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Midterm results of transventricular mitral valve repair: Single-center experience

Published:January 19, 2021DOI:https://doi.org/10.1016/j.jtcvs.2020.12.142

      Abstract

      Objective

      The study objective was to evaluate the midterm outcomes of transventricular mitral valve repair and its association with the initial anatomy of the mitral valve.

      Methods

      This nonrandomized observational study included 88 patients (mean age, 60 years; 69% were men) who underwent transventricular mitral valve repair for severe degenerative mitral regurgitation between 2011 and 2017. Mitral valve function was assessed by echocardiography at 1 and 6 months and annually after the procedure. According to the location of mitral valve pathology, all patients were stratified into 4 anatomic types (A, B, C, and D). Results were assessed using Kaplan–Meier method, mixed-effects continuation ratio model, and multivariable Cox regression.

      Results

      Median follow-up of 42 months (interquartile range, 27-55) was complete for 83 patients (94.3%). There were 3 late deaths: 2 cardiac and 1 noncardiac. Recurrent mitral regurgitation greater than 2+ was observed in 29 patients (33%), and 18 patients (20.5%) underwent repeat surgery. Device success was 82% in type A at 6 months and thereafter; 87%, 85%, and 75% at 6, 12, and 36 months in type B, respectively; and 53% at 1 month and 20% at 24 months in type C. Probability of postoperative mitral regurgitation progression was higher in patients with greater preoperative left ventricular end-diastolic diameter, type B pathology, and type C pathology (P < .05). Risk factors of mitral regurgitation recurrence included increased left ventricle size (hazard ratio, 1.11; 95% confidence interval, 1.04-1.20; P = .001) and type C pathology (hazard ratio, 5.99; 95% confidence interval, 1.87-19.21; P = .003).

      Conclusions

      Initial acceptable mitral regurgitation reduction after transventricular mitral valve repair of isolated P2 prolapse was possible but found durable in only 82% at 3 years. Higher risk of mitral regurgitation recurrence occurred with complex degenerative pathology.

      Graphical abstract

      Key Words

      Abbreviations and Acronyms:

      ePTFE (expanded polytetrafluoroethylene), IQR (interquartile range), LVEDD (left ventricular end-diastolic diameter), MR (mitral regurgitation), MV (mitral valve)
      Figure thumbnail fx2
      Increased preoperative left ventricle size predicts failure of transventricular MV repair at midterm.
      Three-year durability of transventricular MV repair was only 82% in patients with isolated P2 prolapse. Dilated left ventricle and complex degenerative MV disease increased the risk of recurrent MR.
      Patients with isolated P2 prolapse and normal left ventricle end-diastolic diameter had the lowest probability of MR progression after transventricular MV repair. Initial technical success was possible, but the 3-year durability was poor.
      See Commentaries on pages 1829 and 1831.
      Mitral regurgitation (MR) is the most frequent heart valve disease, affecting 2.0 to 2.5 million people in the United States alone,
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      In recent years, conventional mitral surgery techniques have been complemented with new minimally invasive beating-heart transventricular
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      repair procedures, which remain under the scope of scientific investigation worldwide. Transventricular off-pump implantation of expanded polytetrafluoroethylene (ePTFE) sutures as artificial neochordae, using the NeoChord DS1000 Artificial Chordae Delivery System (NeoChord, Inc, St Louis Park, Minn), has been introduced to correct MR under direct 2- and 3-dimensional transesophageal echocardiography guidance. Although the NeoChord procedure has been proven to be safe and effective in selected patients with mitral leaflet prolapse (flail or chordal rupture),
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      data from midterm and long-term follow-up are scarce. This article reports midterm outcomes of transventricular MV repair at a single center.

