (61%), was associated with higher probability of the endpoint versus projected TMG <6 mm Hg (adjusted hazard ratio: 1.8; 95% confidence interval: 1.2 to 2.6; p < 0.01).

CONCLUSIONS

The novel concept of projected TMG, constructed using the observed impact of HR and SV on TMG, significantly improved the concordance of gradient and valve area in MS and provided better risk stratification than TMG.

2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the valvular heart disease guideline provides recommendations for clinicians to diagnose and manage valvular heart disease as well as supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from January 1, 2010, to March 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, Cochrane, Agency for Healthcare Research and Quality Reports, and other selected database relevant to this guideline. Structure: Many recommendations from the earlier valvular heart disease guidelines have been updated with new evidence and provides newer options for diagnosis and treatment of valvular heart disease. This summary includes only the recommendations from the full guideline which focus on diagnostic work-up, the timing and choice of surgical and catheter interventions, and recommendations for medical therapy. The reader is referred to the full guideline for graphical flow charts, text, and tables with additional details about the rationale for and implementation of each recommendation, and the evidence tables detailing the data considered in developing these guidelines.

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.