Mitral Gradients and Frequency of Recurrence of Mitral Regurgitation After Ring Annuloplasty for Ischemic Mitral Regurgitation

Computational Modeling of the Subject-Specific Effects of Annuloplasty Ring Sizing on the Mitral Valve to Repair Functional Mitral Regurgitation

Surgical repair of functional mitral regurgitation (FMR) that occurs in nearly 60% of heart failure (HF) patients is currently performed with undersizing mitral annuloplasty (UMA), which lacks short- and long-term durability. Heterogeneity in valve geometry makes tailoring this repair to each patient challenging, and predictive models that can help with planning this surgery are lacking. In this study, we present a 3D echo-derived computational model, to enable subject-specific, pre-surgical planning of the repair. Three computational models of the mitral valve were created from 3D echo data obtained in three pigs with HF and FMR. An annuloplasty ring model in seven sizes was created, each ring was deployed, and post-repair valve closure was simulated. The results indicate that large annuloplasty rings (> 32 mm) were not effective in eliminating regurgitant gaps nor in restoring leaflet coaptation or reducing leaflet stresses and chordal tension. Smaller rings (≤ 32 mm) restored better systolic valve closure in all investigated cases,but excessive valve tethering and restricted motion of the leaflets were still present. This computational study demonstrates that for effective correction of FMR, the extent of annular reduction differs between subjects, and overly reducing the annulus has deleterious effects on the valve.

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.

Transcatheter edge-to-edge repair following surgical valve repair with ring implantation: Results from the multicentre "Clip-in-Ring" registry

BACKGROUND

Management of mitral regurgitation recurrence after failed surgical valve repair with ring implantation is controversial.

AIM

To describe the French experience regarding midterm safety and efficacy of transcatheter edge-to-edge mitral valve repair (TEER) in patients with failed surgical valve repair with ring implantation.

METHODS

The "Clip-in-Ring" registry is a multicentre registry conducted in 11 centres in France, approved by local institutional review boards, of consecutive TEER following surgical valve repair with ring implantation. Outcomes were Mitral Valve Academic Research Consortium (MVARC) technical success, modified 30-day device and procedural success (where 10mmHg is considered as a cut-off for significant mitral stenosis) and MVARC complications.

RESULTS

Twenty-three patients were studied: mean age, 69±10years; male sex, 74%; EuroSCORE II, 16±17; left ventricular ejection fraction, 53±12%; mitral regurgitation grade 3+/4+, 17%/78%; New York Heart Association class III/IV, 47%/22%; median surgery to TEER delay, 23 (6-94) months. Technical success was 100%. At discharge, residual mitral regurgitation grade was≤2+ in 87% and median transmitral gradient was 4 (3-5) mmHg. Thirty-day modified MVARC device and procedural success was 82%: four patients (17%) had residual mitral regurgitation grade>2+, including two patients who needed complementary surgery. No patient had a 30-day transmitral gradient>7mmHg. No patient died or had a stroke or any life-threatening complications. One patient presented a vascular access complication requiring transfusion. No other MVARC-2 adverse event was reported.

CONCLUSIONS

TEER in patients with failed mitral ring is feasible and safe. Further studies shoulddelineate its exact role in the therapeutic armamentarium for this medical issue.

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.

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.

Clinical Impact of Flow Adjusted Transmitral Pressure Gradient After Surgical Annuloplasty for Functional Mitral Regurgitation

Downsizing of mitral annulus due to mitral annuloplasty for ischemic functional mitral regurgitation (FMR) raises a new issue, functional mitral stenosis (FMS), defined as a decline of mitral hemodynamics. However, common mitral hemodynamic parameters are influenced by transmitral flow, therefore, the clinical impacts are still controversial. The aim of this study is to seek mitral hemodynamic indices (including transmitlra pressure gradient [TMPG] adjusted by left ventricular stroke volume [LVSV]) relevant to the mid-term outcomes after annuloplasty for ischemic functional mitral regurgitation (FMR). This study is a retrospective evaluation of mitral valve hemodynamic status by resting echocardiogram at several weeks after surgery. Eighty-one patients underwent mitral annuloplasty for ischemic FMR between September 2012 and June 2019. Postoperative adverse events occurred in 28 patients (34.6%), and the overall 5-year freedom from adverse events rate was 55.9%. Common mitral hemodynamic parameters were not associated with adverse events, but flow adjusted TMPG can be a correlative factor. By multivariable analysis, postoperative systolic pulmonary artery pressure and peak TMPG/LVSV were detected as independent predictors (adjusted hazard ratio 1.07 and 1.08, P < 0.001 and < 0.001). Additionally, risk stratification by peak TMPG (cut-off: 10 mm Hg) and LVSV (cut-off: 35 mL/m²) reflected the mid-term outcomes, perceptively (P = 0.007). Conventional mitral hemodynamic parameters were not associated with adverse cardiac events after annuloplasty for ischemic FMR. However, flow adjusted TMPG was identfied as an independent predictor, and risk stratification by peak TMPG and LVSV reflected the mid-term outcomes, perceptively.

