Ischemic mitral regurgitation: long-term outcome and prognostic implications with quantitative Doppler assessment

Why We Fail at Heart Failure: Lymphatic Insufficiency Is Disregarded

Is the definition of heart failure too narrow, not allowing research into compensatory mechanisms, comorbidities, right heart function, and lymphatic function?

A review of the absolute mortality of heart failure drugs and devices suggests a modest improvement in outcomes. Absolute mortality from common comorbidities, including renal insufficiency, arrhythmia, conduction deficits, pulmonary hypertension, anemia, obstructive sleep apnea, infection, inflammation, edema, ischemic heart disease, and diabetes II, is significant. The lymphatic function is involved in short, intermediate, and long-term compensation for a failing heart and plays a role in most of the comorbidities.

A better definition of heart failure is: Heart failure is a complex clinical syndrome that results from any structural or functional impairment of right or left ventricular filling or ejection of blood and failure of peripheral compensatory mechanisms. Lymphatic function from the anatomic, fluid management, immune modification standpoints requires study. New therapies from this analysis will improve patients with congestive heart failure.

Mitral Stenosis After MitraClip: How to Avoid and How to Treat

PURPOSE OF REVIEW

The goal of the paper is to highlight the importance of procedural planning and patient selection when using the MitraClip device in treating severe mitral regurgitation (MR).

RECENT FINDINGS

Following the recent results of the COAPT trial and FDA approval for functional MR patients, the indications for mitral clip are continuing to expand. Because of this, mitral stenosis from mitral clip can become a problem if the appropriate patients are not selected. Proper valve imaging, utilizing 3D transesophageal echocardiography to identify the pathology, is important to prevent iatrogenic mitral stenosis. In the unfortunate event of severe mitral stenosis as a result of the MitraClip device, surgery is the only treatment.

The Use of MitraClip in Secondary Mitral Regurgitation and Heart Failure

Secondary (also known as functional) mitral regurgitation (MR) has increased substantially over the last several decades due to an increase in the prevalence of dilated cardiomyopathy (ischemic and non-ischemic). Mortality and morbidity in patients with dilated cardiomyopathy is much greater when associated with MR as compared to without MR. MR will result in further left ventricular (LV) volume overload, LV dilation, and pupillary muscle displacement resulting in deterioration of the severity of MR leading to a vicious cycle. Optimization of heart failure medical therapy, and cardiac resynchronization therapy for those that qualify, can improve severity of MR; however, significant MR will persist in certain patients. Transcatheter mitral valve repair to treat significant MR using the MitraClip (Abbott, Menlo Park, California), which grasps and coapts the posterior and anterior mitral valve leaflets, in appropriately selected patients with dilated cardiomyopathy and secondary MR has been shown to improve quality of life and prolong survival.

Predictors of functional improvement in the short term after MitraClip implantation in patients with secondary mitral regurgitation

Background and objectives

MitraClip implantation is an established therapy for secondary mitral regurgitation (MR) in high-risk patients and has shown to improve several important outcome parameters such as functional capacity. Patient selection is both challenging and crucial for achieving therapeutic success. This study investigated baseline predictors of functional improvement as it was quantified by the six-minute walk distance (6MWD) after transcatheter mitral valve repair.

Methods and results

We retrospectively analyzed 79 patients with secondary MR treated with MitraClip implantation at an academic tertiary care center. Before and four weeks after the procedure, all patients underwent comprehensive clinical assessment, six-minute walk tests and echocardiography. 6MWD significantly improved after MitraClip therapy (295 m vs. 265 m, p < 0.001). A linear regression model including seven clinical baseline variables significantly predicted the change in 6MWD (p = 0.002, R² = 0.387). Female gender, diabetes mellitus and arterial hypertension were found to be significant negative predictors of 6MWD improvement. At baseline, female patients had significant higher left ventricular ejection fraction (49% vs. 42%, p = 0.019) and lower 6MWD (240 m vs. 288 m, p = 0.034) than male patients.

