Long-term Clinical Impacts of Functional Mitral Stenosis After Mitral Valve Repair

Long-term Outcomes of Mitral Valve Repair for Atrial Functional Mitral Regurgitation

BACKGROUND

Atrial functional mitral regurgitation (AFMR), defined by normal left ventricular function, enlarged left atrium, and a dilated mitral valve annulus, has been a concept discussed for >10 years. However, there are still no established guidelines for its treatment in the American College of Cardiology/American Heart Association recommendations. This study aimed to determine the long-term outcomes of mitral annuloplasty as a treatment for AFMR.

METHODS

We analyzed 1435 patients who underwent mitral valve repair at our institution between 2005 and 2020, with 162 classified as having AFMR. Exclusion criteria for AFMR were established based on preoperative echocardiography and operative notes. The primary outcome was overall mortality, and the secondary outcome was MR recurrence, which was defined as moderate or greater mitral regurgitation observed on echocardiography during the follow-up period, analyzed using our hospital's medical records and data from the National Statistical Office.

RESULTS

The median follow-up duration for the entire patient cohort was 6.1 years (interquartile range, 3.2-11.2 years). Patients had a 5-year survival rate of 86% and a 10-year survival rate of 73%, with freedom from MR recurrence rates of 89% and 80% at 5 and 10 years, respectively. Although all 162 patients had moderate or greater MR before surgery, most experienced trivial or mild MR after mitral valve repair throughout the follow-up period.

CONCLUSIONS

In summary, mitral valve repair effectively treats patients with AFMR, addressing survival and mitigating MR recurrence.

Three-dimensional computed tomography analysis of the mitral annulus for mitral annuloplasty in 100 cases of robotic mitral valve repair

Objectives

This study aimed to evaluate the efficacy of preoperative computed tomography in assessing mitral annulus anatomy and the posterior annular plication rate in mitral valve repair with annuloplasty.

Methods

From July 2018 to August 2023, we performed robotic mitral valve repair with ring annuloplasty using a semi-rigid ring in 100 patients. Preoperative anatomical assessment of the mitral annulus was conducted by three-dimensional computed tomography. The ring size was selected based on the perioperative commissure-to-commissure length or the anterior leaflet area.

Results

The mean commissure-to-commissure length, posterior mitral annular length, and minimum distance between the left circumflex artery and mitral annulus values were 31, 109, and 3.8 mm, respectively. No postoperative left circumflex artery injury or ring detachment was recorded. The mean plication rate (length of the posterior side of the prosthetic ring/posterior annular length) was 0.68, and it did not differ among each prosthetic ring size. The posterior plication rate (duplicate ring size 19.4) was a factor influencing the postoperative transmitral mean pressure gradient of 5 mmHg or higher. Freedom from moderate or severe mitral regurgitation was not different between the two groups above and below the posterior plication rate × ring size of 19.4 (p = 0.73), with an event-free rate of 97% vs. 96% in 3 years, respectively.

Conclusions

Preoperative evaluation of the mitral annular anatomy is useful for safe mitral valve repair with ring annuloplasty. Determining ring size by focusing on the posterior annular plication rate may be a new method for ring size selection.

Mitral valve repair with leaflet resection versus preservation for degenerative posterior leaflet prolapse

OBJECTIVES

The optimal technique for repairing posterior mitral valve leaflet prolapse remains undetermined. We aimed to compare leaflet resection and neochordae implantation in patients undergoing mitral valve repair for posterior leaflet prolapse, focusing on transmitral pressure gradient and recurrence of mitral regurgitation.

METHODS

We enrolled patients undergoing mitral valve repair using either leaflet resection or neochordae implantation for single-segment prolapse of posterior mitral valve leaflet between 2000 and 2021 at our institution. Longitudinal outcomes were evaluated after adjustments with inverse-probability-of-treatment weighting. Repeat echocardiographic measurements (n = 3473, 5.4/patient) of transmitral pressure gradient and significant (moderate or severe) mitral regurgitation recurrence were estimated using nonlinear mixed-effect models. Subgroup analyses were conducted based on the size and type of prosthesis.

