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.

The use of transesophageal echocardiography to predict surgical complexity scoring system for degenerative mitral valve repair

BACKGROUND

For severe mitral valve (MV) degenerative disease, repair is recommended. Prediction of repair complexity and referral to high volume centers can increase rates of successful repair. This study sought to demonstrate that TEE is a feasible imaging modality to predict the complexity of surgical MV repair.

METHODS

Two hundred TEE examinations of patients who underwent MV repair (2009-2011) were retrospectively reviewed and scored by two cardiac anesthesiologists. TEE scores were compared to surgical complexity scores, which were previously assigned based on published methods. Kappa values were reported for the agreement of TEE and surgical scores. McNemar's tests were used to test the homogeneity of the marginal probabilities of different scoring categories.

RESULTS

TEE scores were slightly lower (2[1,3]) than surgical scores (3[1,4]). The agreement was 66% between the scoring methods, with a moderate kappa (.46). Using surgical scores as the gold standard, 70%, 71%, and 46% of simple, intermediate and complex surgical scores, respectively, were correctly scored by TEE. P1, P2, P3, and A2 prolapse were easiest to identify with TEE and had the highest agreement with surgical scoring (P1 agreement 79% with kappa .55, P2 96% [kappa .8], P3 77% [kappa .51], A2 88% [kappa .6]). The lowest agreement between the two scores occurred with A1 prolapse (kappa .05) and posteromedial commissure prolapse (kappa .14). In the presence of significant disagreement, TEE scores were more likely to be of higher complexity than surgical. McNemar's test was significant for prolapse of P1 (p = .005), A1 (p = .025), A2 (p = .041), and the posteromedial commissure (p < .0001).

CONCLUSION

TEE-based scoring is feasible for prediction of the complexity of MV surgical repair, thus allowing for preoperative stratification.

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.

Plasma Renin Activity Increases With Cardiopulmonary Bypass and is Associated With Vasoplegia After Cardiac Surgery

OBJECTIVES

To describe the trend in plasma renin activity over time in patients undergoing cardiac surgery on cardiopulmonary bypass, and to investigate if increased plasma renin activity is associated with postcardiopulmonary bypass vasoplegia.

DESIGN

A prospective cohort study.

SETTING

Patients were enrolled from June 2020 to May 2021 at a tertiary cardiac surgical institution.

PATIENTS

A cohort of 100 adult patients undergoing cardiac surgery on cardiopulmonary bypass.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Plasma renin activity was measured at 5 time points: baseline, postoperatively, and at midnight on postoperative days 1, 2, and 3. Plasma renin activity and delta plasma renin activity were correlated with the incidence of vasoplegia and clinical outcomes. The median plasma renin activity increased approximately 3 times from baseline immediately after cardiac surgery, remained elevated on postoperative days 0, 1, and 2, and began to downtrend on postoperative day 3. Plasma renin activity was approximately 3 times higher at all measured time points in patients who developed vasoplegia versus those who did not.

CONCLUSIONS

In patients undergoing cardiac surgery on cardiopulmonary bypass, plasma renin activity increased postoperatively and remained elevated through postoperative day 2. Additionally, patients with vasoplegic syndrome after cardiac surgery on cardiopulmonary bypass had more robust elevations in plasma renin activity than nonvasoplegic patients. These findings support the need for randomized controlled trials to determine if patients undergoing cardiac surgery with high plasma renin activity may benefit from targeted treatment with therapies such as synthetic angiotensin II.

Anatomic classification of mitral annular calcification for surgical and transcatheter mitral valve replacement

BACKGROUND AND AIM OF THE STUDY: A systematic approach to quantify mitral annular calcification (MAC) in all-comers by multidetector computed tomography (MDCT) is essential to guide treatment, but lacking.

METHODS

From September 2015 to July 2019, 82 patients with MAC underwent MDCT at two institutions to evaluate for surgical mitral valve replacement (SMVR), transcatheter mitral valve replacement (TMVR), or medical management. Type 1 MAC was defined as <270° annular calcium and Type 2 as ≥270°. Absence/presence of predicted left ventricular outflow tract (LVOT) obstruction with virtual valve placement was used to further define Type 2 MAC into 2A/B for our treatment algorithm.

RESULTS

Type 1 MAC was present in 51.2%, Type 2A in 18.3%, and Type 2B in 30.5%. Operable Type 1 patients (50.0%) underwent hybrid transatrial TMVR or SMVR. Type 2A underwent a variety of treatments, and Type 2B surgical candidates (40.0%) underwent hybrid transatrial TMVR secondary to difficult suture anchoring with significant MAC and predicted LVOT obstruction. At a follow-up of 29.6 ± 12.0 months, mortality was 42.7% with 46.3% in the intervention group and 39.0% in the medical group (p = 0.47). All percutaneous TMVR patients expired. This translated to a disproportionate number of Type 2A deaths (80.0% with intervention), but all were high/extreme surgical risk. The hybrid TMVR group consisted of 95.0% Type 1/2B patients and had a lower Society of Thoracic Surgeons predicted risk of operative mortality (7.4% vs. 9.2%, p = 0.43)/mortality.

