Ongoing and future directions in percutaneous treatment of mitral regurgitation

Introduction: Mitral regurgitation (MR) is one of the major valvular disease. Although surgical mitral valve (MV) repair is the standard of care for patients with severe MR, an unmet need exists in the management of patients with severe symptomatic MR and high surgical risk. Transcatheter MV therapies are alternative treatment option in such patients with moderate to severe and symptomatic MR.

Areas covered: Literatures to direct the reader to important further reading were searched with relevant websites; www.ncbi.nlm.nih.gov/pubmed using search word ‘transcatheter mitral intervention’.

Expert commentary: A variety of transcatheter techniques have emerged for the percutaneous treatment of MR. We should carefully select one or combination procedure for each patient as an ideal tailor-made transcatheter MV therapy in order to improve the outcomes.     

Atrial fibrillation and mitral valve repair

Atrial fibrillation (AF) is present in 30–40% of patients presenting for mitral valve surgery. In patients undergoing mitral valve repair, the presence of AF may be associated with increased mortality and morbidity and this is also the case in patients in whom AF persists postoperatively. Advances in understanding the pathogenesis of AF led to techniques that include both mitral valve repair and ablation of AF. The concomitant surgical treatment of AF during mitral surgery has become a commonly performed procedure, which was shown to be safe and which may improve the outcome for patients. AF after mitral valve replacement is an accepted indication for anticoagulation, but the data supporting anticoagulation in patients after mitral valve repair who convert to sinus rhythm are sparse. This article reviews the available data regarding outcomes of mitral repair and how they are influenced by AF and its therapy.     

The first two cases of transcatheter mitral valve repair with ARTO system in Asia

BACKGROUND:MAVERIC(Mitral Valve Repair Clinical Trial)validates the safety and effi cacy of the ARTO system.We here report the fi rst two successful cases of utilizing the ARTO system in patients with symptomatic heart failure(HF)with functional mitral regurgitation(FMR)in Asia.METHODS:Two patients,aged 70 and 63,had severe HF with FMR.Transesophageal echocardiography confirmed that the left ventricular ejection fractions were less than 50%with severe mitral regurgitation(MR)in both patients.Optimizing drug treatment could not mitigate their symptoms.Therefore,we used the ARTO system to repair the mitral valve for these patients on March 5 and 6,2019,respectively.RESULTS:Mitral valve repairs using the ARTO system were successfully performed under general anaesthesia for these two patients.MR was decreased immediately after the procedures in both patients.The 30-day and 3-month transthoracic echocardiography(TTE)revealed a moderate to severe MR in both patients,and the New York Heart Association(NYHA)scales were also partially improved.CONCLUSION:The first two cases in Asia indicate that the ARTO system is feasible for patients with heart failure with FMR,and the patient selection appears to be crucial.     

The spectrum of mitral valve pathologies: relevance for surgical and structural interventions

Introduction: The mitral valve apparatus, both functionally and morphologically is composed of a constellation of individual structures, including the annulus, anterior and posterior leaflets, chordae tendineae, and papillary muscles. Most also include the left ventricular wall and the left atrium which are essential for the valve to function normally.

Areas covered: The commonest conditions responsible for mitral valve dysfunction in the Western World are degenerative and functional mitral regurgitation, which are discussed in detail. Treatment strategies in patients at high surgical risk are rapidly evolving, as more options for transcatheter mitral valve repair and replacement become available.

Expert commentary: Although surgery remains the gold standard, many elderly patients with severe comorbidities need intervention as surgery may no longer be an option. Today, transcatheter mitral valve therapies are in their infancy but with advances in technology they will likely become tomorrow’s therapy. The heart team plays an important role, discussing and addressing individualized strategies for each patient. However, a thorough knowledge and the understanding of mitral valve anatomy, pathology, and clinical assessment is mandatory in order to choose the best treatment possible.     

