Early surgery in patients with mitral regurgitation due to flail leaflets: a long-term outcome study

One-year real-world outcomes for patients undergoing transcatheter mitral valve repair: the Gulf MTEER registry (GULF Mitral Transcatheter Edge to Edge Repair)

BACKGROUND

Severe mitral regurgitation (MR) with left ventricular dysfunction portends worse outcomes. Over the course of the last two decades, transcatheter repair of the mitral valve offered an alternative therapeutic modality for those deemed inoperable or high risk. Landmark studies such as the Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation and Multicentre Study of Percutaneous Mitral Valve Repair MitraClip Device in Patients With Severe Secondary Mitral Regurgitation trials have shown conflicting results with respect to all-cause death and heart failure rehospitalisations. The Gulf Mitral Transcatheter Edge to Edge Repair registry (Gulf MTEER registry) is a regional registry that captured outcomes in those undergoing transcatheter repair of the mitral valve. The objectives of this study were to describe the baseline characteristics of patients undergoing transcatheter mitral valve repair in the Gulf region and estimate the cardiovascular effects of the mitral transcatheter therapies in routine practice.

METHODS

The Gulf MTEER registry is an observational, multicentre, retrospective registry that enrolled all patients undergoing transcatheter repair of the mitral valve from four of the Gulf countries (Saudi Arabia, Kuwait, Bahrain, Oman) between 1 January 2017 and 31 December 2019. Baseline characteristics, echocardiographic parameters and immediate procedural success were reported. The primary outcome was a composite of death and rehospitalisations at 1 year. The secondary outcomes were the individual components of the composite endpoint; that is, death and rehospitalisations at 1 year as well as residual or recurrent MR or worsening New York Heart Association class and a need for repeat repair.

RESULTS

A total of 176 patients were enrolled. Men constituted 56.3% of the total. At 1 year the primary outcome occurred in 21.1% (95% CI 15.6, 27.9). The secondary outcomes of death occurred in 5.4% (CI 2.9, 10.0) and rehospitalisations occurred in 16.9% (CI 11.9, 23.3). Univariate analysis revealed that the odds of having death or re-hospitalisation was two times higher if the effective regurgitant orifice (ERO) >40 mm2 irrespective of the therapy.

CONCLUSIONS

The Gulf MTEER registry is the first registry in the Gulf region defining the patient population receiving MTEER therapies and evaluating 1-year outcomes. This is a low risk cohort with a high rate of immediate procedural success and low rate of all-cause death and rehospitalisations at 1 year. The odds of an event was two times higher if the ERO ≥40 mm2 with only a signal to higher odds for low left ventricular ejection fraction and larger end systolic dimension.

Primary Mitral Regurgitation and Heart Failure: Current Advances in Diagnosis and Management

Primary mitral regurgitation is a frequent etiology of congestive heart failure and is best treated with intervention when patients are symptomatic or when additional risk factors exist. Surgical intervention improves outcomes in appropriately selected patients. However, for those at high surgical risk, transcatheter intervention provides less invasive repair and replacement options while providing comparable outcomes to surgery. The excess mortality and high prevalence of heart failure in untreated mitral regurgitation illuminate the need for further developments in mitral valve intervention ideally fulfilled by expanding these types of procedures and eligibility to these procedures beyond only those at high surgical risk.

The role and implications of left atrial fibrosis in surgical mitral valve repair as assessed by CMR: the ALIVE study design and rationale

Background

Patients with mitral regurgitation (MR) commonly suffer from left atrial (LA) remodeling. LA fibrosis is considered to be a key player in the LA remodeling process, as observed in atrial fibrillation (AF) patients. Literature on the presence and extent of LA fibrosis in MR patients however, is scarce and its clinical implications remain unknown. Therefore, the ALIVE trial was designed to investigate the presence of LA remodeling including LA fibrosis in MR patients prior to and after mitral valve repair (MVR) surgery.

Methods

The ALIVE trial is a single center, prospective pilot study investigating LA fibrosis in patients suffering from MR in the absence of AF (identifier NCT05345730). In total, 20 participants will undergo a CMR scan including 3D late gadolinium enhancement (LGE) imaging 2 week prior to MVR surgery and at 3 months follow-up. The primary objective of the ALIVE trial is to assess the extent and geometric distribution of LA fibrosis in MR patients and to determine effects of MVR surgery on reversed atrial remodelling.

Implications

This study will provide novel insights into the pathophysiological mechanism of fibrotic and volumetric atrial (reversed) remodeling in MR patients undergoing MVR surgery. Our results may contribute to improved clinical decision making and patient-specific treatment strategies in patients suffering from MR.

Prognostic value of forward flow indices in primary mitral regurgitation due to mitral valve prolapse

Background

Degenerative mitral regurgitation (DMR) due to mitral valve prolapse (MVP) is a common valve disease associated with significant morbidity and mortality. Timing for surgery is debated for asymptomatic patients without Class I indication, prompting the search for novel parameters of early left ventricular (LV) systolic dysfunction.

Aims

To evaluate the prognostic impact of preoperative forward flow indices on the occurrence of post-operative LV systolic dysfunction.

Methods

We retrospectively included all consecutive patients with severe DMR due to MVP who underwent mitral valve repair between 2014 and 2019. LVOT_TVI, forward stroke volume index, and forward LVEF were assessed as potential risk factors for LVEF <50% at 6 months post-operatively.

Results

A total of 198 patients were included: 154 patients (78%) were asymptomatic, and 46 patients (23%) had hypertension. The mean preoperative LVEF was 69 ± 9%. 35 patients (18%) had LVEF ≤ 60%, and 61 patients (31%) had LVESD ≥40 mm. The mean post-operative LVEF was 59 ± 9%, and 21 patients (11%) had post-operative LVEF<50%. Based on multivariable analysis, LVOT_TVI was the strongest independent predictor of post-operative LV dysfunction after adjustment for age, sex, symptoms, LVEF, LV end systolic diameter, atrial fibrillation and left atrial volume index (0.75 [0.62-0.91], p < 0.01). The best sensitivity (81%) and specificity (63%) was obtained with LVOTTVI ≤15 cm based on ROC curve analysis.

