Mitral valve repair with resection and non-resection techniques in Barlow's disease: A multi-center study.

BACKGROUND: Various mitral valve (MV) repair techniques are nowadays in use. Non-resection techniques, that rely exclusively on Gore-Tex® neochords and annuloplasty, have been popularized; however, their efficacy in Barlow's disease, characterized by large myxomatous leaflets, is yet unclear. METHODS: Consecutive patients undergoing MV repair for Barlow's disease between 2011 and 2019 were selected on the basis of being eligible for resection and non-resection techniques. Study endpoints included overall survival, freedom from MV reintervention and recurrent regurgitation. RESULTS: Of 209 patients meeting the inclusion criteria, 135 (65%) underwent MV repair with and 74 (35%) without resection. There was one early reoperation due to residual regurgitation (resection group). Mean clinical follow-up duration was 6.1 (IQR 3.9-8.5) years. At 6 years after surgery, there was no difference in overall survival or freedom from MV reintervention. Mean echocardiographic follow-up (95% complete) duration was 3.5 (IQR 2.3-5.8) years. At 6 years, there was no difference in freedom from recurrent regurgitation rate (86.1%, 95% CI 78.5-93.7% vs. 83.0%, 95% CI 71.6-94.4%, P = 0.20) between the groups. Inverse probability-of-treatment weighting adjusted analysis demonstrated no significant difference between groups (HR 0.535, 95% CI 0.212-1.349, P = 0.20). Uni- and multivariable Cox proportional regression analysis did not demonstrate an effect of valve repair technique on the occurrence of recurrent regurgitation. CONCLUSIONS: At mid-term, the clinical and echocardiographic results of valve repair for Barlow's disease were very good and MV reintervention was rarely needed. At this time point, the results of non-resection techniques were comparable to the "gold standard" resection techniques.

Doing a double take: when transthoracic echocardiography fails for mitral valve annuloplasty ring endocarditis with Streptococcus pyogenes: a case report.

BACKGROUND: This case highlights several complications of a late and rare presentation of culture-negative Streptococcus pyogenes endocarditis of a previously repaired mitral valve with an annuloplasty ring including recurrent cardioembolic strokes, which was initially missed on transthoracic echocardiography. CASE PRESENTATION: A 66-year-old Caucasian female with prior mitral valve prolapse status post mitral valve annuloplasty and left atrial appendage occlusion, followed by two strokes, presented with supraventricular tachycardia that resolved spontaneously. During an inpatient admission, she developed symptoms of another stroke, and imaging studies were suggestive of recurrent cardioembolic phenomenon. Additional workup revealed two small intra-atrial masses adherent to the mitral annuloplasty ring missed on prior evaluation for recurrent stroke. She underwent surgical repair in the setting of a chronic culture-negative infectious endocarditis with Streptococcus pyogenes and recovered well with no further cardioembolic phenomenon. CONCLUSION: This case serves to highlight the importance of having a higher index of suspicion in any cardiac prosthesis patient for endocarditis when presenting with symptoms such as recurrent stroke, arrhythmias, and abnormal cardiac lab work. It also demonstrates the need for appropriate imaging with transthoracic echocardiography followed by transesophageal echocardiography and reviews surgical indications to diagnose and treat culture-negative endocarditis.

Five-year outcomes of mitral valve repair for leaflet prolapse at a medium-sized Norwegian university hospital.

Objective. To evaluate patient characteristics and 5-year outcomes after surgical mitral valve (MV) repair for leaflet prolapse at a medium-sized cardiothoracic center. Background. Contemporary reports on the outcome of MV repair at medium-sized cardiothoracic centers are sparse. Methods. Patients receiving open-heart surgery with MV repair due to primary mitral regurgitation caused by leaflet prolapse between 2015 and 2021, without active endocarditis, were included. Clinical data, complications, re-interventions, mortality, and echocardiographic data were retrospectively registered from electronical patient charts, both pre-operatively and from post-operative follow-ups. Results. One hundred and three patients were included, 83% male, with a mean age of 62 years. All-cause mortality was 9% during a median follow-up time of 4.9 years. Re-intervention rate on the MV was 4%. Post-operative complications before last available follow-up visit at median 3.0 years were infrequent, with new-onset atrial fibrillation/flutter in 16%, post-operative MV regurgitation grade II or above in 17% and post-operative tricuspid regurgitation grade II or above in 14%. Conclusions. These data demonstrate that surgical MV repair for leaflet prolapse at a medium-sized cardiothoracic center was associated with low re-intervention rate and few severe complications. The presented results are comparable to data from surgical high-volume centers, indicating that surgical MV repair can be safely performed at selected medium-sized cardiothoracic centers.

