Clinical evaluation of functional mitral stenosis after mitral valve repair for degenerative disease: Potential affect on surgical strategy

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.

Respect Versus Resect Approaches for Mitral Valve Repair: A Meta-Analysis of Reconstructed Time-to-Event Data

Mitral valve repair (MVr) has been associated with superior long-term survival and freedom from valve-related complications compared with mitral valve replacement for primary mitral regurgitation (MR). The 2 main approaches for MVr are chordal replacement ("respect approach") and leaflet resection ("resect approach"). We performed a systematic review and a meta-analysis using 3 search databases to compare the long-term end points between both approaches. The primary end point was long-term survival. The secondary end points were long-term MR recurrence and reoperation. After reconstruction of time-to-event data for the individual survival analysis, pooled Kaplan-Meier curves for the end points were generated. A total of 14 studies (5,565 patients) were included in the analysis. The respect approach was associated with superior survival compared with the resect approach in the overall sample (hazard ratio [HR] 0.73, 95% confidence interval [CI] 0.56 to 0.96, p = 0.024, n = 3,901 patients) but not in the risk-adjusted sample (HR 1.00, 95% CI 0.55 to 1.82, p = 0.991, n = 620 patients). There was no difference between the approaches in the rate of MR recurrence in the overall sample (HR 1.39, 95% CI 0.92 to 2.08, p = 0.116, n = 1,882 patients) or in the risk-adjusted sample (HR 1.62, 95% CI 0.76 to 3.47, p = 0.211, n = 288 patients). The data for reoperation were only available in the overall sample and did not reveal a difference (HR 0.92, 95% CI 0.62 to 1.35, p = 0.663, n = 3,505 patients). In conclusion, the current evidence suggests no difference in long-term mortality, MR recurrence, or reoperation between the resect and respect approaches for MVr after adjusting for patient risk factors. More long-term follow-up data are warranted.

Echocardiographic Evaluation of Successful Mitral Valve Repair or Need for a Second Pump Run in the Operating Room

Detailed preoperative and intraoperative echocardiographic assessment of the mitral valve apparatus is critical for a successful repair. The recent advent of 3-dimensional transesophageal echocardiography has added an extra pivotal role to transesophageal echocardiography in the assessment of mitral apparatus and mitral regurgitation. Because surgeons must rapidly decide whether cardiopulmonary bypass should be continued to be weaned off or a second pump run should be selected, the echocardiographer conducting intraoperative transesophageal echocardiography is required to be trained according to a certain algorithm. This review summarizes the current clinical role of intraoperative transesophageal echocardiography in mitral valve repair in the operating room.

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.

The impact of annuloplasty ring or band implantation on post-repair mitral valve haemodynamic performance

OBJECTIVES

The clinical importance of optimal post-repair mitral valve diastolic performance is increasingly being recognized. The haemodynamic effect of a partial annuloplasty band implantation, in comparison to a full ring, remains insufficiently explored.

METHODS

Patients undergoing mitral valve repair for pure degenerative disease between 2011 and 2019 at 2 experienced heart valve centres were eligible for inclusion. Exclusion criteria were concomitant procedures other than tricuspid valve repair and ablation procedures for atrial fibrillation. Pre-discharge and follow-up echocardiograms (1-4 years after surgery) were analysed to assess haemodynamic mitral valve performance.

RESULTS

Of 535 patients meeting the inclusion criteria, 364 (68.0%) patients underwent full annuloplasty ring and 171 (31.0%) partial band implantation. On predischarge echocardiogram, post-repair mitral valve gradient and area did not differ between groups [2.89 mmHg (IQR 2.26-3.72) vs 2.60 mmHg (IQR 1.91-3.55), P = 0.19 and 1.98 cm2 (IQR 1.66-2.46) vs 2.03 cm2 (IQR 1.55-3.06), P = 0.15]. However, multivariable linear regression analysis demonstrated band annuloplasty as a determinant of larger valve area (coefficient 0.467 cm2, standard error 0.105, P < 0.001). On multivariable analysis, no significant impact on post-repair gradient was observed (-0.370 mmHg, standard error 0.167, P = 0.36). At follow-up, the differences between groups disappeared and multivariable regression analysis failed to demonstrate a significant impact of annuloplasty device type on mitral valve gradient (coefficient -0.095 mmHg, standard error 0.171, P = 1.00) or area (coefficient -0.085 cm2, standard error 0.120, P = 1.00). These results were confirmed with a linear mixed model analysis.

CONCLUSIONS

Partial band annuloplasty was related to an improved haemodynamic profile directly after valve repair for degenerative disease but the effect was short-lived. Our results suggest that the type of annuloplasty device has no durable impact on diastolic valve performance.

Predictors of mitral valve haemodynamics after mitral valve repair for degenerative mitral regurgitation

OBJECTIVE

Intraoperative predictors of functional mitral valve (MV) stenosis after surgical repair of mitral regurgitation (MR) caused by prolapse remain poorly characterised. This study evaluated the effect of annuloplasty size on postoperative MV haemodynamics during exercise and evaluated predictors of MV hemodynamics.

METHODS

104 patients were randomly assigned to leaflet resection or preservation for surgical repair of MR in the Canadian Mitral Research Alliance CardioLink-2 study. In this post hoc analysis, we compared MV haemodynamics between the two surgical groups and examined the relationship between annuloplasty size and MV haemodynamics 1 year after repair in the combined groups. Echocardiograms were performed at baseline and intraoperatively. Exercise transthoracic echocardiography was performed 1 year postoperatively. Multivariable linear regression analysis was used to identify predictors of exercise MV gradients at follow-up.

RESULTS

Mean age of participants was 65±10 years, and 83% were male. Median annuloplasty size was 34 (IQR 32-36). Dividing by the median, 48 (46%) had annuloplasty size of <34 mm and 56 (54%) had ≥34 mm. Mean and peak exercise gradients at 1 year were 11±5 mm Hg and 22±9 mm Hg in <34, and 6±3 mm Hg and 14±5 mm Hg in ≥34 (p<0.001). Rate of residual MR was similar in both groups. In multivariable analyses, annuloplasty size of ≥34 mm was associated with lower mean and peak exercise gradients at 12 months, after adjustment for repair type, age, sex, heart rate and body surface area (β -4.1, 95% CI -6 to -3, p<0.001, and β -7 95% CI -10 to -4, p<0.001, respectively). Intraoperative mean and peak MV gradients by transesophageal echocardiography independently predicted mean and peak resting and exercise gradients at follow-up (p<0.001). Similar results were obtained in both leaflet resection and preservation.