Mitral valve prolapse

Introduction: Mitral valve prolapse (MVP) is a common valve pathology with a spectrum of disease from isolated prolapse to myxomatous, multi-scallop Barlow’s disease. The main complications relate to progression of mitral regurgitation, endocarditis, sudden death, and stroke. The timing of intervention in patients with asymptomatic severe mitral regurgitation is controversial.

Areas covered: This article reviews the pathophysiology, genetics, clinical features, diagnostic imaging, complications, long-term outcomes, and indications for intervention in MVP.

Expert commentary: Several key dilemmas in the management of MVP remain. Factors which influence progression of mitral regurgitation are unclear and therefore, we have no therapeutic targets to prevent progression. Evidence-based methods to reduce the risk of sudden death, stroke, and endocarditis have not been identified. In symptomatic patients with severe mitral regurgitation valve surgery is recommended. In asymptomatic patients, careful risk stratification incorporating markers of left ventricular dysfunction, atrial fibrillation, pulmonary hypertension, and valve reparability is required to identify the optimal timing of intervention.     

先天二叶式主动脉瓣畸形合并二尖瓣反流病因分析

目的 探讨先天二叶式主动脉瓣畸形(BAV)患者发生二尖瓣反流的病因和危险因素.方法 对2011年1月至2016年6月在复旦大学附属中山医院确诊为BAV患者的超声心动图数据进行横断面分析.结果 4352例BAV患者中,中至重度二尖瓣反流256例(5.9％),其中195例(76.2％)为男性、206例(80.5％)伴有中至...     

小儿二尖瓣反流瓣环三维超声形态及运动分析

目的通过三维超声心动图对二尖瓣环的形态及瓣环在心动周期中的运动进行定量分析,探讨二尖瓣环异常与反流程度的关系。方法使用与上海交通大学图像处理与模式识别研究所合作研发的二尖瓣运动分析软件(CARDIO 4D VIEW),采用人机交互方式,分析所采集的二尖瓣瓣环的三维图像,以标记二尖瓣瓣膜根部附着点为特征点的方式,重建二尖瓣瓣环的三维超声形态。选取二尖瓣瓣环最高点至最低点的距离(Dh-l)、两个最高点的距离(Dh-h)以及两个最低点的距离(Dl-l)为参数,以腹主动脉直径作为标化参数,分别对18例二尖瓣轻度反流患儿、29例中度反流患儿、7例重度反流患儿及21例正常儿童进行测量,并对舒张末期及收缩末期两个时相的参数结果使用SPSS13.0统计软件进行分析。结果正常儿童组21例和不同程度二尖瓣反流组54例患儿,二尖瓣环均呈马鞍形态,并在整个心动周期中始终保持此形态。收缩末期Dh-l值较舒张末期增大(P0.01),Dh-h值及Dl-l值较舒张末期减小(P0.01)。中度反流组、重度反流组舒张末期及收缩末期Dh-h、DI-I测值比正常组大(P0.01),而Dh-I测值则与正常组之间差异无统计学意义(P0.05);轻度反流组和正常组3项参数(Dh-h、DI-l、Dh-l,差异均无统计学意义(P0.05)。结论三维超声心动图对定量评估二尖瓣瓣环形态及运动以及患儿二尖瓣环异常及反流程度有一定意义。     

