Mitral Valve Intervention in Elderly or High-Risk Patients: A Review of Current Surgical and Interventional Management.

Mitral regurgitation is a prevalent valvular disease, and its management has gained increasing importance because of the aging population. Although traditional surgery remains the gold standard, the field of transcatheter therapies, including transcatheter edge-to-edge repair and, more recently transcatheter mitral valve replacement are advancing and are being explored as viable alternatives, particularly for patients at high surgical risk. It is essential to emphasize the necessity of a multidisciplinary team approach, involving specialized valve teams, imaging experts, cardiac anaesthesiologists, and other relevant specialists, is crucial in achieving optimal outcomes. Furthermore, proper execution of procedures, postprocedural care, and diligent follow-up for these patients are essential components for successful results. It is essential to underscore that traditional mitral valve surgery continues to play a significant role. Simultaneously, it is important to acknowledge the expanding array of transcatheter interventions available for this specific patient population.

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.

Arrhythmic Mitral Valve Prolapse With Only Mild or Moderate Mitral Regurgitation: Characterization of Myocardial Substrate.

BACKGROUND: Sustained ventricular tachycardia and sudden cardiac death due to degenerative mitral valve prolapse (MVP) can occur in the absence of severe mitral regurgitation (MR). A significant percentage of patients with MVP-related sudden death do not have any evidence of replacement fibrosis, suggesting other unrecognized proarrhythmic factors may place these patients at risk. OBJECTIVES: This study aims to characterize myocardial fibrosis/inflammation and ventricular arrhythmia complexity in patients with MVP and only mild or moderate MR. METHODS: Prospective observational study of patients with MVP and only mild or moderate MR underwent ventricular arrhythmia characterization and hybrid positron emission tomography (PET)/magnetic resonance imaging (MRI). Coregistered hybrid 18F-fluorodeoxyglucose (18F-FDG)-PET and MRI late gadolinium enhancement images were assessed and categorized. Recruitment occurred in the cardiac electrophysiology clinic. RESULTS: In 12 patients with degenerative MVP with only mild or moderate MR, of which a majority had complex ventricular ectopy (n = 10, 83%), focal (or focal-on-diffuse) uptake of 18F-FDG (PET-positive) was detected in 83% (n = 10) of patients. Three-quarters of the patients (n = 9, 75%) had FDG uptake that coexisted with areas of late gadolinium enhancement (PET/MRI-positive). Abnormal T1, T2 and extracellular volume (ECV) values were observed in 58% (n = 7), 25% (n = 3), and 16% (n = 2), respectively. CONCLUSIONS: Most patients with degenerative MVP, ventricular ectopy, and mild or moderate MR show myocardial inflammation that is concordant with myocardial scar. Further study is needed to determine whether these findings contribute to the observation that most MVP-related sudden deaths occur in patients with less than severe MR.

Mitral valve surgery after failed transcatheter edge-to-edge repair: a review and word of caution.

PURPOSE OF REVIEW: As transcatheter edge-to-edge mitral valve repair (TEER) evolves and indications broaden to include younger and lower surgical risk patients, it is essential to understand TEER failure trends and potential impact on subsequent mitral valve surgery, especially when pertaining to feasibility of durable valve reconstruction as opposed to de-novo repair. RECENT FINDINGS: Results of the two largest series analysing mitral valve surgery following TEER have demonstrated remarkably low repairability rates with consequent need for valve replacement. Post TEER surgery was associated with high early and late mortalities, likely as a reflection of patient baseline characteristics and acuity of surgery. Presence and correction of concomitant cardiac pathologies were a frequent finding. Centre and surgeon volumes were important factors in optimizing the likelihood of salvage repair and reducing perioperative risks. SUMMARY: Surgical mitral valve repair in reference centres remain the gold standard and the most durable treatment for degenerative mitral disease with excellent perioperative safety outcomes. Given the high likelihood of needing high-risk mitral valve replacement when TEER fails, consideration for potentially less durable transcatheter alternatives should be taken with caution in younger or lower surgical risk patients.

Leadless pacemaker implantation under direct visualization during valve surgery.

