Surgical management of mitral annular calcification

AltaValve Atrial Fixation System for the Treatment of Severe Mitral Regurgitation and Mitral Annular Calcification

Background

Treatment options for patients with mitral regurgitation (MR) and mitral annular calcification (MAC) are limited. The limitations of current transcatheter mitral valve replacement (TMVR) technologies include high screen failure rates, increased risk of left ventricular outflow tract obstruction, and high residual regurgitation. The aim of this study was to evaluate outcomes of TMVR with the AltaValve system (4C Medical, Maple Grove, MN), a supra-annular TMVR with atrial fixation, in patients with severe MR and moderate or severe MAC.

Methods

Six patients with moderate or severe MAC who were treated with AltaValve TMVR had procedural and mid-term outcomes available.

Results

Technical success was achieved in all patients. Median follow-up was 232 days. At discharge, 80% of patients had none/trace MR, and 20% had mild MR. There was no intraprocedural mortality, device malposition, embolization, or thrombosis. One patient expired 3 days postprocedure due to complications related to the transapical access. All other patients were discharged from the hospital without issues. Echocardiography assessments at 30 days showed complete resolution of MR in all patients, with 1 patient with mild MR and a mean mitral valve gradient of 3.7 ± 1.4 mmHg. All patients were in New York Heart Association Class I/II at 30-day follow-up, showing marked improvement as compared with baseline.

Conclusions

In patients with severe MR and severe MAC, the AltaValve TMVR technology may represent a viable treatment option. The atrial fixation minimizes the risk of left ventricular outflow tract obstruction and potentially expands treatable patients, especially in patients with MAC.

Contemporary experience of mitral transcatheter edge-to-edge repair technology in patients with mitral annular calcification

BACKGROUND

Mitral annular calcification (MAC) has been an exclusion for many of the earlier pivotal trials that were instrumental in gaining device approval and indications for mitral transcatheter edge-to-edge repair (M-TEER).

AIMS

To evaluate the impact of MAC on the procedural durability and success of newer generation MitraClip® systems (G3 and G4 systems).

METHODS

Data were collected from Northwell TEER registry. Patients that underwent M-TEER with third or fourth generation MitraClip device were included. Patients were divided into -MAC (none-mild) and +MAC (moderate-severe) groups. Procedural success was defined as ≤ grade 2 + mitral regurgitation (MR) postprocedure, and durability was defined as ≤ grade 2 + MR retention at 1 month and 1 year. Univariate analysis compared outcomes between groups.

RESULTS

Of 260 M-TEER patients, 160 were -MAC and 100 were +MAC. Procedural success was comparable; however, there were three patients who required conversion to cardiac surgery during the index hospitalization in the +MAC group versus none in the -MAC group (though this was not statistically significant). At 1-month follow-up, there were no significant differences in MR severity. At 1-year follow-up, +MAC had higher moderate-severe MR (22.1% vs. 7.5%; p = 0.002) and higher mean transmitral gradients (5.3 vs. 4.0 mmHg; p = 0.001) with no differences in mortality, New York Heart Association functional class or ejection fraction.

CONCLUSION

In selective patients with high burden of MAC, contemporary M-TEER is safe, and procedural success is similar to patients with none-mild MAC. However, a loss of procedural durability was seen in +MAC group at 1-year follow-up. Further studies with longer follow-ups are required to assess newer mTEER devices and their potential clinical implications in patients with a high burden of MAC.

Impact of biological sex on valvular heart disease, interventions, and outcomes

Valvular heart disease (VHD) is common, affecting >14% of individuals aged >75, and is associated with morbidity, including heart failure and arrhythmia, and risk of early mortality. Increasingly, important sex differences are being found between males and females with VHD. These sex differences can involve the epidemiology, pathophysiology, presentation, diagnosis, and outcomes of the disease. Females are often disadvantaged, and female sex has been shown to be associated with delayed diagnosis and inferior outcomes in various forms of VHD. In addition, the unique pathophysiologic state of pregnancy is associated with increased risk for maternal and fetal morbidity and mortality in many forms of VHD. Therefore, understanding and recognizing these sex differences, and familiarity with the attendant risks of pregnancy and management of pregnant females with VHD, is of great importance for any primary care or cardiovascular medicine practitioner caring for the female patient. This review will outline sex differences in aortic, mitral, pulmonic, and tricuspid VHD, with particular focus on differences in pathophysiology, clinical presentation, and outcomes. In addition, the pathophysiology and management implications of pregnancy will be discussed.