Initial Clinical Experience With Mitral Valve Translocation for Secondary Mitral Regurgitation

BACKGROUND

Functional (secondary) mitral regurgitation (FMR) results from altered geometry of the mitral valve apparatus. Repair with restrictive mitral annuloplasty is associated with high rates of recurrent mitral regurgitation (MR). We developed a novel operative repair for FMR that translocates the intact mitral valve towards the apex.

METHODS

The mitral valve was detached circumferentially and translocated into the ventricle with a frustum-shaped glutaraldehyde-treated autologous pericardial patch. Clinical and echocardiographic follow-up was performed.

RESULTS

Fifteen consecutive patients with FMR (mean age, 59 years; 67% female) had mitral valve translocation between 2018 and 2020. Preoperative mean ejection fraction, left ventricular end-diastolic dimension, and systolic pulmonary artery pressure were 40% ± 11%, 59 ± 8 mm, and 49 ± 21 mm Hg, respectively; 33% had atrial fibrillation. Cardiomyopathy was ischemic in 4 and nonischemic in 11. Concomitant procedures included tricuspid valve operation (n = 8), coronary artery bypass grafting (n = 4), and atrial fibrillation ablation (n = 5). Post bypass transesophageal echocardiogram demonstrated none/trace MR in all patients and mean gradient of 3 mm Hg (interquartile range, 2-4 mm Hg). Mean leaflet extent of coaptation was 14 ± 2 mm (range, 11-17 mm). There was no postoperative mortality, stroke, or renal failure. Predismissal echocardiography showed none/trace MR in 14 patients and mild MR in 1. One patient underwent successful late rerepair of a suture line leak. Twelve patients were alive at latest follow-up and MR at 1 and 6 months was mild or less in all patients with mean leaflet extent of coaptation of 14 ± 2 mm (range, 12-16 mm) at 6 months.

CONCLUSIONS

Mitral valve translocation creates a large surface of coaptation and effectively corrects FMR. Further study is needed to demonstrate the long-term durability and clinical utility of this operation.

Impact of recurrent mitral regurgitation after mitral valve repair for functional mitral regurgitation: long-term analysis of competing outcomes

AIMS

Recurrent mitral regurgitation (MR) has been reported after mitral valve repair for functional MR. However, the impact of recurrent MR on long-term survival remains poorly defined. In the present study, mortality-adjusted recurrent MR rates, the clinical impact of recurrent MR and its determinants were studied in patients after mitral valve repair with revascularization for functional MR in the setting of ischaemic heart disease.

METHODS AND RESULTS

Long-term clinical and echocardiographic outcome was evaluated in 261 consecutive patients after restrictive mitral annuloplasty and revascularization for moderate to severe functional MR, between 2000 and 2014. The cumulative incidence of recurrent MR ≥ Grade 2, assessed by competing risk analysis, was 9.6 ± 1.8% at 1-year, 20.3 ± 2.5% at 5-year, and 27.6 ± 2.9% at 10-year follow-up. Cumulative survival was 85.8% [95% confidence interval (CI) 81.0-90.0] at 1-year, 67.3% (95% CI 61.1-72.6%) at 5-year, and 46.1% (95% CI 39.4-52.6%) at 10-year follow-up. Age, preoperative New York Heart Association Class III or IV, a history of renal failure, and recurrence of MR expressed as a time-dependent variable [HR 3.28 (1.87-5.75), P < 0.001], were independently associated with an increased mortality risk. Female gender, a history of ST-elevation myocardial infarction, a preoperative QRS duration ≥120 ms, a higher preoperative MR grade, and a higher indexed left ventricular end-systolic volume were independently associated with an increased likelihood of recurrent MR.

CONCLUSION

Mitral valve repair for functional ischaemic MR resulted in a low incidence of recurrent MR with favourable clinical outcome up to 10 years after surgery. Presence of recurrent MR at any moment after surgery proved to be independently associated with an increased risk for mortality.

The change in the mitral-septal angle after surgery for atrial functional mitral regurgitation

OBJECTIVE

The optimal surgical strategy for atrial functional mitral regurgitation remains uncertain. Preoperative mitral-septal angle ≤ 70° has been reported as a risk factor for an abnormal vortex pattern in mitral valve repair. This study aimed to elucidate the change in the mitral-septal angle after surgery for atrial functional mitral regurgitation and its effect on the mid-term outcomes.

METHODS

Forty patients underwent mitral valve repair for atrial functional mitral regurgitation. The mitral-septal angle was defined as the angle between the mitral annulus and the anteroseptal wall of the left ventricular mid-portion in the parasternal long-axis view on transthoracic echocardiography. All patients underwent mitral ring annuloplasty. Left atrial plication was performed in nine patients. The mean clinical follow-up period was 42 ± 24 months.