Mitral Annular Disjunction in the Context of Mitral Valve Prolapse: Identifying the At-Risk Patient.

Mitral annular disjunction (MAD), a separation between the left atrium/mitral valve annulus and the left ventricular myocardium, is frequently seen in patients with arrhythmic mitral valve prolapse. Although an association exists between MAD and ventricular arrhythmias, little is known regarding the identification of individuals at high risk. Multimodality imaging including echocardiography, computed tomography, cardiac magnetic resonance, and positron emission tomography can play an important role in both the diagnosis and risk stratification of MAD. Due to a paucity of data, clinical decision making in a patient with MAD is challenging and remains largely empirical. Although MAD itself can be corrected surgically, the prevention and treatment of associated arrhythmias may require medical therapy, catheter ablation, and an implantable cardioverter-defibrillator. Prospective data are required to define the role of implantable cardioverter-defibrillators, targeted catheter ablation, and surgical correction in selected, at-risk patients.

Five-year outcomes of different techniques for minimally invasive mitral valve repair in Barlow's disease.

OBJECTIVES: Barlow's disease is a specific sub-form of mitral valve (MV) disease, characterized by diffuse excessive tissue and multi segment prolapse. The anterolateral mini-thoracotomy represents the standard access for MV regurgitation in many centres. It still remains unclear which surgical technique provides the best results. Therefore, the aim of this study was to compare operative safety and mid-term outcomes after (i) isolated annuloplasty, (ii) use of additional artificial chordae or (iii) leaflet resection in patients suffering from Barlow's disease undergoing minimally invasive MV repair. METHODS: A consecutive series of patients suffering from Barlow's disease undergoing minimally invasive MV surgery between 2001 and 2020 were analysed (n = 246). Patients were grouped and analysed according to the used surgical technique. The primary outcome was a modified Mitral Valve Academic Research Consortium combined end-point of mortality, reoperation due to repair failure or reoccurrence of severe mitral regurgitation within 5 years. The secondary outcome included operative success and safety up to 30 days. RESULTS: No significant difference was found between the 3 surgical techniques with regard to operative safety (P = 0.774). The primary outcome did not differ between groups (P = 0.244). Operative success was achieved in 93.5% and was lowest in the isolated annuloplasty group (77.1%). Conversion to MV replacement was increased in patients undergoing isolated annuloplasty (P < 0.001). CONCLUSIONS: Isolated annuloplasty, use of additional artificial chordae and leaflet resection represent feasible techniques in Barlow patients undergoing minimally invasive MV surgery with comparable 5-year results. In view of the increased conversion rate in the annuloplasty group, the pathology should not be oversimplified.

Infant Barlow's Disease in Association with Atrial Septal Defect.

CLINICAL DATA: Female, seven years old, referred to our service complaining about congestive heart failure symptoms due to mitral valve regurgitation and atrial septal defect. Technical description: Echocardiographic findings compatible with Barlow's disease and atrial septal defect, ostium secundum type. OPERATION: She was submitted to mitral valvuloplasty with chordal shortening and prosthetic posterior ring (Gregori-Braile®) along with patch atrioseptoplasty. COMMENTS: Mitral valve regurgitation is a rare congenital heart disease and Barlow's disease is probably rarer. Mitral valve repair is the treatment of choice.

Mid-term clinical outcomes of totally endoscopic repair for mitral regurgitation in Barlow's disease.

OBJECTIVE: This study aimed to confirm the safety and feasibility of totally endoscopic repair for mitral regurgitation (MR) in Barlow's disease. METHODS: From June 2018 to December 2022, 21 consecutive Barlow's disease patients (aged 33 ± 12 years; 57.1% male) underwent totally endoscopic mitral valve (MV) repair with leaflets folding, multiple artificial chordae implantation and ring annuloplasty. The safety and feasibility of this technique was evaluated by its mid-term clinical outcomes. RESULTS: There was no operative death or complications. The mean cardiopulmonary bypass (CPB) time was 190 ± 41 (128-267) min, and the aortic cross-clamp time was 145 ± 32 (66-200) min. The average number of artificial chordae implantation was 2.9 ± 0.7 (1-4) pairs. The mean MV coaptation length was 1.4 ± 0.3 (0.8-1.8) cm, and the median transvalvular gradient was 1 [interquartile range (IQR), 1-2] mmHg. During a median follow-up time of 24 (IQR, 10-38) months, all patients showed persistent effective valve function with no significant MR or systolic anterior motion. CONCLUSIONS: Totally endoscopic repair was a safe, effective, and reproducible procedure with satisfied mid-term clinical outcomes for MR in Barlow's disease. However, further randomized and long-term follow-up studies were warranted to determine its clinical effects.