      Patients and Methods

      Between 2011 and 2017, 94 patients with severe degenerative MR underwent transventricular off-pump MV repair using the NeoChord DS1000 System at Vilnius University Hospital Santaros Klinikos. All patients met indications for surgical treatment according to American College of Cardiology/American Heart Association and European Society of Cardiology/European Association for Cardio-Thoracic Surgery guidelines.
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      • Fleisher L.A.
      • et al.
      2017 AHA/ACC focused update of the 2014 AHA/ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association task force on clinical practice guidelines.
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      • et al.
      2017 ESC/EACTS guidelines for the management of valvular heart disease.
      Patients with echocardiographic evidence of isolated or bileaflet MV prolapse or flail, with or without chordal rupture, were selected for transventricular MV repair. Patients with restrictive mechanism of regurgitation (due to rheumatic disease or cardiomyopathy), ischemic MR, infective endocarditis, and central regurgitation jet were not considered for transventricular approach.
      Three of the 94 patients had an annuloplasty ring in situ after previous conventional MV repair. Two patients required intraoperative conversion to a conventional MV repair due to device-related complications (perforated leaflet and bleeding from the device-entry site). An overall technical success of the procedure was 98%. One patient with an optimal postprocedural MR reduction died of bleeding-related cardiac tamponade on postoperative day 2. Those 6 patients were excluded from further longitudinal analysis (Figure 1).
      Figure thumbnail gr1
      Figure 1Design and midterm actuarial outcomes of a nonrandomized observational study of transventricular MV repair. Between 2011 and 2017, 94 patients underwent transventricular MV repair for severe degenerative MR at a single center. Follow-up data available for 88 patients were included in the longitudinal analysis of repair durability. Patients with normal left ventricle size and isolated P2 prolapse had lower probability of MR progression, and patients with complex MV disease had high rates of early MR recurrence and reoperation. Risk factors and mechanism of MR recurrence are discussed in the manuscript. MV, Mitral valve; MR >2+, more than moderate mitral regurgitation; MR, mitral regurgitation.
      The study cohort included 88 patients. Permission from the local bioethics committee was obtained for this retrospective nonrandomized observational study, and all patients provided an informed consent form before surgery.
      According to the location of MV pathology, all patients were stratified into 4 anatomic types preoperatively (Figure 2): type A—isolated P2 prolapse (22 patients, 25%), type B—P2 and adjacent segments disease (47 patients, 53.4%), type C—isolated or bileaflet prolapse with the paracommissural segments involved (15 patients, 17%), and type D—isolated A2 prolapse (4 patients, 4.5%). All patients underwent transventricular implantation of ePTFE artificial neochordae. The surgical technique has been described by Colli and colleagues.
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      • Besola L.
      • et al.
      Transapical off-pump mitral valve repair with Neochord Implantation (TOP-MINI): step-by-step guide.
      All procedures were performed by the same surgical team of 2 principal operators and 1 to 2 assistants. To determine an impact of the operator learning curve, we examined the outcomes stratified into 3 groups by operation eras. Baseline patient, echocardiographic, and perioperative characteristics were compared among 29, 29, and 30 patients in each group, respectively. Anesthetic management and monitoring under beating-heart conditions were performed as reported by Samalavičius and colleagues.
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      Anesthetic management and procedural outcomes of patients undergoing off-pump transapical implantation of artificial chordae to correct mitral regurgitation: case series of 76 patients.
      Figure thumbnail gr2
      Figure 2Anatomic classification of the MV by lesion location as seen in 3-dimensional transesophageal echocardiography in a zoomed surgical view of the MV from atrial perspective. Type A represents isolated prolapse of the P2 segment; type B represents lesion of the P2 and adjacent segments; type C represents isolated or bileaflet prolapse with involvement of the paracommissural segments; type D represents isolated A2 prolapse.
      Postoperative clinical data and echocardiography assessment of effectiveness of the NeoChord repair were obtained at 1 and 6 months and annually after the procedure until April 1, 2018. Follow-up was considered incomplete if a patient missed last 2 or more visits. The completeness of the follow-up was 94.3%.
      Technical and device success were determined according to the Mitral Valve Academic Research Consortium recommendations.
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      In our study, technical success meant successful deployment of the artificial neochordae at the intended position and retrieval of the delivery system without procedural mortality or need for emergency surgery. Device success characterized continued freedom from MR greater than 2+ without procedural mortality and device-related complications at 30 days and at all follow-up intervals thereafter. MR reduction was considered optimal when postprocedure MR was reduced to trace or absent; MR reduction was considered acceptable when postprocedure MR did not exceed 2+ on intraoperative transesophageal echocardiography.