Conclusion

LVOT_TVI represents an independent marker of myocardial performance impairment in the presence of severe DMR. LVOT_TVI could be an earlier marker than traditional echo parameters and aids in the optimization of the timing of surgery.

Incidence and Predictors of New-Onset Atrial Fibrillation After Transcatheter Edge-to-Edge Repair of the Mitral Valve (from the Nationwide Readmissions Database)

Patients who underwent transcatheter edge-to-edge repair (TEER) for mitral regurgitation with atrial fibrillation (AF) at baseline have higher mortality than those without AF. Data on new-onset AF (NOAF) after TEER are limited. Using the 2016 to 2018 Nationwide Readmissions Database, we identified a cohort of patients who underwent TEER and classified them into 3 groups based on AF presence during the study period. The primary end point was the incidence and timing of NOAF up to 6 months after TEER. Logistic regression modeling identified independent predictors of NOAF at readmission. Of the 6,861patients that underwent TEER, 4,134 (59.9%) had AF at baseline, and 239 (3.5%) developed NOAF. Median time-to-NOAF admission was 47 days (interquartile range 16 to 113), and 37% of patients with NOAF presented within 30 days after TEER. Patients with NOAF experienced costlier and longer index-TEER hospitalization and had more co-morbidities. Chronic kidney disease (odds ratio [OR] 1.51, 95% confidence interval [CI] 1.03 to 2.20), fluid and electrolyte disorders (OR 1.59, 95% CI 1.01 to 2.52), and heart failure (OR 1.86, 95% CI 1.01 to 3.44) were identified as independent predictors of NOAF. Hypertensive complications and heart failure were the leading causes of readmission. In conclusion, those patients that developed NOAF after TEER tended to be an overall sicker group at baseline compared with the remainder of the study cohort. These data, obtained from a nationally representative cohort, highlight a particular group of patients subject to developing NOAF and their association with increased rehospitalization in the post-TEER setting. Predictors of NOAF can be screened for during TEER workup to identify patients at increased risk.

Arrhythmias in Patients With Valvular Heart Disease: Gaps in Knowledge and the Way Forward

The prevalence of both organic valvular heart disease (VHD) and cardiac arrhythmias is high in the general population, and their coexistence is common. Both VHD and arrhythmias in the elderly lead to an elevated risk of hospitalization and use of health services. However, the relationships of the two conditions is not fully understood and our understanding of their coexistence in terms of contemporary management and prognosis is still limited. VHD-induced left ventricular dysfunction/hypertrophy and left atrial dilation lead to both atrial and ventricular arrhythmias. On the other hand, arrhythmias can be considered as an independent condition resulting from a coexisting ischemic or non-ischemic substrate or idiopathic ectopy. Both atrial and ventricular VHD-induced arrhythmias may contribute to clinical worsening and be a turning point in the natural history of VHD. Symptoms developed in patients with VHD are not specific and may be attributable to hemodynamical consequences of valve disease but also to other cardiac conditions including arrhythmias which are notably prevalent in this population. The issue how to distinguish symptoms related to VHD from those related to atrial fibrillation (AF) during decision making process remains challenging. Moreover, AF is a traditional limit of echocardiography and an important source of errors in assessment of the severity of VHD. Despite recent progress in understanding the pathophysiology and prognosis of postoperative AF, many questions remain regarding its prevention and management. Furthermore, life-threatening ventricular arrhythmias can predispose patients with VHD to sudden cardiac death. Evidence for a putative link between arrhythmias and outcome in VHD is growing but available data on targeted therapies for VHD-related arrhythmias, including monitoring and catheter ablation, is scarce. Despite growing evidences, more research focused on the prognosis and optimal management of VHD-related arrhythmias is still required. We aimed to review the current evidence and identify gaps in knowledge about the prevalence, prognostic considerations, and treatment of atrial and ventricular arrhythmias in common subtypes of organic VHD.

Pass On What You Have Learned: A Structured Mentor-Mentee Concept for the Implementation of a Minimally Invasive Mitral Valve Surgery Program

INTRODUCTION

Starting a minimally invasive cardiac surgery (MICS) for mitral valve repair (MVR) program is challenging as it requires a new learning curve, but compromising surgical results at the same time is not acceptable. Here, we describe our surgical educational experience of starting a new MICS program at a university heart center in Germany.

METHODS

A dedicated team for the new MICS program including 2 cardiac surgeons, 1 cardiac anesthetist, 1 perfusionist, and 1 scrub nurse was chosen. The use of long shafted instruments was trained in a low-cost self-assembled MICS simulator, and the EACTS endoscopic dry lab course was visited. Thereafter, 1 MICS center was visited for direct observation and peer-to-peer education for 6 weeks. The mentor observed the first 10 cases performed by the mentee. The surgical mitral valve expertise of 1 single cardiac surgeon was retrospectively analyzed between April 2016 and April 2021.

RESULTS

Before the implementation of the MICS-MVR program, 18 mitral valve operations have been performed through sternotomy between April 2016 and October 2018 including 12 replacements and 6 ring annuloplasties. After starting the MICS-MVR program, 73 mitral operations have been performed by the same surgeon of which 53 video-assisted through minithoracotomy (72.6%). 83.1% of the MICS procedures included complex repair (n = 38) and ring annuloplasty (n = 6). Open heart MV surgery was necessary in 20 patients due to concomitant procedures (n = 8), redo procedures (n = 2), severe endocarditis (n = 4), or contraindication for MICS such as PAD (n = 6). There have been no deaths, 1 stroke, and 1 cardiac vascular (RCX) complication. Two patients required conversion to sternotomy and one pericardiocentesis in the long term.

CONCLUSION

Typically, excellent exposure and high repair rates of the MV has led us offer MICS approach to a majority of patients with isolated MV disease. Careful planning and a strict mentor-mentee concept facilitated a safe startup of an MICS program in a busy university heart center.