CONCLUSION

Annuloplasty size of ≥34 mm is associated with a 4 and 7 mm Hg reduction in mean and peak exercise MV gradients, respectively, 1 year post MV repair regardless of the repair strategy used. Intraoperative TEE MV gradients predict exercise MV gradients 1 year post repair.

TRIAL REGISTRATION NUMBER

NCT02552771.

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.

Mitral stenosis in a teenager after rheumatic mitral valve regurgitation valve repair: A case report

Introduction

Mitral stenosis (MS) is a widely known complication of mitral valve repair for non-rheumatic mitral regurgitation (MR). Few reports are available on the occurrence of MS after mitral valve repair for rheumatic MR in young populations.

Case summary

A 14-year-old girl presented with orthopnea, abdominal distension, and bilateral lower-limb edema. She was cachectic, with a high-pitched holosystolic murmur best heard at the cardiac apex, bilateral basal crackles, tender hepatomegaly, pitting pedal edema, and jugular venous distension. Antistreptolysin O (ASO) titer was elevated. Transthoracic echocardiography (TTE) revealed the loss of central coaptation of the mitral valve with leaflet restriction and MR, annular dilatation of the tricuspid valve, and tricuspid regurgitation (TR). She had AHA/ACC stage D mitral and TR s. Tricuspid annuloplasty and mitral valve repair for rheumatic MR were performed using Carpentier Edwards numbers 30 and 34, respectively. Following surgery, the weight and body mass index (BMI) rapidly normalized. The patient also developed progressive MS.

Discussion

Previous studies in adults have described the etiopathogenesis of MS after non-rheumatic mitral valve repair. There is a paucity of reports describing the development of MS over the span of months after rheumatic MR valve repair in early pubescent children.

Conclusion

Growth spurts during puberty can potentially affect MR repair, as the mitral valve prosthesis based on the preoperative Body Surface Area (BSA) is outgrown. There is a need for research on planning, prognostication, and development of an optimal, individualized, and adaptable approach to MR intervention in early pubescence.

Surgical mitral valve repair technique considerations based on the available evidence

Mitral valve regurgitation is the second most common valve disease in the western world. Surgery is currently the best tool for generating a long-lasting elimination of mitral valve regurgitation. However, the mitral valve apparatus is a complex anatomical and functional structure, and repair results and durability show substantial heterogeneity. This is not only due to differences in the underlying mitral valve regurgitation pathophysiology but also due to differences in repair techniques. Repair philosophies differ substantially from one surgeon to the other, and consensus for the technically best repair strategy has not been reached yet. We had previously addressed this topic by suggesting that ring sizing is "voodoo". We now review the available evidence regarding the various repair techniques described for structural and functional mitral valve regurgitation. Herein, we illustrate that for structural mitral valve regurgitation, resuspension of prolapsing valve segments or torn chordae with polytetrafluoroethylene sutures and annuloplasty can generate the most durable results paired with the best achievable hemodynamics. For functional mitral valve regurgitation, the evidence suggests that annuloplasty alone is insufficient in most cases to generate durable results, and additional subvalvular strategies are associated with improved durability and possibly improved clinical outcomes. This review addresses current strategies but also implausibilities in mitral valve repair and informs the mitral valve surgeon about the current evidence. We believe that this information may help improve outcomes in mitral valve repair as the heterogeneity of mitral valve regurgitation pathophysiology does not allow a one-size-fits-all concept.

Flow adjusted transmitral pressure gradient as a modified indicator of functional mitral stenosis after repair for degenerative mitral regurgitation

Background and Aim

After repair of degenerative mitral regurgitation (DMR), the focus is on functional mitral stenosis (FMS) when there is a decline of mitral hemodynamics. Yet, the clinical impacts and a standardized definition are still undecided. Since common mitral hemodynamic parameters are influenced by transmitral flow, the aim of this study is to seek the impact of flow adjusted transmitral pressure gradient (TMPG) by left ventricular stroke volume (LVSV) on the midterm outcomes.

Methods

Three hundred one patients who had undergone isolated mitral valve repair for degenerative lesions with annuloplasty prosthesis between October 2012 and June 2019 were included. Postoperative adverse events occurred in 20 patients (6.6%). Flow adjusted TMPG was defined as TMPG/LVSV.

Results

Common mitral hemodynamic parameters were not associated with adverse events. By multivariable analysis, patients’ age, left ventricular ejection fraction (LVEF) and mean TMPG/LVSV were isolated as independent predictors (adjusted hazard ratio: 1.05, 0.95, and 1.16; p = .037, .005, and .035). Flow adjusted TMPG was significantly higher in the full ring group compared to the partial band group (0.051 mmHg/ml, [0.038–0.068] vs. 0.041 mmHg/ml, [0.031–0.056]; p < .001) and had a significantly negative correlation with the size of the annuloplasty prosthesis (r = −0.37, p < .001).

Conclusions

Conventional mitral hemodynamic parameters were not associated with adverse cardiac events after repair for DMR. Adjustment by flow has a potential to advance pressure gradient to a more sensitive indicator of FMS associated with clinical outcomes.

Respect versus resect approaches for mitral valve repair: a study-level meta-analysis

Mitral valve repair (MVr) restores leaflets coaptation while preserving the patient's own valve. The two main techniques are: (a) chordal replacement ("respect approach"), whereby artificial neochordae are used to resuspend prolapsed segments of the affected leaflet - and (b) leaflet resection ("resect approach"), whereby diseased leaflet segment is resected, and the remaining segments are sutured together. Both techniques of MVr are associated with better long-term results, fewer valve-related complications and lower mortality when compared with mitral valve replacement (MVR). They also restore quality of life and improve survival to rates equivalent to those of the general population. We performed a meta-analysis to pool data of clinical studies that compared outcomes of MVr stratified by the surgical technique. Seventeen studies accounting for 6,046 patients fulfilled our eligibility criteria. The "respect approach" outperformed the "resect approach" with lower permanent pacemaker implantation rates and lower mean gradients. Despite any possible advantages of one technique over the other, which approach is best for each patient must be decided on a case-by-case basis and more long-term follow-up data are warranted.