      Statistical Analysis

      Statistical analysis was performed using the data collection and analysis software package SPSS 22.0 (IBM Corp, Armonk, NY). For advanced statistical analysis of the longitudinal data, the R statistical software (version 4.0.0, R Foundation for Statistical Computing) was used. The quantitative normality of continuous data was evaluated using the criteria of histograms, rectangular diagrams, and the Shapiro–Wilk test (P > .05). Quantitative data with a normal distribution are presented as a mean value ± standard deviation. The quantitative continuous data distributed outside the normal distribution are presented as the median and quartile intervals. The categorical data are expressed as a percentage. Reoperation-free survival and the device success were estimated using the Kaplan–Meier method and compared using the log-rank test. The censored data include patients who had their follow-up terminated. To determine risk factors associated with MR greater than 2+ recurrence, we constructed several multivariate Cox regression models using significant candidate variables from the univariate analysis. Likelihood-ratio test was used to reduce the nested regression models and fit the final model. Longitudinal outcomes of MR grade were modeled using a mixed-effects continuation model.
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      Candidate variables including all available baseline demographic and echocardiographic characteristics of the patients were screened using univariable analysis. The exact time of echocardiographic measurement and MR grade, preoperative left ventricular end-diastolic diameter (LVEDD), and anatomic MV lesion type (A-D) still showed a significant association with outcome in the multivariable model, and were included in the final model as fixed effects and patient as a random effect. Analysis was performed using the R package GLMMadaptive.
      • Rizopoulos D.
      GLMMadaptive: Generalized Linear Mixed Models using Adaptive Gaussian Quadrature. R package version 0.7-0.

