Characterizing Risks Associated With Mitral Annular Calcification in Mitral Valve Replacement

Early outcomes following transatrial transcatheter mitral valve replacement in patients with severe mitral annular calcification

OBJECTIVE

Implantation of a transcatheter valve-in-mitral annular calcification (ViMAC) has emerged as an alternative to traditional surgical mitral valve (MV) replacement. Previous studies evaluating ViMAC aggregated transseptal, transapical, and transatrial forms of the procedure, leaving uncertainty about each technique's advantages and disadvantages. Thus, we sought to evaluate clinical outcomes specifically for transatrial ViMAC from the largest multicenter registry to-date.

METHODS

Patients with symptomatic MV dysfunction and severe MAC who underwent ViMAC were enrolled from 12 centers across the United States and Europe. Clinical characteristics, procedural details, and clinical outcomes were abstracted from the electronic record. The primary end point was all-cause mortality.

RESULTS

We analyzed 126 patients who underwent ViMAC (median age 76 years [interquartile range {IQR}, 70-82 years], 28.6% female, median Society of Thoracic Surgeons score 6.8% [IQR, 4.0-11.4], and median follow-up 89 days [IQR, 16-383.5]). Sixty-one (48.4%) had isolated mitral stenosis, 25 (19.8%) had isolated mitral regurgitation (MR), and 40 (31.7%) had mixed MV disease. Technical success was achieved in 119 (94.4%) patients. Thirty (23.8%) patients underwent concurrent septal myectomy, and 8 (6.3%) patients experienced left ventricular outflow tract obstruction (7/8 did not undergo myectomy). Five (4.2%) patients of 118 with postprocedure echocardiograms had greater than mild paravalvular leak. Thirty-day and 1-year all-cause mortality occurred in 16 and 33 patients, respectively. In multivariable models, moderate or greater MR at baseline was associated with increased risk of 1-year mortality (hazard ratio, 2.31; 95% confidence interval, 1.07-4.99, P = .03).

CONCLUSIONS

Transatrial ViMAC is safe and feasible in this selected, male-predominant cohort. Patients with significant MR may derive less benefit from ViMAC than patients with mitral stenosis only.

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.

Contemporary surgical techniques for mitral valve replacement in extensive mitral annular calcification

Objectives

Mitral annular calcification remains a formidable lesion in cardiac surgery with significant perioperative morbidity and mortality, particularly when en bloc annular decalcification is implemented. Respect strategies and hybrid approaches have provided safe alternatives. We report the short-term results of our institution's experience with mitral valve replacement in patients with extensive annular calcification.

Methods

This is a retrospective review of 72 consecutive patients with extensive annular calcification who underwent open surgical mitral valve replacement from January 1, 2013, to September 31, 2022. Degree of annular calcification was graded as partial, horseshoe, or circumferential. We excluded patients with calcification involving less than one-third of the annulus and patients with rheumatic heart disease.

Results

Mean patient age was 71.6 ± 10.9 years, and 50 (69.4%) were female. There were 51 patients (70.8%) with New York Heart Association class 3 or greater and 47 patients (65.3%) with pulmonary hypertension. There were 41 patients (56.9%) with partial, 12 patients (16.7%) with horseshoe, and 19 patients (26.4%) with circumferential calcification. Fifty-six patients (77.8%) underwent conventional valve replacement. Sixteen patients underwent a hybrid procedure using balloon-expandable devices. Concomitant procedures were performed in 61 patients (84.7%). In-hospital mortality and 1-year survival were 3.57% and 82.8% in the standard valve replacement cohort and 25.0% and 54.7% in the hybrid cohort, respectively.

Conclusions

Conventional mitral valve replacement using respect strategies is safe and associated with good outcomes in patients with extensive annular calcification. Hybrid approaches using novel devices should remain as a bailout in select patients because of higher perioperative risks and poor short-term outcomes.

Double-layer horizontal cross sutures for intra-atrial mitral valve implantation: An effective surgical method for severe mitral annular calcification

Objective

Severe mitral annular calcification (MAC) can make prosthetic implantation extremely difficult. Although intra-atrial mitral valve prosthesis implantation without annular decalcification offers a simpler approach, it poses a potential rupture risk due to high left ventricular pressure. We developed a double-layer (DL) horizontal cross-suture technique, which ensures close proximity of the valve prosthesis to the calcified annulus and segregates the left atrial wall from the left ventricle. The aim of this study was to compare the outcomes of DL suture with conventional single-layer (SL) suture in patients with severe MAC.

Methods

This retrospective cohort study consecutively enrolled patients with severe MAC undergoing mitral valve replacement at Beijing Anzhen Hospital from May 2018 to December 2022. A detailed description of the DL suture method is described. Follow-up medical evaluations, including transthoracic echocardiography measurements, were obtained through outpatient chart reviews.

