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

Thrombus on Mitral Annular Calcification: A Systematic Review of Management and Outcomes

Background

Mitral annular calcification (MAC) is a common chronic degenerative process of the mitral valve. Thrombus formation on MAC is a rare complication that likely contributes to the increased risk of thromboembolic events. Outcomes and management strategies for this condition are unknown. The aim of this study was to perform a systematic review to describe the management and outcomes of patients who have thrombus on MAC.

Methods

The MEDLINE, Embase, and Cochrane databases were searched. Patients with a prior mitral valve intervention or prosthesis were excluded. The primary outcomes were treatment, mortality, and thromboembolic events.

Results

Fifteen studies, with a total of 22 cases (patients aged 69.1 ± 14.8 years; n = 18 [82%] female) were included. Most patients presented with stroke or a transient ischemic event (n = 15; 68%) or myocardial infarction (n = 4; 18%). All patients were diagnosed with either transthoracic (n = 18; 82%) or transesophageal (n = 4; 18%) echocardiography. Seventeen patients (77%) were treated with anticoagulation therapy alone, and 5 (23%) required surgery. The most common surgical indication was prevention of recurrent embolization (n = 3; 14%). No mortality was reported. Six patients (27%) had thromboembolic events after diagnosis. For those treated with anticoagulation therapy alone, 5 (23%) had persistent thrombus with or without embolization.

Conclusions

In this systematic review, patients with MAC who present with a thromboembolic event require careful echocardiographic assessment of the MAC, to exclude the presence of thrombus. Although most patients can be managed with anticoagulation therapy alone, a significant number will require surgery. Persistent thrombus, despite anticoagulation therapy, and recurrent embolization are common. Larger studies are needed to elucidate what constitutes the optimal long-term care for these patients.

Transcatheter Mitral Valve Replacement Using Annular Reduction by Cinching With TEER in the Commissure (ARCTIC)

BACKGROUND

Mitral annular calcification with valve dysfunction remains a challenging syndrome. Operative risk is high, and available transcatheter therapies are limited.

METHODS

This study describes our initial experience with a novel procedure to address large mitral annuli when no surgical or trial-based transcatheter mitral valve replacement device is available. The rationale was to shorten the intercommissural distance using commissural mitral transcatheter edge-to-edge repair (TEER) followed by valve-in-mitral annular calcification transcatheter mitral valve replacement with a balloon-expandable aortic valve platform. Patients with long intercommissural distances and large mitral annulus areas were selected based on a high perceived risk of transcatheter valve embolization. Patients underwent mitral TEER with MitraClip in a commissural position, followed immediately by transseptal transcatheter mitral valve replacement with a 29 mm SAPIEN 3 valve.

RESULTS

Thirteen patients were included. Median intercommissural distance and annular area were 39.1 mm and 930 mm2, respectively. Commissural mitral TEER was successful in all patients with no instances of single leaflet detachment. In 10 of 13 instances, an NTW device size was used. In 12 of 13 patients, valve implantation was successful, including 1 case that required a second valve for atrial positioning of the first valve. In 1 case, frank valve embolization into the left atrium occurred. Among the 12 successful cases, paravalvular leak was 1+ or less, and there were no instances of paravalvular leak adjacent to the TEER device.

CONCLUSIONS

In patients with large annuli and sufficient annular calcium, a hybrid mitral TEER and valve replacement with the SAPIEN platform can be successfully used to facilitate transcatheter mitral valve replacement.

Prognostic Value of Mitral Annular Calcification in Liver Transplant Patients: Implication in Posttransplant Outcomes

BACKGROUND

With the rise of metabolic diseases and aging in liver transplant (LT) candidates, mitral annular calcification (MAC) is more recognizable. Despite cardiovascular risk becoming a leading cause of mortality in LT recipients, the influence of MAC remains unexamined. This study investigates the prevalence, related factors, and impact of MAC on LT outcomes.

METHODS

We explored 4148 consecutive LT patients who underwent routine pretransplant echocardiography from 2008 to 2019. Multivariate logistic analysis and the tree-based Shapley additive explanation scores in machine learning were used to evaluate the significant and important related factors. The primary outcome was 30-d major adverse cardiac events (MACE), and the secondary outcome was a median of 5-y cumulative all-cause mortality.