Large Animal Translational Validation of 3 Mitral Valve Repair Operations for Mitral Regurgitation Using a Mitral Valve Prolapse Model: A Comprehensive In Vivo Biomechanical Engineering Analysis.

BACKGROUND: Various mitral repair techniques have been described. Though these repair techniques can be highly effective when performed correctly in suitable patients, limited quantitative biomechanical data are available. Validation and thorough biomechanical evaluation of these repair techniques from translational large animal in vivo studies in a standardized, translatable fashion are lacking. We sought to evaluate and validate biomechanical differences among different mitral repair techniques and further optimize repair operations using a large animal mitral valve prolapse model. METHODS: Male Dorset sheep (n=20) had P2 chordae severed to create the mitral valve prolapse model. Fiber Bragg grating force sensors were implanted to measure chordal forces. Ten sheep underwent 3 randomized, paired mitral valve repair operations: neochord repair, nonresectional leaflet remodeling, and triangular resection. The other 10 sheep underwent neochord repair with 2, 4, and 6 neochordae. Data were collected at baseline, mitral valve prolapse, and after each repair. RESULTS: All mitral repair techniques successfully eliminated regurgitation. Compared with mitral valve prolapse (0.54±0.18 N), repair using neochord (0.37±0.20 N; P=0.02) and remodeling techniques (0.30±0.15 N; P=0.001) reduced secondary chordae peak force. Neochord repair further decreased primary chordae peak force (0.21±0.14 N) to baseline levels (0.20±0.17 N; P=0.83), and was associated with lower primary chordae peak force compared with the remodeling (0.34±0.18 N; P=0.02) and triangular resectional techniques (0.36±0.27 N; P=0.03). Specifically, repair using 2 neochordae resulted in higher peak primary chordal forces (0.28±0.21 N) compared with those using 4 (0.22±0.16 N; P=0.02) or 6 neochordae (0.19±0.16 N; P=0.002). No difference in peak primary chordal forces was observed between 4 and 6 neochordae (P=0.05). Peak forces on the neochordae were the lowest using 6 neochordae (0.09±0.11 N) compared with those of 4 neochordae (0.15±0.14 N; P=0.01) and 2 neochordae (0.29±0.18 N; P=0.001). CONCLUSIONS: Significant biomechanical differences were observed underlying different mitral repair techniques in a translational large animal model. Neochord repair was associated with the lowest primary chordae peak force compared to the remodeling and triangular resectional techniques. Additionally, neochord repair using at least 4 neochordae was associated with lower chordal forces on the primary chordae and the neochordae. This study provided key insights about mitral valve repair optimization and may further improve repair durability.

Relationship between fragmented QRS complex and early left ventricular dysfunction after mitral valve repair.

BACKGROUND: Preoperative left ventricular (LV) ejection fraction (PreLVEF) and preoperative LV end-systolic diameter (PreESD) are known predictors for postoperative LV dysfunction after mitral valve repair (MVR). Fragmented QRS (fQRS) evaluated in 12-derivation electrocardiography has widely been accepted as a sign of myocardial fibrosis. In the present study, we aimed to evaluate the relationship between fQRS in preoperative 12­lead electrocardiography (ECG) and postoperative LV dysfunction that develop after MVR in patients with severe primary mitral regurgitation (MR) due to mitral valve prolapse (MVP). METHODS: From 2019 to 2022, 49 patients who had undergone successful MVR surgery for severeMR caused by MVP were enrolled in the study. The preoperative and postoperative echocardiographic data were collected retrospectively. We analyzed the demographic, echocardiographic, operative and postoperative parameters to assess the relationship between fQRS and early postoperative LV dysfunction, defined as an LVEF<60%. RESULTS: PreLVEF of all patients were ≥ %65. A total of 22 patients had fQRS (44.9%) and postoperative LV dysfunction was found to be 36.7%. A significantly higher rate of fQRS was observed in the group with postoperative LV dysfunction compared to the group without (12 (66.7%) vs 10 (32.3%), p: 0.036). In multivariate analysis for fQRS, PreESD, preoperative pulmonary artery systolic pressure (PrePASP), preoperative atrial fibrillation (PreAF), and male gender, only fQRS was found to be a significant predictor of postoperative LV dysfunction (p: 0.003, OR: 4.28, 95% CI (1.15-15.96). CONCLUSION: fQRS was found to be a predictor of postoperative LV dysfunction in the early period after MVR. fQRS may be a readily available and cost-effective test that can be used in clinical practice to predict postoperative LV dysfunction in patients undergoing MVR.