RESULTS

The ratio of left atrial volume to left ventricular end-systolic volume was negatively correlated with the preoperative mitral-septal angle. The postoperative mitral-septal angles were significantly smaller than the preoperative ones. The mitral-septal angle decreased with a decrease in the mitral annuloplasty ring size. Patients who underwent left atrial plication tended to show an increase in the mitral-septal angle postoperatively. There were no significant differences in mid-term morbidities, including heart failure, requiring re-hospitalization and mortalities between patients with postoperative MSA > 70° and those with postoperative MSA ≤ 70°.

CONCLUSIONS

Mitral ring annuloplasty negatively changed the mitral-septal angle, while left atrial plication may induce a positive change to the mitral-septal angle. An association between the mitral-septal angle and mid-term outcomes was not revealed in this study.

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.

A Novel 3-Dimensional Approach for the Echocardiographic Evaluation of Mitral Valve Area After Repair for Degenerative Disease

BACKGROUND

Currently available 2-dimensional (2D) echocardiographic methods for accurately assessing the mitral valve orifice area (MVA) after mitral valve repair (MVr) are limited due to its complex 3-dimensional (3D) geometry. We compared repaired MVAs obtained with commonly used 2D and 3D echocardiographic methods to a 3D orifice area (3DOA), which is a novel echocardiographic measurement and independent of geometric assumptions.

METHODS

Intraoperative 2D and 3D transesophageal echocardiography (TEE) images from 20 adult cardiac surgery patients who underwent MVr for mitral regurgitation obtained immediately after repair were retrospectively reviewed. MVAs obtained by pressure half-time (PHT), 2D planimetry (2DP), and 3D planimetry (3DP) were compared to those derived by 3DOA.

RESULTS

MVAs (mean value ± standard deviation [SD]) after MVr were obtained by PHT (3 ± 0.6 cm), 2DP (3.58 ± 0.75 cm), 3D planimetry (3DP; 2.78 ± 0.74 cm), and 3DOA (2.32 ± 0.76 cm). MVAs obtained by the 3DOA method were significantly smaller compared to those obtained by PHT (mean difference, 0.68 cm; P = .0003), 2DP (mean difference, 1.26 cm; P < .0001), and 3DP (mean difference, 0.46 cm; P = .003). In addition, MVA defined as an area ≤1.5 cm was identified by 3DOA in 2 patients and by 3DP in 1 patient.

CONCLUSIONS

Post-MVr MVAs obtained using the novel 3DOA method were significantly smaller than those obtained by conventional echocardiographic methods and may be consistent with a higher incidence of MVA reduction when compared to 2D techniques. Further studies are still needed to establish the clinical significance of 3D echocardiographic techniques used to measure MVA after MVr.

Predicting functional mitral stenosis after restrictive annuloplasty for ischemic mitral regurgitation

BACKGROUND

Although it has been realized that restrictive mitral valve annuloplasty (MVA) may re-sult in clinically significant functional mitral stenosis (MS), it still cannot be predicted. The purpose of this study was to identify risk factors for clinically significant functional MS following restrictive MVA surgery for chronic ischemic mitral regurgitation (CIMR).

METHODS

One hundred and fourteen patients who underwent restrictive MVA with coronary artery bypass grafting (CABG) for treatment of CIMR were retrospectively reviewed. Clinically significant functional MS was defined as resting transmitral peak pressure gradient (PPG) ≥ 13 mmHg.

RESULTS

During the follow-up period (range 6-12 months), 28 (24.56%) patients developed clinically significant functional MS. The PPG at follow-up was significantly higher than that measured in the early postoperative stage (3-5 days after surgery). Moreover, there was a linear correlation between the two measurements (r = 0.398, p < 0.001). Annuloplasty size ≤ 27 mm and early postoperative PPG ≥ 7.4 mmHg could predict clinically significant functional MS at 6-12 months postoperatively.

CONCLUSIONS

Chronic ischemic mitral regurgitation patients treated with restrictive MVA and CABG have significant increases in PPG postoperatively. Annuloplasty size ≤ 27 mm and early postopera-tive PPG ≥ 7.4 mmHg can predict clinically significant functional MS at 6-12 months after surgery.

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.