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.

Transcatheter Mitral Valve Replacement in Patients with Mitral Annular Calcification: A Review

Mitral annular calcification (MAC) is a progressive degenerative calcification of the mitral valve (MV) that is associated with mitral stenosis, regurgitation or both. Patients with MAC are poor candidates for MV surgery because of technical challenges and high peri-operative mortality. Transcatheter MV replacement (TMVR) has emerged as an option for such high surgical risk patients. This has been described with the use of the SAPIEN transcatheter heart valve (valve-in-MAC) and dedicated TMVR devices. Careful anatomic assessment is important to avoid complications of TMVR, such as left ventricular outflow tract obstruction, valve migration, embolization and paravalvular mitral regurgitation. In this review, we discuss the pathology, importance of preprocedural multimodality imaging for optimal patient selection, clinical outcomes and complications associated with TMVR in patients with MAC.

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.

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.

Imaging Considerations and Clinical Implications of Mitral Annular Disjunction

Mitral annular disjunction is increasingly recognized as an important anatomic feature of mitral valve disease. The presence of mitral annular disjunction, defined as separation between the left atrial wall at the point of mitral valve insertion and the left ventricular free wall, has been associated with increased degeneration of the mitral valve and increased incidence of sudden cardiac death. The clinical importance of this entity necessitates standard reporting on cardiovascular imaging reports if patients are to receive adequate risk stratification and management. We provide a narrative review of the literature pertaining to mitral annular disjunction, its clinical implications, and areas needing further research.

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.

Cardiac Computed Tomography: Application in Valvular Heart Disease

The incidence and prevalence of valvular heart disease (VHD) is increasing and has been described as the next cardiac epidemic. Advances in imaging and therapeutics have revolutionized how we assess and treat patients with VHD. Although echocardiography continues to be the first-line imaging modality to assess the severity and the effects of VHD, advances in cardiac computed tomography (CT) now provide novel insights into VHD. Transcatheter valvular interventions rely heavily on CT guidance for procedural planning, predicting and detecting complications, and monitoring prosthesis. This review focuses on the current role and future prospects of CT in the assessment of aortic and mitral valves for transcatheter interventions, prosthetic valve complications such as thrombosis and endocarditis, and assessment of the myocardium.

Transcatheter edge-to-edge mitral valve repair in patients with mitral annulus calcification

BACKGROUND

MAC is commonly found in patients affected with MR, and it is associated with high morbidity, mortality and worse cardiac surgical outcomes. Transcatheter edge-to-edge repair could be an alternative treatment, although there is little evidence in this population.

AIMS

The aim of this study was to analyse the safety, efficacy and durability of MitraClip implantation in patients affected with mitral regurgitation (MR) and mitral annulus calcification (MAC).

METHODS

We analysed the outcomes of 61 suitable patients affected with severe MR and moderate or severe MAC (the "MAC" group) and 791 patients with no or mild MAC (the "NoMAC" group) treated with the MitraClip device.

RESULTS

Procedural success was similar (91.8% vs 95.1%, p=0.268, in MAC and NoMAC, respectively), with a very low rate of complications. At one-year follow-up, 90.6% of MAC and 79.5% of NoMAC patients had MR grade ≤2 (p=0.129), 80% in both groups remained in NYHA Functional Class ≤II, and a significant reduction in cardiac readmissions was observed (65% vs 78% in MAC vs NoMAC, p=0.145). One-year mortality tended to be higher in MAC patients (19.7% vs 11.3%, p=0.050), with no difference in cardiovascular mortality (15.3% vs 9.2%, p=0.129).

CONCLUSIONS

MitraClip use in selected patients with moderate or severe MAC is safe, feasible and achieves good clinical and echocardiographic results at one-year follow-up.

The impact of pulmonary hypertension on outcomes of transcatheter mitral valve replacement in mitral annular calcification

OBJECTIVES

To assess the impact of pulmonary hypertension (PH) on outcomes of patients with severe mitral annular calcification (MAC) undergoing transcatheter mitral valve replacement (TMVR).

BACKGROUND

PH is associated with poor outcomes after mitral valve surgery. Whether the presence of PH in patients with MAC undergoing (TMVR) is associated with poor outcomes, is unknown.