Conclusion

MitraClip implantation in secondary MR significantly improves functional capacity in high-risk patients even in the short term of four weeks after the procedure. Female gender, diabetes mellitus and arterial hypertension are baseline predictors of a less favourable functional outcome. While further validation in a larger cohort is recommended, these parameters may improve patient selection for MitraClip therapy.

Restrictive mitral annuloplasty with or without coronary artery bypass grafting in ischemic mitral regurgitation

Aims

In patients with ischaemic mitral regurgitation (MR), the impact of mitral valve surgery with concomitant coronary artery bypass grafting (CABG) on post‐operative survival and left ventricular (LV) reverse remodelling remains unknown. Therefore, we investigated these outcomes following restrictive mitral annuloplasty (RMA) with and without CABG in those patients.

Methods and results

This study included 309 patients with chronic MR and ischaemic cardiomyopathy for whom concomitant CABG was indicated (n = 225) or not indicated (n = 84) with RMA. The primary endpoint was all cause mortality during the follow‐up, and the secondary endpoint was defined as the composite of mortality and re‐admission for heart failure. Linear mixed model was used to analyse serial echocardiographic changes in LV function. To reduce the impact of treatment bias and potential confounding in the direct comparisons between patients who underwent RMA with and those who underwent it without CABG, we established weighted Cox proportional‐hazards regression models with inverse‐probability‐of‐treatment weighting. Pre‐operatively, there were no intergroup differences in age (RMA with CABG, 67 ± 9 vs. RMA without CABG, 68 ± 11, P = 0.409) and logistic EuroSCORE II (16 ± 14 vs. 15 ± 15%, P = 0.496). The 30‐day mortalities were 2.7% and 3.6%, respectively (P = 0.67). During follow‐up with a mean duration of 72 ± 37 months (range, 5.6–179), there were 157 deaths and 105 re‐admissions for heart failure. Overall 1‐year and 5‐year survival rates were 83 ± 2% and 58 ± 3%, respectively. Patients who did not receive CABG with RMA had a significantly lower 5‐year survival rate (45% vs. 63%, P = 0.049) and freedom from adverse events defined as mortality and/or admission for heart failure (19% vs. 43%, P < 0.001) than those who did. After adjustments for clinical covariates with inverse‐probability‐of‐treatment weighting, concomitant CABG was identified as an independent protective factor for adverse events (hazard ratio: 0.53; 95% confidence interval: 0.44–0.64; P < 0.001). Along with significant MR reduction, LV function parameters changed over time after surgery in both groups, with greater improvements in patients who underwent RMA with CABG (time effect, P < 0.001; and interaction effect, P = 0.002).

Conclusions

RMA can be performed with an acceptable operative mortality, irrespective of indications for CABG. Patients with ischaemic MR for whom CABG is indicated with RMA are more likely to show better long‐term and event‐free survival and greater improvements in LV systolic function. The optimal revascularization strategy should be discussed with a heart team whenever indicated in patients with ischaemic MR; otherwise, they may miss the opportunity to benefit from concomitant CABG during subsequent RMA.

Echocardiographic analysis of acute effects of percutaneous mitral annuloplasty on severity of secondary mitral regurgitation

AIMS

Percutaneous mitral annuloplasty (PMA) represents a new treatment option for secondary mitral regurgitation (SMR) being associated with higher morbidity and mortality. The present study was aimed to evaluate whether or not acute effects on SMR severity can quantitatively be assessed after PMA.

