Conventional Mitral Valve Research Articles

Abstract 14956: Improved Operative Efficiency for Minimally Invasive Mitral Valve Surgery at a Low-volume Center

Introduction: When implementing a minimally invasive cardiac surgery program, increased surgical times may serve as a deterrent. Results demonstrating parity in operative times between minimally invasive (MIMVR) and conventional mitral valve replacement/repair (CMVR) have been limited to high-volume centers. The purpose of this study was to examine operative efficiency for MIMVR in a low-volume center. Methods: All patients having undergone non-emergent, isolated MIMVR or CMVR at the New Brunswick Heart Centre from 2011-2017 were considered. Detailed peri-operative data, including cross clamp (XC), cardiopulmonary bypass (CPB), skin-to-skin (SS) and total operative (TO) times, were collected. Patients were assigned to one of 3 eras: 2011-2013, 2014-2015, 2016-2017. Unadjusted comparisons were made between MIMVR and CMVR over the entire study period and within each era. Results: A total of 168 patients were included (MIMVR: 64; CMVR: 104). There was an increase in the number of MIMVR cases over time (2011-2013: 19; 2014-2015: 17; 2016-2017: 28). Patients undergoing MIMVR were less likely to be ≥70years (29.7% vs. 47.1%, p=0.04) and to have had NYHA-IV symptoms (17.2% vs. 41.3%, p=0.002), previous cardiac surgery (4.7% vs. 23.1%, p=0.003) or urgent presentation (12.5% vs. 35.6%, p=0.002). Intra-operatively, MIMVR patients were more likely to have undergone a mitral valve repair (65.1% vs. 29.1%, p<0.0001). No differences were noted in rates of in-hospital mortality (0.0% vs. 5.1%, p=0.29). Median operative times were uniformly longer among MIMVR patients between 2011-2013. However, in 2014-2015 and 2016-2017, these times improved to the point where no significant differences in operative efficiency were noted (Figure). Conclusions: Improved operative efficiency may be safely achieved for MIMVR in a low-volume center. The results of this study should encourage low-volume centers to adopt a minimally invasive approach to isolated mitral valve surgery.

Isolated left atrial cryoablation of atrial fibrillation in conventional mitral valve surgery.

Recent trends of surgery for atrial fibrillation (AF) are towards more safe and effective energy sources, as well as to simplified sets of atrial lesions. One hundred eighteen (mean age, 67.4±9.2years) selected patients with paroxysmal/persistent AF and mitral valve (MV) disease underwent cryoablation of AF combined with conventional (not via mini-thoracotomy) MV surgery; the lesion set was limited to only the left atrium. Multivariable analyses identified predictors of cardiac rhythm at hospital discharge and follow-up. There were 7 (5.9%) hospital deaths; 33 (28%) patients were discharged on AF. Higher values of preoperative left atrial volume index (odds ratio [OR]=1.07, 95% confidence interval [95%CI]: 1.01-1.13) and mixed etiology of MV disease (OR=4.19, 95%CI: 1.23-14.2) were predictors of hospital discharge on AF. Seventy-four (66.7%) patients were on stable sinus rhythm at follow-up (median period, 6.6years); the 1, 5, and 10-year nonparametric estimates of adjusted freedom from AF were 98.1%, 89.2% and 45.6%, respectively. Higher values of preoperative systolic pulmonary artery pressure (hazard ratio [HR]=HR=1.04, 95%CI: 1.01-1.08) and AF at hospital discharge (HR=4.14, 95%CI: 1.50-11.4) were predictors of AF at follow-up. During conventional MV surgery, a cryo-lesion set limited to only the left atrium may give good, immediate and long-term results. Left atrial dilation and mixed etiology of MV disease were predictors of hospital discharge on AF. Preoperative pulmonary hypertension and AF at discharge combined with an increased risk of AF at follow-up.

Analysis of clinical outcome and postoperative organ function effects in a propensity-matched comparison between conventional and minimally invasive mitral valve surgery.