METHODS

Retrospective evaluation of 116 patients from 51 centers in 11 countries who underwent TMVR with valve in mitral annular calcification (ViMAC) using balloon-expandable aortic transcatheter valves (THVs) from September 2012 to March 2017. Pulmonary artery systolic blood pressure (PASP) by echocardiogram was available in 90 patients. The subjects were stratified based on PASP: No PH = PASP ≤35 mmHg (n = 11); mild to moderate PH = PASP 36-49 mmHg (n = 21) and severe PH = PASP ≥50 mmHg (n = 58). Clinical, procedural, and echocardiographic outcomes were assessed.

RESULTS

Mean age was 72.7 (±12.8) years, 59 (65.6%) were female, Society of Thoracic Surgeons score was 15.8 + 11.8% and 90.0% where in New York Heart Association (NYHA) class III-IV. There was no significant difference in all-cause mortality at 30 days (no PH = 27.3%, mild-moderate PH = 19.0%, severe PH = 31.6%; p = 0.55) or at 1 year (no PH = 54.5%, mild-moderate PH = 38.1%, severe PH = 56.1%; p = 0.36). No difference in adverse events, NYHA class or amount of residual mitral regurgitation at 1 year were observed between the groups.

CONCLUSION

This study suggests that the presence of PH in patients with predominantly mitral stenosis with MAC undergoing TMVR does not impact mortality or adverse events. Further studies are needed to fully understand the effect of PH in this group of patients.

High Mitral Annulus Calcium Score in Pre-Operative Chest Computerized Tomography and Adverse Outcomes in Mitral Valve Surgery

Background

Severe mitral annulus calcification (MAC) is believed to bear high operative and post-operative risk during mitral valve replacement (MVR) surgery, including longer surgery time, post-surgical valvular leaks and increased rate of embolic phenomena. We hypothesized that quantification of mitral calcium in pre-operative chest computerized tomography (CCT), performed to assess aortic root before cross-clamping may help in risk assessment of adverse intraoperative and postoperative outcomes in patients undergoing MVR.

Methods

We included patients who underwent MVR between the years 2015 and 2018 at Poriya medical center. Preoperative CCT was performed using Philips iCT 256 and Agatston mitral annulus calcium score (MACS) was retrospectively calculated using Philips Intellispace portal version 8.0. Patients were divided into MACS quintiles; 1-3 quintiles were grouped (Low MACS) and compared to the 4-5 quintiles (High MACS) group for demographic, clinical operative and post-operative parameters.

Results

A total of 66 patients had MVR, out of which 61% were males, with mean age of 64±9. Concomitant coronary or valvular procedures were done in 60% of patients. The median MACS was 43. High MACS (≥854) was not associated with longer bypass or cross clamp times. No differences in the MVR results were found between the groups. There were 6 post-operative embolic events; 1 mesenteric and 5 cerebral, which were not associated with MACS.

Conclusion

MACS did not seem to be related to adverse outcomes in MVR. Due to a low event rate and probable pre-selection of patients without extreme mitral annulus calcifications our results should be confirmed in larger prospective study.

Surgical implantation of balloon-expandable heart valves for the treatment of mitral annular calcification

OBJECTIVES

The treatment of mitral valve disease in the presence of mitral annular calcification (MAC) is associated with an increased risk of cardiovascular and all-cause mortality. Various surgical and transcatheter techniques for the treatment of mitral disease with severe MAC have been described. However, these procedures are associated with high risk of operative morbidity and mortality. We describe our experience with open surgical implantation of a balloon-expandable valve (BEV) in patients with severe MAC as an alternative approach.

METHODS

BEV implantation was performed with direct vision through the left atrium via a median sternotomy or minimally invasive approach. The midportion of the anterior leaflet is excised, and a ventricular septal myectomy performed if there is high risk for left ventricular outflow tract obstruction. The primary outcome was technical success according to the Mitral Valve Academic Research Consortium criteria; secondary outcomes were 30-day and 1-year mortality.

RESULTS

From October 2015 through October 2020, 51 patients at 2 institutions underwent BEV-in-MAC (mean age, 73.9 ± 8.8 years; 60.8% [31/51] were female; mean Society of Thoracic Surgeons predicted risk of mortality: 6.8% ± 4.8%). Technical success was 94.1% (48/51). Thirty-day and 1-year mortality were 13.7% (7/51) and 33.3% (15/45), and for stroke 3.9% (2/51) and 4.4% (2/45), respectively.