RESULTS

Among 639 patients, leaflet resection was used in 479 (75.0%) and neochordae implantation was used in 160 (25.0%). In the inverse-probability-of-treatment weighting adjusted cohort, the risk of death (P = .623) and mitral valve reoperation (P = .340) did not significantly differ between the 2 groups during a median follow-up of 97.3 months. Echocardiographic data showed comparable mean (at 5 years, 3.8 vs 4.0 mm Hg; P = .442) and peak (9.6 vs 10.4 mm Hg; P = .131) pressure gradients between groups, which persisted in most subgroup analyses. However, neochordae implantation was associated with a higher probability of significant mitral regurgitation recurrence compared with leaflet resection (at 5 years, 16.1% vs 7.0%; P < .001).

CONCLUSIONS

Leaflet resection yielded similar clinical outcomes and transmitral pressure gradients compared with neochordae implantation after mitral valve repair, with a lower mitral regurgitation recurrence rate. These findings underscore the need to reassess the efficacy of neochordae implantation relative to leaflet resection.

Long-term follow-up of repair-like replacement of mitral valve using autologous pericardium

Objectives

The present study assessed the late results of the operation, which consisted of the construction of a stentless mitral valve using autologous pericardium and valve implantation.

Methods

Between 2011 and 2018, among 1617 consecutive patients who underwent mitral valve operation at our institution, 15 adult patients (0.9%) with unrepairable mitral valves who wished to avoid conventional mitral valve replacement underwent this operation. Ten patients (67%) had a history of valve repair. After discharge, patients were prospectively followed-up with a echocardiographic evaluation up to the end point. The mean follow-up term was 70.8 ± 42.5 months.

Results

There were no hospital deaths or thromboembolic events and only 1 late noncardiac death. Intraoperative transesophageal echocardiography of all patients revealed no or trivial mitral regurgitation. Eight patients (53.3%) underwent redo valve replacement within 12 years. Except 1 late death, the postoperative course was divided into 3 groups depending on the occurrence of redo surgery, as follows: an early reoperation group (reoperation within 4 years; n = 4), a late reoperation group (reoperation after 4 years; n = 4), and a free from reoperation group (n = 6). The latest transthoracic echocardiographic examination performed 7.2 ± 2.9 years after the operation revealed the grade of mitral regurgitation to be none in 2 patients, mild in 2 patients, mild to moderate in 1 patients, and moderate in 1 patient in the free from reoperation group.

Conclusions

Despite the high incidence of reoperation, Normo operation can be a viable option during valve replacement, especially for young patients.

The Predictors and Outcomes of Functional Mitral Stenosis following Surgical Mitral Valve Repair: A Retrospective Analysis

To optimize mitral valve repair outcomes, it is crucial to comprehend the predictors of functional mitral valve stenosis (FMS), to enhance preoperative assessments, and to adapt intraoperative treatment strategies. This study aimed to identify FMS risk factors, contributing valuable insights for refining surgical techniques. Among 228 selected patients, 215 underwent postoperative echocardiography follow-ups, and 36 met the FMS criteria based on a mean trans-mitral pressure gradient of >5 mmHg. Patients with FMS exhibited higher pulmonary systolic arterial pressure and increased late mortality during the follow-up. Univariable logistic regression analysis identified several risk factors for FMS, including end-stage renal disease, anterior leaflet lesion, concomitant aortic valve replacement, smaller ring size, ring type, and neochordae implantation. Conversely, resection alone and resection combined with neochordae implantation had protective effects against FMS. Multivariable logistic regression analysis revealed that smaller ring sizes and patch repair independently predicted FMS. When focusing on degenerative mitral regurgitation, the neochordae implantation without resection in leaflet repair, emerged as an independent predictor of FMS. Surgeons should weigh the substantial impact of surgical procedures on postoperative trans-mitral pressure gradients, emphasizing preoperative evaluation and techniques such as precise ring size assessment and effective leaflet management.

Risk Factors for Postrepair Elevated Mitral Gradient: A Post-hoc Analysis of a Randomized Trial

BACKGROUND

Predischarge elevated mean mitral gradients (>5 mm Hg) may occur after repair for degenerative mitral regurgitation. We sought to identify risk factors associated with elevated gradients and to evaluate its impact on functional outcomes at 12 months in this subanalysis of the Canadian Mitral Research Alliance CardioLink-2 trial.

METHODS

One hundred four patients with degenerative mitral regurgitation undergoing mitral repair were randomized to either a leaflet resection or preservation strategy. Logistic regression was used to identify risk factors associated with an elevated gradient. Functional outcomes at 12 months were compared between participants with and without elevated gradients.