Non-resectional cordal repair for Barlow mitral valve disease.

BACKGROUND: The redundant leaflet tissue and annular pathology of Barlow disease can make surgical repair challenging. We examined perioperative and late outcomes of a large cohort of patients with Barlow disease undergoing surgical repair. METHODS: Patients included in this analysis underwent mitral valve repair from 01/2004-11/2021 by a single surgeon. RESULTS: Of 2798 patients undergoing mitral valve operations, 46% (N.=1292) had degenerative pathology and 7% (N.=184) had Barlow disease. Of the 179 Barlow patients, median age at surgery was 62 (51-70) years; 64% were male (115/179). Rates of non-resectional cordal repair and resectional repair were 86% (154/179) and 14% (25/179). Among patients undergoing non-resectional repair, the median number of cordal pairs inserted on the anterior and posterior leaflets was 2 (2-3) and 4 (3-4). Incidence of return to bypass for systolic anterior motion of the mitral valve, perioperative death, stroke, and renal failure was 2% (4/179), 1% (2/179), 0% (0/179), and 0% (0/179). Rates of clinical and echocardiographic follow-up were 93% (165/177) and 89% (157/177). Median time to latest postoperative clinical and echocardiographic follow-up was 2.4 (0.8-6.1) and 2.1 (0.6-4.7) years. Mitral regurgitation grade at latest follow-up or time of repair failure was none/trace, mild, mild to moderate, and severe in 63% (98/157), 26% (41/157), 8% (12/157), and 4% (6/157); five of six patients with severe MR underwent reoperation. Since 2011 97% (139/144) of patients underwent cordal repair without resection. CONCLUSIONS: Non-resectional artificial cordal repair is safe and feasible in almost all patients with Barlow valves and is associated with excellent mid-term results.

Mitral valve repair for degenerative mitral regurgitation with Carpentier's functional classification type II in elderly patients: a single center experience.

OBJECTIVE: Mitral valve (MV) repair for Carpentier functional classification Type II (C-II) mitral regurgitation (MR) is widely accepted because of its efficacy. It is unclear whether MV repair has the same benefits in elderly patients as in younger patients because of their lower life expectancy. Herein, we examined the midterm results of MV repair for C-II mitral regurgitation, especially in patients aged ≧70 years. METHOD: A retrospective review was performed on 176 patients who underwent MV repair for C-II mitral regurgitation with a median age of 65 years; 55 (31%) patients were ≧70 years, and 124 were male (71%). Lesions of the mitral valve were isolated from the anterior leaflet (48 patients), posterior leaflet (113 patients), and both leaflets (15 patients), and included seven patients with Barlow's disease. We compared the outcomes between patients aged ≧70 years (≧70 years; median age, 76 years) and those aged < 70 years (median age, 60 years). RESULTS: In terms of the durability of MV repair in elderly patients, there were no significant differences in the rates of freedom from reoperation or MR recurrence at 5 years between patients aged < 70 years and those aged ≧70 years (reoperation:98% in < 70 years versus 89% in ≧70 years; P = 0.4053; MR recurrence:95% in < 70 years versus 81% in ≧70 years; P = 0.095). The mitral valve complexity was divided into two grades: Simple (isolated posterior mitral lesion) and Complex (isolated anterior lesion or both lesions). In patients aged < 70 years, there was no significant difference in the rate of freedom from MR recurrence at 5 years between the Simple and Complex groups (96% vs. 91%; P = 0.1029). In contrast, in patients aged ≧70 years, the MR recurrence rate at 3 years in Complex was significantly higher in the Complex group than in the Simple (100% vs. 80%; P = 0.0265). CONCLUSIONS: We studied the outcomes of MV repair for C-II in MR. In elderly patients, MR recurrence was higher in complex lesions than in simple lesions. MV replacement may be considered for elderly patients with complex mitral valve lesions, if appropriately selected.

Mitral valve early systolic billowing induces following annular expansion and leaflet augmentation in Barlow's disease: sequential analysis using 3D echocardiography.

