Management of Incomplete Initial Repair in the Treatment of Degenerative Mitral Insufficiency An Institutional Protocol and Mid-Term Outcomes

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1 CLINICAL STUDY Management of Incomplete Initial Repair in the Treatment of Degenerative Mitral Insufficiency An Institutional Protocol and Mid-Term Outcomes Wenrui Ma, 1 MD, Wei Shi, 1 MD, Wei Zhang, 1 MD, Weihua Wu, 2 MD, Wei Ye, 1 MD and Ye Kong, 1 MD Summary We sought to present our institutional protocol to manage incomplete initial repair of degenerative mitral regurgitation and to evaluate its mid-term outcomes. Eight hundred and fifteen patients with degenerative mitral insufficiency undergoing mitral valve repair were investigated in this study. The initial repair attempt was incomplete in 48 patients, leaving a degree of residual regurgitation > mild, and an elevated transmitral gradient or systolic anterior motion (SAM). These patients were further treated with medication or mitral valve re-repair or replacement under reinstituted cardiopulmonary bypass. Transesophageal echocardiographic reports and operational records were reviewed to identify morphological causes and establish management of incomplete initial repair. Mid-term outcomes of patients with re-repair and complete initial repair were evaluated and compared. Residual mitral regurgitation > mild was detected in 25 patients, an elevated transmitral gradient was detected in seven patients, and SAM was detected in 16 patients. The condition of eight patients with SAM was resolved with medication only. Mitral valve re-repair was performed in 23 patients and replacement was performed in 17, with comparable early mortality and morbidity. At 60.3 ± 25.5 months after surgery, late mitral stenosis and reoperation rate were significantly higher in re-repair patients than in patients with complete initial repair, despite comparable survival, left chamber reverse remodeling, and degree of residual regurgitation. Based on our institutional protocol, acceptable outcomes can be achieved for patients with incomplete initial mitral valve repair. Management should be tailored based on the characteristics of the mitral valve complex, expected repair durability, and operative risk. (Int Heart J 2018; 59: ) Key words: Mitral valve repair, Mitral valve replacement, Cardiopulmonary bypass, Transesophageal echocardiography In recent years, in patients with degenerative mitral regurgitation, mitral valve repair has been preferred to replacement. 1) Unfortunately, even in large reference centers, about 5% of all repair operations might not solve the problem at the initial attempt, leaving significant residual regurgitation, elevated gradients or systolic anterior motion (SAM), as detected by intraoperative transesophageal echocardiography (TEE) after weaning from cardiopulmonary bypass (CPB). 2,3) It is generally accepted that when an incomplete repair is identified, mitral valve re-repair should be considered prior to direct replacement. However, although re-repair could achieve increased left ventricular reverse remodeling and better recovery of cardiac function, and also eliminate the need for lifetime anticoagulation therapy, its early outcomes could be undermined by longer CPB and aortic cross-clamp times. Furthermore, a second manipulation of the autologous tissue inevitably increases frailty and tension on the annulus, leaflets, chordae, and papillary muscles, which may further weaken the durability of repair. So, far, extensive studies outlining the management of incomplete mitral valve repair remain scarce, and current clinical practice is mostly based on the surgeon s preference. The aim of this study was two-fold: 1) to present our institutional protocol for the management of mitral valves with incomplete initial repair; and 2) to compare clinical outcomes of patients who had undergone re-repair and complete initial repair at a mid-term follow-up. From the 1 Department of Cardiovascular Surgery, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China and 2 Department of Echocardiography, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China. *These authors contributed equally to this study. This study was supported by three institutional grants from Shanghai Chest Hospital (Nos. 2014YZDH10301, 2014YZDH10302, and YZ2015-ZX03) and one grant from Shanghai Municipal Commission of Health and Family Planning (No ). Address for correspondence: Wei Zhang, MD, Department of Cardiovascular Surgery, Shanghai Chest Hospital, Shanghai Jiao Tong University, No. 241 Huaihaixi Rd, Shanghai , China. zhangwyyy@hotmail.com Received for publication May 23, Revised and accepted July 30, Released in advance online on J-STAGE May 9, doi: /ihj All rights reserved by the International Heart Journal Association. 510