CONCLUSIONS

Surgical implantation of a BEV in the mitral position offers a treatment option for patients with mitral valve disease complicated by severe MAC who are at increased risk for conventional surgical approaches and at risk for left ventricular outflow tract obstruction with transcatheter approaches.

The Spectrum of Caseous Mitral Annulus Calcifications

Mitral annular calcification (MAC) is a chronic, degenerative condition of the fibrous mitral annulus, which may transform to liquefaction necrosis MAC, a rare variant of caseous MAC. We present a series of experiences, showing the varying manifestations of caseous MAC according to multimodal imaging. (Level of Difficulty: Intermediate.)

Echocardiographic Assessment of the Mitral Valve for Suitability of Repair: An Intraoperative Approach From a Mitral Center

Intraoperative echocardiography of the mitral valve in the precardiopulmonary bypass period is an integral part of the surgical decision-making process for assessment of suitability for repair. Although there are comprehensive reviews in the literature regarding echocardiographic examination of the mitral valve, the authors present a practical stepwise algorithmic workflow to make objective recommendations. Advances in echocardiography allow for quantitative geometric analyses of the mitral valve, along with precise assessment of the valvular apparatus with three-dimensional echocardiography. In the precardiopulmonary bypass period, echocardiographers are required to diagnose and quantify valvular dysfunction, assess suitability for repair, assist in annuloplasty ring sizing, and determine the success or failure of the surgical procedure. In this manuscript the authors outline an algorithmic approach to intraoperative echocardiography examination using two-dimensional and three-dimensional modalities to objectively analyze mitral valve function and assist in surgical decision-making.

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.

Prospective Study of TMVR Using Balloon-Expandable Aortic Transcatheter Valves in MAC: MITRAL Trial 1-Year Outcomes

OBJECTIVES

The aim of this study was to evaluate 1-year outcomes of valve-in-mitral annular calcification (ViMAC) in the MITRAL (Mitral Implantation of Transcatheter Valves) trial.

BACKGROUND

The MITRAL trial is the first prospective study evaluating the feasibility of ViMAC using balloon-expandable aortic transcatheter heart valves.

METHODS

A multicenter prospective study was conducted, enrolling high-risk surgical patients with severe mitral annular calcification and symptomatic severe mitral valve dysfunction at 13 U.S. sites.

RESULTS

Between February 2015 and December 2017, 31 patients were enrolled (median age 74.5 years [interquartile range (IQR): 71.3 to 81.0 years], 71% women, median Society of Thoracic Surgeons score 6.3% [IQR: 5.0% to 8.8%], 87.1% in New York Heart Association functional class III or IV). Access was transatrial (48.4%), transseptal (48.4%), or transapical (3.2%). Technical success was 74.2%. Left ventricular outflow tract obstruction (LVOTO) with hemodynamic compromise occurred in 3 patients (transatrial, n = 1; transseptal, n = 1; transapical, n = 1). After LVOTO occurred in the first 2 patients, pre-emptive alcohol septal ablation was implemented to decrease risk in high-risk patients. No intraprocedural deaths or conversions to open heart surgery occurred during the index procedures. All-cause mortality at 30 days was 16.7% (transatrial, 21.4%; transseptal, 6.7%; transapical, 100% [n = 1]; p = 0.33) and at 1 year was 34.5% (transatrial, 38.5%; transseptal, 26.7%; p = 0.69). At 1-year follow-up, 83.3% of patients were in New York Heart Association functional class I or II, the median mean mitral valve gradient was 6.1 mm Hg (IQR: 5.6 to 7.1 mm Hg), and all patients had ≤1+ mitral regurgitation.

CONCLUSIONS

At 1 year, ViMAC was associated with symptom improvement and stable transcatheter heart valve performance. Pre-emptive alcohol septal ablation may prevent transcatheter mitral valve replacement-induced LVOTO in patients at risk. Thirty-day mortality of patients treated via transseptal access was lower than predicted by the Society of Thoracic Surgeons score. Further studies are needed to evaluate safety and efficacy of ViMAC.

Transcatheter Mitral Valve Implantation Systematic Review: Focus on Transseptal Approach and Mitral Annulus Calcification

INTRODUCTION

This systematic review was performed to evaluate the results of transcatheter mitral valve implantation (TMVI) in the native mitral valve.

