Outcomes of Mitral Valve Repair for Degenerative Mitral Disease: A Single-Centre 10-Year Experience.

OBJECTIVE: To evaluate the long-term outcomes of degenerative mitral valve (MV) repair. METHODS: This study analysed 1,069 patients who underwent MV repair due to degenerative MV disease at Beijing Anzhen Hospital from January 2010 to December 2019. All patients were clinically followed until December 2019, with an average follow-up period of 4.7 years. Perioperative complications, 30-day mortality, long-term outcomes, and risk factors of all-cause death and recurrent mitral regurgitation (MR) were summarised. RESULTS: Ten patients died in the hospital and 33 died during the follow-up period. Recurrent MR occurred in 113 patients. Fourteen patients underwent re-operation. Rates of long-term survival, absence of recurrent MR, and no re-operation were 94.0% (91.6%-96.6%), 81.2% (77.3%-85.3%), and 98.2% (97.2%-99.3%), respectively. The risk factors for long-term all-cause death included age and an ejection fraction (EF) <60%. The risk factors for recurrent MR included age, female sex, E-wave velocity, anterior prolapse, residual 1+MR postoperatively, and lower body mass index. CONCLUSIONS: Mitral valve repair is an effective treatment for degenerative MV disease that, in an experienced heart centre, can be performed with low mortality, recurrence, and re-operation rates. Advanced age and an EF <60% were risk factors for long-term all-cause death. Age, female sex, residual 1+MR postoperatively, lower body mass index, higher peak E-wave velocity, and anterior prolapse were risk factors for recurrent MR.

Comparison of early and late postoperative outcomes between chordal reconstruction and quadrangular resection in patients with posterior mitral valve prolapse: a single-center retrospective study.

BACKGROUND: To compare the early and late postoperative outcomes of chordal reconstruction (CR) and quadrangular resection (QR) in patients with posterior mitral valve prolapse (PMPL). METHODS: Between January 2008 and December 2018, 305 patients with PMPL who underwent mitral valve plasty (MVP) were included in this retrospective analysis. The CR and QR procedures were performed in 169 patients (CR group) and 136 patients (QR group), respectively. Early and late postoperative outcomes were compared between the groups. RESULTS: Follow-up was complete in 96.4% (294/305) of patients, with a mean follow-up of 81.2 ± 30.4 months. No 30-day mortality was observed in any of the patients. The success rate of the mitral valve repair was similar in both groups (99.4% vs. 98.5%, P = 0.850). The incidence of early postoperative hemolysis was lower in the CR group than in the QR group (0.00% vs. 3.0%, P = 0.024). Postoperative left ventricular end-diastolic diameter (LVEDD) decreased more significantly in the CR group than in the QR group at 3 months (8.15 [1.30,12.65] vs. 3.25 [- 0.05, 8.75] mm, P < 0.001). During follow-up, the overall survival rates were 95.1% and 94.6% in the CR and QR groups, respectively. The incidence of reoperation for moderate or severe mitral regurgitation (MR) was similar in both groups (4.3% vs.5.4%, P = 0.653), but the time interval between the initial operation and reoperation was shorter in the QR group than in the CR group (84.3 ± 36.1 vs. 120.9 ± 27.6 months, P = 0.026). The LVEDD enlargement was more significant in the QR group than in the CR group (4.5 [3.6, 4.5] vs. 2.4 [1.3, 2.8] mm, P < 0.001). CONCLUSION: CR and QR are effective techniques for patients with PMPL. Both techniques resulted in a low incidence of recurrent MR. However, CR can reduce early postoperative hemolysis and LVEDD more significantly. During the long-term follow-up, reoperations due to recurrent MR were performed at a longer interval after the initial operation. LVEDD expansion was better avoided in the CR group.

Predictors of left ventricular reverse remodeling after percutaneous therapy for mitral regurgitation with the MitraClip system.