RESULTS

MAC was found in 123 (3.0%) patients. Significant and important related factors included age, alcoholic liver disease, chronic kidney disease, hyperuricemia, hypertension, and coronary artery disease. The MACE rate was higher in patients with MAC compared with those without MAC at 30 d ( P  < 0.001, adjusted hazard ratio 1.67; 95% confidence interval, 1.08-2.57). Patients with MAC had poorer cumulative overall survival probability compared with those without MAC ( P  = 0.0016; adjusted hazard ratio 1.47; 95% confidence interval, 1.01-2.15). Specifically, women with MAC had a poorer survival probability compared with men without MAC (65.0% versus 80.7%, P  < 0.001) >10 y post-LT.

CONCLUSIONS

The presence of MAC before LT was linked to increased 30-d MACE and lower long-term survival rates, especially in women. Identification and management of MAC and potential risk factors are crucial for improving post-LT survival.

Embolic strokes of undetermined source: a clinical consensus statement of the ESC Council on Stroke, the European Association of Cardiovascular Imaging and the European Heart Rhythm Association of the ESC

One in six ischaemic stroke patients has an embolic stroke of undetermined source (ESUS), defined as a stroke with unclear aetiology despite recommended diagnostic evaluation. The overall cardiovascular risk of ESUS is high and it is important to optimize strategies to prevent recurrent stroke and other cardiovascular events. The aim of clinicians when confronted with a patient not only with ESUS but also with any other medical condition of unclear aetiology is to identify the actual cause amongst a list of potential differential diagnoses, in order to optimize secondary prevention. However, specifically in ESUS, this may be challenging as multiple potential thromboembolic sources frequently coexist. Also, it can be delusively reassuring because despite the implementation of specific treatments for the individual pathology presumed to be the actual thromboembolic source, patients can still be vulnerable to stroke and other cardiovascular events caused by other pathologies already identified during the index diagnostic evaluation but whose thromboembolic potential was underestimated. Therefore, rather than trying to presume which particular mechanism is the actual embolic source in an ESUS patient, it is important to assess the overall thromboembolic risk of the patient through synthesis of the individual risks linked to all pathologies present, regardless if presumed causally associated or not. In this paper, a multi-disciplinary panel of clinicians/researchers from various backgrounds of expertise and specialties (cardiology, internal medicine, neurology, radiology and vascular surgery) proposes a comprehensive multi-dimensional assessment of the overall thromboembolic risk in ESUS patients through the composition of individual risks associated with all prevalent pathologies.

Mitral Annular Calcification-Related Valvular Disease: A Challenging Entity

Mitral valve annular calcification-related valvular disease is increasingly common due to the rising prevalence of age-related mitral annular calcifications. Mitral annular calcification alters the structure and function of the mitral valve annulus, which in turn causes mitral valve regurgitation, stenosis, or both. As it frequently coexists with comorbid conditions and overlapping symptoms, mitral annular calcification-related valvular disease poses significant diagnostic and therapeutic challenges. For instance, left ventricular diastolic dysfunction hinders the assessment of mitral valvular disease. Detection of mitral annular calcifications and assessment of related mitral valve disease hinge on two-dimensional echocardiography. Comprehensive assessment of mitral annular calcifications and related mitral valve disease may require multidetector computed tomography and three-dimensional echocardiography. Invasive hemodynamic testing with exercise helps identify the cause of symptoms in patients with comorbid conditions, and transcatheter interventions have emerged as a viable therapeutic option for older patients. After an outline of the normal mitral annulus, we examine how mitral annular calcifications lead to mitral valve disease and how to accurately assess mitral regurgitation and stenosis. Lastly, we review surgical and transcatheter approaches to the management of mitral annular calcification-related mitral valve regurgitation, stenosis, or both.