Stress Echocardiography after Mitral Valve Repair using a Semirigid Partial Band

BACKGROUND

The reduction in exercise capacity following mitral valve repair (MVr) for severe degenerative mitral regurgitation is an unsolved issue. This study aimed to evaluate hemodynamics after MVr using a partial semirigid band during exercise stress echocardiography and identify predictive factors for achieving better exercise capacity after MVr.

METHODS

We retrospectively analyzed 48 patients using exercise stress echocardiography within 5 years of having undergone MVr using a partial semirigid band between 2013 and 2019. Values of maximal workload were converted into numbers of metabolic equivalents (METs) achieved for each patient. Age- and gender-predicted METs (eMETs) were obtained, and %eMETs (achieved METs/eMETs × 100) were calculated. Multivariable linear regression analysis was used to identify the determinants of %eMETs.

RESULTS

Only one-third of patients achieved eMETs. Significant determinants of %eMETs were age at exercise stress echocardiography (β coefficient, 0.64; 95% confidence interval, 0.31-0.96; p<0.001), female sex (β coefficient, 16.9; 95% confidence interval, 8.58-25.17; p<0.001), and larger indexed device size (device size/body surface area; β coefficient, 4.10; 95% confidence interval, 1.74-6.46; p=0.001). Receiver operating characteristic curve analysis revealed that a cut-off value of ≥19.5 mm/m² indexed device size was optimal for achieving %eMETs >100%, with a sensitivity and specificity of 87% and 79%, respectively.

CONCLUSIONS

Patients with larger indexed device size achieved greater exercise capacity after MVr using a partial semirigid band. Preoperative evaluation to decide whether we can use an annuloplasty device larger than 19.5 mm/m² may be important for patients who intend to exercise with high intensity.

Echocardiographic Evaluation of Successful Mitral Valve Repair or Need for a Second Pump Run in the Operating Room

Detailed preoperative and intraoperative echocardiographic assessment of the mitral valve apparatus is critical for a successful repair. The recent advent of 3-dimensional transesophageal echocardiography has added an extra pivotal role to transesophageal echocardiography in the assessment of mitral apparatus and mitral regurgitation. Because surgeons must rapidly decide whether cardiopulmonary bypass should be continued to be weaned off or a second pump run should be selected, the echocardiographer conducting intraoperative transesophageal echocardiography is required to be trained according to a certain algorithm. This review summarizes the current clinical role of intraoperative transesophageal echocardiography in mitral valve repair in the operating room.

Effect of Mitral Valve Gradient After MitraClip on Outcomes in Secondary Mitral Regurgitation: Results From the COAPT Trial

OBJECTIVES

The authors sought to evaluate the association between mean mitral valve gradient (MVG) and clinical outcomes among patients who underwent MitraClip treatment for secondary mitral regurgitation (SMR) in the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) trial.

BACKGROUND

In the COAPT trial, patients with heart failure (HF) and severe SMR who remained symptomatic despite guideline-directed medical therapy had marked 2-year reductions in mortality and HF hospitalizations after treatment with MitraClip.

METHODS

MitraClip-treated patients were divided into quartiles (Q) based on discharge echocardiographic MVG (n = 250). Endpoints including all-cause mortality, HF hospitalization, and health status measures at 2 years were compared between quartiles.

RESULTS

Mean MVG after MitraClip was 2.1 ± 0.4 mm Hg, 3.0 ± 0.2 mm Hg, 4.2 ± 0.5 mm Hg, and 7.2 ± 2.0 mm Hg in Q1 (n = 63), Q2 (n = 61), Q3 (n = 62), and Q4 (n = 64), respectively. There was no difference across quartiles in the 2-year composite endpoint of all-cause mortality or HF hospitalization (43.2%, 49.2%, 40.6%, and 40.9%, respectively; p = 0.80), nor in improvements in New York Heart Association functional class, Kansas City Cardiomyopathy Questionnaire score, or 6-min walk time. Results were similar after adjustment for baseline clinical and echocardiographic characteristics, post-procedure MR grade, and number of clips (all-cause mortality or HF hospitalization Q4 [44.6%] vs. Q1 to Q3 [40.3%]; adjusted hazard ratio: 1.23, 95% confidence interval: 0.60 to 2.51; p = 0.57).

CONCLUSIONS

Among HF patients with severe SMR, higher MVGs on discharge did not adversely affect clinical outcomes following MitraClip. These findings suggest that in select patients with HF and SMR otherwise meeting the COAPT inclusion criteria, the benefits of MR reduction may outweigh the effects of mild-to-moderate mitral stenosis after MitraClip.

Long-Term Results of Mitral Repair With Complete Semi-Rigid Rings vs Posterior Flexible Bands

BACKGROUND

The aim of the study was to evaluate whether the type of ring used had an impact on the long-term results of mitral repair for degenerative mitral regurgitation (MR), due to posterior leaflet prolapse, treated with quadrangular or triangular resection.

METHODS

From January 2002 to December 2008, 1406 patients with severe MR due to posterior leaflet prolapse underwent mitral repair. Of these patients, we selected 452 consecutive patients treated with the same repair approach. Mitral annuloplasty to complete the repair was performed with a posterior flexible band (n = 260) or a complete semi-rigid ring (n = 192). The 2 groups were comparable at baseline, and their clinical and echocardiographic outcomes were compared at long-term follow-up.

RESULTS

Overall survival at 14 years was similar (P = .29). The cumulative incidence function of cardiac death, with noncardiac death as competing risk, showed no difference (P = .71). At 14 years, probability of recurrence of MR greater than or equal to 3+ was 1.11% in the flexible band group and 3.25% in the semi-rigid ring group (P = .073). At 14 years, probability of recurrence of MR greater than or equal to 2 was 13.49% in the band group vs 10.78% in the semi-rigid ring group (P = .897).

CONCLUSIONS

In patients requiring mitral valve repair for posterior leaflet prolapse, treated with the same repair approach, the type of annuloplasty ring has no impact on the incidence of cardiac death and recurrence of MR at 14 years. Whether these findings remain stable at longer follow-up should be further investigated.