A Comparison of 2 Mitral Annuloplasty Rings for Severe Ischemic Mitral Regurgitation: Clinical and Echocardiographic Outcomes

Controversies regarding the choice of annuloplasty rings for treatment of ischemic mitral regurgitation still exist. Aim of the study is to compare early performance of 2 different rings in terms of rest and exercise echocardiographic parameters (transmitral gradient, systolic pulmonary artery pressure, and mitral valve area), clinical outcomes, and recurrence of mitral regurgitation. From January 2008 till December 2013, prospectively collected data of patients who underwent coronary artery bypass grafting and undersizing mitral valve annuloplasty for severe chronic ischemic mitral regurgitation at our Institution were reviewed. A total of 93 patients were identified; among them 44 had semirigid Memo 3D ring implanted (group A) whereas 49 had a rigid profile 3D ring (group B). At 6 months, recurrent ischemic mitral regurgitation, equal or more than moderate, was observed in 4 and 6 patients in the group A and B, respectively (P = 0.74). Group A showed certain improved valve geometric parameters such as posterior leaflet angle, tenting area, and coaptation depth. Transmitral gradient was significantly higher at rest in the group B (P < 0.0001). During exercise, significant increase of transmitral gradient and systolic pulmonary artery pressure was observed in group B (P < 0.0001). Mitral valve area was not statistically significantly smaller at rest in between groups (P = 0.09); however, it significantly decreased with exercise in group B (P = 0.01). At midterm follow-up, patients in group B were more symptomatic. In patients with chronic ischemic mitral regurgitation, use of semirigid Memo 3D ring when compared to the rigid Profile 3D may be associated with early improved mitral valve geometrical conformation and hemodynamic profile, particularly during exercise. No difference was observed between both groups in recurrent mitral regurgitation.

Mitral Valve Stenosis after Open Repair Surgery for Non-rheumatic Mitral Valve Regurgitation: A Review

Mitral stenosis (MS) after mitral valve (MV) repair is a slowly progressive condition, usually detected many years after the index MV surgery. It is defined as a mean transmitral pressure gradient (TMPG) >5 mmHg or a mitral valve area (MVA) <1.5 cm(2). Pannus formation around the mitral annulus or extending to the mitral leaflets is suggested as the main mechanism for developing delayed MS after MV repair. On the other hand, early stenosis is thought to be a direct result of an undersized annuloplasty ring. Furthermore, in MS following ischemic mitral regurgitation (MR) repair, subvalvular tethering is the hypothesized pathophysiology. MS after MV repair has an incidence of 9-54%. Several factors have been associated with a higher risk for developing MS after MV repair, including the use of flexible Duran annuloplasty rings versus rigid Carpentier-Edwards rings, complete annuloplasty rings versus partial bands, small versus large anterior leaflet opening angle, and anterior leaflet tip opening length. Intraoperative echocardiography can measure the anterior leaflet opening angle, the anterior leaflet tip opening dimension, the MVA and the mean TMPG, and may help identify patients at risk for developing MS after MV repair.

Mitral valve area during exercise after restrictive mitral valve annuloplasty: importance of diastolic anterior leaflet tethering

BACKGROUND

Restrictive mitral valve annuloplasty (RMA) for secondary mitral regurgitation might cause functional mitral stenosis, yet its clinical impact and underlying pathophysiological mechanisms remain debated.

OBJECTIVES

The purpose of our study was to assess the hemodynamic and clinical impact of effective orifice area (EOA) after RMA and its relationship with diastolic anterior leaflet (AL) tethering at rest and during exercise.

METHODS

Consecutive RMA patients (n = 39) underwent a symptom-limited supine bicycle exercise test with Doppler echocardiography and respiratory gas analysis. EOA, transmitral flow rate, mean transmitral gradient, and systolic pulmonary arterial pressure were assessed at different stages of exercise. AL opening angles were measured at rest and peak exercise. Mortality and heart failure readmission data were collected for at least 20 months after surgery.

RESULTS

EOA and AL opening angle were 1.5 ± 0.4 cm(2) and 68 ± 10°, respectively, at rest (r = 0.4; p = 0.014). EOA increased significantly to 2.0 ± 0.5 cm(2) at peak exercise (p < 0.001), showing an improved correlation with AL opening angle (r = 0.6; p < 0.001). Indexed EOA (EOAi) at peak exercise was an independent predictor of exercise capacity (maximal oxygen uptake, p = 0.004) and was independently associated with freedom from all-cause mortality or hospital admission for heart failure (p = 0.034). Patients with exercise EOAi <0.9 cm(2)/m(2) (n = 14) compared with ≥0.9 cm(2)/m(2) (n = 25) had a significantly worse outcome (p = 0.048). In multivariate analysis, AL opening angle at peak exercise (p = 0.037) was the strongest predictor of exercise EOAi.

CONCLUSIONS

In RMA patients, EOA increases during exercise despite fixed annular size. Diastolic AL tethering plays a key role in this dynamic process, with increasing AL opening during exercise being associated with higher exercise EOA. EOAi at peak exercise is a strong and independent predictor of exercise capacity and is associated with clinical outcome. Our findings stress the importance of maximizing AL opening by targeting the subvalvular apparatus in future repair algorithms for secondary mitral regurgitation.

Influence of procedural differences on mitral valve configuration after surgical repair for functional mitral regurgitation: in which direction should the papillary muscle be relocated?

Background

After restrictive mitral annuloplasty (RMAP) for functional mitral regurgitation (MR), the MR frequently recurs. Papillary muscle relocation (PMR) should reduce the recurrence rate. We assessed the influence of procedural differences in PMR on the postoperative mitral valve configuration.