Transcatheter mitral valve therapies: State of the art

Mitral regurgitation (MR) is one of the most prevalent valvular pathologies in the developed world. There continues to be a growing population of aging patients with MR who may be too high risk for surgical management. The rapid adoption and remarkable success of transcatheter aortic valve replacement (TAVR) generated enthusiasm for transcatheter mitral valve therapies; however, the complex anatomy and pathophysiology of the mitral valve confers several unique challenges for a fully percutaneous approach. Nevertheless, several devices are under development and in various phases of preclinical or clinical testing, both for transcatheter mitral valve replacement and repair. MitraClip (Abbott Vascular), which has received FDA approval, is the most established percutaneous repair strategy and has been performed in over 80,000 patients as of 2019. The following article serves as a review of the available and upcoming devices for the various etiologies of mitral valvular disease, as well as the unique challenges and potential complications of transcatheter mitral valve intervention.

Structural Heart Interventions During COVID-19

The spread of Coronavirus Disease 2019 (COVID-19) pandemic across the globe and the United States presented unprecedented challenges with dawn of new policies to reserve resources and protect the public. One of the major policies adopted by hospitals across the nations were postponement of non-emergent procedures such as transaortic valve replacement (TAVR), left atrial appendage closure device (LAAC), MitraClip and CardioMEMS. Guidelines were based mainly on the avoidable clinical outcomes occurring during COVID-19 era. As our understanding of the SARS-CoV-2 evolved, advanced cardiac procedures may safely continue through careful advanced coordination. We aim to highlight the new guidelines published by different major cardiovascular societies, and discuss solutions to safely perform procedures to improve outcomes in a patient population with high acuity of illness during the COVID-19 pandemic era.

Mitral Valve Prolapse and Its Motley Crew-Syndromic Prevalence, Pathophysiology, and Progression of a Common Heart Condition

Mitral valve prolapse (MVP) is a commonly occurring heart condition defined by enlargement and superior displacement of the mitral valve leaflet(s) during systole. Although commonly seen as a standalone disorder, MVP has also been described in case reports and small studies of patients with various genetic syndromes. In this review, we analyzed the prevalence of MVP within syndromes where an association to MVP has previously been reported. We further discussed the shared biological pathways that cause MVP in these syndromes, as well as how MVP in turn causes a diverse array of cardiac and noncardiac complications. We found 105 studies that identified patients with mitral valve anomalies within 18 different genetic, developmental, and connective tissue diseases. We show that some disorders previously believed to have an increased prevalence of MVP, including osteogenesis imperfecta, fragile X syndrome, Down syndrome, and Pseudoxanthoma elasticum, have few to no studies that use up-to-date diagnostic criteria for the disease and therefore may be overestimating the prevalence of MVP within the syndrome. Additionally, we highlight that in contrast to early studies describing MVP as a benign entity, the clinical course experienced by patients can be heterogeneous and may cause significant cardiovascular morbidity and mortality. Currently only surgical correction of MVP is curative, but it is reserved for severe cases in which irreversible complications of MVP may already be established; therefore, a review of clinical guidelines to allow for earlier surgical intervention may be warranted to lower cardiovascular risk in patients with MVP.

Causes and mechanisms of isolated mitral regurgitation in the community: clinical context and outcome

AIMS

To define the hitherto unknown aetiology/mechanism distributions of mitral regurgitation (MR) in the community and the linked clinical characteristics/outcomes.

METHODS AND RESULTS

We identified all isolated, moderate/severe MR diagnosed in our community (Olmsted County, MN, USA) between 2000 and 2010 and classified MR aetiology/mechanisms. Eligible patients (n = 727) were 73 ± 18 years, 51% females, with ejection fraction (EF) 49 ± 17%. MR was functional (FMR) in 65%, organic (OMR) in 32% and 2% mixed. Functional MR was linked to left ventricular remodelling (FMR-v) 38% and isolated atrial dilatation (FMR-a) 27%. At diagnosis FMR-v vs. FMR-a, vs. OMR displayed profound differences (all P < 0.0001) in age (73 ± 14, 80 ± 10, 68 ± 21years), male-sex (59, 33, 51%), atrial-fibrillation (28, 54, 13%), EF (33 ± 14, 57 ± 11, 61 ± 10%), and regurgitant-volume (38 ± 13, 37 ± 11, 51 ± 24 mL/beat). Dominant MR mechanism was Type I (normal valve-movement) 38%, Type II (excessive valve-movement) 25%, Type IIIa (diastolic movement-restriction) 3%, and Type IIIb (systolic movement-restriction) 34%. Outcomes were mediocre with excess-mortality vs. general-population in FMR-v [risk ratio 3.45 (2.98-3.99), P < 0.0001] but also FMR-a [risk ratio 1.88 (1.52-2.25), P < 0.0001] and OMR [risk ratio 1.83 (1.50-2.22), P < 0.0001]. Heart failure was frequent, particularly in FMR-v (5-year 83 ± 3% vs. 59 ± 4% FMR-a, 40 ± 3% OMR, P < 0.0001). Mitral surgery during patients' lifetime was performed in 4% of FMR-v, 3% of FMR-a, and 37% of OMR.

CONCLUSION

Moderate/severe isolated MR in the community displays considerable aetiology/mechanism heterogeneity. Functional MR dominates, mostly FMR-v but FMR-a is frequent and degenerative MR dominates OMR. Outcomes are mediocre with excess-mortality particularly with FMR-v but FMR-a, despite normal EF incurs notable excess-mortality and frequent heart failure. Pervasive undertreatment warrants clinical trials of therapies tailored to specific MR cause/mechanisms.