2 IntHeartJ May 2018 MANAGEMENT OF INCOMPLETE MITRAL VALVE REPAIR 511 Methods Study cohort: The study was reviewed by the Ethics Committee of Patients of Shanghai Chest Hospital and the requirement for informed consent was waived because of the retrospective nature of the study. From January 2005 to January 2015, 3743 patients underwent mitral valve operations at our institution. Exclusion criteria included patients who underwent mechanical or bioprosthetic mitral valve replacement (n = 2565), concomitant aortic valve surgery (n = 56), atrial ablation (n = 116), coronary artery bypass grafting (n = 14), and prior cardiac surgery (n = 21). We also excluded patients undergoing mitral valve repair for non-degenerative mitral pathology (n = 156). After screening, 815 patients undergoing mitral valve repair for significant degenerative mitral insufficiency were studied. Of those patients, 48 (5.9%) with incomplete initial repair (defined as a degree of residual regurgitation > mild, or mean transmitral gradient [mtmg] > 6 mmhg, or presence of SAM, as detected by intraoperative TEE) were included in the study. Forty patients underwent reintervention on a second bypass. Mitral regurgitation was assessed by echocardiographers, using transthoracic echocardiography (TTE) measurement of color flow jet area. The severity was graded as the following: none (0, no detected jet), trivial (1+, jet area/left atrial area < 5%), mild (2+, jet area/left atrial area 5%-20%), moderate (3+, jet area/left atrial area 20%-40%), and severe (4+, jet area/left atrial area > 40%), according to current guidelines. 4) Management of incomplete repair: All operations were performed under mild hypothermia, aortobicaval cannulation and cold cardioplegic arrest through median sternotomy. Before CPB commenced, pre-bypass TEE was used to reassess the degree, location and orientation of regurgitant jets, as well as the structural properties of the valvular apparatus. The mitral valve was exposed and assessed through an incision on the left atrium or atrial septum. The degenerative etiology of the mitral valve lesion was confirmed by gross inspection of the valve by the surgeon and from pathological reports. Mitral valve repair was performed with selective use of one or more techniques, including posterior leaflet resection, artificial chordal implantation, chordal transfer, and edge-to-edge suturing, the details of which have been described in previous studies. 5-7) After the repair attempt was complete and saline testing showed a satisfactory result, annuloplasty was performed using a Carpentier-Edwards Physio I ring or a Cosgrove band (Edwards Lifesciences, Irving, CA, USA). Concomitant tricuspid annuloplasty was then performed on eight cases of the study cohort. The aortic cross-clamp was removed and patients were gradually weaned from CPB. TEE was not performed until the mean arterial pressure reached 75 mmhg. One repair attempt was considered incomplete if TEE detected greater than a mild degree of residual mitral regurgitation (jet area/left atrial area > 20%), stenosis (mtmg > 6 mmhg) or SAM. When an incomplete repair was identified, the surgeon located the regurgitation, clarified the mechanism of residual valve insufficiency and decided on subsequent manipulations with the assistance of an experienced echocardiographer (Dr. W.W.). The overall protocol is presented in Figure 1. Typically, at our institution the criteria for mitral valve re-repair of significant residual regurgitation included: 1) regional regurgitation confined within one segment or commissure; 2) favorable mobility of the anterior leaflet; and 3) no distinct technical failure in the initial attempt, namely dehiscence of the annuloplasty ring or tissue rupture. Direct replacement was performed when residual regurgitation was extensive and the anterior leaflet was restricted or poor in structural strength. For patients with an mtmg > 6 mmhg, reinstitution of CPB was considered if persistent stenosis was detected after maintaining the heart rate at < 100 bpm. The decision to either re-repair or replace the valve was made based on anterior leaflet mobility and on the repair techniques utilized. More than one technique could have been employed on the initial attempt, and edge-to-edge suturing was performed most frequently as an additional procedure to correct complicated regurgitation. Re-repair was only considered for patients with a mobile anterior leaflet, in the absence of the edge-to-edge technique. For patients with SAM, CPB was recommenced only when there was a persistence of both regurgitation > mild, and left ventricular outflow