Methods

Thirty-nine patients who underwent mitral valve repair for functional MR were enrolled. In limited tethering cases, RMAP alone was performed (RMAP group; n = 23). In severe tethering cases, in addition to RMAP, bilateral papillary muscles were relocated in the direction of the posterior annulus (posterior PMR group; n = 10) or anterior annulus (anterior PMR group; n = 6). We performed pre- and postoperative transthoracic echocardiographic studies, introducing a new index, mitral inflow angle (MIA), to assess the diastolic mitral leaflet excursion. MIA was measured as the angle between the mitral annular plane and the bisector of the anterior and posterior leaflets.

Results

Postoperative MR grade was significantly reduced in each group (P < 0.001). Follow-up echocardiography showed recurrent MR in 13% of the patients in RMAP group. In contrast, no recurrent MR was observed in either the anterior PMR or the posterior PMR group. After surgery, MIA was significantly reduced in both the RMAP group (P < 0.01) and the posterior PMR group (P < 0.001), but was preserved in the anterior PMR group (NS). None of the postoperative variables showed any significant difference between the early and late postoperative phases.

Conclusions

In the surgical treatment of functional MR, a PMR procedure in addition to RMAP was effective in reducing systolic MR. However, mitral valve opening assessed by MIA was restricted even after RMAP alone. The restriction was severely augmented after additional posterior PMR, but was attenuated after additional anterior PMR. The papillary muscle should be relocated in the direction of the anterior annulus to preserve the diastolic opening of the mitral valve.

Electronic supplementary material

The online version of this article (doi:10.1186/s13019-014-0185-6) contains supplementary material, which is available to authorized users.

Ischemic mitral regurgitation: mechanisms, intraoperative echocardiographic evaluation, and surgical considerations

Ischemic mitral regurgitation (IMR) is a subcategory of functional rather than organic, mitral valve (MV) disease. Whether reversible or permanent, left ventricular remodeling creates IMR that is complex and multifactorial. A comprehensive TEE examination in patients with IMR may have important implications for perioperative clinical decision making. Several TEE measures predictive of MV repair failure have been identified. Current practice among most surgeons is to typically repair the MV in patients with IMR. MV replacement is usually reserved for situations in which the valve cannot be reasonably repaired, or repair is unlikely to be tolerated clinically.

Surgical management of ischemic mitral regurgitation: indications, procedures, and future prospects

Ischemic mitral regurgitation (IMR) is one of the most important risk factors affecting prognosis of patients who suffer from myocardial infarction. The mechanisms of IMR, the indications for surgical intervention, the operative procedures, and the limitations of surgical procedures are discussed in this review article.

Mitral stenosis after IMR ETlogix ring annuloplasty for ischemic regurgitation

Objectives: Ring annuloplasty combined with coronary artery bypass grafting is the standard approach for treatment of patients with ischemic mitral regurgitation. We evaluated mitral valve hemodynamic performance and recurrence of mitral regurgitation after ring annuloplasty.

Patients and methods: 40 consecutive patients (mean age, 70 ± 8 years) with chronic ischemic mitral regurgitation grade ≥2+ received annuloplasty with an IMR ETlogix ring. During follow-up (25.9 ± 15.5 months), 84% of surviving patients underwent exercise stress echocardiography to assess recurrence of mitral regurgitation and differences between rest and exercise mitral valve hemodynamic performance.

Results: Hospital mortality was 10%. During follow-up, we found no significant differences between left ventricular ejection fraction or end-diastolic and end-systolic diameters pre- and postoperatively (41% vs. 45%, 59 vs. 56 mm, and 49 vs. 46 mm, respectively), but there was a significant increase in mitral mean gradient with exercise (3.3 ± 1.2 vs. 7.8 ± 4 mm Hg, p < 0.001). Two patients had mitral regurgitation ≥grade III–IV.

Conclusions: Mitral annuloplasty with the IMR ETlogix ring provides effective correction of chronic ischemic mitral regurgitation, but this technique may induce functional mitral stenosis.

Mitral valve surgery in low ejection fraction, severe ischemic mitral regurgitation patients: should we repair them all?

PURPOSE OF REVIEW

The optimal surgical treatment of chronic ischemic mitral regurgitation still is the subject of much debate in the surgical and cardiological communities. Although combined restrictive mitral annuloplasty and revascularization has demonstrated good results with regard to improvement of clinical status, low rates of recurrent mitral regurgitation and sustained left ventricular reverse remodeling, a survival benefit still has not been demonstrated. In addition, not all patients improve. Remaining issues in this field relate to identification of patients who will benefit from treatment, and to further improve and individualize treatment modalities.