Relations of Augmented Systolic Annular Expansion and Leaflet/Papillary Muscle Dynamics in Late-Systolic Mitral Valve Prolapse Evaluated by Echocardiography with a Speckle Tracking Analysis

The mechanism of systolic annular expansion in mitral valve prolapse (MVP) is not clarified. Since annular expansion is systolic outward shift of MV leaflet/chorda tissue complex at superior and outer ends, annular expansion could be related to inward (superior) shift of the complex at another inferior and inner end of the papillary muscle (PM) tip and/or systolic lengthening of the tissue complex, especially MV leaflets.MV annulus systolic expansion, PMs' systolic superior shift, and MV leaflets' systolic lengthening were evaluated by echocardiography with a speckle tracking analysis in 25 normal subjects, 25 subjects with holo-systolic MVP and 20 subjects with late-systolic MVP.PMs' superior shift, MV leaflets' lengthening, MV annular area at the onset of systole and subsequent MV annulus expansion were significantly greater in late-systolic MVP than in holo-systolic MVP (4.6 ± 1.6 versus 1.5 ± 0.7 mm/m², 2.5 ± 1.4 versus 0.6 ± 2.0 mm/m², 6.8 ± 2.5 versus 5.7 ± 1.0 cm²/m² and 1.6 ± 0.8 versus 0.1 ± 0.5 cm²/m², P < 0.001, respectively). Multivariate analysis identified MV leaflets' lengthening and PMs' superior shift as independent factors associated with MV annular expansion.Conclusions: These results suggest that systolic MV annular expansion in MVP is related to abnormal MV leaflets' lengthening and PMs' superior shift.

Color Doppler Splay: A Clue to the Presence of Significant Mitral Regurgitation

BACKGROUND

The authors describe a previously unreported Doppler signal associated with mitral regurgitation (MR) as imaged using transthoracic echocardiography. Horizontal "splay" of the color Doppler signal along the atrial surface of the valve may indicate significant regurgitation when the MR jet otherwise appears benign.

METHODS

Splay was defined as a nonphysiologic arc of color centered at the point at which the MR jet emerges into the left atrium. The authors present a series of 10 cases of clinically significant MR (moderately severe or severe as defined by transesophageal echocardiography) that were misclassified on transthoracic echocardiography as less than moderate. The splay signal was present on at least one standard transthoracic view in each case. To better characterize the splay signal, two groups were created from existing clinically driven transthoracic echocardiograms: 100 consecutive patients with severe MR and 100 with mild MR.

RESULTS

Splay was present in the majority of severe MR cases (81%) regardless of vendor machine, ejection fraction, or MR etiology. Splay was particularly prevalent among patients with wall-hugging jets (28 of 30 [93%]). In patients with mild MR, splay was present less often (16%), on fewer frames per clip, and had smaller dimensions compared with severe MR. Color scale did not differ between subjects with and those without splay, but color gain was higher when splay was present (P = .04). Machine settings were further explored in a single subject with prominent splay: increasing transducer frequency reduced splay, while increasing color gain increased it.

CONCLUSIONS

The authors describe a new transthoracic echocardiographic sign of MR. Horizontal splay may be a clue to the presence of severe MR when the main body of the jet is out of the imaging plane. Splay is likely generated as a side-lobe artifact due to a high-flux regurgitant jet.

The most influential papers in mitral valve surgery; a bibliometric analysis

This study is an analysis of the 100 most cited articles in mitral valve surgery. A bibliometric analysis is a tool to evaluate research performance in a given field. It uses the number of times a publication is cited by others as a proxy marker of its impact. The most cited paper Carpentier et al. discusses mitral valve repair in terms of restoring the geometry of the entire valve rather than simply narrowing the annulus (Carpentier, J Thorac Cardiovasc Surg 86:23–37, 1983). The first successful mitral valve repair was performed by Elliot Cutler at Brigham and Women’s Hospital in 1923 (Cohn et al., Ann Cardiothorac Surg 4:315, 2015). More recently percutaneous and minimally invasive techniques that were originally designed as an option for high risk patients are being trialled in other patient groups (Hajar, Heart Views 19:160–3, 2018). Comparison of percutaneous method with open repair represents an expanding area of research (Hajar, Heart Views 19:160–3, 2018). This study will analyse the top 100 cited papers relevant to mitral valve surgery, identifying the most influential papers that guide current management, the institutions that produce them and the authors involved.

Prognostic significance of moderate primary mitral regurgitation and concomitant paroxysmal atrial fibrillation

BACKGROUND

Severe primary mitral regurgitation [degenerative MR (DMR)] is associated with poor outcomes, including cardiac death and hospitalization due to worsening heart failure. However, little information is available regarding the characteristics of moderate DMR and their impacts on prognostic outcome. The aim of the present study was to investigate the prognosis and its determinants in patients with moderate DMR.

METHODS

We retroactively reviewed 13,700 consecutive patients who underwent transthoracic echocardiography and selected those with moderate DMR but without other underlying cardiac diseases. We assessed the characteristics and event-free rate of patients with moderate DMR compared with those of age- and gender-matched patients with mild or no MR.

RESULTS

The cohort included 182 (1%) patients with moderate DMR, and these were compared with 182 age- and gender-matched patients with mild or no MR. During the follow-up period of 1376 ± 652 days, 30 patients (8%) met the composite endpoint defined as cardiac death or hospitalization due to worsening heart failure. Kaplan-Meier analysis showed that patients with moderate DMR were significantly associated with a poor outcome compared to patients with mild or no MR (log-rank test p < 0.0001). Cox proportional hazard ratio revealed that moderate DMR and paroxysmal atrial fibrillation (PAF) were the independent predictors of the composite endpoint.

CONCLUSIONS

Patients with moderate DMR and concomitant PAF had a significantly worse outcome compared to those with mild or no MR. Active surveillance and some intervention for patients with PAF and moderate DMR may be required.

Possible mechanism of late systolic mitral valve prolapse: systolic superior shift of leaflets secondary to annular dilatation that causes papillary muscle traction