tract gradient > 50 mmhg after adjustment of the heart rate and blood pressure. Replacement was performed in patients with a high risk of recurrent SAM (annuloplasty ring < 28 mm, aorto-mitral angle < 110 and coaptation-septum distance < 20 mm) for enhanced durability. All re-repaired mitral valves were rechecked using saline testing and post-bypass TEE to confirm successful reconstruction, which was defined as jet area/left atrial area < 20%, mtmg < 6 mmhg, and an absence of SAM. For all cases ineligible for re-repair, mitral valve replacement was performed with preservation of the subvalvular apparatus. Early mortality was defined as any death within 30 days of surgery. Early major morbidities included low cardiac output syndrome, neurologic events, renal failure, prolonged ventilatory support, deep wound infection, and reoperation for bleeding. Baseline clinical and echocardiographic variables, operative data, and early events between the re-repair group and the replacement group were compared (Table I, II). Follow-up data: Routine follow-up of clinical and TTE evaluation was performed at the discretion of the surgeons or referring cardiologists. For patients with more than one follow-up TTE report, the most recent data were selected for analysis. Survival, reoperation for recurrent mitral valve pathology and echocardiographic data were compared between patients undergoing re-repair and those who underwent complete initial repair (one-repair group). Statistical analysis: Continuous variables were presented as means ± standard deviation and were compared using the Student s t-test or Mann-Whitney U-test. Categorical variables were defined by numbers and percentages, and analyzed using the chi-squared test or Fisher s exact test, as appropriate. Reoperation rate, New York Heart Association (NYHA) functional class, degree of residual regurgitation and parameters of the left heart dimensions were compared. The Kaplan-Meier method and log-rank test were used to evaluate and compare survival between patients in the re-repair and one-repair groups. A P-value <

3 512 Ma, ET AL IntHeartJ May 2018 Figure 1. Management of incomplete initial repair for degenerative mitral regurgitation was considered statistically significant. All statistical analyses were performed using the SAS v8.0 software (SAS Institute, Inc., Cary, NC, USA). Results Study population: The baseline clinical and echocardiographic data are presented in Table I. Among 40 patients subjected to reintervention, 27 were males. The mean age was 58.3 years (range, years). Among the entire cohort, 22 patients (55%) were designated as NYHA functional class III or IV. Most clinical characteristics were comparable between the two subgroups, except for the prevalence of atrial fibrillation. A trend towards increasing age and chronic lung disease in the replacement subgroup was observed, although these differences were not statistically significant (P = 0.06 and 0.07, respectively). Most of the study cohort had severe mitral regurgitation, and more than half had insufficient mitral valves with bileaflet lesions. Various types of valvular lesion were similarly distributed between the two subgroups, and only one patient with isolated posterior leaflet pathology underwent a replacement operation. For patients who underwent mitral valve replacement, there was a trend toward greater preoperative left atrial and ventricular dimensions and toward reduced left ventricular systolic function that did not reach significance. Tenting height, posterior leaflet angle and aorto-mitral angle were comparable between the two subgroups. Operative data: The operative demographics and early outcomes are presented in Table II. Thirty-day mortality was 2.5% (n = 1). One patient who underwent two incomplete repair attempts died of multi-organ failure induced by low cardiac output and acute respiratory distress syndrome after being weaned from extracorporeal membrane oxygenation support, eight days after surgery. Fifteen out of 23 patients were re-repaired because of surgical imperfectness of the initial repair, which included inappropriate lengths or implantation sites of artificial chordae and inaccurate resection of posterior leaflets. Clefts on the posterior leaflets, without extension to the mitral annulus, were discovered and closed in four patients. For one patient with increased mtmg (7.2 mmhg) in the absence of edge-to-edge suturing, we explanted the 28 mm full annuloplasty ring and reimplanted a 30 mm ring. The mtmg then declined to 4.5 mmhg after reintervention. Three patients had persistent SAM; in one patient with an 18 mm-thick basal septum (Figure 2), we performed sep-