OBJECTIVE: The leadless cardiac pacemaker is typically implanted percutaneously and has been widely used for patients who have already undergone valve surgery. We sought to determine the feasibility and safety of implanting the leadless pacemaker under direct visualization during valve surgery. METHODS: We performed a retrospective analysis of consecutive adult patients (n = 15) who underwent implantation of a leadless pacemaker under direct visualization at the time of valve surgery. Indications for single-chamber pacing were sick sinus syndrome with pauses (53.3%), atrial fibrillation with slow ventricular rates (13.3%) or complete heart block (6.6%), and elevated risk for postoperative heart block (26.6%). Leadless pacemaker performance and pacing percentage were assessed. RESULTS: Patients' age was 67.5 ± 17 years, 6 patients (40%) were male, and 14 patients (93%) had atrial fibrillation. Isolated tricuspid valve replacement was performed in 5 patients (33.3%), and the remainder underwent multivalve surgery that included concomitant tricuspid valve repair/replacement. In 93% of the patients (n = 14), the immediate post-cardiopulmonary bypass pacing thresholds were normal (≤2.0 V at 0.24 ms) and normalized in the remaining patient by the next morning. The impedance/sensing values were normal and stable through follow-up (151 ± 119 days) in all patients. Reliable leadless pacemaker performance allowed for deferral of temporary epicardial wires in 11 patients (73%). There were no procedural complications or device malfunction. CONCLUSIONS: Leadless cardiac pacemaker implantation during valve surgery is feasible and safe. This hybrid approach to pacing may simplify the perioperative management of patients undergoing valve surgery who have an indication for single-chamber pacing.

Imaging for Native Mitral Valve Surgical and Transcatheter Interventions.

There has been rapid progress in transcatheter therapies for mitral regurgitation. These developments have elevated the need for the imager to have a core understanding of the functional mitral valve anatomy. Pre- and intraoperative echocardiography for surgical mitral valve repair for mitral regurgitation has defined contemporary interventional imaging in many ways. The central tenets of these principles apply to interventional imaging of transcatheter mitral valve interventions. However, the heightened emphasis on procedural planning and procedural imaging is one of the new challenges posed by transcatheter interventions. This need for accurate and reliable information has required the imager to be agnostic to the imaging modality. Cardiac computed tomography has become critical in procedural planning in this new paradigm. The expanded use of pre-procedural cardiac magnetic resonance to quantify mitral regurgitation and characterize the left ventricle is another illustration of this newer approach. Other illustrations of the new world of interventional imaging include the expanded use of 3-dimensional (3D) transesophageal echocardiography and real-time fusion of echocardiography and fluoroscopy images. Imaging data are also the basis for computational modeling, 3D printing, and artificial intelligence. These technologies are being increasingly explored to improve therapy selection and prediction of procedural outcomes. This review provides an update of the essentials in present interventional imaging for surgical and transcatheter interventions for mitral regurgitation.

Lessons from reoperations for mitral stenosis after mitral valve repair.

BACKGROUND: The durability of mitral valve repair (MVr) is usually defined by the absence of recurrent significant mitral regurgitation. Postrepair mitral stenosis (MS) is a less frequent and less studied mode of failure of MVr. We analyzed our experience in patients who underwent reoperation for postrepair MS to characterize mechanisms resulting in MS and to summarize reoperative surgical strategies and mid-term outcomes. METHODS: Using a prospective database, we retrospectively analyzed data on 35 consecutive patients who underwent reoperation for symptomatic moderate to severe MS between January 1, 2011, and February 1, 2020. RESULTS: The mean patient age was 61.4 ± 11.4 years, and 69% were female. The median annuloplasty ring size used at the initial repair was 28 mm (interquartile range, 26-30 mm). Additional repair techniques at the initial operation included leaflet resection in 12 patients (34%) and commissuroplasty or edge-to-edge repair in 6 patients (18%). At reoperation, the most common mechanism of MS was pannus ingrowth in 20 patients (57%), leaflet calcification in 12 (34%), commissural fusion in 5 (14%), and tunnel effect (functional MS) in 3 (9%). Twenty-two patients (63%) underwent valve replacement, and 13 (37%) underwent valve re-repair. In patients who underwent re-repair, annuloplasty revision was performed in all patients, with 6 patients (46%) converted from complete ring to band, 4 (11%) converted from ring to pericardial annuloplasty, 2 (6%) converted to no annuloplasty, and 1 (8%) with annuloplasty ring upsizing. There were no in-hospital or 1-year mortalities. Survival at the 5-year follow-up was 93.9%. CONCLUSIONS: MS causing late failure of MVr is frequently associated with smaller ring sizes and inflammatory or calcific changes in the valve. Highly selected patients may be good candidates for mitral valve re-repair.

Hybrid Positron Emission Tomography/Magnetic Resonance Imaging in Arrhythmic Mitral Valve Prolapse.