Progressive superior shift of the mitral valve (MV) during systole is associated with abnormal papillary muscle (PM) superior shift in late systolic MV prolapse (MVP). The causal relation of these superior shifts remains unclarified. We hypothesized that the MV superior shift is related to augmented MV superiorly pushing force by systolic left ventricular pressure due to MV annular dilatation, which can be corrected by surgical MV plasty, leading to postoperative disappearance of these superior shifts. In 35 controls, 28 patients with holosystolic MVP, and 28 patients with late systolic MVP, the MV coaptation depth from the MV annulus was measured at early and late systole by two-dimensional echocardiography. The PM tip superior shift was monitored by echocardiographic speckle tracking. MV superiorly pushing force was obtained as MV annular area × (systolic blood pressure - 10). Measurements were repeated after MV plasty in 14 patients with late systolic MVP. Compared with controls and patients with holosystolic MVP, MV and PM superior shifts and MV superiorly pushing force were greater in patients with late systolic MVP [1.3 (0.5) vs. 0.9 (0.6) vs. 3.9 (1.0) mm/m², 1.3 (0.5) vs. 1.2 (1.0) vs. 3.3 (1.3) mm/m², and 487 (90) vs. 606 (167) vs. 742 (177) mmHg·cm²·m^-2, respectively, means (SD), P < 0.001]. MV superior shift was correlated with PM superior shift ( P < 0.001), which was further related to augmented MV superiorly pushing force ( P < 0.001). MV and PM superior shift disappeared after surgical MV plasty for late systolic MVP. These data suggest that MV annulus dilatation augmenting MV superiorly pushing force may promote secondary superior shift of the MV (equal to late systolic MVP) that causes subvalvular PM traction in patients with late systolic MVP. NEW & NOTEWORTHY Late systolic mitral valve prolapse (MVP) is associated with mitral valve (MV) and papillary muscle (PM) abnormal superior shifts during systole, but the causal relation remains unclarified. MV and PM superior shifts were correlated with augmented MV superiorly pushing force by annular dilatation and disappeared after surgical MV plasty with annulus size and MV superiorly pushing force reduction. This suggests that MV annulus dilatation may promote secondary superior shifts of the MV (late systolic MVP) that cause subvalvular PM traction.

Transcatheter Mitral Valve Therapy: Defining the Patient Who Will Benefit

PURPOSE OF REVIEW

This report aims to define the clinical and anatomic variables key in determining patient suitability for transcatheter mitral valve therapies.

RECENT FINDINGS

Candidacy for transcatheter mitral valve repair requires weighing the clinical variables that may impact the ability to improve patient symptoms and prolong survival that include left ventricular ejection fraction, symptom severity, pulmonary hypertension, and magnitude of residual regurgitation or stenosis. Individualized selection of transcatheter repair or replacement based on patho-anatomy is being explored. The primary goal is achieving significant reduction in mitral regurgitation. Transcatheter mitral valve replacement requires rigorous anatomic screening using computed tomography and candidates should be able to take oral anticoagulation. Selection of patients for transcatheter mitral valve repair is complex and requires intimate knowledge of clinical variables and specific device limitations.

RESULTS OF SURGICAL MANAGMENT OF PRIMARY MITRAL REGURGITATION IN A SINGLE-CENTER STUDY

Mitral regurgitation (MR) remains the second dominant defect in the structure of valvular cardiac diseases. It affects more than 2 million people in the USA. Basic causes are classified as degenerative (with valve prolapse) and ischemic (due to ischemic heart disease) in advanced countries or rheumatic ones (in developing countries). Alone radical method of MR treatment is surgical correction through mitral valve repair (MVRe) or replacement (MVR) yielding definitely higher survival percentage and improvement of heart failure (HF) class comparing to pharmacotherapy. Evolution of approaches to the management of non-ischemic MR passed through some stages starting from predominantly MVR to organ-preserving approaches like plastic repair. In the prospective single-center study were analyzed the results of treatment of 72 patients with primary MR (PMR) who were subjected to mitral valve replacement (MVR) or plastic mitral valve repair (MVRe) performed in the Department of cardiac surgery affiliated with Lviv regional clinical hospital (Ukraine) since October, 2013 till February, 2016. The conclusions of performed study are next: 1) Key direct cause of MR is the chordal rupture of MV cusps; etiological factor in the majority of advanced countries is degenerative changes in contrast to rheumatic changes in the developing countries. 2) Principal method of MR surgical correction in out center is MVR, though the preferable global trend is MVRe. 3) Complications and lethality percentages in this study were higher among the patients from MVR group. Improvement of HF class according to NYHA was more evident in the MVRe group. This corresponds to results of other studies and guidelines that recommend MVRe as optional method for MR correction.

Multi-Modality Imaging in the Evaluation and Treatment of Mitral Regurgitation

OPINION STATEMENT

Mitral regurgitation (MR) is frequent and associated with increased mortality and morbidity when severe. It may be caused by intrinsic valvular disease (primary MR) or ventricular deformation (secondary MR). Imaging has a critical role to document the severity, mechanism, and impact of MR on heart function as selected patients with MR may benefit from surgery whereas other will not. In patients planned for a surgical intervention, imaging is also important to select candidates for mitral valve (MV) repair over replacement and to predict surgical success. Although standard transthoracic echocardiography is the first-line modality to evaluate MR, newer imaging modalities like three-dimensional (3D) transesophageal echocardiography, stress echocardiography, cardiac magnetic resonance (CMR), and computed tomography (CT) are emerging and complementary tools for MR assessment. While some of these modalities can provide insight into MR severity, others will help to determine its mechanism. Understanding the advantages and limitations of each imaging modality is important to appreciate their respective role for MR assessment and help to resolve eventual discrepancies between different diagnostic methods. With the increasing use of transcatheter mitral procedures (repair or replacement) for high-surgical-risk patients, multimodality imaging has now become even more important to determine eligibility, preinterventional planning, and periprocedural guidance.

Cardiovascular events and hospital resource utilization pre- and post-transcatheter mitral valve repair in high-surgical risk patients

MitraClip is an approved therapy for mitral regurgitation (MR); however, health care resource utilization pre- and post-MitraClip remains understudied.

METHODS

Patients with functional and degenerative MR at high surgical risk in the EVEREST II High-Risk Registry and REALISM Continued-Access Study were linked to Medicare data. Pre- and post-MitraClip all-cause death, stroke, myocardial infarction, heart failure (HF), and bleeding hospitalizations were identified. Inpatient costs, adjusted to 2010 US dollars, were calculated, and event rate ratios and cost ratios were estimated with multivariable modeling.

RESULTS

Among 403 linked patients, the mean age was 80 years, 60% were male, mean baseline left ventricular ejection fraction was 49.6%, 83.3% were New York Heart Association class III/IV, 78.2% were MR grade 3+/4+, and 63.3% had functional MR. All-cause hospitalization decreased from 1,854 to 1,435/1,000 person-years (P<.001). HF hospitalization decreased following MitraClip (749 vs 332/1000 person-years, P<.001), but bleeding increased (199 vs 298/1000 person-years, P<.001). Changes in stroke and myocardial infarction were not statistically significant. Overall mean Medicare costs per patient were similar pre- and post-MitraClip, although there was a significant decrease in mean costs among those that survived a full year after MitraClip ($18,131 [SD $25,130] vs $11,679 [SD $22,486], P=.02).