4 IntHeartJ May 2018 MANAGEMENT OF INCOMPLETE MITRAL VALVE REPAIR 513 Table I. Baseline Clinical Characteristics and Echocardiographic Data Demographics Total (n = 40) Re-repair (n = 23) Replacement (n = 17) P Age (years) 58.3 ± ± ± Male 27 (67.5) 15 (65.2) 12 (70.6) 0.72 NYHA functional class III-IV 22 (55) 11 (47.8) 7 (41.2) 0.68 Hypertension 7 (17.5) 4 (17.4) 3 (17.7) 0.98 Diabetes mellitus 4 (10.0) 3 (13.0) 1 (5.9) 0.62 Atrial fibrillation 11 (27.5) 2 (8.7) 9 (52.9) < 0.01 Chronic lung disease 3 (7.5) 0 (0) 3 (17.7) 0.07 Renal dysfunction 0 (0) 0 (0) 0 (0) - Cerebrovascular disease 2 (5.0) 2 (8.7) 0 (0) 0.50 Coronary artery disease 4 (10.0) 2 (8.7) 2 (11.8) 1.00 Prior cardiac intervention 1 (2.5) 0 (0) 1 (5.9) 0.43 EuroSCORE II (%) 1.1 ± ± ± Echocardiographic parameters LAD (mm) 48.4 ± ± ± LVESD (mm) 36.2 ± ± ± LVEDD (mm) 58.8 ± ± ± LVEF (%) 61.2 ± ± ± Systolic pulmonary artery pressure > 40mmHg 21 (52.5) 10 (43.5) 11 (64.7) 0.18 Mitral regurgitation (degree + ) 3.7 ± ± ± Anterior leaflet lesion 11 (27.5) 6 (26.1) 5 (29.4) 1.00 Posterior leaflet lesion 8 (20) 7 (30.4) 1 (5.9) 0.11 Bileaflet lesion 21 (52.5) 10 (43.5) 11 (64.7) 0.18 Tenting height (mm) 8.4 ± ± ± Posterior leaflet angle ( ) 32.1 ± ± ± Aorto-mitral angle ( ) ± ± ± Continuous variables are presented as means ± standard deviations and categorical variables as number (%). LAD indicates left atrial diameter; LVEDD, left ventricular end-diastolic diameter; LVEF, left ventricular ejection fraction; LVESD, left ventricular end-systolic diameter; and NYHA, New York Heart Association. Table II. Operative Data and Early Events Demographics Total (n = 40) Re-repair (n = 23) Replacement (n = 17) P Total CPB duration (minutes) ± ± ± Aortic cross-clamp duration (minutes) ± ± ± Tricuspid annuloplasty 8 (20.0) 5 (21.7) 3 (17.7) 0.75 Annuloplasty ring size (mm) ± Full annuloplasty ring - 8 (34.8) - - Prosthetic valve size (mm) ± Early mortality 1 (2.5) 1 (4.3) 0 (0) 1.00 Postoperative morbidities 7 (17.5) 4 (17.4) 3 (17.7) 0.98 Low cardiac output syndrome 2 (5.0) 1 (8.7) 1 (5.9) 0.74 Neurologic events 1 (2.5) 1 (4.3) 0 (0) 1.00 Renal dysfunction 1 (2.5) 1 (4.3) 0 (0) 1.00 Ventilator support > 3 days 1 (2.5) 0 (0) 1 (5.9) 0.43 Deep wound infection 1 (2.5) 0 (0) 1 (5.9) 0.43 Reoperation for bleeding 1 (2.5) 1 (4.3) 0 (0) 1.00 Continuous variables are presented as means ± standard deviations and categorical variables as number (%). CPB indicates cardiopulmonary bypass. tal myectomy, and in the other two patients we performed additional shortened artificial chordae and edge-to-edge repair. Mitral valve replacement was performed on 17 patients who did not meet the criteria for re-repair. The mean total CPB and aortic cross-clamp times were ± 24.0 minutes and ± 21.1 minutes, respectively, and operation duration was significantly longer in patients treated with re-repair than in those treated with replacement (P = 0.04 and 0.03, respectively). The prevalence of major postoperative morbidities was 17.5% (n = 7), and they included low cardiac output syndrome (n = 2), neurologic event (n = 1), acute kidney injury (n =1), prolonged ventilator support (n = 1), deep wound infection (n = 1), and reoperation for bleeding (n =1).Nosignificant differences in early mortality and morbidity were discovered between two subgroups. Clinical outcomes: Follow-up data were available in 100% of the 39 patients with incomplete initial repair and 76.1% (590/775) of those patients who underwent complete initial repair. The most recent follow-up clinical data

5 514 Ma, ET AL IntHeartJ May 2018 Figure 2. A: Systolic anterior motion (SAM) was detected in one patient with thickened basal ventricular septum (18 mm). B: SAM was resolved after septal myectomy. The resected myocardium measured 2 cm 1 cm 1 cm. of each patient were collected at 60.3 ± 25.5 months (ranging from 15 to 144 months) after surgery. Three patients in the re-repair group underwent mitral valve reoperation for severe recurrent regurgitation (n = 1) and late mitral stenosis (n = 2), and no patient in the replacement group was subjected to reoperation after the initial surgery. The TTE reports showed comparable repair durability for mitral insufficiency, but the prevalence of late mitral stenosis and reoperation for recurrent mitral valve pathology was significantly higher in the re-repair group than in the one-repair group (9.1% vs. 1.0%, P = 0.03; 13.6% vs. 2.5%, P = 0.02, respectively). No significant difference in cardiac mortality, NYHA functional class, left chamber dimensions, and left ventricular systolic function was observed (Table III, Figure 3). Discussion Mitral valve repair is the gold standard treatment of degenerative mitral regurgitation, according to current guidelines. 