OBJECTIVES: To investigate the predictors and clinical impact of left ventricular reverse remodeling (LVRR) after MitraClip (MC) therapy for degenerative (DMR) and functional mitral regurgitation (FMR). BACKGROUND: MC therapy induces LVRR in patients with mitral regurgitation (MR) at high-risk for surgery. However, specific data on predictors of LVRR therapy are limited. METHODS: This study included 164 patients treated by MC implantation with complete clinical and echocardiographic evaluation at baseline, 6 months, and 12 months. LVRR was defined as a decrease of ≥10% of the left ventricular end-diastolic diameter after 12 months and was found in 49% of the patients. RESULTS: LVRR was associated with significantly reduced event rate 2 years after MC procedure. In the total cohort, multivariate regression analysis determined severe recurrent/residual MR after 12 months (p = .010, odds ratio [OR] = 0.26), male gender (p = .050, OR = 0.49) and left ventricular ejection fraction (LVEF) <20% (p = .046, OR = 0.24) as predictors of absence of LVRR. In the subgroup analysis according to etiology of MR, multivariate regression analysis revealed severe recurrent/residual MR after 12 months (p = .04, OR = 0.184) to inversely predict LVRR only in the DMR subgroup. In FMR, residual severe tricuspid regurgitation (TR) inversely predicts LVRR (p = .032, OR = 0.361). CONCLUSIONS: LVRR occurs in half of the patients after MC and is associated with reduced MACCE rates at follow-up. Combined information on residual/recurrent MR, baseline LVEF and gender predict LVRR after MC procedure. While residual/recurrent MR is the independent predictor for the absence of LVRR in DMR, in FMR only severe residual TR independently predict LVRR.

Predictors of ischemic mitral regurgitation improvement after surgical revascularization plus mitral valve repair for moderate ischemic mitral regurgitation.

BACKGROUND AND AIM: Ischemic mitral regurgitation (IMR) recurrence after combined coronary artery bypass grafting (CABG) and mitral valve repair does occur, with a prevalence of 20% to 30% at the 2- to 4-year follow-up. This single-center study aims to identify the predictors of IMR improvement after surgical revascularization plus mitral valve repair for moderate IMR. METHODS: A total of 201 eligible patients were entered into an improved group (n = 141) or a control group (n = 60) according to whether moderate or more mitral regurgitation occurred at the 2-year postoperative time point. Clinical outcomes between groups were compared. RESULTS: The left ventricular endo-diastolic diameter (LVEDD), type of ring (rigid complete ring), and the use of repair techniques (restrictive annuloplasty associated with subvalvular and/or leaflet repair) were three predictors of IMR improvement after surgery (odds ratio [OR] = 0.921, 95% confidence interval [CI], 0.865-0.976, P = .025; OR = 7.753, 95% CI, 3.168-17.742, P < .001; and OR = 0.168, 95% CI, 0.076-0.423, P = .004, respectively). The cutoff value of the LVEDD was 65 mm with a sensitivity of 80.0% and a specificity of 65.2%. Patients in the improved group compared with those in the control group demonstrated better cumulative survival during a median follow-up of 41.0 months (χ2 = 4.559, logrank P = .033) and a reduced ratio of the New York Heart Association class III-IV at the latest follow-up (5.7% vs 38.4%, P < .001). CONCLUSIONS: An LVEDD of less than 65 mm, the use of a rigid complete ring, and combined restrictive annuloplasty and subvalvular and/or leaflet repair are associated with IMR improvement after CABG plus mitral valve repair for the treatment of moderate IMR; IMR improvement 2 years after surgery is associated with improved midterm outcomes.

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.

Repeat MitraClip for early recurrent mitral regurgitation.

Treatment for recurrent mitral regurgitation (MR) after MitraClip therapy remains a challenging issue. This study reports the efficacy of repeat MitraClip therapy for recurrent MR during the early phase after the index MitraClip procedure. We present a case series of four consecutive patients who underwent repeat MitraClip procedures for severe recurrent MR during the early phase. Partial clip detachment (PCD) was the suspected cause of recurrent MR in these cases. All patients received additional clip(s). PCD could be stabilized and MR grade improved in all cases compared with that before the second procedure. Repeat MitraClip procedures for recurrent MR due to PCD are feasible during the early phase. However, patients having PCD with paracommissural MR may not be good candidates for repeat MitraClip.