      Results

      In the study cohort of 88 patients, mean age was 60.1 ± 12.4 years and body mass index was 26.8 ± 4.5. A total of 61 patients (69.3%) were male. The preoperative risk was estimated using Society of Thoracic Surgeons and European System for Cardiac Operative Risk Evaluation II calculators: 0.45 (interquartile range [IQR], 0.24-0.74) and 0.81 (IQR, 0.67-1.35), respectively. Five patients (5.7%) had paroxysmal or chronic atrial fibrillation. Twelve patients (13.6%) had severe pulmonary hypertension (>55 mm Hg). Preoperative renal dysfunction of glomerular filtration rate less than 85 mL/min was present in one-third of the patients (33%). Medical history of hypertension, diabetes, stroke, and chronic obstructive pulmonary disease was significant in 48 patients (54.5%), 1 patient (1.1%), 4 patients (4.5%), and 3 patients (3.4%), respectively. One patient had undergone an aortic valve replacement 9 years before the transventricular mitral repair. The preoperative patient characteristics and echocardiographic data are summarized in Table 1.
      Table 1Baseline demographics and comorbidities
      Patients, n88 (100%)
      Male gender, n (%)61 (69.3%)
      Age (y)60.1 ± 12.4
      BMI (kg/m2)26.8 ± 4.5
      Society of Thoracic Surgeons score (%)0.45 (0.24-0.74)
      euroSCORE II (%)0.81 (0.67-1.35)
      Functional classification
       NYHA II, n (%)48 (54.5%)
       NYHA III, n (%)34 (38.6%)
      Atrial fibrillation, n (%)5 (5.7%)
      Pulmonary hypertension (>55 mm Hg), n (%)12 (13.6%)
      GFR <85 mL/min, n (%)29 (33%)
      Hypertension, n (%)48 (54.5%)
      Diabetes, n (%)1 (1.1%)
      Stroke, n (%)4 (5%)
      COPD, n (%)3 (3.4%)
      Preoperative echocardiography details
       Severe MR, n (%)88 (100%)
       LVEF (%)55 (55-55)
       LVEDD (mm)59.1 ± 6.2
       Dilated LV,
      Dilated LV was defined by LVEDD greater than 53 mm in female patients or LVEDD greater than 59 mm in male patients, as per echocardiography reference values at our institution.
      n (%)
      55 (62.5%)
       LVESD (mm)35.4 ± 6.3
       LA length (mm)67 (64-74)
       LA width (mm)56 (51-62)
       LA volume (mL)139 (111-164)
       MV annular dimensions
      Anterior-posterior diameter (mm)36 (33-39)
      Dilatation (>35 mm), n (%)45 (51.1%)
      Medio-lateral diameter (mm)45.1 ± 6.3
      Perimeter (mm)137 (126-149)
       AMVL area (mm2)824 (725-963)
       PMVL area (mm2)865 (705-1080)
      BMI, Body mass index; euroSCORE, European System for Cardiac Operative Risk Evaluation; NYHA, New York Heart Association; GFR, glomerular filtration rate; COPD, chronic obstructive pulmonary disease; MR, mitral regurgitation; LVEF, left ventricular ejection fraction; LVEDD, left ventricular end-diastolic diameter; LV, left ventricle; LVESD, left ventricular end-systolic diameter; LA, left atrium; MV, mitral valve; AMVL, anterior mitral valve leaflet; PMVL, posterior mitral valve leaflet.
      Dilated LV was defined by LVEDD greater than 53 mm in female patients or LVEDD greater than 59 mm in male patients, as per echocardiography reference values at our institution.
      Demographic data were comparable among the 4 anatomic types. Forty-five patients (51%) had an MV anterior-posterior annular diameter greater than 35 mm. One patient (1%) had a severely dilated annulus greater than 50 mm. Yet, no significant association between MV annular dilatation and MR greater than 2+ recurrence or reoperation was observed (P > .05).
      At exit from the operating room, MR reduction was acceptable (MR ≤2+) in 86 patients (98%), including 5 patients with residual MR2+. Optimal MR reduction (to none or trace) was achieved in 61 patients (69.3%) (Video 1). Two type C patients (2.3%) had residual MR3+ postprocedure with no further intervention.
      At the early postoperative period, the median drainage was 200 mL, and most of the patients were classified as type 2 according to the Bleeding Academic Research Consortium classification.
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      • Rao S.V.
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      • Caixeta A.
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      • et al.
      Standardized bleeding definitions for cardiovascular clinical trials: a consensus report from the bleeding academic research consortium.
      Red blood cell transfusion was required in only 4 patients (4.5%), and reexploration was required in 2 patients (2.3%) for bleeding. Era analysis demonstrated a significant reduction in the median intraoperative blood loss since the beginning of our study: 645 mL in the first third versus 400 mL in the last third of the study (P = .004). Rate of postoperative atrial fibrillation was 13.6%. Two patients underwent permanent pacemaker implantation for preoperatively known sick sinus syndrome.
      At discharge, 81 patients (92%) exhibited MR 2+ or less, 6 patients (6.8%) had recurrent severe MR (including 5 type C patients), and 1 patient underwent reoperation. The median follow-up of 42 months (IQR, 27-55 months) was complete for 83 patients (94.3%). At the end of observation, recurrent MR greater than 2+ was revealed in 29 patients (33%) and repeat surgery was performed in 18 patients (20.5%). Median time from the transventricular repair to reoperation was 266 days. Ten patients (11.4%) underwent reoperation within 6 months.