EVIDENCE ACQUISITION

Medline, EMBASE, and the Cochrane Central register were systematically searched for studies that reported results of TMVI in mitral valve regurgitation and/or stenosis and mitral annular calcification. To improve the sensitivity of the literature search, we performed citation chasing in Google Scholar, Scopus, and Web of Science.

EVIDENCE SYNTHESIS

Twelve studies reporting results of TMVI in mitral regurgitation were retrieved and included 347 patients. The transseptal approach represented 28% of cases. Secondary mitral regurgitation was the predominant indication in 63% of cases. Thirty-day mortality was 11% and was lowered with the transseptal approach (7%). Technical success was 92%. Surgical conversion was needed in 5% of patients. Only one patient presented moderate to severe mitral regurgitation. These hemodynamic results were sustainable up to one year of follow-up. Three series focused on results of TMVI in mitral annulus calcification including 167 patients. Only nine patients were treated with TMVI dedicated prosthesis. Eighty-seven patients had their prosthesis delivered through a transseptal approach. Mitral stenosis was present in 63% of cases. Thirty-day mortality was 24%, and none with TMVI prosthesis. Technical success was achieved in 71% of cases and was improved by using TMVI prosthesis (89%). The main complication was left ventricular outflow tract obstruction (20%). Post procedural moderate to severe mitral regurgitation was observed in 4% of cases.

CONCLUSION

TMVI seems to be feasible, achieving good technical success and predictable and durable MR reduction.

Current Devices in Mitral Valve Replacement and Their Potential Complications

Mitral regurgitation is one of the most prevalent valvulopathies worldwide, and its surgical treatment is not feasible in all cases. The elderly and frail with several comorbidities and left ventricular dysfunction are often managed conservatively. Percutaneous treatment (repair or replacement) of the mitral valve has emerged as a potential option for those patients who are at a high risk for surgery. Mitral valve repair with the Mitraclip device proved both increased safety and mortality reduction in patients with severe mitral regurgitation. On the other hand, in the last decade, percutaneous mitral replacement opened new frontiers in the field of cardiac structural interventions. There are few mitral devices; some are in the early phase of development and some are waiting for CE mark of approval. The evolution of these devices was more complicated compared to the aortic technology due to the native mitral valve's complexity and access. This review aims to provide an overview of the current devices, their specific features, and their potential complications.

Neo-LVOT and Transcatheter Mitral Valve Replacement: Expert Recommendations

With the advent of transcatheter mitral valve replacement (TMVR), the concept of the neo-left ventricular outflow tract (LVOT) was introduced and remains an essential component of treatment planning. This paper describes the LVOT anatomy and provides a step-by-step computed tomography methodology to segment and measure the neo-LVOT while discussing the current evidence and outstanding challenges. It also discusses the technical and hemodynamic factors that play a major role in assessing the neo-LVOT. A summary of expert-based recommendations about the overall risk of LVOT obstruction in different scenarios is presented along with the currently available methods to reduce the risk of LVOT obstruction and other post-procedural complications.

Alcohol Septal Ablation to Prevent Left Ventricular Outflow Tract Obstruction During Transcatheter Mitral Valve Replacement: First-in-Man Study

OBJECTIVES

This study evaluates outcomes of pre-emptive alcohol septal ablation (ASA) to prevent iatrogenic left ventricular outflow tract (LVOT) obstruction after transcatheter mitral valve replacement (TMVR).

BACKGROUND

LVOT obstruction is a life-threatening complication of TMVR. Bail-out ASA has been described as a therapeutic option for patients with outflow obstruction during TMVR, but little is known about pre-emptive ASA.

METHODS

Multicenter registry of patients with severe mitral valve disease who underwent pre-emptive ASA to mitigate LVOT obstruction risk after TMVR. High risk of LVOT obstruction was predicted in all patients by pre-procedural computed tomographic imaging.

RESULTS

Thirty patients (age 76.1 ± 7.7 years; women 76.7%) with severe mitral valve disease underwent pre-emptive ASA to mitigate TMVR-induced LVOT obstruction risk. Twenty patients underwent mitral valve replacement (14 transseptal, 3 transatrial, 1 transapical, 1 transseptal with percutaneous laceration of anterior mitral leaflet, 1 treated with surgical mitral valve replacement). Eight patients experienced clinical improvement post-ASA. Two patients died before TMVR. Median increase in neo-LVOT surface area post-ASA was 111.2 mm² (interquartile range: 71.4 to 193.1 mm²). Five patients (16.7%) required pacemaker implantation post-ASA. In-hospital and 30-day mortality post-ASA was 6.7% (2/30 patients). After ASA, TMVR was performed successfully in 100% of attempted cases. In-hospital and 30-day mortality post-TMVR was 5.3% (1/19). Mortality of entire cohort was 10% (3/30 patients: 2 post-ASA before TMVR, 1 died 30 days post-TMVR).