Randomized, Controlled Trial Comparing Mitral Valve Repair With Leaflet Resection Versus Leaflet Preservation on Functional Mitral Stenosis

Background:

Equipoise exists between the use of leaflet resection and preservation for surgical repair of mitral regurgitation caused by prolapse. We therefore performed a randomized, controlled trial comparing these 2 techniques, particularly in regard to functional mitral stenosis.

Methods:

One hundred four patients with degenerative mitral regurgitation surgically amenable to either leaflet resection or preservation were randomized at 7 specialized cardiac surgical centers. Exclusion criteria included anterior leaflet or commissural prolapse, as well as a mixed cause for mitral valve disease. Using previous data, we determined that a sample size of 88 subjects would provide 90% power to detect a 5–mm Hg difference in mean mitral valve gradient at peak exercise, assuming an SD of 6.7 mm with a 2-sided test with α=5% and 10% patient attrition. The primary end point was the mean mitral gradient at peak exercise 12 months after repair.

Results:

Patient age, proportion who were female, and Society of Thoracic Surgeons risk score were 63.9±10.4 years, 19%, and 1.4±2.8% for those who were assigned to leaflet resection (n=54), and 66.3±10.8 years, 16%, and 1.9±2.6% for those who underwent leaflet preservation (n=50). There were no perioperative deaths or conversions to replacement. At 12 months, moderate mitral regurgitation was observed in 3 subjects in the leaflet resection group and 2 in the leaflet preservation group. The mean transmitral gradient at 12 months during peak exercise was 9.1±5.2 mm Hg after leaflet resection and 8.3±3.3 mm Hg after leaflet preservation ( P =0.43). The participants had similar resting peak (8.3±4.4 mm Hg versus 8.4±2.6 mm Hg; P =0.96) and mean resting (3.2±1.9 mm Hg versus 3.1±1.1 mm Hg; P =0.67) mitral gradients after leaflet resection and leaflet preservation, respectively. The 6-minute walking distance was 451±147 m for those in the leaflet resection versus 481±95 m for the leaflet preservation group ( P =0.27).

Conclusions:

In this adequately powered randomized trial, repair of mitral prolapse with either leaflet resection or leaflet preservation was associated with similar transmitral gradients at peak exercise at 12 months postoperatively. These data do not support the hypothesis that a strategy of leaflet resection (versus preservation) is associated with a risk of functional mitral stenosis.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier NCT02552771.

Continued follow-up of the free margin running suture technique for mitral repair

OBJECTIVES

The free margin running suture (FMRS) technique was recently proposed to treat complex degenerative mitral lesions. Limited follow-up data are available. We evaluated the midterm reliability of this technique and the associated mitral valve parameters using rest/stress echocardiography.

METHODS

One-hundred-eight consecutive patients at 2 European centres were included. Prospective follow-up was performed (266.1 patient-years, average duration 2.5 ± 2.5 years). Echocardiographic scans at rest were obtained for all patients at hospital discharge and at follow-up. Stress echocardiography was also performed in 17 patients.

RESULTS

There were no operative deaths. FMRS was performed through a right minithoracotomy in 86.1% of patients, with a robotic-assisted technique in 5.6% and through a sternotomy in 8.3%. Bileaflet disease was noted in 31.4%. One patient (0.9%) presented a 2+/4+ residual mitral regurgitation at discharge; lower-degree or no residual regurgitation was noted in the remaining patients. At the follow-up examination, 1 patient (0.9%) presented with a 2+/4+ mitral regurgitation. Coaptation length at discharge versus that at follow-up was 1.3 ± 0.2 vs 1.3 ± 0.1 cm (P = 0.13); the average transmitral gradient was 4.8 ± 1.5 vs 3.5 ± 0.9 mmHg (P < 0.001). In a subpopulation, follow-up echocardiography indicated that the average transmitral gradient at rest versus that at peak effort was 3.2 ± 0.7 vs 5.1 ± 1.3 mmHg (P < 0.001), with no appearance of significant mitral regurgitation and marginally significant increases in pulmonary artery systolic pressures (P = 0.049).

CONCLUSIONS

Data indicate effectiveness and reproducibility of FMRS, with stability of valve function at midterm. FMRS was also associated with promising outcomes in diastolic performance both at rest and during exercise.

Impact of type and size of annuloplasty prosthesis on hemodynamic status after mitral valve repair for degenerative disease

Objective

The aim of this study is to evaluate mitral valve hemodynamics after mitral valve repair for degenerative disease, and seek the impact of type/size of annuloplasty prosthesis on resting cardiac hemodynamics.

Methods

Between October 2012 and June 2019, 301 patients underwent isolated mitral valve repair for degenerative disease were enrolled. Correlation between postoperative mitral hemodynamics and type/size of annuloplasty prosthesis was evaluated.

Results

There were significant correlations between annuloplasty size and peak velocity (r = -0.41, p < 0.001), peak transmitral pressure gradient (TMPG) (r = -0.40, p < 0.001), mean TMPG (r = -0.41, p < 0.001), effective orifice area (EOA) (r = 0.26, p < 0.001), and pulmonary artery systolic pressure (r = -0.15, p = 0.010). In patients with larger annuloplasty prostheses (≥30 mm), the type of annuloplasty prosthesis (band or ring) did not influence the mitral hemodynamics, however, mean TMPG was significantly greater in patients with a full ring (2.9 mmHg [2.1-3.7] vs. 4.0 mmHg [2.8-5.0], p < 0.001) in patients with smaller annuloplasty (<30 mm). Left ventricular ejection fraction and stroke volume were significantly associated with an increase of TMPG (r = 0.14, p = 0.016 and r = 0.24, p < 0.001).

Conclusions

A larger partial band had the potential to improve mitral hemodynamics after mitral repair for degenerative disease. However, echocardiographic mitral hemodynamics was influenced by LV function. Therefore, a more accurate method is required to elucidate the true impact of mitral repair on hemodynamics.

Complications Following Percutaneous Mitral Valve Repair

Mitral valve disease affects more than 4 million people in the United States and it is the second most prevalent valvulopathy in Europe. The gold standard of treatment in these patients is surgical repair or mitral valve replacement. In the last decade, numerous transcatheter therapies have been developed to overcome the increased number of subjects with symptomatic severe mitral regurgitation and high surgical risk. The Mitraclip (Abbott Vascular, Menlo Park, CA), PASCAL (Edwards Lifesciences, Irvine, CA, USA), the Carillon™ Mitral Contour System™ (Cardiac Dimension Inc., Kirkland, WA, USA), the Mitralign™ (Mitralign, Tewksbury, Massachusetts), and the Cardioband (Edwards Lifesciences, Irvine, CA) are the principal percutaneous devices for mitral valve repair. We present an evidence-based clinical update that provides an overview of these technologies and their potential complications.