CONCLUSIONS

MitraClip was associated with a reduced rate of all-cause and HF hospitalizations and an increased rate of bleeding hospitalizations. One-year Medicare costs were reduced in those who survived a full year after the MitraClip procedure. Payors and providers seeking to reduce HF hospitalizations and associated Medicare costs may consider MitraClip among appropriate patients likely to survive 1 year.

Primary mitral valve regurgitation: Update and review

Mitral regurgitation is the second most common valvular disorder requiring surgical intervention worldwide. This review summarizes the current understanding of primary, degenerative mitral regurgitation with respect to etiology, comprehensive assessment, natural history and management. The new concept of staging of the valvular disorders, newer predictors of adverse and controversy of “watchful waiting” versus “early surgical intervention” for severe, asymptomatic, primary mitral regurgitation are addressed.

Comparative Histopathological Analysis of Mitral Valves in Barlow Disease and Fibroelastic Deficiency

Whether Barlow disease (BD) and fibroelastic deficiency (FED), the main causes of mitral valve prolapse (MVP), should be considered 2 distinct diseases remains unknown. Mitral valves from patients who required surgery for severe mitral regurgitation due to degenerative nonsyndromic MVP were analyzed. Intraoperative diagnosis of BD or FED was based on leaflet redundancy and thickness, number of segments involved, and annular dimension. The removed medial scallop of the posterior leaflet and attached chordae were used for histopathological and immunohistological assessment. Histologically, compared to normal controls (n = 3), BD (n = 14), and FED (n = 9) leaflets demonstrated an altered architecture and increased thickness. Leaflet thickness was greater and chordae thickness lower in BD than FED (P < 0.0001). In BD, increased thickness was owing to spongiosa expansion (proteoglycan accumulation) and intimal thickening on fibrosa and atrialis; in FED, local thickening was predominant on the fibrosa side, with accumulation of proteoglycan-like material around the chordae. Collagen accumulation was observed in FED leaflets and chords and decreased in BD. Fragmented elastin fibers were present in BD and FED; elastin decreased in BD but increased in FED leaflets and around chordae. Activated myofibroblasts accumulate in both diseased leaflets and chords, but more abundantly in FED chordae (P < 0.0001), independently of age, suggesting a role of these cells in chordal rupture. There were more CD34-positive cells in BD leaflets and in FED chordae (P < 0.01). In BD leaflets (but not chordae) proliferative Ki67-positive cells were more abundant (P < 0.01) and matrix metalloproteinase 2 levels were increased (P < 0.01) indicating tissue remodeling. Upregulation of transforming growth factor beta and pERK signaling pathways was evident in both diseases but more prominent in FED leaflets (continued on next page)(P < 0.001), with pERK upregulation in FED chordae (P < 0.0001). Most cellular and signaling markers were negligible in control valves. Quantitative immunohistopathological analyses demonstrated distinct changes between BD and FED valves: predominant matrix degradation in BD and increased profibrotic signaling pathways in FED, indicating that BD and FED are 2 different entities. These results may pave the way for genetic studies of MVP and development of preventive drug therapies.

Transcatheter mitral valve interventions: pathophysiological considerations in choosing reconstruction versus transcatheter valve implantation

Over the last few years, several surgical procedures to treat mitral regurgitation (MR) in high-risk or inoperable patients have inspired percutaneous devices, including valve repair and valve replacement technologies. As the field of transcatheter mitral valve intervention is rapidly developing, the interventional community is wondering whether valve implantation should become the leading percutaneous mitral valve therapy, and whether the introduction of reliable replacement technology will reduce the clinical value of repair approaches. Since clinical experience with transcatheter mitral valve implantation (TMVI) is at a preliminary stage and all the patients treated with this approach so far are really sick candidates with prohibitive risk, it is difficult to define properly which patients could benefit more from TMVI versus transcatheter mitral valve repair (TMVR). The specific aim of this report is to state few important clinical and pathophysiological considerations in order to clarify when and why a repair strategy should be preferred over replacement.

Mitral valve disease--current management and future challenges

The field of mitral valve disease diagnosis and management is rapidly changing. New understanding of disease pathology and progression, with improvements in and increased use of sophisticated imaging modalities, have led to early diagnosis and complex treatment. In primary mitral regurgitation, surgical repair is the standard of care. Treatment of asymptomatic patients with severe mitral regurgitation in valve reference centres, in which successful repair is more than 95% and surgical mortality is less than 1%, should be the expectation for the next 5 years. Transcatheter mitral valve repair with a MitraClip device is also producing good outcomes in patients with primary mitral regurgitation who are at high surgical risk. Findings from clinical trials of MitraClip versus surgery in patients of intermediate surgical risk are expected to be initiated in the next few years. In patients with secondary mitral regurgitation, mainly a disease of the left ventricle, the vision for the next 5 years is not nearly as clear. Outcomes from ongoing clinical trials will greatly inform this field. Use of transcatheter techniques, both repair and replacement, is expected to substantially expand. Mitral annular calcification is an increasing problem in elderly people, causing both mitral stenosis and regurgitation which are difficult to treat. There is anecdotal experience with use of transcatheter valves by either a catheter-based approach or as a hybrid technique with open surgery, which is being studied in early feasibility trials.

Mitral valve disease--morphology and mechanisms

Mitral valve disease is a frequent cause of heart failure and death. Emerging evidence indicates that the mitral valve is not a passive structure, but--even in adult life--remains dynamic and accessible for treatment. This concept motivates efforts to reduce the clinical progression of mitral valve disease through early detection and modification of underlying mechanisms. Discoveries of genetic mutations causing mitral valve elongation and prolapse have revealed that growth factor signalling and cell migration pathways are regulated by structural molecules in ways that can be modified to limit progression from developmental defects to valve degeneration with clinical complications. Mitral valve enlargement can determine left ventricular outflow tract obstruction in hypertrophic cardiomyopathy, and might be stimulated by potentially modifiable biological valvular-ventricular interactions. Mitral valve plasticity also allows adaptive growth in response to ventricular remodelling. However, adverse cellular and mechanobiological processes create relative leaflet deficiency in the ischaemic setting, leading to mitral regurgitation with increased heart failure and mortality. Our approach, which bridges clinicians and basic scientists, enables the correlation of observed disease with cellular and molecular mechanisms, leading to the discovery of new opportunities for improving the natural history of mitral valve disease.