CONCLUSIONS

Pre-emptive ASA is associated with a significant increase in predicted neo-LVOT area before TMVR and may enable safe TMVR in patients usually excluded secondary to prohibitive risk of LVOT obstruction.

Outcomes After Transcatheter Mitral Valve Repair in Patients With Renal Disease

BACKGROUND

Renal disease is associated with poor prognosis despite guideline-directed cardiovascular therapy, and outcomes by sex in this population remain uncertain.

METHODS AND RESULTS

Patients (n=5213) who underwent a MitraClip procedure in the National Cardiovascular Data Registry Transcatheter Valve Therapy registry were evaluated for the primary composite outcome of all-cause mortality, stroke, and new requirement for dialysis by creatinine clearance (CrCl). Centers for Medicare and Medicaid Services-linked data were available in 63% of patients (n=3300). CrCl was <60 mL/min in 77% (n=4010) and <30 mL/min in 23% (n=1183) of the cohort. Rates of primary outcome were higher with lower CrCl (>60 mL/min, 1.4%; 30-<60 mL/min, 2.7%; <30 mL/min, 5.2%; dialysis, 7.8%; P<0.001), and all low CrCl groups were independently associated with the primary outcome (30-<60 mL/min: adjusted odds ratio, 2.32; 95% CI, 1.38-3.91; <30 mL/min: adjusted odds ratio, 4.44; 95% CI, 2.63-7.49; dialysis: adjusted hazards ratio, 4.52; 95% CI, 2.08-9.82) when compared with CrCl >60 mL/min. Rates of 1-year mortality were higher with lower CrCl (>60 mL/min, 13.2%; 30-<60 mL/min, 18.8%; <30 mL/min, 29.9%; dialysis, 32.3%; P<0.001), and all low CrCl groups were independently associated with 1-year mortality (30-<60 mL/min: adjusted hazards ratio, 1.50; 95% CI, 1.13-1.99; <30 mL/min: adjusted hazards ratio, 2.38; 95% CI, 1.78-3.20; adjusted hazards ratio: dialysis, 2.44; 95% CI, 1.66-3.57) when compared with CrCl >60 mL/min.

CONCLUSIONS

The majority of patients who undergo MitraClip have renal disease. Preprocedural renal disease is associated with poor outcomes, particularly in stage 4 or 5 renal disease where 1-year mortality is observed in nearly one-third. Studies to determine how to further optimize outcomes in this population are warranted.

Utility of Cardiac CT for Preoperative Evaluation of Mitral Regurgitation: Morphological Evaluation of Mitral Valve and Prediction of Valve Replacement

OBJECTIVE

We aimed to investigate the diagnostic accuracy of cardiac computed tomography (CT) for the detection of mitral valve (MV) prolapse in mitral regurgitation (MR) with surgical findings as the standard reference, and to assess the predictability of MV replacement based on morphologic CT findings.

MATERIALS AND METHODS

A total of 156 patients who had undergone preoperative cardiac CT and subsequently received MV surgery due to severe MR were retrospectively enrolled. Non-repairable MV was defined when at least one of the following conditions was met: 1) anterior leaflet prolapse, 2) bi-leaflet prolapse, or 3) valve morphology (leaflet thickening, calcification, or mitral annular calcification [MAC]). Diagnostic performance of CT for the detection of the prolapsed segment was assessed with surgical findings as the standard reference. Logistic regression analysis was performed to evaluate the value of CT findings to predict actual valve replacement.

RESULTS

During surgery, MV prolapse was identified in 72.1%. The sensitivity, specificity, and diagnostic accuracy for the detection of MV prolapse were 99.1%, 81.4%, and 94.2%, respectively, per patient. One-hundred eighteen patients (75.6%) underwent MV repair and the remaining 38 patients received MV replacement. Bi-leaflet prolapse and valve morphology were independent predictors of valve replacement after adjusting for clinical variables (adjusted odds ratio, [OR] 8.63 for bi-leaflet prolapse; OR, 4.14 for leaflet thickening; and OR, 5.37 for leaflet calcium score > 5.6; p < 0.05).

