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

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.

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.

Impact of Pulmonary Hypertension on Outcomes in Patients With Mitral Annular Calcium and Associated Mitral Valve Dysfunction

The prevalence of mitral annular calcium (MAC) is increasing in our aging population. However, data regarding prognostication in MAC-related mitral valve (MV) disease remain limited. This retrospective observational study aims to explore the prognostic impact of systolic pulmonary artery pressure (SPAP) in MAC-related MV dysfunction and define its determinants. We identified 4,384 patients (mean age 78 ± 11 years and 69% female) with MAC-related MV dysfunction (documented transmitral gradient ≥3 mm Hg) from a large institutional echocardiographic database between 2001 and 2019. In Cox regression analysis, higher SPAP strongly associated with all-cause mortality, independent of cardiovascular risk factors and indices of MV dysfunction (adjusted hazard ratio 1.22 per 10 mm Hg SPAP increase, 95% confidence interval 1.17 to 1.27). Patients with SPAP ≥50 mm Hg had significantly higher mortality compared with SPAP <50 mm Hg (log-rank p <0.001), a finding that was consistent across different transmitral gradient subgroups (≤5, 5 to 10, and ≥10 mm Hg). Independent determinants of SPAP included the mean transmitral gradient, mitral regurgitation severity, left ventricular ejection fraction, and ≥moderate aortic stenosis (adjusted p <0.05), and atrial fibrillation and left atrial dimension. The impact of concomitant mitral regurgitation on SPAP decreased at higher transmitral gradients and was no longer significant at gradients ≥10 mm Hg (p = 0.100). In conclusion, SPAP strongly associates with mortality in MAC, independent of cardiovascular risk factors and indices of MAC-related MV dysfunction. These findings suggest an incremental role for SPAP in the risk stratification and prognostication in this increasingly prevalent condition with expanding the scope of possible interventions.

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.

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.

State-of-the-art Structural Interventions in Heart Failure

Heart failure (HF) is a leading cause of hospitalisation and healthcare costs worldwide. Acute decompensated heart failure accounts for more than 1 million hospitalisations in the US. Despite advances in the quality of acute and chronic HF disease management, gaps in knowledge about effective interventions to support the transition of care for patients with HF remain. Despite multiple trials of promising therapies, standard care consists of decongestion with IV diuretics and haemodynamic support with vasodilators and inotropes and this has remained largely unchanged during the past 45 years. Newer advances in medical innovations and structural heart disease interventions have now given promise to improved survival, outcomes and quality of life for patients with advanced HF of multiple aetiologies. In this article, we focus on structural interventions in the treatment of patients with HF.

A meta-analysis of impact of mitral stenosis on outcomes after transcatheter aortic valve implantation

OBJECTIVES

To determine whether concomitant mitral stenosis (MS) impairs outcomes after transcatheter aortic valve implantation (TAVI) in patients with severe aortic stenosis (AS), we performed a meta-analysis of currently available evidence.

METHODS

To identify all observational comparative studies of outcomes after TAVI for AS in patients with MS vs patients with no-MS, we searched databases (MEDLINE and EMBASE) using web-based search engines (PubMed and OVID). Studies meeting the following criteria were included; the design was an observational study; the study population was patients undergoing TAVI for AS; outcomes in patients with MS were compared with those in patients with no-MS. Study-specific estimates were then pooled using inverse variance-weighted averages of logarithmic odds and hazard ratios in the random-effects model.

RESULTS

We identified six eligible studies including 111 621 patients undergoing TAVI. In pooled analyses, postprocedural incidence of ≥ moderate paravalvular aortic regurgitation (PAR) (P = .02), early all-cause mortality (P = .008), early incidence of myocardial infarction (MI) (P = .01), and midterm all-cause mortality (P = .03) after TAVI were significantly higher in patients with MS than in patients with no-MS. There were no significant differences in early incidence of stroke, major bleeding, acute kidney injury, and new permanent pacemaker implantation after TAVI between patients with MS and patients with no-MS. When the study for mitral annular calcification was excluded in the pooled analyses, no results except for MI were substantially altered but the significance for early incidence of MI disappeared (P = .10).

CONCLUSION

Postprocedural incidence of ≥ moderate PAR, early all-cause mortality, early incidence of MI, and midterm all-cause mortality after TAVI are higher in patients with MS than in patients with no-MS.