Results

The study included 10 patients in the DL suture group and 20 in the SL suture group. All patients in the DL group and all but 3 in the SL group achieved technical success. Compared with the SL group, the DL suture technique was associated with lower rates of perivalvular leakage, stroke, new-onset atrial fibrillation, reoperation, and 30-day mortality. Follow-up was complete, with 1 late mortality in the DL group due to stroke and 4 cardiovascular deaths in the SL group.

Conclusions

The DL horizontal cross-suture technique offers a more effective and safer approach for intra-atrial mitral valve implantation in severe MAC cases than the conventional SL suture method.

Noncontrast cardiac computed tomography-derived mitral annular calcification scores in mitral valve disease

BACKGROUND AND AIMS

Mitral annular calcification (MAC) by computed tomography (CT) is reported as an independent predictor of poor outcomes. However, it currently remains unclear if quantitative MAC parameters provide more value for mitral valve disease (MVD) management, therefore, we examined the prognostic value of MAC scores using noncontrast cardiac-CT in MVD patients.

METHODS

Between January 2020 and December 2021, we prospectively enrolled 300 consecutive patients with MVD (MAC-present = 80 and MAC-absent = 220) undergoing preoperative cardiac-CT and mitral valve (MV) surgery. Noncontrast cardiac-CT images were used to qualitatively detect MAC (present or absent) and evaluate MAC scores. For analyses, we also collected baseline clinical data, intraoperative conversion (from MV repair to MV replacement), and follow-up arrhythmia data.

RESULTS

Compared with the MAC-absent group, MAC-present patients were older (62 ± 7 vs. 58 ± 9 years, p < .001), mostly women (55% vs. 39.5%, p = .017), and also had aortic valve calcification (57.5% vs. 23.2%, p < .001), mitral stenosis (82.5% vs. 61.8%, p < .001), atrial fibrillation (30% vs. 11.8%, p < .001), and larger left atrial end-diastolic dimension (LADD, 49 [44-56] versus 46 [41-50], p = .001]. Furthermore, MAC-present patients underwent more MV replacements (61.8% vs. 82.5%, p = .001) and experienced a higher intraoperative conversion prevalence (11.8% vs. 61.3%, p < .001). Multiple logistic regression analyses showed that the female gender (odds ratio [OR]/95% confidence interval [CI]/p = 2.001/1.042-3.841/0.037) and MAC scores (OR/95% CI/p = 10.153/4.434-23.253/p < .001) were independent predictors of intraoperative conversion. During a follow-up of 263 ± 134 days, MAC-present patients had more arrhythmias (42.5% vs. 9.5%, p < .001). Also, MAC-scores (hazard ratio [HR]/95% CI/p = 6.841/3.322-14.089/p < .001) and LADD (HR/95% CI/p = 1.039/1.018-1.060/p < .001) were independently associated with arrhythmias by Cox regression analyses.

CONCLUSIONS

Noncontrast cardiac CT-derived MAC-scores showed a high risk for intraoperative conversion and follow-up arrhythmias in MVD-patients.

National trends in utilization of transatrial transcatheter mitral valve replacement and postoperative outcomes

OBJECTIVE

Transatrial transcatheter mitral valve replacement reduces complexity during mitral valve replacements involving high-risk patients with mitral annular calcification. This study examines trends in transatrial transcatheter mitral valve replacement use and outcomes.

METHODS

Patients in the Society of Thoracic Surgeons database from 2014 to 2021 with mitral annular calcification undergoing transatrial transcatheter mitral valve replacement were included. Exclusion criteria were hypertrophic cardiomyopathy, congenital mitral valve disease, ventricular assist device placement, or prior mitral valve surgery. Primary outcomes were operative mortality and major adverse cardiac events compared between the Early (2014-2017, N = 71) and Recent (2018-2021, N = 151) eras. Parsimonious multivariable regression assessed select possible confounders for trends in major adverse cardiac events.

RESULTS

Overall, 222 transatrial transcatheter mitral valve replacements at 104 hospitals were identified. Annual volume increased from 6 in 2014 to 43 in 2021. Median hospital volume was 1, maximum hospital volume was 17, and 10 or more replacements were performed at 4 hospitals. Mortality and major adverse cardiac events occurred in 10.4% and 22.5% of patients, respectively. Compared with the Early era patients, Recent era patients were more often elective (79.5% vs 64.8%) and were approached via sternotomy (90.1% vs 80.3%, all P < .05). Despite similar predicted risk of mortality (9.6% ± 11.1% vs 11.0% ± 6.0%; P = .61), Recent patients had reduced mortality (3.3% vs 25.4%, P < .001) and major adverse cardiac events (18.5% vs 31.0%; P = .057). On univariate and multivariable analyses, the Recent surgical era was significantly associated with lower mortality (0.10 [0.04-0.29]; P < .001) and lower major adverse cardiac events (0.48 [0.25-0.94]; P = .032), respectively. There were no preoperative characteristics that were significant confounders for the difference in major adverse cardiac events.