CONCLUSION

Cardiac CT can have high diagnostic performance for detecting the prolapsed segment of the MV and predictability of valve replacement before surgery. Bi-leaflet prolapse and valve morphology, such as leaflet thickening, or calcification or MAC, are the most important predictors of valve replacement.

The Relationship Between Mitral Annular Calcification, Metabolic Syndrome and Thromboembolic Risk

INTRODUCTION

Metabolic syndrome (MetS) is defined as an association between diabetes, hypertension, obesity and dyslipidemia and an increased risk of cardiovascular disease. Mitral annular calcification (MAC) is associated with several cardiovascular disorders, including coronary artery disease, atrial fibrillation (AF), heart failure, ischemic stroke and increased mortality. The CHA2DS2-VASc score is used to estimate thromboembolic risk in AF. However, the association among MAC, MetS and thromboembolic risk is unknown and was evaluated in the current study.

METHODS

The study group consisted of 94 patients with MAC and 86 patients with MetS. Patients were divided into two groups: those with and those without MAC.

RESULTS

Patients with MAC had a higher MetS rate (P<0.001). In patients with MAC, the CHA2DS2-VASc scores and the rate of cerebrovascular accident and AF were significantly higher compared to those without MAC (P<0.001, for both parameters). The results of the multivariate regression analysis showed that history of smoking, presence of MetS and high CHA2DS2-VASc scores were associated with the development of MAC. ROC curve analyses showed that CHA2DS2-VASc scores were significant predictors for MAC (C-statistic: 0.78; 95% CI: 0.706-0.855, P<0.001). Correlation analysis indicated that MAC was positively correlated with the presence of MetS and CHA2DS2-VASc score (P=0.001, r=0.264; P<0.001, r=0.490).

CONCLUSION

We have shown that CHA2DS2-VASc score and presence of MetS rates were significantly higher in patients with MAC compared without MAC. Presence of MAC was correlated with CHA2DS2-VASc score, presence of MetS, AF and left atrial diameter and negatively correlated with left ventricular ejection fraction.

Clinical outcomes of mitral valve intervention in patients with mitral annular calcification: A systematic review and meta-analysis

BACKGROUND

Mitral valve (MV) disease with mitral annular calcification (MAC) poses a surgical challenge and the clinical outcomes of MV surgery as well as transcatheter mitral valve replacement (TMVR) remain relatively unexplored. We performed a systematic review and meta-analysis to assess the effects of MAC on clinical outcomes following MV surgery and TMVR.

METHODS

We searched MEDLINE and EMBASE databases until February 2019 for studies comparing clinical outcomes of MV surgery or TMVR in patients with and without MAC. Data were extracted by two independent investigators. Outcomes were perioperative and midterm complications and mortality.

RESULTS

Seven observational studies enrolling 2902 patients were included. MAC patients were older, more likely to be female with greater chronic lung disease and kidney failure. Perioperative mortality was similar between patients with and without MAC undergoing MV surgery (risk ratio [RR], 1.15; 95% confidence interval [CI], 0.50-2.65; P = .74). MAC was associated with a higher risk of bleeding, permanent pacemaker implantation, and periprosthetic leak. Midterm mortality was greater in MAC patients undergoing MV surgery (incident rate ratio [IRR], 1.32; 95% CI, 1.05-1.67; P = .02). MAC patients undergoing TMVR had higher perioperative (RR, 4.65; 95% CI, 2.93-7.38; P < .01) and 1-year (RR, 5.44; 95% CI, 3.49-8.49; P < .01) mortality, decreased procedural success, greater left ventricular outflow tract obstruction and need for conversion to surgery when compared with patients undergoing TMVR for dysfunction of a bioprosthetic valve or annuloplasty ring.

CONCLUSION

MV procedures in patients with MAC are associated with higher mortality and morbidity. This is largely driven by the high-risk patient profile associated with MAC. TMVR holds promise but has important limitations and should be reserved for select patients.

Degenerative mitral valve stenosis: Diagnosis and management

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

Open Atrial Transcatheter Mitral Valve Replacement in Patients With Mitral Annular Calcification

BACKGROUND

Mitral valve replacement in the setting of severe mitral annular calcification remains a surgical challenge. Transcatheter mitral valve replacement (TMVR) using an aortic balloon-expandable transcatheter heart valve is emerging as a potential treatment option for high surgical risk patients. Transseptal, transapical, or transatrial access is not always feasible, so an understanding of alternative implantation techniques is important.