      Survival data were available from 89 patients including the single patient who died of cardiac tamponade on postoperative day 2. Overall reoperation-free survival was 97%, 89%, 82%, and 79% at 1, 12, 24, and 36 months, respectively (Figure 3, A). At 6 months, estimated reoperation-free survival was 86%, 91%, and 87% in the type A, B, and C patients, respectively, and decreased to 86%, 84%, and 56% at 36 months, respectively (Figure 3, B). In the type D group, reoperation-free survival remained 80% at all follow-up intervals. There were less reoperations and deaths in female patients compared with the male group (log-rank test, P = .033). A total of 11 patients with recurrent severe MR refused a repeat surgery and continued with the follow-up. Because reoperation-free survival does not represent the proportion of MR recurrence, we report device success as a binary measure of transventricular repair durability.
      Figure thumbnail gr3
      Figure 3Reoperation-free survival after transventricular MV repair. Overall, 77% of patients treated in our study were free from reoperation and death at a median of 42 months after the surgery (A). The 3-year reoperation-free survival was 86%, 84%, and 80% in the type A, B, and D groups (B), respectively. Freedom from reoperation and death was only 56% in patients with the leaflet pathology and paracommissural lesions (type C). Color dotted lines indicate the 95% confidence limits (N = 89, including the single patient who died of cardiac tamponade on postoperative day 2). MR, Mitral regurgitation.
      The estimated device success was 96%, 94%, and 53% at 1 month in the type A, B, and C groups, respectively, decreased to 82% in the type A group at 6 months, and remained thereafter (Figure 4). Device success was 87%, 85%, 80%, and 75% in the type B group at 6, 12, 24, and 36 months, respectively. The 3-year freedom from recurrent severe MR was 82%, 75%, and 20% in the type A, B, and C groups, respectively. Severe MR recurred in approximately one-half of the type C group after 1 month and in 1 of the 4 patients in the type D group after 22 months. Of 29 patients with MR recurrence, 26 (89.7%) had increased LVEDD preoperatively (>53 mm for female patients and >59 mm for male patients, as per echocardiography reference values at our institution). An oversized left ventricle was found to be significantly associated with lower device success rate after the transventricular repair (chi-square, 13.609; P = .0002) (Figure 5).
      Figure thumbnail gr4
      Figure 4Estimated device success after transventricular MV repair. In our study, acceptable MR reduction was durable (device success) in 82% of patients with isolated P2 prolapse only (type A). Recurrent MR greater than 2+ (device failure) was revealed in 80% of patients with the leaflet and paracommissural pathology (type C). At the beginning of the first 2 years, patients with isolated A2 prolapse (type D) demonstrated excellent device success (n = 4). Color dotted lines indicate the 95% confidence limits. MR, Mitral regurgitation.
      Figure thumbnail gr5
      Figure 5Increased preoperative left ventricle size predicts failure of transventricular MV repair at midterm. LV, Left ventricle.
      To investigate the probability of exhibiting recurrent MR greater than 2+ over time, while accounting for the correlation in serial echocardiographic MR measurements, a mixed-effects continuation ratio model was used. Covariates significantly associated with increasing grade of recurrent MR were longer time since the repair (P < .0001), greater preoperative LVEDD (P = .004), and both anatomic type B (P = .012) and type C (P < .0001). Type A was a reference in the model. The probability of a particular recurrent MR grade at a particular time after the transventricular MV repair for patients with preoperative LVEDD at values of 50, 60, and 70 mm is plotted in Figure 6. As shown, the probability of postoperative MR progression was higher in patients with greater preoperative LVEDD. Patients with isolated P2 prolapse (type A) had the lowest probability of the repair failure. In type B pathology, MR was demonstrated to progress more rapidly than in the type A patients. Patients with the leaflet and paracommissural disease (type C) demonstrated the highest progression rate earlier in the observation period (Figure 6).
      Figure thumbnail gr6
      Figure 6Marginal probabilities from the mixed-effects continuation ratio model for MR. Profiles represent association between different anatomic types of the MV lesion (A-D); preoperative LVEDD at values of 50, 60, and 70 mm; and probability of postoperative MR progression over time. In our study, probability of postoperative MR progression was higher in patients with greater preoperative LVEDD and type B and C pathology (P < .05). LVEDD, Left ventricular end-diastolic diameter; MR, mitral regurgitation.
      The multivariate Cox regression analysis revealed significant predictors of MR progression after the transventricular mitral repair. Greater preoperative LVEDD was significantly associated with MR greater than 2+ recurrence (HR, 1.11; 95% CI, 1.04-1.20; P = .001). The type C pathology was the strongest indicator of an increased risk of MR greater than 2+ recurrence (HR, 5.99; 95% CI, 1.87-19.21; P = .003).