CONCLUSIONS

Mortality and major adverse cardiac events after transatrial transcatheter mitral valve replacement have decreased significantly in the contemporary era independent of changes in major patient and operative characteristics. Transatrial transcatheter mitral valve replacement will have a future role in patients with mitral annular calcification.

Diagnosis, Classification, and Management Strategies for Mitral Annular Calcification: A Heart Valve Collaboratory Position Statement

Mitral annular calcium (MAC) with severe mitral valvular dysfunction presents a complex problem, as valve replacement, either surgical or transcatheter, is challenging because of anatomy, technical considerations, concomitant comorbidities, and advanced age. The authors review the clinical and anatomical features of MAC that are favorable (green light), challenging (yellow light), or prohibitive (red light) for surgical or transcatheter mitral valve interventions. Under the auspices of the Heart Valve Collaboratory, an expert working group of cardiac surgeons, interventional cardiologists, and interventional imaging cardiologists was formed to develop recommendations regarding treatment options for patients with MAC as well as a proposed grading and staging system using both anatomical and clinical features.

Mitral Valve Replacement for Mitral Stenosis Secondary to Massive Mitral Annular Calcium

Mitral annular calcium (MAC) may produce mitral stenosis (MS) if its quantity is massive. We define massive MAC as the presence of a huge quantity of calcium underlying the posterior mitral leaflet and extending across all or nearly all of the ventricular aspect of the anterior mitral leaflet. This report was prompted to emphasize the hazards of performing mitral valve replacement in patients with MS secondary to massive MAC. The clinical data and morphology of the operatively excised mitral valves from the 11 patients who had mitral valve replacement for MS secondary to massive MAC are described. Of the 11 patients, 6 died postoperatively, 5 of whom had 4+/4+ MAC. The high mortality in these patients suggests that the decision to perform mitral valve replacement needs to be carefully considered if the quantity of MAC is massive.

Mitral annular calcification in patients with significant mitral valve disease: An old problem with new solutions

Mitral annular calcification (MAC) is a chronic process involving mitral valve annulus, linked with an increased cardiovascular mortality and morbidity. Since its first autoptic description, a progressive evolution in diagnostic tools brought cardiac computed tomography (CT) scan to become the gold standard in MAC detection and classification. The treatment of significant mitral valve disease in patients with annular calcifications has always represented an issue for cardiac surgeons, being it linked with an increased risk of atrioventricular groove rupture, circumflex artery injury, or embolism. As a consequence, different surgical techniques have been developed over time in order to reduce the incidence of these fearsome complications. Recently, transcatheter mitral valve replacement (TMVR) has emerged as a valid alternative to surgery in high-risk patients. Both hybrid transatrial, transfemoral, or transapical approaches have been described to deliver balloon-expandable or self-expanding aortic transcatheter valves into the calcified annulus, with conflicting early and long-term results. Tendyne (Abbott Structural Heart, Santa Clara, CA, USA) is a promising transapical-delivered option. Early results have shown effectiveness and safety of this device in patients with MAC and severe mitral valve disease, with the lowest rate of embolization, mortality, and left ventricular outflow tract obstruction (LVOTO) reported so far.

The 40th Anniversary of Percutaneous Balloon Valvuloplasty for Mitral Stenosis: Current Status

Percutaneous balloon mitral valvuloplasty (PBMV), once the most complex of percutaneous cardiac procedures and essentially the first adult structural heart intervention, set the stage for a host of new technologies. Randomized studies comparing PBMV to surgery were the first to provide a high-level evidence base in structural heart. The devices used have changed little in 40 years, but the advent of improved imaging and the expertise gained in interventional cardiology has provided some additional procedural safety. However, with the decline in rheumatic heart disease, PBMV is being performed in fewer patients in industrialized nations; in turn, these patients have more comorbidities, less favorable anatomy, and thus a higher rate of procedure-related complications. There remain relatively few experienced operators, and the procedure is distinct enough from the rest of the structural heart intervention world that it has its own steep learning curve. This article reviews the use of PBMV in a variety of clinical settings, the influence of anatomic and physiologic factors on outcomes, the changes in the guidelines, and alternative approaches. PBMV remains the procedure of choice in patients with mitral stenosis with ideal anatomy and a useful tool in patients with less than ideal anatomy who are poor surgical candidates. In the 40 years since its first performance, PBMV has revolutionized the care of mitral stenosis patients in developing countries and remains an important option for suitable patients in industrialized nations.