Novel Trigone-Based Sizing Method for Mitral Ring Annuloplasty

BACKGROUND

We devised a novel trigone-based sizing method, setting the trigones at one-quarter of the annular circumference, and used it for mitral annuloplasty in patients with mitral regurgitation (MR).

METHODS

Between 1999 and 2017, 436 patients with degenerative (n = 192), nonischemic functional (n = 124), or ischemic (n = 120) MR underwent mitral valvuloplasty at our institution using an incomplete ring. The intertrigonal distance and prerepair and postrepair annular diameter were measured. Then the diameters predicted from body surface area, the intertrigonal distance, and the ratios of these diameters to observed data were computed. We investigated the influence of these measurements on MR recurrence, transmitral pressure gradient, and systolic anterior motion.

RESULTS

Initial repair was successful in 433 patients (99%), but 3 patients with systolic anterior motion and MR required conversion to valve replacement. After 1, 5, and 10 years (mean follow-up, 6.3 years), the rate of freedom from grade 2 or higher recurrent MR was 96%, 92%, and 86% in the degenerative group, 99%, 97%, and 90% in the nonischemic functional group, and 95%, 90%, and 79%, respectively, in the ischemic group (P = .052). The observed/body surface area predicted diameter ratio was negatively correlated with the mean transmitral pressure gradient (mm Hg); 12.3 - 8.2 × (ratio) (R = -0.37, P < .001), despite a smaller ratio (<0.9) not being associated with less recurrence of MR. In the degenerative group, systolic anterior motion developed in 7 of 71 patients (10%) with an observed/intertrigonal distance predicted diameter ratio of less than 0.9 (P < .001).

CONCLUSIONS

Our trigone-based sizing method achieved satisfactory control of MR, while avoiding functional mitral stenosis and systolic anterior motion.

A Novel Sizing Technique for Mitral Annuloplasty

Although sizing for mitral annuloplasty (MAP) is a critical part of mitral valve repair, no consistent method is used, and precise size adjustment is done somewhat by intuition. We developed a new original ring size tester and have been applying it to our mitral valve repair procedure. The concept is that the tester shapes the annulus into exactly the same size and form as the target annuloplasty while confirming a good leaflet coaptation with a saline test to simulate annuloplasty. This original tester provides the best ring size for MAP that is neither too large nor too small. In this paper, we introduce our original ring size tester and describe how it is used for MAP.

Interscallop indentation closure as an adjunctive technique in mitral valve repair for degenerative mitral valve disease

BACKGROUND

Interscallop indentation closure is a useful adjunctive technique which presents several different effects in repairing degenerative mitral regurgitation. However, there are some concerns that it might reduce mitral valve area by restricting the posterior leaflet mobility. We aim to assess postoperative echocardiographic findings after mitral valve repair using this technique.

METHODS

Between January 2009 and December 2015, 897 patients underwent mitral valve repair for degenerative mitral regurgitation at our institutions. We reviewed 98 patients in which we used indentation closure technique, and we analyzed operative and echocardiographic data.

RESULTS

Ring annuloplasty and concomitant repair techniques such as leaflet resection and neochordal placement were used in all patients. Specific purposes of indentation closure included gap closure (n = 57), prolapse repair (n = 11), leaflet redundancy repair (n = 16), and leaflet deficiency repair (n = 12). Eleven patients had double indentation closure. Postoperative pre-discharge echocardiography showed no moderate or greater residual mitral regurgitation, mean transmitral pressure gradient of 3.4 ± 1.4 mmHg, and mitral valve area of 2.7 ± 0.7 cm². Follow-up echocardiography performed at 43.7 ± 23.9 months after surgery showed six cases (6.4%) with recurrent moderate or greater mitral regurgitation, mean transmitral pressure gradient of 3.3 ± 1.3 mmHg, and mitral valve area of 2.5 ± 0.6 cm².

CONCLUSIONS

Interscallop indentation closure is a simple and effective adjunctive technique which can be used for several different purposes. It achieves excellent control of mitral regurgitation with preserved mitral valve area when it is used in addition to standard mitral valve repair techniques in selected cases.

Transvalvular pressure gradients for different methods of mitral valve repair: only neochordoplasty achieves native valve gradients

OBJECTIVES

Many surgical and interventional methods are available to restore patency for patients with degenerative severe mitral valve regurgitation. Leaflet resection and neochordoplasty, which both include ring annuloplasty, are the most frequently performed techniques for the repair of posterior mitral leaflet flail. It is unclear which technique results in the best haemodynamics. In this study, we investigated the effect of different mitral valve reconstruction techniques on mitral valve haemodynamics and diastolic transvalvular pressure gradient in an ex vivo porcine model.

METHODS

Eight porcine mitral valves were tested under pulsatile flow conditions in an in vitro pulsatile flow loop for haemodynamic quantification. Severe acute posterior mitral leaflet flail was created by resecting the posterior marginal chorda. The acute mitral valve regurgitation was corrected using 4 different repair techniques, in each valve, in a strictly successive order: (i) neochordoplasty with polytetrafluoroethylene sutures alone and (ii) with ring annuloplasty, (iii) edge-to-edge repair and (iv) triangular leaflet resection, both with ring annuloplasty. Valve haemodynamics were measured and quantified for all valve configurations (native, rupture and each surgical reconstruction). The results were analysed using a validated statistical linear mixed model, and the P-values were calculated using a 2-sided Wald test.

RESULTS

All surgical reconstruction techniques were able to sufficiently correct the acute mitral valve regurgitation. Neochordoplasty without ring annuloplasty was the only reconstruction technique that resulted in haemodynamic properties similar to the native mitral valve (P-values from 0.071 to 0.901). The diastolic transvalvular gradient remained within the physiological range for all reconstructions but was significantly higher than in the native valve for neochordoplasty with ring annuloplasty (P < 0.000), edge-to-edge repair (P < 0.000) and leaflet resection (P < 0.000). Neochordoplasty without ring annuloplasty resulted in a significantly better pressure gradient than neochordoplasty with a ring annuloplasty (P < 0.000). Additionally, neochordoplasty with a ring annuloplasty resulted in significantly lower transvalvular pressure gradients than edge-to-edge repair (P < 0.000) and leaflet resection (P < 0.000).