      Recurrent Mitral Regurgitation

      By the end of the observation, recurrent MR greater than 2+ was revealed in 29 patients: 4 patients (18.2%), 12 patients (25.5%), 12 patients (80%), and 1 patient (25%) in type A, B, C, and D groups, respectively. Repeat surgery was performed in 18 patients (20.5%), including 10 patients (55.6%) of both type A and B. Thirteen patients (72.2%) underwent a conventional MV repair, 3 patients (16.7%) had a neochordal length readjustment, 2 patients (11.1%) had redo transventricular MV repair, and 1 patient had MV replacement. We identified several etiological factors of recurrent MR after transventricular MV repair (Table 2).
      Table 2Mechanism of recurrent mitral regurgitation greater than 2+ and reinterventions after transventricular mitral valve repair
      Follow-up interval1 mo6 mo12 mo24 mo36 mo
      Recurrent MR >2+
       n1218212929
       % of study cohort13.6%20.5%23.9%33%33%
      Mechanism of recurrent MR >2+
       Rupture of native chordae710101313
       Rupture of artificial chordae25677
       Elongation of artificial chordae22255
       Dehiscence from leaflet edge11233
       Leaflet restriction12333
      Reintervention
       n210101517
       % of study cohort2.3%11.4%11.4%17%19%
       MV repair266911
       MV replacement---11
       Readjustment of the length-2233
       Re-do transventricular repair-2222
       No intervention108111412
      MR, Mitral regurgitation; MV, mitral valve.
      Rupture of native or artificial chordae, neochordal elongation or dehiscence from the leaflet edge, or a combination of these factors was demonstrated in 25 of 29 patients (86.2%) with recurrent severe MR. More than 1 failure mechanism was reported in 7 patients (24.1%). Rupture of the artificial neochordae was seen in 7 patients (24.1%), both in the middle part and at the level of the apex of the ventricle. Mechanical damage of the neochord during the implantation is the most likely mechanism. Four patients underwent MV repair.
      Thirteen patients (44.8%) were found to have ruptured native chordae, predominantly those of the anterior MV leaflet (69%). We believe this may have occurred spontaneously or was induced by mechanical interactions with the artificial chordae. Eight patients (61.5%) underwent MV repair, 2 patients (15.4%) underwent a redo transventricular repair with artificial neochordae, and 1 patient underwent MV replacement.
      Relative elongation of the artificial chordae was reported in 6 patients (20.7%). Three patients underwent a subsequent transventricular length readjustment of the neochordae (followed by further conventional MV repair in 1 patient). Dehiscence of the artificial chordae from the edge of the leaflet was observed in 3 patients (10.3%). There was a rupture of the native chordae detected in 2 patients; thus, it remains unclear which mechanism was primary. Leaflet restriction caused a recurrent MR in 3 patients (10.3%).

      Mortality and Causes of Death

      In our study, the overall survival was 95.5%. One patient died of bleeding-related cardiac tamponade on postoperative day 2. There were 3 late deaths at the follow-up: 1 noncardiac (the anatomic type A patient with an optimal MR reduction and 2-year device success died of hepatic carcinoma) and 2 cardiac related (both were type C pathology).
      A 64-year-old patient was diagnosed with recurrent MR 2.5 years after the transventricular mitral repair and died of sepsis and multiple organ failure 4 weeks after a conventional MV repair, 34 months after transventricular repair. Another cardiac death was in a 72-year-old patient who had a successful transventricular repair; however, a recurrent severe MR was revealed at the 1-month follow-up. He underwent MV replacement with a tissue valve 14 months later. After 4 months, he was readmitted to the hospital with an infective endocarditis of the prosthetic valve and a spontaneous intracerebral hemorrhage. The patient was managed medically and died 1 month later, 20 months after the transventricular repair.