OBJECTIVES

The authors sought to present a step-by-step description of a contemporary transatrial TMVR technique using balloon-expandable aortic transcatheter heart valves. This procedure has evolved over time to address valve migration, left ventricular outflow tract obstruction, and paravalvular leak. The authors present a refined technique that has been associated with the most reproducible outcomes.

METHODS

A step-by-step description of the TMVR technique and outcomes of 8 patients treated using this technique are described. Baseline patient clinical and echocardiographic characteristics and 30-day post-TMVR outcomes are presented.

RESULTS

Eight patients underwent transatrial TMVR at a single institution. Five had previous cardiac surgery. Mean STS score was 8%. Technical success by MVARC (Mitral Valve Academic Research Consortium) criteria was 100%. There was zero in-hospital and 30-day mortality. Procedural success by MVARC criteria at 30 days was 100%. Paravalvular leak immediately post-implant was none or trace in 6 and mild in 1.

CONCLUSIONS

The technique described is reproducible and was associated with favorable outcomes in this early experience. It represents a useful technique for the treatment of mitral valve disease in the setting of severe annular calcification. A structured and defined implantation technique is critical to investigators as this field evolves.

Predictors of adverse outcomes after transcatheter mitral valve replacement

Introduction: Transcatheter mitral valve replacement (TMVR) is still a recent technology with numerous unknowns but also great promises. The risk of complications reported in observational studies have limited its adoption by interventional cardiology and surgical communities. Areas covered: Some of the major setbacks of TMVR are complications related to the devices and those related to the pathway. Device-related complications include left ventricle outflow tract (LVOT) obstruction, transcatheter heart valve (THV) dislocation or embolization, thrombosis, and stroke. The transapical approach currently remains the main pathway for TMVR but is associated with high risk of major bleeding and residual apical myocardial scarring. Complication prediction and prevention seem possible. Device-related complication prediction is based on pre-operative imaging including multi-slice computed tomography with 3-dimensional reconstructions and echocardiography which allow LVOT obstruction prediction and appropriate sizing aiming at avoiding dislocation. Industry should aim at the development of transfemoral delivery systems. Nevertheless, several recent feasibility observational studies suggested acceptable safety and efficacy of transcatheter mitral valve replacement. Expert opinion: TMVR complications and transapical delivery are some of the main setbacks which need to be addressed for TMVR to be adopted for broad clinical use.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Degenerative Mitral Stenosis: From Pathophysiology to Challenging Interventional Treatment

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

Energy Dispersive X-ray (EDX) microanalysis: A powerful tool in biomedical research and diagnosis

The Energy Dispersive X-ray (EDX) microanalysis is a technique of elemental analysis associated to electron microscopy based on the generation of characteristic Xrays that reveals the presence of elements present in the specimens. The EDX microanalysis is used in different biomedical fields by many researchers and clinicians. Nevertheless, most of the scientific community is not fully aware of its possible applications. The spectrum of EDX microanalysis contains both semi-qualitative and semi-quantitative information. EDX technique is made useful in the study of drugs, such as in the study of drugs delivery in which the EDX is an important tool to detect nanoparticles (generally, used to improve the therapeutic performance of some chemotherapeutic agents). EDX is also used in the study of environmental pollution and in the characterization of mineral bioaccumulated in the tissues. In conclusion, the EDX can be considered as a useful tool in all works that require element determination, endogenous or exogenous, in the tissue, cell or any other sample.

Ventricular Perforation During Open Surgical Balloon Expandable Mitral Valve Replacement: A Case Report

A 79-year-old woman with severe mitral annular calcification was scheduled for mitral valve replacement. A SAPIEN 3 valve was implanted in mitral position using an open surgical approach. Immediately after cardiopulmonary bypass, bleeding from an unidentified source was encountered. Cardiopulmonary bypass was emergently resumed and a laceration of the left ventricular apex due to the valve delivery system was detected. Risk factors specific to the open surgical approach include a decompressed ventricle, decreased annulus to apical distance, and the absence of continuous fluoroscopic and echocardiographic imaging. These create a clinical scenario where risk of ventricular perforation is increased compared with traditional intravascular transcatheter valve delivery.