CONCLUSIONS

Neochordoplasty with or without ring annuloplasty was the reconstruction technique that almost achieved native physiological haemodynamics after repair of posterior mitral leaflet flail after acute isolated chordal rupture in our ex vivo porcine model.

Intermediate-term outcomes of our original multiple-knot technique using ePTFE sutures for anterior mitral leaflet prolapse

PURPOSE

To define the outcomes of our original simple chordal replacement technique using ePTFE sutures for mitral regurgitation.

METHODS

Between January, 2004 and March, 2014, 38 patients underwent mitral valve repair using our chordal replacement technique for anterior leaflet prolapse. The mitral regurgitation was caused by degenerative disease in 34 patients and infective endocarditis in 4 patients.

RESULTS

The follow-up period was 66 ± 37 months and the 5-year survival rate was 95 ± 4%. Two patients had recurrent mitral regurgitation, caused by degenerative change not associated with the procedure. The 5-year rate of freedom from recurrent mitral regurgitation was 94 ± 4%. In the late postoperative period, 15 (42%) patients had a mean pressure gradient > 5 mmHg. Stepwise logistic regression analysis showed that the use of a full ring (odds ratio 8.9; 95% confidence interval 1.2-64; p = 0.031) and a 26 mm annuloplasty (odds ratio 7.5; 95% confidence interval 1.1-50; p = 0.037) were significant independent risk factors for a mean pressure gradient > 5 mmHg.

CONCLUSION

The intermediate-term outcomes of our original chordal replacement technique were not inferior to those in previous reports, although a 26 mm annuloplasty was found to be associated with a higher mitral valve gradient at rest.

Virtual downsizing for decision support in mitral valve repair

PURPOSE

Various options are available for the treatment of mitral valve insufficiency, including reconstructive approaches such as annulus correction through ring implants. The correct choice of general therapy and implant is relevant for an optimal outcome. Additional to guidelines, decision support systems (DSS) can provide decision aid by means of virtual intervention planning and predictive simulations. Our approach on virtual downsizing is one of the virtual intervention tools that are part of the DSS workflow. It allows for emulating a ring implantation based on patient-specific lumen geometry and vendor-specific implants.

METHODS

Our approach is fully automatic and relies on a lumen mask and an annulus contour as inputs. Both are acquired from previous DSS workflow steps. A virtual surface- and contour-based model of a vendor-specific ring design (26-40 mm) is generated. For each case, the ring geometry is positioned with respect to the original, patient-specific annulus and additional anatomical landmarks. The lumen mesh is parameterized to allow for a vertex-based deformation with respect to the user-defined annulus. Derived from post-interventional observations, specific deformation schemes are applied to atrium and ventricle and the lumen mesh is altered with respect to the ring location.

RESULTS

For quantitative evaluation, the surface distance between the deformed lumen mesh and segmented post-operative echo lumen close to the annulus was computed for 11 datasets. The results indicate a good agreement. An arbitrary subset of six datasets was used for a qualitative evaluation of the complete lumen. Two domain experts compared the deformed lumen mesh with post-interventional echo images. All deformations were deemed plausible.

CONCLUSION

Our approach on virtual downsizing allows for an automatic creation of plausible lumen deformations. As it takes only a few seconds to generate results, it can be added to a virtual intervention toolset without unnecessarily increasing the pipeline complexity.

Elevated gradient after mitral valve repair: The effect of surgical technique and relevance of postoperative atrial fibrillation

OBJECTIVES

We sought to investigate the effect of surgical technique in mitral valve repair on postoperative transmitral gradient (PTMG) and the relationship between PTMG and postoperative atrial fibrillation (AF).

METHODS

In this retrospective study, 390 patients who underwent mitral valve repair for degenerative mitral regurgitation without AF were included. PTMG was measured using transthoracic echocardiography before patient discharge. At follow-up, occurrences of AF within 6 months of surgery (early AF) and 6 months after surgery (late AF), as well as clinical and echocardiographic data were documented and investigated.

RESULTS

The in-hospital mortality was 0, and the mean gradient was 3.1 ± 1.2 mm Hg before patient discharge. The risks for higher PTMG included cleft closure, edge-to-edge technique, full ring annuloplasty, and smaller indexed prosthetic size (P < .05 for all). After a median follow-up of 46 months, stable sinus rhythm was maintained in 73.1% of the overall cohort and early AF occurred in 22.7% of patients. A total of 32 patients (8.5%) had late AF, which was significantly associated with PTMG (odds ratio, 3.93; P = .004). The minimum P value approach identified a mean gradient of ≥4.5 mm Hg as the best threshold for predicting late AF (χ² = 40.704; P < .001).

CONCLUSIONS

Patients who undergo mitral valve repair for degenerative mitral insufficiency might benefit from modification of the existing leaflet repair and annuloplasty techniques to achieve a lower PTMG level, which is associated with a decreased incidence of late AF during midterm follow-up.

Excessive leaflet tissue in mitral valve repair for isolated posterior leaflet prolapse-leaflet resection or shortening neochords? A propensity score adjusted comparison

BACKGROUND

Chordal replacement techniques are progressively used to treat posterior mitral valve leaflet (PMVL) prolapse while leaflet resection remains commonly in use to address excessive leaflet tissue. For excessive tissue in height, shortening neochords can be used alternatively. Use of chordal replacement techniques has been suggested to result in lower diastolic transvalvular gradients, higher freedom from reoperation and improved left ventricular function.

METHODS

From 1/2005 to 12/2016, 150 patients underwent valve repair for isolated PMVL prolapse with excessive tissue. Excessive tissue in height was treated by leaflet resection (N.=99) or shortening neochords (N.=51). Excessive tissue in width was always resected. Logistic regression was used to generate propensity scores for risk-adjusted comparison.