      Discussion

      Conventional MV repair has been established as the gold standard to treat degenerative MR. Since the 1980s, the use of ePTFE artificial chordae has become a standard tool in modern cardiac surgery and is one of the most commonly used components of the repair nowadays. MV repair using artificial chordae is associated with good long-term durability and good hemodynamic parameters of the reconstructed valve. In the literature, the reported freedom from recurrent moderate or severe MR after conventional MV repair varies from 71% at 7 years
      • Flameng W.
      • Herijgers P.
      • Bogaerts K.
      Recurrence of mitral valve regurgitation after mitral valve repair in degenerative valve disease.
      to 81% at 10 years.
      • Shimokawa T.
      • Kasegawa H.
      • Katayama Y.
      • Matsuyama S.
      • Manabe S.
      • Tabata M.
      • et al.
      Mechanisms of recurrent regurgitation after valve repair for prolapsed mitral valve disease.
      In a large long-term study by David and colleagues,
      • David T.E.
      • David C.M.
      • Tsang W.
      • Lafreniere-Roula M.
      • Manlhiot C.
      Long-term results of mitral valve repair for regurgitation due to leaflet prolapse.
      the probability of recurrent moderate or severe MR was 12.5% at 20 years.
      In recent years, the NeoChord technology has emerged and successfully complemented the list of safe and reproducible surgical techniques. Moreover, it has received approval from the US Food and Drug Administration and subjects are being enrolled in the Randomized Trial of the NeoChord DS1000 System Versus Open Surgical Repair (ReChord) prospective, multicenter, randomized clinical trial (ClinicalTrials.gov NCT02803957), which is expected to prove whether ring annuloplasty is imperative for durable long-term mitral repair as opposed to neochordae alone.
      To date, the transventricular NeoChord procedure has been successfully performed in more than 1200 patients in Europe and the United States, respectively.
      • Colli A.
      • Adams D.
      • Fiocco A.
      • Pradegan N.
      • Longinotti L.
      • Nadali M.
      • et al.
      Transapical NeoChord mitral valve repair.
      ,
      • Grinberg D.
      • Le M.Q.
      • Kwon Y.J.
      • Fernandez M.A.
      • Audigier D.
      • Ganet F.
      • et al.
      Mitral valve repair based on intraoperative objective measurement.
      ,
      • Fiocco A.
      • Nadali M.
      • Speziali G.
      • Colli A.
      Transcatheter mitral valve chordal repair: current indications and future perspectives.
      The majority of publications on transventricular MV repair present only intraoperative and early postoperative results.
      • Gerosa G.
      • D'Onofrio A.
      • Besola L.
      • Colli A.
      Transoesophageal echo-guided mitral valve repair using the Harpoon system.
      ,
      • Colli A.
      • Manzan E.
      • Rucinskas K.
      • Janusauskas V.
      • Zucchetta F.
      • Zakarkaite D.
      • et al.
      Acute safety and efficacy of the NeoChord procedure.
      ,
      • Colli A.
      • Manzan E.
      • Zucchetta F.
      • Bizzotto E.
      • Besola L.
      • Bagozzi L.
      • et al.
      Transapical off-pump mitral valve repair with Neochord implantation: early clinical results.
      No long-term durability data of transventricular MV repair are available yet.
      In 2018, Colli and colleagues
      • Colli A.
      • Manzan E.
      • Aidietis A.
      • Rucinskas K.
      • Bizzotto E.
      • Besola L.
      • et al.
      An early European experience with transapical off-pump mitral valve repair with NeoChord implantation.
      reported overall survival of 98% ± 1% from the early European experience with a follow-up to 1 year. The overall composite end point, including freedom from recurrent severe MR, was achieved in 84% ± 2.5% of patients and in 94% ± 2.6%, 82.6% ± 3.8%, and 63.6% ± 8.4% of patients in the type A, type B and type C groups, respectively (P < .0001). Such findings, in line with our results, suggest a high rate of MR recurrence in patients with a complex MV disease. There were no intraoperative deaths in either the study by Colli and colleagues
      • Colli A.
      • Manzan E.
      • Aidietis A.
      • Rucinskas K.
      • Bizzotto E.
      • Besola L.
      • et al.
      An early European experience with transapical off-pump mitral valve repair with NeoChord implantation.
      or in our study. Kiefer and colleagues
      • Kiefer P.
      • Meier S.
      • Noack T.
      • Borger M.A.
      • Ender J.
      • Hoyer A.
      • et al.
      Good 5-year durability of transapical beating heart off-pump mitral valve repair with neochordae.
      reported 50% durability of transventricular NeoChord repair with only mild to moderate recurrent MR in a small cohort of 6 patients at 5-year follow-up.
      Our study demonstrated an overall 67% freedom from recurrent severe MR at 42 months after the transventricular MV repair. The operator learning curve had no impact on the midterm results. Patients with isolated or bileaflet prolapse and paracommissural disease (type C) were 6 times more likely to develop MR recurrence than the patients with isolated P2 prolapse (type A). Complex MV pathology and dilated left ventricle significantly increased the risk of MR progression over time.