The future of transcatheter mitral valve interventions: competitive or complementary role of repair vs. replacement?

Transcatheter mitral interventions has been developed to address an unmet clinical need and may be an alternative therapeutic option to surgery with the intent to provide symptomatic and prognostic benefit. Beyond MitraClip therapy, alternative repair technologies are being developed to expand the transcatheter intervention armamentarium. Recently, the feasibility of transcatheter mitral valve implantation in native non-calcified valves has been reported in very high-risk patients. Acknowledging the lack of scientific evidence to date, it is difficult to predict what the ultimate future role of transcatheter mitral valve interventions will be. The purpose of the present report is to review the current state-of-the-art of mitral valve intervention, and to identify the potential future scenarios, which might benefit most from the transcatheter repair and replacement devices under development.

Echocardiographic predictors of survival in dogs with myxomatous mitral valve disease

OBJECTIVES

To evaluate vena contracta and other echocardiographic measures of myxomatous mitral valve disease (MMVD) severity in a multivariable analysis of survival in dogs.

ANIMALS

70 dogs diagnosed with MMVD from stored echocardiographic images that met study inclusion criteria.

METHODS

Left heart dimensions were measured as well as mitral regurgitant jet area/left atrial area (JAR), early mitral filling velocity (Evel), extent of mitral valve prolapse in right and left views (ProlR, ProlL), Prol indexed to aortic diameter (ProlR:Ao, ProlL:Ao), presence of a flail leaflet (FlailR, FlailL), and mitral regurgitation vena contracta diameter (VCR, VCL) indexed to aortic diameter (VCR:Ao, VCL:Ao). Follow-up from referring veterinarians was obtained by questionnaire or telephone to determine survival times. Inter- and intra-observer agreement was evaluated with Bland-Altman plots and weighted Kappa analysis. Survival was analyzed using Kaplan-Meier curves, logrank tests and Cox's proportional hazards.

RESULTS

Logrank analysis showed VCL:Ao, VCR:Ao, FlailL, ProlR:Ao, ProlL:Ao, left ventricular internal dimension in diastole indexed to aortic diameter (LVIDD:Ao) >2.87, left atrium to aorta ratio (LA/Ao) >1.6, and Evel >1.4 m/s were predictors of cardiac mortality. In a multivariable analysis, the independent predictors of cardiac mortality were Evel >1.4 m/s [hazard ratio (HR) 5.0, 95% confidence interval (CI) 2.5-10.3], FlailL (HR 3.1, 95% CI 1.3-7.9), and ProlR:Ao (HR 2.8, 95% CI 1.3-6.3).

CONCLUSIONS

Echocardiographic measures of mitral regurgitation severity and mitral valve pathology provide valuable prognostic information independent of chamber enlargement in dogs with MMVD.

Myxomatous mitral valve disease bench to bedside: LDL-density-pressure regulates Lrp5

The myxomatous mitral valve is the most common form of valvular heart disease. The pathologic presentation of myxomatous mitral valve disease varies between valve thickness, degree of leaflet prolapse and the presence or absence of flail leaflets. Recent molecular biology studies have confirmed that the myxomatous changes in mitral valve prolapse equals a cartilage phenotype, which is regulated by the Lrp5 receptor. Clinically, echocardiography defines the valve pathology to determine the surgical approach to valve repair or replacement. Furthermore, the timing of surgical valve repair is controversial and is the subject of a current multicenter trial. The results will resolve the timing of whether watchful waiting versus early surgical valve repair decreases morbidity and mortality of this disease process. This review will summarize the current understanding of the cellular and hemodynamic mechanisms of myxomatous mitral valve disease, which may have future implications in the targeted therapy of this disease process.

Mitral valve repair in asymptomatic patients with severe mitral regurgitation: pushing past the tipping point

Degenerative mitral valve regurgitation (MR) is the one of the most frequent valvular heart conditions in the Western world and is increasingly recognized as an important preventable cause of chronic heart failure. This condition also represents the most common indication for mitral surgery and is of particular interest because the mitral valve can be repaired in most patients with very low surgical risk. Historical single-center studies have supported the performance of "early mitral valve repair" in asymptomatic patients with severe degenerative MR to normalize survival and improve late outcomes. Emerging recent evidence further indicates for the first time that the prompt surgical correction of severe MR due to flail mitral leaflets within 3 months following diagnosis in asymptomatic patients without classical Class I indications (symptoms or left ventricular dysfunction) conveys a 40% decrease in the risk of late death and a 60% diminution in heart failure incidence. A 10-point rationale based on the weight of rapidly accumulating clinical data, supports the performance of early mitral valve repair even in the absence of symptoms, left ventricular dysfunction, or guideline-based triggers; when effective operations can be provided using conventional or minimally invasive techniques at very low surgical risk.

Valvular repair or replacement for mitral endocarditis: 7-year cohort study

Background

A few studies have compared mitral valve repair and replacement in the setting of infective endocarditis, with varying results. We compared the characteristics and outcomes of mitral repair and replacement in endocarditis patients.

Methods

All patients undergoing mitral valve repair or replacement for active mitral endocarditis during 2005–2011 were included. Operative and follow-up mortality, composite morbidity, recurrent endocarditis, and redo operations were prespecified endpoints for analyses.