RESULTS

Two patients died postoperatively. In the Neochords group, resection of excessive tissue in width was still needed in 28 (55%) cases. Postoperative echocardiography demonstrated residual (≥2+) mitral regurgitation in 2/150 patients (Resect group). No differences in anuloplasty ring size, postoperative diastolic transvalvular gradients or left ventricular function were observed. Median clinical follow-up duration was 4.4 (IQR 2.0-7.0; 98% complete) years. There was no inter-group difference in overall survival or freedom from reintervention. Mean echocardiographic follow-up was 3.0 (IQR 1.2-5.4; 93% complete) years. In the matched population, the 6-year freedom from recurrent mitral regurgitation rates were 91.3% (95% CI: 81.9-100%) and 97.2% (95% CI: 91.9-100%) for the Resect and Neochords group, respectively (P=0.43).

CONCLUSIONS

Both leaflet resection and shortening neochords provide a valuable tool to address excessive PMVL height. Repair durability is excellent regardless of the technique utilized.

Functional mitral stenosis following mitral valve repair

PURPOSE OF REVIEW

This review summarizes the evidence describing functional mitral stenosis (MS) following surgical mitral valve repair.

RECENT FINDINGS

Functional MS is an evolving concept and has been implicated in the repair of functional and organic mitral regurgitation. Following repair of functional mitral regurgitation, an elevation in peak transmitral gradient and pulmonary artery pressure has been observed under physiologic stress. These changes have been associated with worse functional status early after restrictive annuloplasty. Following repair of organic mitral regurgitation, functional MS has also been observed and appears associated with worse functional status late after surgery.

SUMMARY

Because repair of functional mitral regurgitation commonly involves restrictive annuloplasty, the issue of functional MS must be weighed against the benefits and durability of repair. Functional MS following repair of degenerative mitral regurgitation, however, may be modifiable. Research evaluating various repair techniques and their impact on functional MS following repair of organic is ongoing.

Management of Incomplete Initial Repair in the Treatment of Degenerative Mitral Insufficiency

We sought to present our institutional protocol to manage incomplete initial repair of degenerative mitral regurgitation and to evaluate its mid-term outcomes. Eight hundred and fifteen patients with degenerative mitral insufficiency undergoing mitral valve repair were investigated in this study. The initial repair attempt was incomplete in 48 patients, leaving a degree of residual regurgitation > mild, and an elevated transmitral gradient or systolic anterior motion (SAM). These patients were further treated with medication or mitral valve re-repair or replacement under reinstituted cardiopulmonary bypass. Transesophageal echocardiographic reports and operational records were reviewed to identify morphological causes and establish management of incomplete initial repair. Mid-term outcomes of patients with re-repair and complete initial repair were evaluated and compared. Residual mitral regurgitation > mild was detected in 25 patients, an elevated transmitral gradient was detected in seven patients, and SAM was detected in 16 patients. The condition of eight patients with SAM was resolved with medication only. Mitral valve re-repair was performed in 23 patients and replacement was performed in 17, with comparable early mortality and morbidity. At 60.3 ± 25.5 months after surgery, late mitral stenosis and reoperation rate were significantly higher in re-repair patients than in patients with complete initial repair, despite comparable survival, left chamber reverse remodeling, and degree of residual regurgitation. Based on our institutional protocol, acceptable outcomes can be achieved for patients with incomplete initial mitral valve repair. Management should be tailored based on the characteristics of the mitral valve complex, expected repair durability, and operative risk.

Reference Values for Physical Stress Echocardiography in Asymptomatic Patients after Mitral Valve Repair

Background

Clinical decision-making in symptomatic patients after mitral valve (MV) repair remains challenging as echocardiographic reference values are lacking. In native MV disease intervention is recommended for mean transmitral pressure gradient (TPG) >15 mmHg or systolic pulmonary artery pressure (SPAP) >60 mmHg at peak exercise. Insight into standard stress echo parameters after MV repair may therefore aid to clinical decision-making during follow-up.

Hypothesis

Stress echocardiography derived parameters in asymptomatic patients after successful MV repair differ from current guidelines for native valves.

Material and methods

In 25 patients (NYHA I) after MV repair stress echocardiography was performed on a semi-supine bicycle. Doppler flow records and MV related hemodynamics at rest and peak were obtained. Linear regression analysis was performed for mean TPG and SPAP at peak, using predetermined variables and confounders.

Results

Mean TPG at rest (3.2 ± 1.4 mmHg) significantly increased at peak (15.0 ± 3.4 mmHg) but was always <25 mmHg. Mean SPAP at rest (21.4 ± 3.8 mmHg) significantly increased at peak (41.8 ± 8.9 mmHg) but was never >57 mmHg. Only the indexed MV ring diameter was inversely correlated to mean TPG at peak in a multivariable model.

Conclusion

In contrast to current recommendations in native MV disease, our data indicate that the standard value for mean TPG during stress echocardiography in asymptomatic patients after successful MV repair was above the guideline threshold of 15 mmHg in >50%, but always <25 mmHg. For SPAP, patients never reached the guideline cutoff (60 mmHg). Long-term follow-up data are needed to provide insight in clinical consequences. Baseline stress echocardiography may indicate individual reference values to compare with during follow-up.

Clinical trial registration

https://clinicaltrials.gov/ct2/show/NCT02371863?term=chamuleau+AND+Mitral&rank=1.

Late onset of atrial fibrillation in patients undergoing mitral valve repair for type II dysfunction

BACKGROUND

There are few reports regarding factors related to late-onset of atrial fibrillation (Af) after mitral valve repair, which can compromise long-term outcome. We analyzed the risk factors for late Af after mitral valve repair.

METHODS AND RESULTS

Between 2001 and 2015, 318 patients (214 males; median, 57.7 years) underwent mitral valve repair for degenerative mitral insufficiency (MI) without concomitant aortic valve disease in our institute. Patients with a history of paroxysmal or chronic Af preoperatively were excluded. Serial follow-up echocardiography was used to evaluate cardiac function. The follow-up rate was 99%. The mean follow-up period was 6.0±4.1 years. There was no early death and there were nine late deaths. A total of 29 (9.1%) patients developed late Af. Freedom from late Af was 94.0% at 5 years and 82.9% at 10 years. Small ring annuloplasty, left atrial diameter, and pressure half time, which were measured at follow-up echocardiography, were considered as significant (p<0.05) risk factors for late Af. Patients who had late Af developed recurrent MI more frequently than those who did not (p<0.05).