AIMS: Although systolic expansion of the annulus has been recognized in Barlow's disease, the mechanisms of the unique pathological movement of the annulus and its relation to the leaflet augmentation have not yet been clarified. We aimed to investigate the detailed mechanisms of the characteristic mitral apparatus dynamics in Barlow's disease by frame-by-frame sequential geometric analysis using real-time 3D transoesophageal echocardiography. METHODS AND RESULTS: Fifty-three patients with Barlow's disease and severe mitral regurgitation without torn chordae, as well as 10 controls, were included. We evaluated geometric changes in the mitral complex using 3D transoesophageal echocardiography at five points during systole. To identify early systolic billowing of leaflets, the annulo-leaflet angle was measured. We also performed a more detailed analysis in four consecutive frames just before and after leaflet free-edge prolapse above the annulus plane. The median annulo-leaflet angle of both leaflets in early systole was >0° (above annulus plane) in patients with Barlow's disease, and billowing of the leaflet body was observed from early systole. The prolapse volume of both leaflets increased markedly from early to mid-systole [1.60 (0.85-2.80) to 4.00 (2.10-6.45) mL; analysis of variance (ANOVA), P < 0.001; post hoc, P < 0.05]. With frame-by-frame analysis, dynamic augmentation of the annulus and leaflets developed between frames just before and just after leaflet free-edge prolapse (ANOVA, P < 0.01; post hoc, P < 0.05). CONCLUSION: In Barlow's disease, early systolic billowing of the mitral leaflet induces systolic annulus expansion followed by leaflet augmentation and leaflet free-edge prolapse.

Biomechanical engineering analysis of neochordae length's impact on chordal forces in mitral repair.

OBJECTIVES: Artificial neochordae implantation is commonly used for mitral valve (MV) repair. However, neochordae length estimation can be difficult to perform. The objective was to assess the impact of neochordae length changes on MV haemodynamics and neochordal forces. METHODS: Porcine MVs (n = 6) were implanted in an ex vivo left heart simulator. MV prolapse (MVP) was generated by excising at least 2 native primary chordae supporting the P2 segments from each papillary muscle. Two neochordae anchored on each papillary muscle were placed with 1 tied to the native chord length (exact length) and the other tied with variable lengths from 2× to 0.5× of the native length (variable length). Haemodynamics, neochordal forces and echocardiography data were collected. RESULTS: Neochord implantation repair successfully eliminated mitral regurgitation with repaired regurgitant fractions of approximately 4% regardless of neochord length (P < 0.01). Leaflet coaptation height also significantly improved to a minimum height of 1.3 cm compared with that of MVP (0.9 ± 0.4 cm, P < 0.05). Peak and average forces on exact length neochordae increased as variable length neochordae lengths increased. Peak and average forces on the variable length neochordae increased with shortened lengths. Overall, chordal forces appeared to vary more drastically in variable length neochordae compared with exact length neochordae. CONCLUSIONS: MV regurgitation was eliminated with neochordal repair, regardless of the neochord length. However, chordal forces varied significantly with different neochord lengths, with a preferentially greater impact on the variable length neochord. Further validation studies may be performed before translating to clinical practices.

Feasibility of concomitant exclusion of left atrial appendage during novel transapical off-pump beating heart mitral valve repair.

The AtriClip device enables the safe and reproducible epicardial clipping of the left atrial appendage. Transapical off-pump beating heart mitral valve repair using NeoChord DS100 Artificial Chordae Delivery System has matured and become more standardized. We aim to evaluate the feasibility of combining NeoChord repair and left atrial appendage exclusion in a single procedure through the same minithoracotomy in patients with mitral valve prolapse and atrial fibrillation. From 2018 to 2019, seven patients with severe mitral regurgitation and atrial fibrillation underwent transesophageal echocardiography-guided transapical off-pump mitral valve repair with the novel NeoChord DS 1000 system and concomitant left atrial appendage exclusion using the AtriClip Pro II device. Both procedures were performed via left mini-thoracotomy. The AtriClip device was applied after the NeoChord repair was done. All seven patients had less than moderate mitral regurgitation after the NeoChord repair and successful left atrial appendage occlusion. There were no device or procedure-related complications. Clinical follow-up revealed significant symptomatic improvement, and no cardiovascular complications were reported. Transesophageal echocardiography at 6-12 months post-procedure showed stable left atrial appendage occlusion with no residual flow between the left atrium and the left atrial appendage and a stump of less than 5 mm. Beating heart epicardial clipping of the left atrial appendage using AtriClip concomitant with transapical mitral valve repair using Neochord DS 1000 system is a feasible and safe treatment option in mitral valve prolapse and atrial fibrillation in patients with limited indications. However, its safety needs to be confirmed in a larger series of patients.