The Role of Advanced Glycation End-Product Levels Measured by Skin Autofluorescence in the Development of Mitral Annular Calcification

As a person ages, mitral annular calcification develops in the mitral annulus with increasing frequency. Lipid deposition, inflammation, and aging-related degeneration have been cited as potential causes of this pathophysiology, though there is currently no conclusive evidence to support this. AGEs accumulate in tissues due to the glycation of proteins and lipids, increasing the release of proinflammatory cytokines secondary to oxidative stress through the AGE receptor. The AGE levels increase in diabetic microvascular complications and degenerative aortic valve disease. Our study was planned prospectively as a case-control study involving 94 MAC-positive patients and 94 MAC-negative patients. The demographics, echocardiographic data and AGE levels of the patients were measured and recorded using the skin autofluorescence method. AGE levels were significantly higher in the MAC-positive patient group (3.2 vs. 2.7; p < 0.001). The AGE levels were observed as an independent predictor of MAC development in a regression analysis (OR: 8.05, 95% CI: 3.74-17.33, p < 0.001). In a ROC-curve analysis, the AUC was 0.79 (95% CI: 0.72-0.85). At a cut-off value of 2.7, 79.7% sensitivity and 69.1% specificity were observed. AGE levels can be used to cheaply, easily and non-invasively identify patients at risk of developing MAC.

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.

Echocardiographic Mitral Annular Calcification is Associated With Atrial Fibrillation Recurrence After Catheter Ablation

There is a significant relation between mitral annular calcification (MAC) and the development of atrial fibrillation (AF) and major adverse cardiovascular events. However, the influence of MAC on the outcome of AF ablation remains unknown. The study cohort included 785 consecutive patients who underwent successful ablation. AF recurrence was monitored 3 months after ablation. Cox proportional hazards models were used to assess the association between MAC and AF recurrence. Kaplan-Meier analysis was performed to calculate the incidence of AF recurrence. Over a follow-up period of 16 ± 10 months, 190 patients (24.2%) experienced AF recurrence after ablation. MAC by echocardiography was identified in 42 patients (22%) with AF recurrence but only 60 without (10%, p <0.001). Patients with MAC were older (p <0.001), more often women (p <0.001), with a higher prevalence of hypertension (p <0.001) and diabetes mellitus (p<0.001), moderate/severe mitral regurgitation (p <0.001), larger left atrial dimension (p <0.001), and higher CHA₂DS₂-VASc score (p <0.001). Patients with MAC were more likely to develop AF recurrence than those without (36% vs 22%, respectively, p = 0.002). MAC was significantly associated with AF recurrence in the unadjusted analysis (hazard ratio 1.77, 95% confidence interval 1.26 to 2.58, p <0.001) and remained statistically significant after the multivariate adjustment (hazard ratio 1.48, 95% confidence interval 1.13 to 1.95, p = 0.001). In conclusion, echocardiographic MAC is significantly associated with an increased risk of AF recurrence after successful ablation, demonstrating an independent predictive value other than the established risk factors.

Midterm outcomes of mitral valve repair versus replacement in elderly patients: A propensity score-matched analysis

BACKGROUND

Current literature reports better short-term mortality rates in mitral valve repair over replacement in elderly patients. However, valve durability, postoperative complications, and reintervention rates in these cohorts remain understudied. As such, we aimed to investigate 5-year rates of mortality and reoperation after initial mitral repair or replacement in elderly patients.

METHODS

Using the TriNetX Research Network database, we identified patients aged ≥70 who underwent mitral valve repair or replacement for nonrheumatic mitral insufficiency between January 2010 and December 2020. We 1:1 propensity score-matched cohorts for 33 covariates including demographics, comorbidities, and surgical history. After matching, we compared 5-year mortality and reoperation rates between cohorts using Kaplan-Meier estimates and multivariable Cox proportional hazards models.

RESULTS

We compared 823 mitral valve repair patients to a propensity score-matched cohort of 823 mitral valve replacement patients over a 5-year follow-up period. All variables of interest were adequately matched. Cumulative 5-year mortality rate was significantly lower among mitral valve repair patients (17.0% vs. 24.9%; hazard ratio [HR]: 0.66, 95% confidence interval [95% CI]: 0.51-0.87, p < 0.0025). Reoperation rates at 5-year did not differ (2.6% vs. 2,1%; HR: 1.34, 95% CI: 0.67-2.68, p = 0.401).

CONCLUSIONS

We observed lower 5-year mortality rates and nonsignificantly different reoperation rates among elderly patients with mitral regurgitation undergoing mitral valve repair compared to replacement. Our data support the current understanding that mitral valve repair should be considered as the first treatment line whenever possible, even in elderly patients.