Results

There were 25 and 35 patients undergoing mitral valve repair and replacement, respectively. They were followed-up for 3.9 ± 2.5 years. Valve replacement patients were older ( p = 0.029), had a higher prevalence of intracardiac abscess ( p = 0.035), previous endocarditis ( p = 0.036), atrial fibrillation ( p = 0.001), worse renal function ( p = 0.013), higher risk scores ( p = 0.004–0.020), and longer operation times ( p < 0.001). Repair and replacement had similar rates of operative mortality (4.0% vs. 8.6%, p = 0.634), composite morbidity (16.0% vs. 28.6%, p = 0.357), survival ( p = 0.564), recurrent endocarditis ( p = 0.081), and redo operations ( p = 0.813). Independent predictors of operative mortality were preoperative inotropic or intraaortic balloon pump support. The independent predictor of mortality during follow-up was dialysis. Independent predictors of composite morbidity were intracardiac abscess and hypercholesterolemia. The independent predictor of recurrent endocarditis was previous endocarditis, and the independent predictor of redo operation was previous stroke.

Conclusion

Mitral valve replacement candidates had more baseline risk factors and higher raw rates of postoperative mortality and morbidity, which did not reach statistical significance.

Clinical outcomes through 12 months in patients with degenerative mitral regurgitation treated with the MitraClip® device in the ACCESS-EUrope Phase I trial

OBJECTIVES

Percutaneous treatment with the MitraClip device represents an alternative option for selected patients with degenerative mitral regurgitation (DMR) considered ineligible for surgery due to contraindications or high surgical risk by an inter-disciplinary heart team. We describe 12-month outcomes following treatment with the MitraClip device in DMR patients.

METHODS

The MitraClip Therapy Economic and Clinical Outcomes Study Europe (ACCESS-EU) Study has completed the enrolment of 567 patients as of April 2011, 117 of whom were DMR. Baseline demographics, procedural and acute safety results at 30 days and survival at 12 months were evaluated in the DMR subset. Effectiveness results, defined by a reduction in MR, and improvement in clinical outcomes based on changes in New York Heart Association (NYHA) functional Class, 6-min walk test (6MWT) and quality-of-life data were also assessed. Furthermore, DMR patients were stratified into high- and low-risk subgroups (logistic European System of Cardiac Operative Risk Evaluation I (logEuroSCORE I ≥20% or <20%, respectively) and differentially evaluated.

RESULTS

One hundred and seventeen DMR patients underwent the MitraClip procedure with a 94.9% rate (111 of 117) of successful clip implantation. Baseline characteristics and comorbidities included NYHA Class III/IV (74%), left ventricular ejection fraction (LVEF) <40% (9%), prior cardiac surgery (24%) and prior myocardial infarction (MI) (22%). Mean logEuroSCORE I was 15.5 ± 13.3%. Mortalities at 30 days and 12 months were 6.0 and 17.1%, respectively. At 12 months, 74.6% (53 of 71) of patients in follow-up achieved MR ≤grade 2+ and 80.8% (63 of 78) were in NYHA functional class I/II. Both Minnesota Living with Heart Failure questionnaire (MLHFQ) scores and 6MWT distance improved significantly at 12 months compared with baseline (P = 0.03 and P < 0.0001, respectively).

CONCLUSIONS

The MitraClip procedure resulted in significant reductions in MR and improvements in clinical outcomes at 12 months in selected patients with severe DMR. MitraClip therapy may serve as a complementary non-surgical therapeutic option for DMR patients who are considered at high risk or ineligible for surgery by an inter-disciplinary dedicated heart team. Interventional treatment should be indicated following the discussion of patients in an inter-disciplinary conference of cardiologists and cardiac surgeons as suggested by current international guidelines.

Valvular and aortic diseases in osteogenesis imperfecta

Osteogenesis imperfecta (OI) is an inheritable connective tissue disorder caused by defective collagen synthesis with the principal manifestations of bone fragility. OI has been associated with left sided valvular regurgitation and aortic dilation. Valve and aortic surgery are technically feasible in patients with OI but are inherently high risk due to the underlying connective tissue defect. This report reviews the valvular and aortic pathology associated with OI and their management. We describe two cases of patients with OI who have significant aortic and mitral valve regurgitation, one of whom has been managed conservatively and the other who has undergone successful mitral valve repair and aortic valve replacement. The latter case represents the fifth case of mitral valve repair in a patient with OI reported in the medical literature.

Heart valve disease

Heart valve disease is often characterized by a prolonged asymptomatic period that lasts for years and presents primary care physicians with an opportunity to detect disease before irreversible heart failure or other cardiac complications develop. Acute valvular disease can masquerade as respiratory illness or present with nonspecific systemic symptoms, and an astute examination by a primary care physician can direct appropriate care. Therefore, an understanding of the common pathologies and presentations of valvular heart disease is critical. This review focuses on the 2 most common valve lesions, aortic stenosis and mitral regurgitation, and provides an overview of other valve disease topics.

Early mitral valve repair versus watchful waiting in patients with severe asymptomatic organic mitral regurgitation; rationale and design of the Dutch AMR trial, a multicenter, randomised trial

BACKGROUND

Asymptomatic severe mitral valve (MV) regurgitation with preserved left ventricular function is a challenging clinical entity as data on the recommended treatment strategy for these patients are scarce and conflicting. For asymptomatic patients, no randomised trial has been performed for objectivising the best treatment strategy.

METHODS

The Dutch AMR (Asymptomatic Mitral Regurgitation) trial is a multicenter, prospective, randomised trial comparing early MV repair versus watchful waiting in asymptomatic patients with severe organic MV regurgitation. A total of 250 asymptomatic patients (18-70 years) with preserved left ventricular function will be included. Intervention will be either watchful waiting or MV surgery. Follow-up will be 5 years. Primary outcome measures are all-cause mortality and a composite endpoint of cardiovascular mortality, congestive heart failure, and hospitalisation for non-fatal cardiovascular and cerebrovascular events. Secondary outcome measures are total costs, cost-effectiveness, quality of life, echocardiographic and cardiac magnetic resonance parameters, exercise tests, asymptomatic atrial fibrillation and brain natriuretic peptide levels. Additionally, the complication rate in the surgery group and rate of surgery in the watchful waiting group will be determined.

IMPLICATIONS

The Dutch AMR trial will be the first multicenter randomised trial on this topic. We anticipate that the results of this study are highly needed to elucidate the best treatment strategy and that this may prove to be an international landmark study.