RECENT FINDINGS

More data support the use of restrictive mitral annuloplasty and revascularization. New surgical techniques to improve mitral competence (posterior leaflet augmentation) and to promote left ventricular reverse remodeling in severely dilated hearts (addressing the subvalvular apparatus) are promising. Disease-specific annuloplasty rings have not (yet) proven additional value. New imaging modalities are available to assess the many components that constitute the complex pathophysiology of remodeling.

SUMMARY

The remaining challenge for cardiologists and surgeons is how to integrate data from different imaging techniques that assess mitral valve geometry and left ventricular size, geometry, function and potential functional recovery in order to individualize and optimize the surgical approach to patients with chronic ischemic mitral regurgitation.

Surgical treatment of functional mitral regurgitation

Incidence of functional mitral regurgitation (FMR) is increasing due to aging and better survival after acute myocardial infarction, the most frequent cause of FMR. At the basis of FMR there is a displacement of one of both papillary muscle(s) and/or annular enlargement, which can be primitive or, more often, secondary. There is general agreement that its natural history is unfavorable, as witnessed by a considerable body of evidences. However, even if there is no clear evidence that surgical treatment of FMR changes consistently the outcome of patients with this disease, at least in terms of survival, there are some studies which show that function improves, as well as the global quality of life. The guidelines reflect this uncertainty, providing no clear indications, even in the gradation of severity of the FMR. Surgical techniques are variable and are mainly addressed to the annulus (restrictive annuloplasty), which is only a part of the anatomic problem related to FMR. Insertion of a prosthesis inside the native valve is appearing more and more a valuable option rather than a bail out procedure. On the other side, techniques addressed to modify the position of the papillary muscles appear to be still under investigation and not yet in the armamentarium of surgical treatment of FMR. Even after many years, rules are not established and results are fluctuating, but how and when to treat FMR is becoming more and more a topic of interest in cardiac surgery.

Long-term echocardiographic follow-up after posterior mitral annuloplasty using a vascular strip for ischemic mitral regurgitation: ten-years of experience at a single center

Management of ischemic mitral regurgitation (MR) is challenging. The aim of this study was to investigate long-term clinical and echocardiographic results of restrictive mitral annuloplasty for ischemic MR. From 2001 through 2010, 96 patients who underwent myocardial revascularization with restrictive mitral annuloplasty using a vascular strip for ischemic MR were analyzed. Patients were stratified into two groups based on left ventricular ejection fraction (LVEF): group I, n = 50, with LVEF > 35% and group II, n = 46, with LVEF ≤ 35%. The early mortality rate was 2.1% (2/96) and the late cardiac mortality rate was 11.5% (11/96). MR grade was reduced at discharge (0.8 ± 0.7) but increased during follow-up (1.1 ± 0.8, P = 0.001). There was no intergroup difference in terms of freedom from recurrent MR ≥ moderate eight years after surgery (94.1% ± 5.7%, group I vs 87.8% ± 7.2%, group II; P = 0.575). NYHA functional class (odds ratio [OR], 2.2; P = 0.044) and early postoperative residual MR ≥ mild (OR, 25.4; P < 0.001) were independent predictors of recurrent MR. Restrictive mitral annuloplasty using a vascular strip is effective in ischemic MR. It is important to avoid early postoperative residual MR.

Evaluation of transmitral pressure gradients in the intraoperative echocardiographic diagnosis of mitral stenosis after mitral valve repair

Objective

Acute mitral stenosis (MS) following mitral valve (MV) repair is a rare but severe complication. We hypothesize that intraoperative echocardiography can be utilized to diagnose iatrogenic MS immediately after MV repair.

Methods

The medical records of 552 consecutive patients undergoing MV repair at a single institution were reviewed. Post-cardiopulmonary bypass peak and mean transmitral pressure gradients (TMPG), and pressure half time (PHT) were obtained from intraoperative transesophageal echocardiographic (TEE) examinations in each patient.

Results

Nine patients (9/552 = 1.6%) received a reoperation for primary MS, prior to hospital discharge. Interestingly, all of these patients already showed intraoperative post-CPB mean and peak TMPGs that were significantly higher compared to values for those who did not: 10.7±4.8 mmHg vs 2.9±1.6 mmHg; p<0.0001 and 22.9±7.9 mmHg vs 7.6±3.7 mmHg; p<0.0001, respectively. However, PHT varied considerably (87±37 ms; range: 20–439 ms) within the entire population, and only weakly predicted the requirement for reoperation (113±56 vs. 87±37 ms, p = 0.034). Receiver operating characteristic curves showed strong discriminating ability for mean gradients (AUC = 0.993) and peak gradients (area under the curve, AUC = 0.996), but poor performance for PHT (AUC = 0.640). A value of ≥7 mmHg for mean, and ≥17 mmHg for peak TMPG, best separated patients who required reoperation for MS from those who did not.

Conclusions

Intraoperative TEE diagnosis of a peak TMPG ≥17 mmHg or mean TMPG ≥7 mmHg immediately following CPB are suggestive of clinically relevant MS after MV repair.