CONCLUSIONS

Remodeling of the atrium caused by functional mitral stenosis is important for late Af, as well as recurrent MI. To prevent these problems, avoiding selection of a small ring at primary mitral repair for type II dysfunction and durable repair are required.

Elevated Mitral Valve Pressure Gradient After MitraClip Implantation Deteriorates Long-Term Outcome in Patients With Severe Mitral Regurgitation and Severe Heart Failure

OBJECTIVES

This single-center study was performed to analyze the effect of an increased transvalvular gradient after the MitraClip (MC) (Abbott Laboratories, Abbott Park, Illinois) procedure on patient outcome during follow-up.

BACKGROUND

Percutaneous transcatheter repair of the mitral valve with the MC device has been established as a novel technique for patients with severe mitral regurgitation and high surgical risk. This study investigated the influence of an increased pressure gradient after MC implantation on the long-term outcome of patients.

METHODS

A total of 268 patients were enrolled, who received MC implantation between April 2009 and July 2014 in our institution (75 ± 9 years of age, 68% men, weight 76 ± 15 kg, median N-terminal pro-B-type natriuretic peptide 3,696 [interquartile range: 1,989 to 7,711] pg/ml, left ventricular ejection fraction 39 ± 16%, log European System for Cardiac Operative Risk Evaluation score 20% [interquartile range: 12% to 33%]). Pressure in the left atrium and left ventricle were measured during the procedure using fluid-filled catheters. The pressure gradients over the mitral valve were determined simultaneously invasively and echocardiographically directly after MC deployment. A Kaplan-Meier analysis was performed and correlated with the pressure gradients. We used a combined primary endpoint: all-cause-mortality, left ventricular assist device, mitral valve replacement, and redo procedure.

RESULTS

The Kaplan-Meier-analysis showed a significantly poorer long-term-outcome in the case of an invasively determined mitral valve pressure gradient (MVPG) in excess of 5 mm Hg at implantation for the combined endpoint (p = 0.001) and for all-cause mortality (p = 0.018). For the echocardiographically determined MVPG the cutoff value was 4.4 mm Hg. Propensity score matching was used to balance baseline differences between the groups. In a Cox model the increased residual MVPG >5 mm Hg was a significant outcome predictor in univariate and multivariate analysis (hazard ratio: 2.3; 95% confidence interval: 1.4 to 3.8; p = 0.002, multivariate after adjustment for N-terminal pro-B-type natriuretic peptide, age, and remaining mitral regurgitation).

CONCLUSIONS

It is recommended that the quality of the implantation result be analyzed carefully and repositioning of the MC be considered in the case of an elevated pressure gradient over the mitral valve.

Relation of Residual Mitral Regurgitation Despite Elevated Mitral Gradients to Risk of Heart Failure Hospitalization After MitraClip Repair

Achieving minimal residual mitral regurgitation (MR) after percutaneous MitraClip repair is limited by iatrogenic mitral stenosis. It is unknown whether allowing moderately elevated postprocedural mean mitral gradients (MMGs) to achieve < moderate residual MR is preferable to moderate residual regurgitation. Patients with less-than-moderate residual MR but a MMG of ≥5 mm Hg (Group 1) were compared with patients with moderate residual MR (Group 2). The primary end point was heart failure hospitalization. Secondary end points included mortality, subsequent mitral valve surgery, and MR at 1 year. Seventy-eight patients were included in the study. Group 1 included 48 patients (median MMG 6, interquartile range 5-6 mm Hg). Group 2 included 30 patients (median MMG 3.5, interquartile range 2-5 mm Hg). Age, baseline MR severity, and type of MR were not different between groups. Freedom from heart failure hospitalization at 1 year was 91.2 ± 4.2% in Group 1 versus 70.8 ± 8.7% in Group 2 (p = 0.021). Achieved differences in MR reduction between groups persisted at 1 year (p = 0.007). Survival was not different (p = 0.402), and subsequent mitral valve surgery occurred in 4 of 48 (8%) and in 4 of 30 patients (13%) in Group 1 and Group 2, respectively (p = 0.476). By multivariate Cox regression analysis, less-than-moderate residual MR, despite moderately elevated mitral gradients, was associated with a hazard ratio of 0.21 (95% confidence interval 0.04 to 0.96) for subsequent heart failure hospitalization (p = 0.044). In conclusion, patients with less-than-moderate residual MR despite a MMG of ≥5 had a 79% reduction in hazard for subsequent heart failure hospitalization compared with patients with moderate residual MR.

Systematic review and meta-analysis of chordal replacement versus leaflet resection for posterior mitral leaflet prolapse

OBJECTIVES

To compare outcomes of chordal replacement versus leaflet resection techniques for repair of isolated posterior mitral leaflet prolapse.

METHODS

We searched MEDLINE and EMBASE databases for studies that compared chordal replacement ("neo-chord" group) versus leaflet resection ("resection" group) techniques for the treatment of posterior mitral leaflet prolapse. Data were extracted by 2 independent investigators and subjected to a meta-analysis using a random-effects model.

RESULTS

One randomized controlled trial (RCT), 1 propensity-matched study, and 6 unadjusted observational studies, with a total of 1926 patients, met our inclusion criteria. Two studies reported only perioperative outcomes; mean follow-up ranged from 1.0 to 5.9 years in the remaining studies. In pooled data from unadjusted observational studies, annuloplasty ring diameter was higher in the neo-chord group (+1.5 mm; P = .0003), but with high heterogeneity (I² = 91%). Based on limited data, postprocedural left ventricular ejection fraction may be greater in the neo-chord group, but this difference reached statistical significance only in the RCT (+3.4%; P = .03), and not in 2 observational studies that reported this outcome (+2.7%; P = .10). There was no difference in recurrent mitral regurgitation at follow-up between the resection and neo-chord groups; however, patients in the neo-chord group had a lower rate of mitral valve reoperation at follow-up in the unadjusted observational studies (incidence rate ratio, 0.22; P = .0008 [I² = 0%; 4 studies, 1331 patients]).

CONCLUSIONS

Chordal replacement may be associated with greater freedom from reoperation and may lead to improved postoperative left ventricular function compared with leaflet resection. However, these conclusions are supported primarily by data from unadjusted observational studies, and high-quality RCTs of chordal replacement versus leaflet resection are needed.