实时三维经食管超声心动图对二尖瓣脱垂瓣器结构与反流程度的定量研究

目的  应用实时三维经食管超声心动图（RT-3D-TEE）评估二尖瓣脱垂病变瓣器结构改变与反流程度之间的相关性。方法  纳入于我院就诊行经胸超声心动图检查确诊为二尖瓣脱垂伴反流的患者40例,另选取10例作为对照组。50例患者均行RT-3D-TEE检查并采集二尖瓣三维图像,使用4D Auto MVQ脱机工作站进行图像后处理和定量分析。结果  瓣环三维面积、瓣环二维面积、瓣环周长、前后直径、前外-后内侧直径、非平面角度、总瓣叶面积、后叶面积随反流程度增加而增大,瓣高联合比随反流程度增加而减小,组间差异均有统计学意义（P < 0.05）。瓣环三维面积、瓣环二维面积、瓣环周长、前后直径、总瓣叶面积与反流程度呈极强相关关系（r=0.847、0.843、0.845、0.854、0.854,P < 0.05)。A Total是导致重度二尖瓣反流发生的危险因素（P < 0.01,B=1.576,OR=4.834）。总瓣叶面积（截点值=8.9 cm²）预测重度二尖瓣反流的敏感度为91.7%,特异性为87.5%,曲线下面积为0.948（P < 0.01）。结论  二尖瓣瓣环大小、扁平程度、瓣叶大小与反流程度呈正相关。总瓣叶面积是导致二尖瓣脱垂患者二尖瓣反流程度加重的危险因素。     

Pseudo-mitral-valve echogram following prosthetic mitral valve replacement

Echocardiographic recordings from a patient with a prosthetic mitral valve revealed echoes within the left ventricular cavity that mimicked the motion pattern of a "normal" anterior mitral leaflet. The echo pattern was continuous, recorded from multiple views, and by two-dimensional images it was localized to the level of the papillary muscles. Although thrombus and vegetation are possibilities, this echo probably originates from a pliable chordal structure severed but not removed at the time of surgery. The apparent responsiveness to hemodynamic influences was striking, and we suggest that the prevalence and pathophysiologic implications of such findings are of potential import.     

术前左心功能对二尖瓣修复术疗效的影响

目的评价术前左心功能对二尖瓣修复术(MVR)疗效的影响。方法对120例MVR患者随访超声心动图,根据术前左室射血分数(LVEF)将其分为:①心功能减退组34例,术前LVEF<60%;②心功能正常组86例,术前LVEF≥60%。比较两组术后二尖瓣反流(MR)程度、左房室的大小、左室功能等指标。结果两组性别、年龄、术前MR程度及左房内径差异均无统计学意义,但心功能减退组中合并心肌梗死或扩张型心肌病的患者较多(52.94%对1.16%,P<0.01),且术前左室扩张更明显[左室舒张末期内径(67.29±7.88)mm对(59.20±9.14)mm,P<0.01]。与心功能正常组相比,心功能减退组术后左室内径较大[(57.26±8.64)mm对(48.56±5.73)mm,P<0.01];术后MR程度较重(1.57±0.88对1.23±0.80,P<0.05),MR的改善程度较差(1.79±0.86对2.24±0.81,P<0.01),MR复发较多(14.71%对2.33%,P<0.05);术后LVEF较低[(53.00±13.25)%对(65.26±7.81)%,P<0.01],且心功能进一步恶化比例明显高于心功能正常组(29.41%对9.30%,P<0.01)。结论术前左室功能对MVR的中晚期疗效有显著影响。术前超声心动图不仅可以对二尖瓣关闭不全的病理机制作出准确诊断,还可以对左室功能进行评价,对于选择合适的手术时机具有重要价值。     

实时三维超声心动图对正常二尖瓣与功能性反流二尖瓣闭合线的对比研究

目的 应用实时三维超声心动图对正常人和功能性反流者的二尖瓣闭合线形态进行对比,探讨功能性反流状态下二尖瓣闭合线形态的变化规律.方法 二维超声筛选功能性二尖瓣反流的成年患者20例,随后进行实时三维超声心动图检查,采集二尖瓣数据导入TomTec三维工作站进行脱机分析;并与20例正常人二尖瓣闭合线数据进行对照,对照指标包括：闭合线两端点之间的直线距离,投影平面上的闭合线曲线长度,闭合线高度（h）,α和β角,并计算｜α-β｜.结果 显著功能性二尖瓣反流的闭合线形态不规则且不对称,与正常人比较,功能性反流二尖瓣闭合线直线距离、α角、β角测值差异均有统计学意义（P〈0.05）,曲线长度、高度（h）及计算所得的｜α-β｜值差异均有统计学意义（P〈0.01）.结论 显著功能性反流二尖瓣闭合线相对正常状态下有显著差异,这种改变与功能性反流时瓣环形状改变和瓣下牵拉状态异常有关.     