RESULTS

Elevated gradients was identified in 15 participants (14.4%), which was not significantly different based on allocation to each repair strategy (P = .10). Patients with elevated gradients were more likely to be women (odds ratio [OR], 4.28; 95% confidence interval [CI], 1.29-14.19; P = .02) and to have a lower preoperative hemoglobin level (OR, 0.93; 95% CI, 0.89-0.98; P = .01) and smaller intercommissural diameter (OR, 0.86; 95% CI, 0.76-0.97; P = .02) and mitral annuloplasty size (OR, 0.71; 95% CI, 0.57-0.87; P = .001). The ratio of intercommissural diameter-to-annuloplasty size was similar between those with and without elevated gradients (both 0.8 ± 0.1, P = .69). At 12 months those with elevated gradients had a worse New York Heart Association functional status (P = .0001), lower peak oxygen saturation in exercise test (P = .01), smaller body weight-walk distance product (P = .02), and higher Borg scale (P = .01) in the 6-minute walk test.

CONCLUSIONS

Female gender, smaller mitral anatomy sizes, and lower preoperative hemoglobin levels were associated with postoperative elevated mitral gradients, which was in turn were associated with reduced functional status. Further research is warranted to investigate these potential risk factors.

ROVING PEN

Cardiac surgeons wish to spare most of their time in the operating rooms with their patients. However, in their busy schedule, sparing few minutes to update with the important global research is quite essential. These are summaries of few recent articles in cardiac surgery from important journals which might help in better patient care.

What Can We Learn from the Past by Means of Very Long-Term Follow-Up after Aortic Valve Replacement?

Background: Studies on very long-term outcomes after aortic valve replacement are sparse. Methods: In this retrospective cohort study, long-term outcomes during 25.1 ± 2.8 years of follow-up were determined in 673 patients who underwent aortic valve replacement with or without concomitant coronary artery bypass surgery for severe aortic stenosis and/or regurgitation. Independent predictors of decreased long-term survival were determined. Cumulative incidence rates of major adverse events in patients with a mechanical versus those with a biologic prosthesis were assessed, as well as of major bleeding events in patients with a mechanical prosthesis under the age of 60 versus those above the age of 60. Results: Impaired left ventricular function, severe prosthesis–patient mismatch, and increased aortic cross-clamp time were independent predictors of decreased long-term survival. Left ventricular hypertrophy, a mechanical or biologic prosthesis, increased cardiopulmonary bypass time, new-onset postoperative atrial fibrillation, and the presence of symptoms did not independently predict decreased long-term survival. The risk of major bleeding events was higher in patients with a mechanical in comparison with those with a biologic prosthesis. Younger age (under 60 years) did not protect patients with a mechanical prosthesis against major bleeding events. Conclusions: Very long-term outcome data are invaluable for careful decision-making on aortic valve replacement.

Mitral Valve Annuloplasty Failure and Percutaneous Treatment Options

PURPOSE OF REVIEW

Mitral valve repair is a common surgical procedure for both primary and secondary mitral regurgitation. With operations performed earlier in disease progression and increased patient longevity, the need for a repeat intervention is not infrequent. With the associated risks of reoperation and patient comorbidities, percutaneous techniques for acute or delayed failure after ring annuloplasty are emerging.

RECENT FINDINGS

Current commercially available devices, used in "off-label" ways, such as the MitraClip, may be effective in repairing recurrent mitral regurgitation after annuloplasty. Similarly, a valve-in-ring transcatheter mitral valve replacement can be considered in patients at high risk for surgical reoperation. These procedures are not without risk, for example, resultant mitral stenosis in the setting of edge-to-edge repair or left ventricular outflow tract (LVOT) obstruction with valve-in-ring transcatheter mitral valve replacement. Newer devices are emerging to permit more options for this subset of patients, which include transcatheter valves that are specifically designed for the mitral position. Undoubtedly, surgical reoperation has increased risk as compared to primary operation. Though percutaneous options are evolving, use in this patient population is currently limited to "off-label" use and is also associated with procedural complexities and risk. It is prudent for cardiologists, surgeons, and anesthesiologists to weigh risks, benefits, and limitations when considering patients for surgical reoperation, percutaneous repair, or transcatheter replacement after failed mitral annuloplasty.