Comparison of Outcomes of Mitral Valve Repair for Leaflet Prolapse with Advanced versus Mild/Moderate Myxomatous Degeneration.

There is limited information on long-term outcomes of mitral valve repair for mitral regurgitation (MR) caused by different degrees of myxomatous degeneration. The aim of this study was to compare the surgical results of patients with advanced and mild/moderate myxomatous mitral valve degeneration (MVD). We identified 130 patients (25 advanced and 105 mild/moderate MVD patients) who underwent mitral valve repair for MR and were pathologically diagnosed as myxomatous degeneration. Follow-up was 100% complete (mean length, 5.1 ± 1.8 years). Survival differed significantly between the advanced and mild/moderate MVD groups (76.0 ± 9.7% versus 95.0 ± 5.4% at 8 years, P < 0.001). The univariate predictors of mortality were advanced myxomatous degeneration, recurrent MR, and early series (surgeries before 2011). The mild/moderate MVD group had higher freedom from a moderate or severe MR rate compared with the advanced MVD group (77.4 ± 4.5% versus 50.5 ± 10.2% at 7 years, P = 0.003). Multivariable Cox analysis revealed advanced myxomatous degeneration and residual MR as independent predictors of recurrent moderate or severe MR. A total of 25 patients (19.2%) had persistent atrial fibrillation (AF) after repair. In multivariate analysis, advanced myxomatous degeneration was found to be an independent predictor of postoperative persistent AF.In conclusion, the long-term outcomes of mitral valve repair in patients with advanced MVD are poorer than in those with mild/moderate MVD. Advanced myxomatous degeneration is an independent predictor of recurrent moderate or severe MR and postoperative persistent AF in MVD patients performing repair, which deserves more attention before and after surgery.

Mitral regurgitation in atrial fibrillation: Is a simple repair enough to tackle a complex problem?

BACKGROUND: Clinical and echocardiographic results of valve repair for mitral regurgitation in the setting of atrial fibrillation are poorly studied. METHODS: Between January 2008 and December 2020, 89 patients underwent valve repair for mitral regurgitation in the setting of atrial fibrillation. Clinical and echocardiographic follow-up data were collected and studied. The primary composite endpoint consisted of all-cause mortality or hospitalization for heart failure. RESULTS: Valve repair with true-sized annuloplasty was performed in 83 (93 %) and restrictive annuloplasty in 6 (7 %) patients. Early mortality occurred in 3 (3 %) and residual mitral regurgitation in 1 (1 %) patient. During a median follow-up of 5.4 years (interquartile range 3.4-9.5), 25 patients died, 6 due to end-stage heart failure. Ten patients were hospitalized for heart failure. The estimated event-free survival rate at 10 years was 48.2 % (95 % CI 33.5 %-62.9 %). Recurrent mitral regurgitation was observed in 14 patients and most often caused by leaflet tethering. When analyzed as a time-dependent variable, recurrent regurgitation was related to the occurrence of the primary endpoint (hazard ratio 3.192, 95 % CI 1.219-8.359, p = 0.018). On exploratory sub-analyses, no recurrent regurgitation was observed after restrictive annuloplasty or in patients with paroxysmal atrial fibrillation. Moreover, recurrent regurgitation was observed more often when signs of left ventricular impairment were present preoperatively. CONCLUSIONS: Despite good initial results, recurrent regurgitation was a frequent observation after valve repair for mitral regurgitation in atrial fibrillation and had an effect on heart failure related morbidity and mortality. Refinements in the timing of surgery and surgical technique might help improve outcomes.

Impact of Recurrent Mitral Regurgitation on Left Ventricular Mass Regression and Cardiac Events following Mitral Valve Repair.