Minimally invasive mitral valve (MV) surgery (MIVT) is increasingly performed with excellent clinical outcome, despite longer procedural times. This study analyzes clinical outcomes and effects on secondary organ functions in a propensity-matched comparison with conventional MV surgery. Out of 439 patients undergoing MV surgery from January 2005 to May 2017, 233 patients were included after propensity-matching: 90 sternotomy patients and 143 MIVT patients. Endpoints focused on survival, quality of MV repair, and organ function effects through analysis of biomarkers and functional parameters. Regardless of longer cardiopulmonary bypass (sternotomy: 101(IQR33) min-MIVT:143(IQR45) min, p < .001) and cardioplegic arrest times(sternotomy: 64(IQR25) min-MIVT:90(IQR34) min, p < .001), no differences in survival nor complication rate were found. Effect on renal function(creatinine, p = .751 - ureum, p = .538 - glomerular filtration, p = .848), myocardial damage by troponine I level (sternotomy:1.8 ± 3.9 ng/ml - MIVT:1.2 ± 1.3 ng/ml, p = .438) and prolonged ventilatory support >24 h (sternotomy:5.5% - MIVT:8.4%, p = .417) were comparable. The systemic inflammatory reaction by postoperative C-reactive protein count was markedly lower for MIVT(p < .001). Increased rhadomyolysis was found after MIVT surgery, based on a significant elevation of creatinine-kinase levels(sternotomy: 431 ± 237 U/L - MIVT: 701 ± 595 U/L, p < .001). Despite an inherent learning curve, minimally invasive MV surgery guarantees a clinical outcome and MV repair quality, at least non-inferior to those of MV surgery via sternotomy. Notwithstanding longer cardiopulmonary bypass and cardiac arrest times, the impact on secondary organ function is negligible, except for a lower systemic inflammatory response. The postoperative increase of CK-enzymes suggestive for enhanced rhabdomyolysis needs to be accounted for when procedural times tend to exceed the critical time threshold for severe limb ischemia.

MITRACLIP VS SURGERY IN PATIENTS WITH ISCHEMIC MITRAL REGURGITATION: A PROPENSITY SCORE ANALYSIS

Ischemic mitral regurgitation (IMR) results from adverse left ventricular remodeling after myocardial infarction. Mitral valve (MV) surgery is a common treatment for patients with severe symptomatic IMR. MitraClip, a transcatheter MV repair procedure has also been used for high-risk patients. In this study, we sought to compare postoperative and three-years outcomes of MV surgery and MitraClip in patients with IMR. Retrospective cohort study of patients undergoing surgical (2003-2006) or transcatheter (2010-2016) therapy for severe IMR at the Montréal Heart Institute. Outcomes were compared using Cox regression models including propensity score as an independent variable. 307 patients with IMR were treated: 221 (72%) received conventional MV surgery, while 86 (28%) had MitraClip. The MitraClip cohort was older (p <0.001), had larger ventricular diameters (p <0.001) but had similar ejection fraction as the surgery group (p= 0.297). The adjusted analysis showed that MitraClip had a lower in-hospital mortality (OR 0.05 [0.01-0.31] p=0.001) and lower acute kidney injury (OR 0.13 [0.04-0.39]; P <0.001). There were no differences in postoperative bleeding, or rates of atrial fibrillation. The surgery group had a significantly longer postoperative hospital length of stay (9.50 ± 5.50 vs 4.60 ±2.60 days, p <0.001). At three-year follow-up, MitraClip was associated with a lower mortality (HR 0.45 [0.21-0.86]; p=0.017). There was no difference between the groups for hospitalization for congestive heart failure (HR 1.31 [0.29-5.84]; p= 0.724). Recurrence of MR > 2 was higher in the MitraClip cohort, 27% compared to 4.7% in the surgery group (HR 10.11 [1.24-82.51]; p= 0.031). In this retrospective cohort study of IMR, treatment with MitraClip was associated with lower in-hospital and long-term mortality, lower postoperative complications and a shorter hospital length of stay than conventional MV surgery. At three years there was a higher recurrence of MR > 2 in the MitraClip group but this was not associated with worse NYHA class or hospitalization for heart failure.

Beating-Heart Mitral Valve Repair Using a Novel ePTFE Cordal Implantation Device: A Prospective Trial

BackgroundConventional mitral valve (MV) operations allow direct anatomic assessment and repair on an arrested heart, but require cardiopulmonary bypass, aortic cross-clamping, sternotomy or thoracotomy, and cardioplegic cardiac arrest, and are associated with significant perioperative disability, and risks of morbidity and mortality. ObjectivesThis study evaluated safety and performance of a transesophageal echocardiographic-guided device designed to implant artificial expanded polytetrafluoroethylene (ePTFE) cords on mitral leaflets in the beating heart. MethodsIn a prospective multicenter study, 30 consecutive patients with severe degenerative mitral regurgitation (MR) were treated with a mitral valve repair system (MVRS) via small left thoracotomy. The primary (30-day) endpoint was successful implantation of cords with MR reduction to moderate or less. ResultsThe primary endpoint was met in 27 of 30 patients (90%). Three patients required conversion to open mitral surgery. There were no deaths, strokes, or permanent pacemaker implantations. At 1 month, MR was mild or less in 89% (24 of 27) and was moderate in 11% (3 of 27). At 6 months, MR was mild or less in 85 % (22 of 26), moderate in 8% (2 of 26), and severe in 8% (2 of 26). Favorable cardiac remodeling at 6 months included decreases in end-diastolic (161 ± 36 ml to 122 ± 30 ml; p < 0.001) and left atrial volumes (106 ± 36 ml to 69 ± 24 ml; p < 0.001). The anterior-posterior mitral annular dimension decreased from 34.7 ± 5.8 mm to 28.2 ± 5.1 mm; p < 0.001 as did the mitral annular area (10.0 ± 2.7 cm2 vs. 6.9 ± 2.0 cm2; p < 0.0001). ConclusionsMVRS ePTFE cordal implantation can reduce the invasiveness and morbidity of conventional MV surgery. The device’s safety profile is promising and prospective trials comparing the outcomes of the MVRS to conventional MV repair surgery are warranted. (CE Mark Study for the Harpoon Medical Device [TRACER]; NCT02768870)

Transapical Beating-Heart Mitral Valve Repair With an Expanded Polytetrafluoroethylene Cordal Implantation Device: Initial Clinical Experience.

Degenerative mitral valve (MV) disease is a common cause of severe mitral regurgitation (MR) and accounts for the majority of MV operations. Conventional MV surgery requires cardiopulmonary bypass, aortic cross-clamping, cardioplegia, and a thoracotomy or sternotomy and, therefore, is associated with significant disability, risks, and unpredictable rates of MV repair. Transesophageal echocardiography-guided beating-heart MV repair with expanded polytetrafluoroethylene cordal insertion has the potential to significantly reduce surgical morbidity. We report the first-in-human clinical experience with a novel preformed expanded polytetrafluoroethylene knot implantation device (Harpoon TSD-5) designed to treat degenerative MR. Through a small left thoracotomy, the device was inserted into the heart and guided by transesophageal echocardiography to the ventricular surface of the prolapsed leaflet. Multiple expanded polytetrafluoroethylene cords were anchored in the leaflet and then adjusted to the correct length to restore MV leaflet coaptation and secured at the epicardium. Eleven patients with posterior leaflet prolapse and severe MR, with mean±SD age of 65±13 years and mean ejection fraction of 69±7%, were treated with 100% procedural success. Immediate postprocedural mean MR grade was trace. At 1 month, the mean MR grade was mild with significant decreases in end-diastolic volume (139 to 107 mL; P=0.03) and left atrial volume (118 to 85 mL; P=0.04). A novel device used for beating-heart image-guided MV repair demonstrates a significant reduction in MR with favorable left ventricular and left atrial reverse remodeling. This approach has the potential to decrease invasiveness and surgical morbidity. Further follow-up is necessary to assess long-term efficacy. URL: https://clinicaltrials.gov. Unique identifier: NCT02432196.

Randomized Comparison of Percutaneous Repair and Surgery for Mitral Regurgitation: 5-Year Results of EVEREST II

BackgroundIn EVEREST II (Endovascular Valve Edge-to-Edge Repair Study), treatment of mitral regurgitation (MR) with a novel percutaneous device showed superior safety compared with surgery, but less effective reduction in MR at 1 year. ObjectivesThis study sought to evaluate the final 5-year clinical outcomes and durability of percutaneous mitral valve (MV) repair with the MitraClip device compared with conventional MV surgery. MethodsPatients with grade 3+ or 4+ MR were randomly assigned to percutaneous repair with the device or conventional MV surgery in a 2:1 ratio (178:80). Patients prospectively consented to 5 years of follow-up. ResultsAt 5 years, the rate of the composite endpoint of freedom from death, surgery, or 3+ or 4+ MR in the as-treated population was 44.2% versus 64.3% in the percutaneous repair and surgical groups, respectively (p = 0.01). The difference was driven by increased rates of 3+ to 4+ MR (12.3% vs. 1.8%; p = 0.02) and surgery (27.9% vs. 8.9%; p = 0.003) with percutaneous repair. After percutaneous repair, 78% of surgeries occurred within the first 6 months. Beyond 6 months, rates of surgery and moderate-to-severe MR were comparable between groups. Five-year mortality rates were 20.8% and 26.8% (p = 0.4) for percutaneous repair and surgery, respectively. In multivariable analysis, treatment strategy was not associated with survival. ConclusionsPatients treated with percutaneous repair more commonly required surgery for residual MR during the first year after treatment, but between 1- and 5-year follow-up, comparably low rates of surgery for MV dysfunction with either percutaneous or surgical therapy endorse the durability of MR reduction with both repair techniques. (EVEREST II Pivotal Study High Risk Registry; NCT00209274)

Trimetazidine improves health-related quality of life in operated valvular heart disease

Purpose: Successful surgical intervention in valvular heart disease has been shown to prolong and improve quality of life. We aimed to evaluate postoperative health-related quality of life (HRQoL) in patients following trimetazidine therapy. Methods: 120 patients [aged 53.2±2.1 years, 60% males] 2–4 weeks after conventional aortic (n=64) and mitral (n=56) valve replacement by mechanical prostheses (40% due to degenerative, 35% rheumatic, 10% myxomatous, 8.3% congenital valve diseases and 6.7% infectious endocarditis) were randomized 1:1 to receive either conventional therapy or trimetazidine (35 mg twice daily) added to standard treatment. HRQoL was assessed at baseline and 12 months using the Short Form (SF-36 v.1) Health Survey. Results: There were no significant differences between trimetazidine and control group at baseline. Patients reported poor postoperative HRQoL. In both groups, SF-36 scores substantially rose after follow-up. Trimetazidine patients had significant higher improvements in HRQoL over time compared to controls. One patient died in the control group (p=0.89). View this table: Health-related quality of life Conclusions: Mechanical valves patients commonly suffer from severe HRQoL impairment. Long-term trimetazidine, added to conventional treatment, greatly improves HRQoL. The results provide support for trimetazidine as a promising therapy for patients with heart valve prostheses.

Evaluating the Effect of Three-Dimensional Visualization on Force Application and Performance Time during Robotics-Assisted Mitral Valve Repair

The purpose of this study was to determine the effect of three-dimensional (3D) binocular, stereoscopic, and two-dimensional (2D) monocular visualization on robotics-assisted mitral valve annuloplasty versus conventional techniques in an ex vivo animal model. In addition, we sought to determine whether these effects were consistent between novices and experts in robotics-assisted cardiac surgery. A cardiac surgery test-bed was constructed to measure forces applied during mitral valve annuloplasty. Sutures were passed through the porcine mitral valve annulus by the participants with different levels of experience in robotics-assisted surgery and tied in place using both robotics-assisted and conventional surgery techniques. The mean time for both the experts and the novices using 3D visualization was significantly less than that required using 2D vision (P < 0.001). However, there was no significant difference in the maximum force applied by the novices to the mitral valve during suturing (P = 0.7) and suture tying (P = 0.6) using either 2D or 3D visualization. The mean time required and forces applied by both the experts and the novices were significantly less using the conventional surgical technique than when using the robotic system with either 2D or 3D vision (P < 0.001). Despite high-quality binocular images, both the experts and the novices applied significantly more force to the cardiac tissue during 3D robotics-assisted mitral valve annuloplasty than during conventional open mitral valve annuloplasty. This finding suggests that 3D visualization does not fully compensate for the absence of haptic feedback in robotics-assisted cardiac surgery.

Can the edge-to-edge technique provide durable results when used to rescue patients with suboptimal conventional mitral repair?

The 'edge-to-edge' technique (EE) can be used as a bailout procedure in case of a suboptimal result of conventional mitral valve (MV) repair. The aim of this study was to assess the long-term outcomes of this technique used as a rescue procedure. From 1998 to 2011, of 3861 patients submitted to conventional MV repair for pure mitral regurgitation (MR), 43 (1.1%) underwent a rescue edge-to-edge repair for significant residual MR at the intraoperative hydrodynamic test or at the intraoperative transoesophageal echocardiography. Residual MR was due to residual prolapse in 30 (69.7%) patients, systolic anterior motion in 12 (27.9%) and post-endocarditis leaflet erosion in 1 (2.3%). According to the location of the regurgitant jet, the edge-to-edge suture was performed centrally (60.5%) or in correspondence with the anterior or posterior commissure (39.5%). The original repair was left in place. There were no hospital deaths. Additional cross-clamp time was 15.2 ± 5.6 min. At hospital discharge, all patients showed no or mild MR and no mitral stenosis. Clinical and echocardiographic follow-up was 97.6% complete (median length 5.7 years, up to 14.6 years). At 10 years, actuarial survival was 89 ± 7.4% and freedom from cardiac death 100%. Freedom from reoperation and freedom from MR ≥ 3+ at 10 years were both 96.9 ± 2.9%. At the last echocardiogram, MR was absent or mild in 37 patients (88%), moderate in 4 (9.5%) and severe in 1 (2.4%). No predictors for recurrence of MR ≥ 2+ were identified. The mean MV area and gradient were 2.8 ± 0.6 cm(2) and 2.7 ± 0.9 mmHg. NYHA I-II was documented in all cases. A 'rescue' EE can be a rapid and effective option in case of suboptimal result of 'conventional' MV repair. Long-term durability of the repair is not compromised.

Conventional versus complete chordal-sparing mitral valve replacement: eff ects on left ventricular function and end-systolic stress

Background This study aims to assess the eff ects of bileafl et preservation versus conventional technique during mitral valve replacement (MVR) on left ventricular functions and end-systolic stress (ESS).Methods Between September 2005 and January 2009, sixty-fi ve patients with mitral regurgitation underwent MVR surgery. In a non-randomized fashion, 34 patients had conventional MVR without chordal/leafl et preservation (group I, c-MVR), and 31 had MVR with total chordal/bileafl et preservation (group II, b-MVR). A prospective clinical and echocardiographic follow-up of patients was performed preoperatively, at 3 months and by 1 year postoperatively.Results Left ventricular end-systolic/end-diastolic dimensions and volumes decreased by 1 year in the b-MVR group. Left ventricular ESS decreased only in the bileafl et sparing MVR group after surgery, and this decrease was signifi cant by 1 year, compared with the c-MVR group (P= 0.008). Left atrial diameter signifi cantly decreased in both groups. Only one patient died, due to posterior wall rupture after a c-MVR procedure. One patient undergoing a b-MVR procedure needed re-operation because of prosthetic valve endocarditis.Conclusion Bileafl et preservation during MVR has a benefi cial eff ect on left ventricular function, compared with conventional MVR. Left ventricular ESS improves after bileafl et-sparing MVR and may be an important indicator of myocardial function after mitral valve surgery.

The Role of Intraoperative Transesophageal Echocardiography in Robotic Mitral Valve Repair

Robotic mitral valve (MV) repair is a new surgical technique that uses small incisions. Previous studies have demonstrated the importance of intraoperative transesophageal echocardiography (TEE) for conventional MV surgery with the use of a median sternotomy incision. The aim of the present study was to delineate the utility of intraoperative TEE in robotic MV repair. Intraoperative TEE was performed in 22 consecutive patients undergoing robotic MV repair for severe degenerative mitral regurgitation (MR) over a period of 2 years. Before cardiopulmonary bypass (CPB), TEE was used to define the lesions of degenerative MR and the localization of the prolapsed leaflets, and to evaluate the severity of MR. During establishment of peripheral CPB, TEE was used to guide placement of the cannulae in the inferior vena cava (IVC), superior vena cava (SVC), and ascending aorta (AAO). After weaning from CPB, TEE was used to assess immediately the competency of the surgical repair. Agreement between TEE and surgical findings was excellent: 92.3% (kappa, 0.873) for the lesions of degenerative MR, and 98.5% (kappa, 0.943) for the localization of the prolapsed leaflets. Under TEE guidance, all the cannulae (100%) in the SVC, IVC, and AAO were placed correctly. TEE demonstrated all the patients (100%) had successful robotic MV repairs. Intraoperative TEE is a valuable adjunct in the assessment of robotic MV repair. (Echocardiography 2011;28:85-91).