Importance: Myocardial replacement fibrosis has been reported to occur in one-third of patients with mitral valve prolapse (MVP) and significant mitral regurgitation (MR). However, it remains unknown whether there are detectable changes in myocardial metabolism suggestive of inflammation or ischemia that accompany the development of fibrosis. Objectives: To characterize the burden and distribution of fluorine 18-labeled (18F) fluorodeoxyglucose (FDG) uptake and late gadolinium enhancement (LGE) in patients with degenerative MVP and ventricular ectopy. Design, Setting, and Participants: Prospective observational study of 20 patients with MVP and significant primary degenerative MR who were referred for mitral valve repair and underwent hybrid positron emission tomography/magnetic resonance imaging (PET/MRI). Ventricular arrhythmias were categorized as either complex (n = 12) or minor (n = 8). Coregistered hybrid 18F FDG-PET and MRI LGE images were assessed and categorized. Recruitment occurred in the new patient clinic of a mitral valve repair reference center. This study was conducted from January 11, 2018, to June 26, 2019. Exposures: Simultaneous cardiac 18F FDG-PET and MRI with LGE imaging on a hybrid PET/MRI system and ambulatory rhythm monitoring. Main Outcomes and Measures: Patients were categorized by the presence and pattern of FDG uptake and LGE, the severity of ventricular arrhythmias, and the indication for mitral valve surgery. Results: In the cohort of 20 patients, the median age was 59.5 years (interquartile range, 52.5-63.2 years). Focal, or focal-on-diffuse uptake, of 18F-FDG (PET positive) was detected in 17 of 20 patients (85%). The FDG uptake coexisted with areas of LGE (PET/MRI positive) in 14 patients (70%). Of the 5 asymptomatic patients with normal ventricular indices and absence of any surgical indications, all were PET/MRI positive. Conclusions and Relevance: In this pilot study, we demonstrate a novel association between degenerative MVP and FDG uptake, a surrogate for myocardial inflammation and/or ischemia. Such evidence of myocardial injury, even in asymptomatic patients, suggests an ongoing subclinical disease process. These findings warrant further investigation into whether imaging for myocardial inflammation, ischemia, and scar has a role in arrhythmic risk stratification and whether it provides incremental prognostic value in patients with chronic severe mitral regurgitation undergoing active surveillance.

Surgical management of mitral annular calcification.

PURPOSE OF REVIEW: The aim of the article is to discuss different therapeutic options for patients with severe mitral valve dysfunction because of mitral annular calcification (MAC), including mitral valve repair, conventional mitral valve replacement, percutaneous transcatheter mitral valve replacement (TMVR), and hybrid procedures. RECENT FINDINGS: Optimal management of severe mitral valve disease because of MAC remains challenging. Various 'resect' or 'respect' repair strategies have been standardized and are applicable in eligible patients. Mitral valve replacement with a standard surgical bioprosthesis is often possible in nonrepair candidates, especially with noncircumferential MAC. TMVR has evolved as a feasible option for anatomically and/or clinically prohibitive open-surgery cases, with the caveat of strict anatomic eligibility criteria. Hybrid TMVR provides the advantages of both open-surgery and TMVR and has emerged as a promising alternative in select patients. SUMMARY: Surgical management of MAC and severe mitral valve disease continues to evolve. The addition of transcatheter valve options may benefit many patients previously considered inoperable and are now candidates for intervention. This review will summarize state-of-the-art management options for patients with MAC.

Second crossclamp to perfect degenerative mitral valve repair: Decision-making algorithm, safety, and outcomes.

OBJECTIVES: Residual mitral regurgitation reduces the efficacy of mitral repair and is associated with worse outcomes. We adopted a policy using a second bypass run for patients with residual mitral regurgitation (>+1) and described our decision-making algorithm and outcomes. METHODS: From January 1, 2011, to December 31, 2016, 40 patients with degenerative disease underwent a second bypass run to address residual mitral regurgitation. The echocardiographic criteria for a second bypass run was the presence of moderate or greater mitral regurgitation or mild mitral regurgitation with unfavorable mechanism. RESULTS: A second bypass run was used in 40 patients. The mean age was 57.3 ± 13.5 years (21-79 years), and 14 patients (35%) were asymptomatic. Residual mitral regurgitation was mild in 25 patients, moderate in 9 patients, and moderate/severe in 6 patients. The cause of postbypass mitral regurgitation was technical or residual pathology in 35 patients and systolic anterior motion in 5 patients. Re-repair techniques were cleft closure in 22 patients, primary suture repair in 13 patients, and expanded polytetrafluoroethylene chordoplasty in 9 patients. After re-repair, 34 patients (85%) had no mitral regurgitation, 4 patients (10%) had trace mitral regurgitation, and 2 patients (5%) had mild mitral regurgitation. Median total cardiopulmonary bypass time was 208.5 minutes, first crossclamp time was 106 minutes, and second crossclamp time was 34 ± 12 minutes. Median intensive care stay was 2 days, and hospital stay was 8 days. On discharge, there was no mitral regurgitation in 13 patients (33%), trace in 23 patients (58%), and mild mitral regurgitation in 4 patients (10%). Freedom from moderate or greater mitral regurgitation at 5 years was 100%. CONCLUSIONS: Residual mitral regurgitation can be effectively treated using a second bypass run with good long-term outcome and minimal incremental risk.