1) Because it is more technically demanding than replacement, successful repair depends on a thorough assessment of the valve, proper selection of techniques, and precise surgical manipulations. Data have shown that about 5% of all repair operations for degenerative mitral insufficiency fail at the initial attempt and require another bypass, even in high volume centers with more experienced surgeons. 2,3) The most common causes of incomplete repair include significant residual regurgitation, iatrogenic mitral stenosis and SAM. Despite the proposal of detailed algorithms to manage SAM in previous studies, 8,9) pertinent data to evaluate the management of other causes of incomplete repair remain scarce. To the best of our knowledge, this is the first report to present a protocol for the management of incomplete mitral valve repair and its mid-term outcomes. In the present study, in the subgroup of 25 patients with residual regurgitation > mild, the criteria for re-repair included regional mild-to-moderate regurgitation, mobile anterior leaflet, and stable initial repair. Eccentric regurgitant jets of a mild-to-moderate degree were mainly caused by surgical imperfectness of the initial repair, with adequate total leaflet area and confined regurgitation, conditions that facilitate purposeful remedies. Anterior leaflets with fine mobility on TEE demonstrated less tethering of autologous or artificial chordae, as well as acceptable leaflet rigidity, both of which are required to prevent mitral stenosis after re-repair. 10) Stable valvular apparatus after initial repair facilitates further durable reconstruction. Fifteen patients who met the eligibility criteria underwent mitral valve re-repair. The frequency of surgical imperfectness can be considerably reduced by the hands of surgeons who are more experienced, advances in threedimensional TEE reconstruction and novel measuring techniques and devices. Eleven out of 15 patients underwent operations before 2009, indicating a distinct improvement in surgical experience over the past decade. Four patients who underwent re-repair had incomplete clefts on the posterior leaflet that did not reach the mitral annulus, a finding that was also reported by Wyss, et al. 11) Incomplete clefts are usually located between two neighboring scallops (P1-P2 or P2-P3) and do not necessarily generate significant regurgitation before surgery. Such a phenomenon could be explained by the fact that before the initial repair, two thickened, fibrotic edges of a cleft usually restrict major regurgitant jets. After initial manipulations of the posterior leaflet (commonly, triangular resection and reattachment) were performed, tension on the leaflet tissue was increased, resulting in wider gaps and recurrent regurgitation. The techniques used for significant residual regurgitation included additional implantation of artificial chordae, edge-to-edge suturing and cleft closure. Edge-to-edge suturing has been confirmed as a quick, durable technique that effectively eliminates regurgitant jets. Typically, at our institution, this technique is only used concomitantly to reinforce coaptation, if employment of the other repair techniques does not achieve a favorable result after saline testing. However, combined repair techniques increase the mtmg, especially when the edge-toedge technique is used. 12,13) In this study, despite efforts to

6 IntHeartJ May 2018 MANAGEMENT OF INCOMPLETE MITRAL VALVE REPAIR 515 Table III. Clinical and Echocardiographic Data before Discharge and during Follow-Up: Re-Repair Group Versus One-Repair Group Parameters Re-repair (n = 22) One-repair (n = 590) P Post-bypass TEE Mitral regurgitation None 6 (27.3) 170 (28.8) 0.55 Trivial 14 (63.6) 395 (67.0) Mild 2 (9.1) 25 (4.2) Follow-up duration (months) 54.9 ± ± Late cardiac mortality 0 (0) 6 (1.0) 1.00 Reoperation for recurrent mitral valve pathology 3 (13.6) 15 (2.5) 0.02 NYHA functional class (class) 1.7 ± ± Follow-up echocardiography Mitral regurgitation None 5 (22.7) 112 (19.0) 0.85 Trivial 13 (59.1) 388 (65.8) Mild 3 (13.6) 68 (11.5) Moderate 0 (0) 13 (2.2) Severe 1 (9.1) 9 (1.5) Mitral stenosis 2 (9.1) 6 (1.0) 0.03 mtmg (mmhg) 3.3 ± ± LAD (mm) 38.8 ± ± LVESD (mm) 30.5 ± ± LVEDD (mm) 50.5 ± ± LVEF (%) 61.2 ± ± Continuous variables are presented as means ± standard deviation and categorical variables as number (%). LAD indicates left atrial diameter; LVEDD, left ventricular end-diastolic diameter; LVEF, left ventricular ejection fraction; LVESD, left ventricular end-systolic diameter; mtmg, mean transmitral gradient; NYHA, New York Heart Association; and TEE, transesophageal echocardiography. Figure 3. The Kaplan-Meier curves to compare survival between patients undergoing re-repair and one-repair.