Management of Patients With Severe Mitral Annular Calcification: JACC State-of-the-Art Review

Mitral annular calcification (MAC) is a common and challenging pathologic condition, especially in the context of an aging society. Surgical mitral valve intervention in patients with MAC is difficult, with varying approaches to the calcified annular anatomy, and the advent of transcatheter valve interventions has provided additional treatment options. Advanced imaging provides the foundation for heart team discussions and management decisions concerning individual patients. This review focuses on the prognosis of, preoperative planning for, and management strategies for patients with MAC.

Ultrasonic Emulsification of Severe Mitral Annular Calcification During Mitral Valve Replacement

PURPOSE

Severe mitral annular calcification (MAC) increases surgical complexity and is independently associated with increased operative mortality for mitral valve replacement (MVR). Recently we adopted ultrasonic emulsification/aspiration for annular decalcification to address these risks and describe our early experience with this new technology.

DESCRIPTION

Excluding previous mitral valve surgery or endocarditis, 179 patients with MAC underwent MVR at a single institution between January 2015 and March 2020. Of these, 15 consecutive patients with severe MAC (≥50% of the annulus) underwent annular decalcification with ultrasonic emulsification/aspiration as an adjunct treatment during MVR from April 2019 to March 2020.

EVALUATION

Mean patient age was 68 ± 12 years, and 72% (n = 128) were female. Mean preoperative left ventricular ejection fraction was 60% ± 11%, and mean mitral valve gradient was 9.1 ± 4.4 mm Hg. Concomitant procedures included antiarrhythmia (n = 52), aortic valve replacement (n = 32), and coronary artery bypass grafting (n = 20). There were no operative deaths or strokes in the group undergoing ultrasonic emulsification and aspiration.

CONCLUSIONS

The use of ultrasonic emulsification and aspiration in severe MAC patients may help mitigate the risks of MVR and facilitate operative success in this challenging, high-risk population.

Early outcomes of transatrial mitral valve replacement in severe mitral annular calcification

Objective

Mitral valve replacement (MVR) in the setting of severe mitral annular calcification is a technically challenging operation with increased morbidity and mortality. Transseptal/apical transcatheter MVR (TMVR) in mitral annular calcification has emerged as an option for these cases, although may not be feasible due to anatomical reasons. Transatrial TMVR is a potential treatment option for this subgroup of patients.

Methods

Patients who underwent transatrial TMVR between June 2018 and November 2020 at a single institution were included. Patients were selected by a structural heart team based on their surgical risk, pattern of mitral annular calcification, risk of valve migration, left ventricular outflow obstruction, and paravalvular leak.

Results

A total of 11 patients underwent transatrial TMVR. Mean patient age was 74.2 years and mean Society of Thoracic Surgeons predicted risk of mortality score was 9.1%. All patients had the presence of both mitral stenosis and regurgitation—dominant etiology—was mitral stenosis in 81.2%, and mitral regurgitation in 18.8%. Among patients, 54.5% had a concomitant cardiac procedure. There was no in-hospital or 30-day mortality. Technical success defined by the Mitral Valve Academic Research Consortium was achieved in 90.9% of patients. Postoperative paravalvular leak was mild or less in all patients.

Conclusions

In this series, transatrial TMVR was shown to be a safe and effective treatment option for patients who are high risk for surgical MVR and should be in surgeons' armamentarium in the treatment of this high-risk patient population. Dissemination of safe technique will be critical in the successful conduct of this surgery.

Severe Mitral Paravalvular Leak Treated with Percutaneous Paravalvular Leak Closure with Underlying Severe Mitral Annular Calcium

Standard operative mitral valve replacement for mitral stenosis in the setting of severe mitral annular calcium has been associated with increased morbidity and mortality. Inability to ensure a well seated prosthesis may lead to periprosthetic leak. We present a case of severe paravalvular leak, causing significant hemolysis, after mitral valve replacement with underling severe mitral annular calcium. The leak was successfully repaired using a transseptal percutaneous approach, with subsequent resolution of hemolysis.

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.

STS Adult Cardiac Surgery Database: 2021 Update on Outcomes, Quality, and Research

The Society of Thoracic Surgeons Adult Cardiac Surgery Database is the most mature and comprehensive cardiac surgery database. It has been the foundation for quality measurement and improvement activities in cardiac surgery, facilitated the generation of accurate risk adjusted performance benchmarks and serves as a platform for novel research. Recent enhancements have added to the database's functionality, ease of use, and value to multiple stakeholders. This report is the sixth in a series of annual reports that provide updated volumes, outcomes, database-related developments, quality improvement initiatives, and research summaries using the Adult Cardiac Surgery Database in the past year.