Does stringent restrictive annuloplasty for functional mitral regurgitation cause functional mitral stenosis and pulmonary hypertension?

BACKGROUND

It remains controversial whether restrictive mitral annuloplasty (RMA) for functional mitral regurgitation (MR) can induce functional mitral stenosis (MS) that may cause postoperative residual pulmonary hypertension (PH).

METHODS AND RESULTS

One hundred eight patients with left ventricular (LV) dysfunction and severe MR underwent RMA with stringent downsizing of the mitral annulus. Systolic pulmonary artery pressure (PAP) and mitral valve performance variables were determined by Doppler echocardiography prospectively and 1 month after RMA. Fifty-eight patients underwent postoperative hemodynamic measurements. Postoperative echocardiography showed a mean pressure half-time of 92 ± 14 ms, a transmitral mean gradient of 2.9 ± 1.1 mm Hg, and a mitral valve effective orifice area of 2.4 ± 0.4 cm(2), consistent with functional MS. Doppler-derived systolic PAP was 32 ± 8 mm Hg, which correlated weakly with the transmitral mean gradient (ρ=0.23, P=0.02). Postoperative cardiac catheterization also showed significant improvements in LV volume and systolic function, pulmonary capillary wedge pressure, cardiac index, and systolic PAP; the latter was associated with LV end-diastolic pressure [standardized partial regression coefficient (SPRC)=0.51], pulmonary vascular resistance (SPRC=0.47), cardiac index (SPRC=0.37), and transmitral pressure gradient (SPRC=0.20). In a multivariate Cox proportional hazard model, postoperative PH (systolic PAP >40 mm Hg), but not mitral valve performance variables, was strongly associated with adverse cardiac events.

CONCLUSIONS

RMA for functional MR resulted in varying degrees of functional MS. However, our data were more consistent with the residual PH being caused by LV dysfunction and pulmonary vascular disease than by the functional MS. The residual PH, not functional MS, was the major predictor of post-RMA adverse cardiac events.

Pseudoprolapse of the anterior leaflet in chronic ischemic mitral regurgitation: identification and repair

OBJECTIVE

Recurrence rates as high as 30% have been observed 6 months after treatment of chronic ischemic mitral regurgitation (CIMR) with isolated annuloplasty. We postulated that the high early recurrence rates resulted from the presence of untreated pseudoprolapse of the anterior leaflet.

METHODS

We conducted a retrospective study of all mitral valve repairs for CIMR performed by a single surgeon (S.W.H.) from 1995 to 2011. After annuloplasty, Gore-Tex neochordae were added if the high-pressure saline test indicated the presence of pseudoprolapse of the anterior leaflet.

RESULTS

A total of 47 patients underwent mitral valve repair for CIMR. Of the 47 patients, 24 (51%) were found to have pseudoprolapse requiring the addition of neochordae. For all patients, the average age was 65.1 years, and 65.2% were men. Fourteen (30%) had had a preoperative intra-aortic balloon pump placed by cardiologists. Fourteen (30%) had severe pulmonary hypertension. Concomitant coronary artery bypass grafting was performed in 40 patients, with an average of 2.2 grafts; 7 had previously undergone coronary artery bypass grafting. Mitral Carpentier-Edwards physio annuloplasty rings were used in all patients with a mean size of 29 mm. One patient died postoperatively. Follow-up data were available for all 47 patients at an average of 4.9 years. The 5-year survival rate was 82.5%. The mean pre- and postoperative New York Heart Association class, ejection fraction, and mitral regurgitation grade were 3 and 1.52 (P < .0001), 34% and 41% (P = .0006), and 3.51 and 1.08 (P < .0001), respectively. Two patients developed greater than moderate mitral regurgitation.

CONCLUSIONS

Effective repair of CIMR should include surgical techniques to correct pseudoprolapse of the anterior leaflet, when present. The selective addition of Gore-Tex neochordae to an undersized annuloplasty nearly eliminates recurrent regurgitation after mitral valve repair for CIMR.

Effects of different annuloplasty ring types on mitral leaflet tenting area during acute myocardial ischemia

OBJECTIVE

The study objective was to quantify the effects of different annuloplasty rings on mitral leaflet septal-lateral tenting areas during acute myocardial ischemia.

METHODS

Radiopaque markers were implanted along the central septal-lateral meridian of the mitral valve in 30 sheep: 1 each to the septal and lateral aspects of the mitral annulus and 4 and 2 along the anterior and posterior mitral leaflets, respectively. Ten true-sized Carpentier-Edwards Physio, Edwards IMR ETLogix, and GeoForm annuloplasty rings (Edwards Lifesciences, Irvine, Calif) were inserted in a releasable fashion. Marker coordinates were obtained using biplane videofluoroscopy with ring inserted at baseline (RING_BL) and after 90 seconds of left circumflex artery occlusion (RING_ISCH). After ring release, another dataset was acquired before (No_Ring_BL) and after left circumflex artery occlusion (No_Ring_ISCH). Anterior and posterior mitral leaflet tenting areas were computed at mid-systole from sums of marker triangles with the midpoint between the annular markers being the vertex for all triangles.