BACKGROUND: Mitral valve regurgitation results in volume overload, followed by left ventricular remodeling. Variation of reverse remodeling following mitral repair influences the clinical outcomes. We aimed to evaluate the association between recurrent mitral regurgitation and mass regression following mitral valve repair and the impact on major adverse cardiovascular events. METHODS: A retrospective cohort study was conducted on 164 consecutive patients with severe mitral regurgitation who underwent elective mitral valve repair. Subgroups were classified based on the presence of recurrent mitral regurgitation exceeding moderate severity. The hemodynamic parameters were evaluated according to geometry, mass, and function with Doppler echocardiography before and after surgery. Cox regression analysis was performed to evaluate the association between hemodynamics and mass regression and clinical outcomes. RESULTS: The results for MR indicated 110 cases with non-recurrent MR and 54 with recurrent MR, along with 31 major adverse cardiovascular events. The tracked echocardiographic results revealed less reduction in dimension and volume, along with less mass regression in the recurrent MR subgroup. Significant differences were revealed in the relative change of the LV end-diastolic volume index and relative mass regression between subgroups. The relative change in the LVEDVI was proportionally correlated with relative mass regression. Cox regression analysis identified correlations with major adverse cardiovascular events, including suture annuloplasty, recurrent mitral regurgitation, tracked LV mass, relative LV mass regression, and systolic dysfunction. CONCLUSION: LV mass regression and relative change of the LV end-diastolic volume could be risk predictors of recurrent mitral regurgitation. The extent of LV mass regression is correlated with adverse cardiac events.

Repeat Mitral Transcatheter Edge-to-Edge Repair for Recurrent Significant Mitral Regurgitation.

Background There are limited data on repeat mitral transcatheter edge-to-edge repair for recurrent significant mitral regurgitation (MR). Methods and Results We conducted a single-center, retrospective analysis of consecutive patients referred to a second mitral transcatheter edge-to-edge repair after a technically successful first procedure. Clinical, laboratory, and echocardiographic measures were assessed up to 1 year after the intervention. The composite of all-cause death or heart failure (HF) hospitalizations constituted the primary outcome. A total of 52 patients (median age, 81 [interquartile range, 76-87] years, 29 [55.8%] men, 26 [50.0%] with functional MR) met the inclusion criteria. MR recurrences were mostly related to progression of the underlying cardiac pathology. All procedures were technically successful. At 1 year, most patients with available records (n=24; 96.0%) experienced improvement in MR severity or New York Heart Association functional class that was statistically significant but numerically modest. Fourteen (26.9%) patients died or were hospitalized due to HF. These were higher-risk cases with predominantly functional MR who mostly underwent an urgent procedure and exhibited more severe HF indices before the intervention, as well as an attenuated 1-month clinical and echocardiographic response. Overall, 1-year course was comparable to that experienced by patients who underwent only a first transcatheter edge-to-edge repair at our institution (n=902). Tricuspid regurgitation of greater than moderate grade was the only baseline parameter to independently predict the primary outcome. Conclusions Repeat mitral transcatheter edge-to-edge repair is feasible, safe, and clinically effective, especially in non-functional MR patients without concomitant significant tricuspid regurgitation.

Prognosis for Mitral Valve Repair Surgery in Functional Mitral Regurgitation.

PURPOSE: Our aim was to evaluate the development of new significant mitral regurgitation and long-term survival after mitral repair surgery in functional mitral regurgitation. METHODS: A retrospective observational analysis of the recurrence of functional mitral regurgitation (ischemic and nonischemic) and global mortality during follow-up of 176 patients who underwent mitral repair surgery between 1999 and 2018 in our center was conducted. RESULTS: The etiology of functional mitral regurgitation was ischemic in 55.7% of cases. After surgery, mitral regurgitation was 0-I in 92.3% of cases. We conducted a long-term clinical follow-up of a mean 42.2 months and an echocardiographic follow-up of a mean 41.8 months. We observed mitral regurgitation of at least grade II in 52 patients (36.9%). Survival at 1, 3, and 5 years was 78.8%, 66.7%, and 52.3%, respectively. Predictive factors for global mortality were age (hazard ratio = 1.038, p = 0.01) and a depressed preoperative ejection fraction. After a competing risk analysis, we found the only predictive factor for the recurrence of mitral regurgitation in our series to be age (sub-hazard ratio = 1.03, 95% confidence interval = 1.01-1.06, p = 0.016). CONCLUSION: Repair surgery for functional mitral regurgitation shows age as the only independent predictor of recurrence. Age and depressed ejection fraction were predictors of mortality.