      Conclusions

      Transventricular MV repair may be an initially safe method of treatment of degenerative MR characterized by the low incidence of postoperative adverse events in the early postoperative period. However, durability of transventricular repair was poor at 3 years. Patients with degenerative disease more than P2 prolapse and dilated left ventricle are at high risk of early MR recurrence.

      Conflict of Interest Statement

      A.D. is working as a proctor for NeoChord Inc. D.Z. and A.A. have worked as proctors for NeoChord Inc. All other authors reported no conflicts of interest.
      The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest.

      Supplementary Data

      • Video 1

        MV anatomy before the repair demonstrating isolated P2 prolapse (white arrow). The “finger test” was used to identify the ideal left ventricle entry site by pushing the myocardium with a finger 2 to 4 cm from the apex toward the posterolateral left ventricular wall. Two-dimensional and 3-dimensional transesophageal echocardiography was used for the selection of the ventriculotomy site. A zoomed 3-dimensional volumetric data set was cropped to remove the MV to identify the left ventricular apical area compressed by the finger. The left ventricle entry site is shown between the papillary muscles (white arrow). Positioning of the device: The jaws of the device are opened in the left atrium, and the prolapsing P2 segment is captured. Finally, the artificial chord is deployed and the leaflet is pulled down toward the left ventricle apex. An excellent anatomic result with complete resolution of the P2 prolapse is confirmed on 3- and 2-dimensional images. Video available at: https://www.jtcvs.org/article/S0022-5223(21)00060-X/fulltext.

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      Linked Article

      • Commentary: Transventricular mitral valve repair: Are we ready to move in reverse to repair P2 prolapse?
        The Journal of Thoracic and Cardiovascular SurgeryVol. 164Issue 6
        • Preview
          Budra and colleagues1 report their single center, midterm experience with the DS1000 Neochord (NeoChord Inc, St Louis Park, Minn) transventricular mitral valve (MV) repair system.1 This is a beating-heart, transapical device that captures and attaches polytetrafluoroethyelene chords to the prolapsing segment of the MV and exteriorizes the chords to the left ventricular (LV) epicardium while providing tension to the repaired prolapse leaflet. They reported outcomes of 89 patients who underwent the procedure between 2011 and 2017, with a wide range of prolapse pathology, including 22 isolated P2 segment prolapses (type A), 47 multisegment posterior leaflet prolapses (type B), 15 bi-leaflet and/or commissural prolapses (type C), and 4 isolated anterior leaflet prolapses (type D).
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        • PDF
      • Commentary: Striking the right chord
        The Journal of Thoracic and Cardiovascular SurgeryVol. 164Issue 6
        • Preview
          In this issue of the Journal, Budra and colleagues1 report the first mid-term results of transventricular mitral valve (MV) repair with the NeoChord DS1000 Artificial Chordae Delivery System (NeoChord, St Louis Park, Minn). This device aims to treat primary mitral regurgitation (MR) by implantation of expanded polytetrafluoroethylene (ePTFE) sutures to prolapsing or flail MV leaflet segments via a transapical approach on the beating heart. The highly experienced surgeon coauthors with access to the NeoChord device before current clinical trials were among the first to perform these operations.
        • Full-Text
        • PDF