CONCLUSIONS

The highest mortality was seen in percutaneous TMVR Type 2A MAC patients, but they were at the greatest risk. Here we provide an objective MAC treatment algorithm for all-comers based on operability/anatomy.

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.

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.

Attempt at off-label balloon valvuloplasty post-dilation for intuity sutureless valve

Alternatives to traditional aortic valve replacement now form part of the valve surgeon's armamentarium. Sutureless valves offer decreased bypass and crossclamp times, excellent maneuverability, and promising outcomes. We present a case of a sutureless aortic valve replacement for a late failed David procedure, complicated by postoperative development of severe paravalvular regurgitation. We attempted off-label balloon post-dilation to improve expansion of the valve, however paravalvular regurgitation persisted. The patient underwent subsequent aortic valve replacement using a mechanical valve and experienced no further paravalvular leak.

Relation of Mitral Valve Surgery Volume to Repair Rate, Durability, and Survival

BACKGROUND

Degenerative mitral valve repair rates remain highly variable, despite established benefits of repair over replacement. The contribution of surgeon-specific factors is poorly defined.

OBJECTIVES

This study evaluated the influence of surgeon case volume on degenerative mitral valve repair rates and outcomes.

METHODS

A mandatory New York State database was queried and 5,475 patients were identified with degenerative mitral disease who underwent mitral valve operations between 2002 and 2013. Mitral repair rates, mitral reoperations within 12 months of repair, and survival were analyzed using multivariable Cox modeling and restricted cubic spline function.

RESULTS

Median annual surgeon volume of any mitral operations was 10 (range 1 to 230), with a mean repair rate of 55% (n = 20,797 of 38,128). In the subgroup of patients with degenerative disease, the mean repair rate was 67% (n = 3,660 of 5,475), with a range of 0% to 100%. Mean repair rates ranged from 48% (n = 179 of 370) for surgeons with total annual volumes of ≤10 mitral operations to 77% (n = 1,710 of 2,216) for surgeons with total annual volumes of >50 mitral operations (p < 0.001). Higher total annual surgeon volume was associated with increased repair rates of degenerative mitral valve disease (adjusted odds ratio [OR]: 1.13 for every additional 10 mitral operations; 95% confidence interval [CI]: 1.10 to 1.17; p < 0.001); a steady decrease in reoperation risk until 25 total mitral operations annually; and improved 1-year survival (adjusted hazard ratio: 0.95 for every additional 10 operations; 95% CI: 0.92 to 0.98; p = 0.001). For surgeons with a total annual volume of ≤25 mitral operations, repair rates were higher (63.8%; n = 180 of 282) if they operated in the same institution as a surgeon with total annual mitral volumes of >50 and degenerative mitral valve repair rates of >70%, compared with surgeons operating in the other institutions (51.3%; n = 580 of 1,130) (adjusted OR: 1.79; 95% CI: 1.24 to 2.60; p < 0.001).

CONCLUSIONS

This study suggests that individual surgeon volume is a determinant of not only mitral repair rates, but also freedom from reoperation, and survival. The data from this study support the guideline's concept of reference referral to experienced mitral surgeons to improve outcomes in patients with degenerative mitral valve disease.

Left ventricular assists device insertion via small right axillary incision in a pediatric patient

We report the use of a right axillary skin incision to institute a ventricle assist device support in a two-year-old 14 kg male with fulminant myocarditis. The ease of conversion to a long-term support, avoidance of a sternotomy, and a less visible incision made this approach an attractive option in this group of sick patients.

Emergency valve re-replacement for embolization of prosthetic mitral valve disc during catheterization procedure

A 47-year-old woman with a mechanical mitral valve underwent a catheter-based atrial fibrillation ablation procedure, which was complicated by the dislodgment and immediate embolization of one of the valve leaflets. Acute severe mitral regurgitation and cardiogenic shock developed, necessitating emergency reoperative mitral valve re-replacement. She subsequently underwent a successful staged retrieval of the embolized leaflet from the abdominal aorta.

Cardiac tamponade as a sequela to ventriculoatrial shunting for congenital hydrocephalus

Cardiac tamponade is a life-threatening condition that demands prompt diagnosis and emergency intervention to prevent the sequelae of persistent low cardiac output, cardiopulmonary failure, and death. Cardiac tamponade due to pericardial collection of cerebrospinal fluid is a rare but recognized sequela associated with ventriculoatrial shunts used in the management of congenital hydrocephalus.Herein, we describe the treatment of an 8-month-old infant with multiple congenital anomalies who presented with cardiac tamponade. This condition was caused by cardiac perforation by the distal tip of a ventriculoatrial shunt catheter. Timely pericardiostomy and repair of the cardiac perforation through a left anterior thoracotomy resulted in an uneventful recovery.