MitraClip After Failed Surgical Mitral Valve Repair-An International Multicenter Study.

Background Recurrence of mitral regurgitation (MR) after surgical mitral valve repair (SMVR) varies and may require reoperation. Redo mitral valve surgery can be technically challenging and is associated with increased risk of mortality and morbidity. We aimed to assess the feasibility and safety of MitraClip as a treatment strategy after failed SMVR and identify procedure modifications to overcome technical challenges. Methods and Results This international multicenter observational retrospective study collected information for all patients from 16 high-volume hospitals who were treated with MitraClip after failed SMVR from October 29, 2009, until August 1, 2017. Data were anonymously collected. Technical and device success were recorded per modified Mitral Valve Academic Research Consortium criteria. Overall, 104 consecutive patients were included. Median Society of Thoracic Surgeons score was 4.5% and median age was 73 years. At baseline, the majority of patients (82%) were in New York Heart Association class ≥III and MR was moderate or higher in 86% of patients. The cause of MR pre-SMVR was degenerative in 50%, functional in 35%, mixed in 8%, and missing/unknown in 8% of patients. The median time between SMVR and MitraClip was 5.3 (1.9-9.7) years. Technical and device success were 90% and 89%, respectively. Additional/modified imaging was applied in 21% of cases. An MR reduction of ≥1 grade was achieved in 94% of patients and residual MR was moderate or less in 90% of patients. In-hospital all-cause mortality was 2%, and 86% of patients were in New York Heart Association class ≤II. Conclusions MitraClip is a safe and less invasive treatment option for patients with recurrent MR after failed SMVR. Additional/modified imaging may help overcome technical challenges during leaflet grasping.

Persistent reduction of mitral regurgitation by implantation of a transannular mitral bridge: durability and effectiveness of the repair at 2 years-results of a prospective trial†.

OBJECTIVES: Ring annuloplasty reduces the septal-lateral diameter (SLD) indirectly by circumferential annular cinching and frequently results in the recurrence of mitral regurgitation (MR) in patients with functional MR (FMR). Our goal was to report the results from the trial and the 2-year post-trial surveillance data. We evaluated whether direct reduction of the SLD with a transannular mitral bridge could achieve significant and durable MR reduction in patients with FMR. METHODS: In a prospective trial, 34 consecutive patients with FMR had a mitral bridge implanted surgically. Primary end points were MR ≤1+ at 1, 3 and 6 months postimplant and freedom from subsequent surgical mitral valve repair or replacement. RESULTS: Thirty-two of 34 (94.1%) patients met the primary end points with MR ≤1+ at 6 months. At 2 years, there were no strokes or device-related adverse events. At 2 years, MR was reduced from 3.32 ± 0.47 to 0.50 ± 0.83 (P ≤ 0.001) with ≤1+ MR in 33/34 patients, including 4 reinterventions for periprosthetic recurrent MR ≥3 without mitral bridge explants or conventional mitral repair or replacement. At 2 years, the mean mitral gradient was 2.15 ± 0.82 mmHg; the mitral annular SLD decreased from 40.4 ± 2.91 mm to 28.9 ± 1.55 mm (P ≤ 0.001). The left ventricular ejection fraction increased (57.9 ± 10.4-62.4 ± 9.7%; P ≤ 0.001). The New York Heart Association functional class improved (2.19 ± 0.76-1.41 ± 0.61; P ≤ 0.001). CONCLUSIONS: The single-centre trial data indicate that direct reduction in the SLD with a mitral bridge is feasible, safe and efficacious in patients with FMR. Validation in a larger population of patients and comparison to conventional annuloplasty ring are necessary. CLINICAL TRIAL REGISTRATION NUMBER: NCT03511716.