Cardiac resynchronisation therapy after percutaneous mitral annuloplasty

Percutaneous approaches to reduce mitral regurgitation in ischemic cardiomyopathy have stirred interest recently. Patients with ischemic cardiomyopathy and functional mitral regurgitation often meet criteria for cardiac resynchronisation therapy to improve left ventricular function as well as mitral regurgitation, and alleviate symptoms. This case shows that implantation of a pacing lead in the coronary sinus to restore synchronous left and right ventricular contraction is feasible, despite the presence of a remodeling device in the coronary sinus.     

实时三维超声心动图二尖瓣定量分析的临床应用

随着实时三维超声心动图在图像采集、存储及分析等方面技术的逐步提高,尤其是经食管实时三维超声心动图的开发,大幅度改进了心脏动态三维图像的质量,其基础研究及临床应用日渐广泛,最新研究拓展到复杂的二尖瓣装置。本文综述了二尖瓣装置的动态三维成像及其定量分析的研究进展,包括二尖瓣环径线及构型、二尖瓣叶角度及面积、乳头肌牵张长度、二尖瓣对合面积及对合指数等在不同二尖瓣疾病中的病理生理改变,有助于进一步深化临床对二尖瓣装置功能的理角年,增进临床对二尖瓣疾病的认识与处理。     

二尖瓣成形术治疗先天性心脏病合并二尖瓣关闭不全

目的总结二尖瓣成形术在合并二尖瓣关闭不全的先天性心脏病中的应用经验,并探讨影响疗效的相关因素。方法对本院收治的合并有二尖瓣关闭不全的先天性心脏病患者147例,分别采用瓣膜裂隙修补、交界环缩、瓣环环缩、人工环成形、人工腱索、腱索延长等方法行成形术,39例(26.5%)同时运用2种以上成形技术。结果术后早期死亡6例(4.1%),术后7个月死亡1例。死亡与手术年龄(≤12岁)、体外循环时间(≥120 min)、主动脉阻断时间(≥80 min)及合并心脏畸形有关。随访结果为2例因二尖瓣反流再发,分别于术后半年和1年行二尖瓣置换术。其余病例术后心功能有不同程度改善,超声心动图检查术后瞬时反流量显著低于术前。结论二尖瓣成形术治疗先天性心脏病合并的二尖瓣关闭不全早、中期疗效满意。     

Multiple organ failure after mitral valve repair with intravascular hemolysis and its recovery due to mitral valve replacement

We present a patient with evidence of severe intravascular hemolysis after mitral valve repair, an established method for the surgical treatment of mitral valve disease to avoid prosthesis related complications. The coincidence of this uncommon complication with hemodynamic instability due to pre-existing myocardial dysfunction and Gram-negative pneumonia promoted the development of simultaneous dysfunction of liver, kidney and the cardio-respiratory system. Elimination of the source of hemolysis by re-operation with mitral valve replacement on the ninth postoperative day allowed prompt recovery from severe organ dysfunction. Free hemoglobin may have perpetuated progressive organ failure in our patient.     

Transcatheter mitral valve repair: where are we?

Mitral valve regurgitation is the second most common form of valve pathology after aortic stenosis needing surgery. While open surgical repair is still the gold standard, innovative interventional approaches have emerged as an alternative treatment option for high-risk patients. While only a few of these new techniques have been approved for the clinical setting, many others are currently under development or in pre-clinical testing. This editorial will attempt to summarize all current transcatheter-based innovations targeting the mitral valve and explore their potential for the future.