7 516 Ma, ET AL IntHeartJ May 2018 maintain as large a remnant orifice area as possible, an elevated mtmg was detected in six patients who had undergone edge-to-edge suturing. Considering the fact that removal of the suture would again lead to significant regurgitation, replacement of the mitral valve was performed. We reimplanted a larger annuloplasty ring for one patient, without using the edge-to-edge technique, and the mtmg was instantly reduced on TEE after re-repair. For patients on who the development of SAM was observed after the initial repair, we implemented a similar strategy based on the algorithm proposed by Varghese, et al. 8) No surgical reintervention was employed if SAM could have been resolved or attenuated with the administration of medical therapy alone. In eight cases for which medications proved futile, CPB was recommenced after assessment of the entire aorto-mitral complex and ventricular septum on TEE. We performed valve replacement to ensure total resolution of SAM for five patients with increased risk of recurrent SAM. 14,15) On one patient with an 18 mm-thick basal septum, we performed septal myectomy to alleviate left ventricular outflow obstruction and SAM spontaneously disappeared. Two patients each having a medium-sized annulus were treated with additional shortened artificial chordae and edge-to-edge repair. Although the ideal repair rate of degenerative mitral regurgitation is 100%, precautions must be taken for patients who have complex valvular pathology, high operational risk, and a previous incomplete repair attempt. Reintervention of incomplete valve repair prolongs operating time, aggravates the inflammatory response, and can lead to organ dysfunction. Moreover, surgical difficulty is further increased in mitral valve re-repair because: 1) rerepair is mostly performed based on initial repair and annuloplasty, with a restricted annular size and a less exposed leaflet area on which to work; and 2) second manipulations might increase the probability of mitral stenosis and tissue rupture. Similar to our results, Goldstone, et al. reported that, out of 26 patients with an incomplete initial repair requiring reintervention, one patient died because of an atrioventricular groove disruption after three failed repair attempts. 2) Therefore, to prevent repeated repair attempts, protocols to determine the criteria for mitral valve re-repair should be established. Regarding mid-term outcomes, re-repair patients were more susceptible to late mitral stenosis and reoperation than those with a successful initial repair, suggesting that mitral valve replacement is justified when re-repair is expected to be too fragile or complicated. Although this result might be influenced by the complexity of mitral valve pathologies (more than 50% of the patients had bileaflet lesions or Barlow s syndrome), reoperation risks should also be considered when designing a management plan that is tailored to each patient. 16) For young patients with low operative risk and who are eligible for further interventions on the mitral valve, a second repair attempt could be preferentially made for better long-term surgical outcomes and less anticoagulation-related complications. Mitral valve replacement could be recommended for difficult cases that have been subjected to one incomplete repair, to avoid protraction of operating time and a high reoperation rate, particularly in patients at an advanced age with high operative risk and permanent atrial fibrillation. Several limitations of the present study must be considered. First, this is a retrospective study, and the results might be biased by disparities in medical and surgical management. Second, the size of the re-repair group is relatively small, a feature that may weaken the power of evidence. Third, since experience and institutional practice in the management of incomplete mitral valve repair can vary