RESULTS

Compared with No_Ring_BL, mitral regurgitation grades and all tenting areas significantly increased with No_Ring_ISCH. Compared with No_Ring_ISCH, (1) all rings significantly prevented mitral regurgitation and reduced all tenting areas; (2) Edwards IMR ETLogix and GeoForm rings reduced posterior mitral leaflet area, but not anterior mitral leaflet tenting area, to a significantly greater extent than the Carpentier-Edwards Physio ring; and (3) Edwards IMR ETLogix and GeoForm rings affected tenting areas similarly.

CONCLUSIONS

In response to acute left ventricular ischemia, disease-specific functional/ischemic mitral regurgitation rings (Edwards IMR ETLogix, GeoForm) more effectively reduced posterior mitral leaflet area, but not anterior mitral leaflet tenting area, compared with true-sized physiologic rings (Carpentier-Edwards Physio). Despite its radical 3-dimensional shape and greater amount of mitral annular septal-lateral downsizing, the GeoForm ring did not reduce tenting areas more than the Edwards IMR ETLogix ring, suggesting that further reduction in tenting areas in patients with FMR/IMR may not be effectively achieved on an annular level.

Influence of patient age on procedural selection in mitral valve surgery

BACKGROUND

Previous studies suggest that mitral valve replacement is comparable to repair in the elderly, and a national trend exists toward tissue valves. However, few direct comparison data are available, and this study evaluated the effects of patient age on risk-adjusted survival after mitral procedures.

METHODS

From 1986 to 2006, 2,064 patients underwent isolated primary mitral operations (±CABG). Maximal follow-up was 20 years with a median of 5 years. Valve disease etiology was the following: degenerative, 864; ischemic, 450; rheumatic, 416; endocarditis, 98; and "other," 236. Overall, 58% had repair and 39% had concomitant coronary artery bypass grafting. Survival differences were evaluated with a Cox proportional hazards model that included baseline characteristics, valve disease etiology, and choice of repair versus replacement with tissue or mechanical valves.

RESULTS

Baseline risk profiles generally were better for mechanical valves, and age was the most significant multivariable predictor of late mortality [hazard ratio = 1.4 per 10-year increment, Wald χ(2) = 32.7, p < 0.0001]. As compared with repair, risk-adjusted survival was inferior with either tissue valves [1.8, 27.6, <0.0001] or mechanical valves [1.3, 8.1, 0.0044], and no treatment interaction was observed with age (p = 0.18). At no patient age did tissue valves achieve equivalent survival to either repair or mechanical valves.

CONCLUSIONS

Mitral repair is associated with better survival than valve replacement across the spectrum of patient age. If replacement is required, mechanical valves achieve better outcomes, even in the elderly. These data suggest that tissue valves should be reserved only for patients with absolute contraindications to anticoagulation who are not amenable to repair.

Polymer injection therapy to reverse remodel the papillary muscles: efficacy in reducing mitral regurgitation in a chronic ischemic model

BACKGROUND

Ischemic mitral regurgitation (MR) results from displacement of the papillary muscles caused by ischemic ventricular distortion. Progressive left ventricular (LV) remodeling has challenged therapy. Our hypothesis is that repositioning of the papillary muscles can be achieved by injection of polyvinyl-alcohol (PVA) hydrogel polymer into the myocardium in chronic MR despite advanced LV remodeling.

METHODS AND RESULTS

Ten sheep underwent ligation of the circumflex branches to produce chronic ischemic MR over 8 weeks. PVA was injected into the myocardium underlying the infarcted papillary muscle. Two-dimensional and 3D echocardiograms and hemodynamic data were obtained before infarct (baseline), before PVA (chronic MR), and after PVA. PVA injection significantly decreased MR from moderate to severe to trace (MR vena contracta, 5.8±1.2 to1.8±1.3 mm; chronic MR to post-PVA stage; P=0.0003). This was associated with a decrease in infarcted papillary muscle-to-mitral annulus tethering distance (30.3±5.7 to 25.9±4.6 mm, P=0.02), tenting volume (1.8±0.7 to 1.4±0.5 mL, P=0.01), and leaflet closure area (8.8±1.3 cm(2)to 7.6±1.3 cm(2), P=0.004) from chronic MR to post-PVA stages. PVA was not associated with significant decreases in LV ejection fraction (41±3% versus 40±3%, P=NS), end-systolic elastance, τ (82±36 ms to 72±26, P=NS), or LV stiffness coefficient (0.05±0.04 to 0.03±0.01).

CONCLUSIONS

PVA hydrogel injections improve coaptation and reduce remodeling in chronic MR without impairing LV systolic and diastolic function. This new approach offers a potential alternative for relieving tethering and ischemic MR by correcting papillary muscle position.