Outcomes after mitral valve repair: A single-center 16-year experience.

OBJECTIVE: To evaluate outcomes after mitral valve repair. METHODS: Between May 1999 and June 2015, 446 patients underwent mitral valve repair. Isolated mitral valve annuloplasty was excluded. A total of 398 (89%) had degenerative valve disease. Mean follow-up was 5.5 ± 3.8 years. Postoperative echocardiograms were obtained in 334 patients (75%) at a mean of 24.3 ± 13.7 months. RESULTS: Survival was 97%, 96%, 95%, and 94% at 1, 3, 5, and 10 years. Risk factor analysis showed age >60 years and nondegenerative etiology predict death (hazard ratio, 2.91; 95% confidence interval, 1.06-8.02, P = .038; and hazard ratio, 1.87; 95% confidence interval, 1.16-3.02, P = .010, respectively). Considering competing risks due to mortality, the cumulative incidence of reoperation was 2.8%, 4.2%, 5.1%, and 9.6% at 1, 3, 5, and 10 years. Competing risk proportional hazard survival regression identified nondegenerative etiology and previous cardiac surgery as predictors of reoperation, and posterior repair was protective (all P < .05). Cumulative incidence of progression of mitral regurgitation (2 or more grades) with mortality as a competing risk was 4.7%, 10.5%, 21.0%, and 35.8% at 1, 3, 5, and 10 years. Patients with previous sternotomy, repair or coronary artery bypass grafting, and concurrent tricuspid valve procedure or isolated anterior leaflet repair were more likely to develop progression of mitral regurgitation (all P < .05), and posterior leaflet repair was protective (P = .038). On multivariate analysis diabetes, previous coronary artery bypass grafting and concurrent tricuspid valve intervention predicted MR progression. CONCLUSIONS: Mitral valve repair has excellent outcomes. Our results demonstrate failures appear to occur less in those who undergo posterior leaflet repair.

Re-repair of the mitral valve as a primary strategy for early and late failures of mitral valve repair.

OBJECTIVES: With the expanding uptake of mitral valve repair as the primary therapy for mitral valve regurgitation, an increasing cohort of patients are presenting with failures following valve repair. These patients have traditionally been treated by mitral valve replacement. We have adopted an aggressive strategy of valve re-repair for failures of mitral valve repair and present our mid-term results. METHODS: Fifty-three consecutive adults underwent reoperation by a single surgical team for failed non-rheumatic mitral valve repair. Primary valve repair had been done for degenerative (n=38), congenital (n=6), infective (n=3), functional (n=1) or unknown (n=5) mitral disease. The reoperative mitral procedure occurred at a median interval of 3 (interquartile range 0.9-6.5) years from the primary mitral valve repair. Valve re-repair was attempted if the anterior leaflet was sufficiently pliable, and lesions causing recurrence were identifiable and deemed treatable. Standard repair techniques were employed in re-repair procedures. RESULTS: Valve analysis showed that the mode of failure was progression of original disease in 19 (36%), technical failure in 20 (38%) and new disease in 14 (26%) patients. Valve re-repair was successfully accomplished in 45 (85%) patients. Re-repair was most frequent when the prior aetiology was degenerative (34 of 38, 90%) as opposed to non-degenerative (11 of 15, 73%). There were no hospital deaths. Four-year patient survival was 97%. Freedoms from moderate mitral regurgitation were 100, 95, 88 and 80% at discharge and at 1, 3, and 4 years, respectively. There were no reoperations in the follow-up period. CONCLUSIONS: Re-repair of the mitral valve is feasible in most of the cases of failed mitral valve repair of non-rheumatic aetiology and has acceptable mid-term outcomes. The relatively high prevalence of technical failures as the mechanism of failure of the primary mitral valve repair suggests the need for ongoing surgical education and continuing development and refinement of repair techniques.