greatly, we cannot provide a universal quantitative strategy (using 3-dimensional TEE or dual-source computed tomography 17) ) to determine when to re-repair or replace the valve. Nevertheless, a detailed protocol for each institution should be established to avoid unnecessary additional attempts at re-repair and imprudent direct replacement. Disclosures Conflicts of interest: None. References 1. Nishimura RA, Otto CM, Bonow RO, et al 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 Practice Guidelines. Circulation 2014; 129: e Goldstone AB, Cohen JE, Howard JL, et al. A repair-all strategy for degenerative mitral valve disease safely minimizes unnecessary replacement. Ann Thorac Surg 2015; 99: Kitai T, Okada Y, Shomura Y, et al. Timing of valve repair for severe degenerative mitral regurgitation and long-term left ventricular function. J Thorac Cardiovasc Surg 2014; 148: Zoghbi WA, Enriquez-Sarano M, Foster E, et al. Recommendations for evaluation of the severity of native valvular regurgitation with two-dimensional and Doppler echocardiography. J Am Soc Echocardiogr 2003; 16: Chen X, Turley RS, Andersen ND, Desai BS, Glower DD. Minimally invasive edge-to-edge mitral repair with or without artificial chordae. Ann Thorac Surg 2013; 95: Padala M, Cardinau B, Gyoneva LI, Thourani VH, Yoganathan AP. Comparison of artificial neochordae and native chordal transfer in the repair of a flail posterior mitral leaflet: an experimental study. Ann Thorac Surg 2013; 95: Varghese R, Itagaki S, Anyanwu AC, Milla F, Adams DH. Predicting early left ventricular dysfunction after mitral valve reconstruction: the effect of atrial fibrillation and pulmonary hypertension. J Thorac Cardiovasc Surg 2014; 148: Varghese R, Anyanwu AC, Itagaki S, Milla F, Castillo J, Adams DH. Management of systolic anterior motion after mitral valve repair: an algorithm. J Thorac Cardiovasc Surg 2012; 143: S Dohi M, Doi K, Okawa K, Yamanami M, Yaku H. Delayedonset systolic anterior motion of the mitral valve after aortic valve replacement for severe aortic stenosis. Int Heart J 2013; 54: Castillo JG, Anyanwu AC, Fuster V, Adam DH. A near 100% repair rate for mitral valve prolapse is achievable in a reference center: implications for future guidelines. J Thorac Cardiovasc Surg 2012; 144: Wyss CA, Enseleit F, van der Loo B, Grünenfelder J, Oechslin EN, Jenni R. Isolated cleft in the posterior mitral valve leaflet: a congenital form of mitral regurgitation. Clin Cardiol 2009; 32: Mesana TG, Lam BK, Chan V, Chen K, Ruel M, Chan K. Clinical evaluation of functional mitral stenosis after mitral valve repair for degenerative disease: potential affect on surgical strategy. J Thorac Cardiovasc Surg 2013; 146:

8 IntHeartJ May 2018 MANAGEMENT OF INCOMPLETE MITRAL VALVE REPAIR De Bonis M, Lapenna E, Taramasso M, et al. Very long-term durability of the edge-to-edge repair for isolated anterior mitral leaflet prolapse: up to 21 years of clinical and echocardiographic results. J Thorac Cardiovasc Surg 2014; 148: Varghese R, Itagaki S, Anyanwu AC, Trigo P, Fischer G, Adams DH. Predicting systolic anterior motion after mitral valve reconstruction: using intraoperative transoesophageal echocardiography to identify those at greatest risk. Eur J Cardiothorac Surg 2014; 45: Izumo M, Shiota M, Kar S, et al. Comparison of real-time three-dimensional transesophageal echocardiography to twodimensional transesophageal echocardiography for quantification of mitral valve prolapse in patients with severe mitral regurgitation. Am J Cardiol 2013; 111: Kubo T, Baba Y, Hirota T, et al. Prognostic significance of nondilated left ventricular size and mitral regurgitation in patients with dilated phase of hypertrophic cardiomyopathy. Int Heart J 2017; 58: Zhang L, Qiu J, Yu L, Chen S, Sun K, Yao L. Quantitative assessment of mitral apparatus geometry using dual-source computed tomography in mitral regurgitation. Int Heart J 2015; 56: