Percutaneous mitral valve repair: A new treatment for mitral regurgitation

Mitral valve disease affects more than 4 million people in the United States. The gold standard of treatment in these patients is surgical repair or replacement of the valve with a prosthesis. The MitraClip (Abbott Vascular, Menlo Park, CA) is a new technology, which offers an alternative to open surgical repair or replacement via a minimally invasive route. We present an evidence-based clinical update that provides an overview of this technology as it relates to managing patients with significant mitral regurgitation. This review article is particularly useful to noninterventional cardiologists and interventional cardiologists who will be managing patients with this novel technology in increased volumes over the next decade but who do not perform this procedure.     

Percutaneous mitral valve repair for secondary mitral valve regurgitation: A systematic review and meta-analysis

BackgroundThe first two randomized control trials (RCTs) studying the role of MitraClip in patients with secondary mitral regurgitation (MR) had antagonizing results. We, therefore, performed an updated meta-analysis of RCTs and propensity score-matched observational studies investigating the role of MitraClips in patients with secondary MR. A novel method of Kaplan Meier Curve reconstruction from derived individual patient data will be used to compare the survival probability of control groups in COAPT and MITRA HF trail, and hence, access inter-study heterogeneity.MethodsMedline and Cochrane databases was used for systematic search. We used the Mantel-Haenszel method with a random-effect model to calculate risk ratio (RR) with 95% confidence interval (CI) and inverse variance method with a random-effect model to calculate the mean difference (MD) with 95% confidence interval (CI). We used a fixed-effect approach for meta-regression.ResultsMitraClip reduced the risk of all-cause mortality [RR: 0.72, CI: 0.55–0.95, P value = 0.02, I2 = 55%, χ²P-value = 0.08] and readmission [RR: 0.62, CI: 0.42–0.92, P value = 0.02, I² = 90%, χ²P-value<0.01] at two years follow-up. There was no effect of MitraClip on change in cardiovascular mortality and 6 m walking distance at 12 months follow-up. Meta-regression indicated left ventricular end diastolic volume and age among the factors affecting outcomes. Reconstructed Kaplan Meier curves confirmed considerable heterogeneity among patients randomized in MITRA HF and COAPT trial.ConclusionThe present meta-analysis confirms the beneficial role of percutaneous mitral valve repair in patients with secondary MR. However, all the results were associated with considerable heterogeneity.     

Percutaneous transcatheter repair for mitral regurgitation

Percutaneous mitral valve repair for patients with mitral regurgitation is emerging as an exciting new area in interventional cardiology. Because of the complex etiologies of mitral regurgitation, multiple technologies are being tested in preclinical and clinical settings to evaluate their efficacy and safety. Direct percutaneous repair of the mitral valve is undergoing Phase II and Phase I trials using the Evalve mitral clip and Edwards mitral suture devices, respectively. Devices placed in the coronary sinus might be applicable for specific patient populations where the mitral annulus and coronary sinus have favorable anatomic relationships. Other devices employ intra-atrial or intra-ventricular approaches to the mitral annulus to move the posterior annulus forward and thereby improve mitral valve coaptation. How many of these new techniques will ultimately be successful for clinical use will depend on the results of ongoing clinical trials.     

Mitral valve repair for mitral regurgitation

We analyzed the results of mitral valve repair in 81 consecutive patients with severe mitral regurgitation. Of these patients, 66.6% had myxomatous degeneration, 11% ischemic disease, 8% chordal rupture, 5% congenital disease, and 3.7% endocarditis. Repair could not be achieved in five patients, and valve replacement was necessary. Six died during surgery (mortality 7%). During follow-up (mean 30 [8] months), there was one death due to refractory ischemic heart failure and mitral regurgitation (>or= 2/4) was observed in 11 patients. A good result (i.e., survival without a prosthesis, major complications, or mitral regurgitation >1/4) was obtained in 78% of patients with myxomatous degeneration versus 48% of those with other etiologies (P=.023). A good result was obtained more frequently in cases of isolated posterior cusp degeneration than in those involving degeneration of both cusps (85% vs 70%; P=.03).     

Troublesome factors in mitral valve repair for mitral valve regurgitation

Limitations in the long-term results of medical treatment for mitral regurgitation are well recognized, but the advances in its surgical repair have produced good results. Therefore, early surgical intervention has been the focus of treatment in Europe and America. Increased surgical intervention depends on the development of technical skills in mitral reconstruction. This study investigated presurgical factors making surgical reconstruction difficult in 103 patients who underwent mitral operations performed from April 1994 to September 1997 in our hospital. Records were reviewed retrospectively for etiology, type of operation, and the immediate result of operation. The etiology of mitral regurgitation was prolapse in 65 patients (63%), restriction in 14, normal in 11, infectious endocarditis in 10, and others in 3. The type of prolapse involved the anterior leaflet in 22 patients (34%), posterior in 28 (43%), and both leaflets in 15 (23%). Valve repair was attempted in 74 patients, of which 16 were switched to valve replacement during operation. These included anterior leaflet prolapse in 9 patients, posterior leaflet in 1, both leaflets in 3, restriction in 2 and infectious endocarditis in 1. The success rate for reconstruction of anterior leaflet prolapse was not high. The cause of mitral regurgitation was mostly prolapse of the mitral valve, in our country as well as in Europe and America. Prolapsed posterior leaflet is much more common in Europe and America, and there is a high success rate reported for its valve reconstruction. In contrast, this study cannot recommend earlier surgical intervention because of difficult repair for anterior leaflet prolapse.     

Percutaneous approaches to mitral valve regurgitation

Mitral regurgitation is a common problem associated with significant morbidity and mortality. Mitral valve surgery has been the treatment of choice for symptomatic patients with severe mitral regurgitation or asymptomatic patients with high-risk clinical features. However, a significant number of patients remain untreated related mainly due to a projected high surgical risk. Therefore, alternative percutaneous treatments including indirect annuloplasty, which takes advantage of the coronary sinus, and direct annuloplasty have recently been explored. Most recently, promising results of the first randomized trial comparing conventional mitral valve surgery to percutaneous therapy with a clip creating a double orifice much like the surgical Alfieri approach have been presented. Finally, percutaneous mitral valve replacement in an animal model has been pursued. This review serves to familiarize the reader with some anatomical concepts and devices for percutaneous mitral repair.     

非风湿性二尖瓣关闭不全的外科治疗

目的 评价二尖瓣瓣膜成形术(MVP)对非风湿性二尖瓣关闭不全的疗效.方法 2001年1月至2005年12月我院非风湿二尖瓣关闭不全心脏患者23例接受手术治疗,男性13例,女性10例,年龄16～71(49.4±5.7)岁.非风湿性二尖瓣关闭不全病因中,其中先天性5例,退行性改变12例,缺血性改变4例,感染性病变2例.术前超声心动图示二尖瓣均为大量返流,术前患者心功能Ⅲ级19例,Ⅳ级4例.瓣环成形13例,腱索短缩3例,裂修补1例,腱索转移1例,后瓣环成形 裂修补4例,部分瓣膜切除 裂修补1例.同期冠状动脉搭桥术5例,主动脉瓣膜置换术3例.结果 早期死亡率4.3%(1例),术后超声心动图示无或少量二尖瓣反流13例,少量到中量反流8例,大量反流1例.随访6～60个月(平均27个月),出院后2例患者死亡,再次手术1例.存活20例,心功能Ⅰ～Ⅱ级.结论 应用二尖瓣膜成形术治疗非风湿性二尖瓣关闭不全是可行的,可以取得良好的效果,外科技术值得进一步推广.     

Mitral valve repair for nonrheumatic mitral regurgitation

BACKGROUND: We studied the results of mitral valve repair in patients with severe mitral regurgitation of nonrheumatic etiology. METHODS AND RESULTS: Between January 1988 and April 2002, 116 patients, of which 59 were male and 57 female, with severe mitral regurgitation of nonrheumatic etiology, underwent mitral valve repair using a variety of techniques. Their mean age was 26.4 years (range 2-67 years). The cause of mitral regurgitation was congenital in 56 patients, myxomatous in 44, infective endocarditis in 7, and ischemic in 9. Ninety patients were in preoperative New York Heart Association class III, and 26 in class IV. Reparative procedures included posterior teflon felt collar annuloplasty (modified Cooley's) in 80 patients, chordal shortening in 37, cusp excision in 34, cleft closure in 8, chordal transfer in 6, and neochordae in 3. The early mortality was 3.4% (4 patients). Follow-up ranged from 1 to 167 months (mean 47 months), and was 95% complete. There were 2 late deaths (1.7%). Six patients (5.2%) underwent reoperation for severe mitral regurgitation post-repair. Of the remaining 104 patients, 90 (86.5%) had no or trivial mitral regurgitation at the last follow-up. Actuarial, reoperation-free, and event-free survival at 130 months was 93%+/-3.6%, 89.9%+/-6%, and 69.7%+/-13.7%, respectively. Ninety-two patients (88.5%) were in New York Heart Association class I at the last follow-up. CONCLUSIONS: Mitral valve repair in nonrheumatic mitral regurgitation patients provides satisfactory results with current surgical techniques, and is the preferred option in this subset of patients.     

Percutaneous leaflet repair and annuloplasty for mitral regurgitation

Percutaneous therapy for the treatment of mitral regurgitation has emerged rapidly over the past few years. Most of the percutaneous approaches are modifications of existing surgical approaches to mitral annuloplasty or leaflet repair. Catheter-based devices mimic these surgical approaches with less procedural morbidity and mortality as a consequence of their less invasive nature. Percutaneous annuloplasty can be achieved indirectly via the coronary sinus or directly from retrograde left ventricular access. Catheter-based leaflet repair is accomplished using an implantable clip to mimic the surgical edge-to-edge technique. Several of these percutaneous approaches have been successfully used in patients to demonstrate proof of concept, while others have already stopped further development. There is increasing experience in both trials and practice to begin to define the clinical utility of percutanenous leaflet repair, and annuloplasty approaches are undergoing significant development.     

Percutaneous edge-to-edge mitral valve repair

In the past few years, a myriad of technologies have been developed for percutaneous repair of the mitral valve for patients with severe mitral regurgitation (MR) and at high risk for traditional open-heart mitral valve surgery. Among them, MitraClip has emerged as the only clinically safe and effective method for percutaneous mitral valve repair. This device mimics the surgical edge-to-edge mitral valve repair initially described by Dr. Alfieri. In this article, we review the current clinical evidence on the use of the MitraClip—from the randomized control trial EVEREST II to the information derived from expert high-volume centers.     

Outcome after mitral valve repair for functional ischemic mitral regurgitation

BACKGROUND AND AIM OF THE STUDY: Functional ischemic mitral regurgitation (MR) can occur secondary to coronary artery disease. Controversy exists regarding management of these patients. Mitral valve annuloplasty in conjunction with coronary artery bypass grafting (CABG), accepted as the best treatment for severe MR, has been disputed for lesser degrees of regurgitation due to higher mortality. The results of a combined procedure approach were reviewed. METHODS: Between February 1992 and June 1999, 100 consecutive patients (mean age 67+/-11 years) with functional ischemic MR underwent mitral valve repair + CABG. The repair was limited to a Duran flexible annuloplasty ring. Among patients, 72% had a preoperative myocardial infarction and 51% required perioperative intra-aortic balloon pump. NYHA functional class was III-IV in 72%; preoperative MR by transesophageal echocardiography (TEE) was grade 3-4+ in 80% and grade 2+ in 20%. RESULTS: Intraoperative completion TEE indicated 0-1+ MR in 98%. Early mortality was 12% and late mortality 14%, for an overall survival of 74%. The mean follow up was 35.8 months. Follow up TEE on 82% of patients showed zero to trivial MR in 42% of patients, grade 1+ MR in 29%, 2+ MR in 24%, and 3-4+ MR in 5%. Follow up NYHA class was I-II in 81% of patients and III-IV in 19%. A significant correlation was found between recurrent MR and declining left ventricular function on follow up only, as well as the occurrence of preoperative myocardial infarction. CONCLUSION: Functional ischemic MR remains a difficult problem to treat, and has a poor long-term outcome. Ring annuloplasty for functional ischemic MR with coronary artery disease achieves immediate valve competence. However, a significant number of patients develop recurrent MR at intermediate follow up.     

Analysis of recurrent mitral regurgitation after mitral valve repair

Mitral valve repair was performed in 437 patients with mitral regurgitation from January 1994 to January 2002. The causes of mitral regurgitation were degenerative in 238 (54%), rheumatic in 134 (31%), and others in 65 (15%). The most frequently employed surgical techniques were ring annuloplasty in 417 (95%) cases, new chordae formation in 216 (50%), and quadrangular resection in 117 (27%). The mean follow-up was 29.04 +/- 22.81 months. There were 5 (1.2%) early and 5 (1.2%) late deaths. The reoperation rate was 1.6% with 41 (9%) cases of recurrent mitral regurgitation. Of these 22 were procedure-related: incomplete repair in 13, discordant new chordal length in 7, suture dehiscence and leaflet perforation in 1 case each. There were 19 cases of valve related failures: progression of rheumatic disease in 18 and subacute infective endocarditis in 1. Valve-related failure strongly correlated with progression of rheumatic disease. As initial operative success was the prime determinant of repair durability, intraoperative repair assessment with transesophageal echocardiography was essential.     

Superiority of mitral valve repair in surgery for degenerative mitral regurgitation

OBJECTIVES: We aimed to assess the influence of type of operation on outcomein degenerative mitral regurgitation. METHODS: We compared outcomes in 278 consecutive patients who underwentmitral valve repair (167 patients), replacement with subvalvularpreservation (22 patients) and without subvalvular preservation(89 patients) for degenerative mitral regurgitation. RESULTS: There was a trend towards lower mortality with repair and replacementwith subvalvular preservation compared to replacement withoutsubvalvular preservation. Thirty-day mortality was 1·2%vs 0·0% vs 4·7% (ns) respectively. Six-year survivalwas, respectively, 67·8±7·4% (P=0·088)vs 80·8±11·0% (P=0·25 vs 63·3±5·9%for all-cause death, 78·5±6·8% (P=0·063)vs 95·5±4·4% (P=0·092) vs 67·6±5·9%for all complication-related death and 80·5±6·9%(P=0·076) vs 100·0±0·0% (P=0·045)vs 72· ± 5·8% for complication-relateddeath due to myocardial failure. Multivariate analysis confirmedindependent beneficial effects from repair compared to replacementwithout subvalvular preservation on complication-related death(hazard ratio 0·42, P=0·010) and death from myocardialfailure (hazard ratio 0·40 P=0·014), and fromrepair compared to mechanical replacement on thromboembolism(hazard ratio 0·45, P=0·029) and anticoagulation-relatedhaemorrhage (hazard ratio 0·19, P=0·026). CONCLUSIONS: Mitral valve repair is superior to replacement. The greatestsurvival advantage is in reduced mortality from myocardial failure.Repair should be the operation of choice for degenerative mitralregurgitation.