METHODS AND RESULTS

PMA was performed in 30 patients (mean age 76 ± 9; 37% males) with moderate (n = 14) or severe (n = 16) SMR. Vena contracta (VC), left ventricular (LV) velocity-time-integral ratio (VTI_MV/LVOT ), effective regurgitant orifice area (EROA) by two-dimensional proximal isovelocity surface area (PISA), regurgitant volume (RVol_PISA ) and regurgitant fraction (RF_PISA ) by PISA, RVol_volume and RF_volume by LV volume analyses, and parameters describing LV morphology, function, and cardiac performance were assessed by transthoracic echocardiography prior to and after PMA. According to RF_PISA /RF_volume , 14 patients showed mild, 15 moderate, and 1 severe SMR after PMA. Mean RF, RVol, EROA, VC, and VTI_MV/LVOT were lower directly after PMA (RF_PISA : 49% ± 11 vs. 34% ± 13, P < 0.001; RF_volume : 46% ± 10 vs. 34% ± 13, P < 0.001; RVol_PISA : 33 mL ± 13 vs. 25 mL ± 12, P < 0.001; RVol_volume : 28 mL ± 17 vs. 20 mL ± 14, P < 0.05; EROA_PISA : 0.24 cm²  ± 0.1 vs. 0.19 cm²  ± 0.1, P < 0.05; VC: 5.2 ± 0.1 vs. 4.1 ± 0.2, P < 0.001; VTI_MV/LVOT : 1.9 ± 0.4 vs. 1.6 ± 0.5, P < 0.05). Parameters of LV morphology, function, and cardiac performance did not change directly after PMA.

CONCLUSIONS

PMA leads to a reduction of MR severity in >80% of SMR patients. Acute effects of PMA can quantitatively be assessed by transthoracic echocardiography.

Mitral regurgitation after transcatheter aortic valve replacement

Patients undergoing transcatheter aortic valve replacement (TAVR) might have an associated significant MR that can potentially lead to left ventricular (LV) failure after procedure. Considering the specific alterations in the mitral valve in TAVR scenario and the widespread use of TAVR in recent years, it appears important to know and understand the anatomical, functional and clinical implications to develop adequate strategies for the future. Patients with severe mitral regurgitation (MR) have been generally excluded from randomized clinical trials, making poor the impact that associated MR can have on clinical outcomes after TAVR. Several factors must be considered whose presence influences the severity of MR. For example, the elevated prevalence of coronary disease with consequent ischemic MR may account for LV dilation observed at the end stage of aortic stenosis. Evidence randomized studies and registries suggests that the rate of concomitant moderate-to-severe MR in patients undergoing TAVR oscillates between 2% and 33%, and patients with moderate to severe MR may have hemodynamic frailty with clinical deterioration during mechanical intervention. Short- and long-term outcomes, including cardiac mortality, appear to be influenced by the existence of preoperative moderate-to-severe MR or by the postprocedural worsening of mild MR, generally due to adverse LV remodeling. The incidence and the prognostic effect of concomitant MR in patients undergoing TAVR requires specific attention as might trigger adjunctive strategy treatment which should be carefully evaluated in clinical trials.

KEYWORDS

Mitral regurgitation (MR); mitral valve; transcatheter aortic valve; transcatheter aortic valve replacement (TAVR).

Mitral valve leaflet response to ischaemic mitral regurgitation: from gene expression to tissue remodelling

Ischaemic mitral regurgitation (IMR), a frequent complication following myocardial infarction (MI), leads to higher mortality and poor clinical prognosis if untreated. Accumulating evidence suggests that mitral valve (MV) leaflets actively remodel post MI, and this remodelling increases both the severity of IMR and the occurrence of MV repair failures. However, the mechanisms of extracellular matrix maintenance and modulation by MV interstitial cells (MVICs) and their impact on MV leaflet tissue integrity and repair failure remain largely unknown. Herein, we sought to elucidate the multiscale behaviour of IMR-induced MV remodelling using an established ovine model. Leaflet tissue at eight weeks post MI exhibited significant permanent plastic radial deformation, eliminating mechanical anisotropy, accompanied by altered leaflet composition. Interestingly, no changes in effective collagen fibre modulus were observed, with MVICs slightly rounder, at eight weeks post MI. RNA sequencing indicated that YAP-induced genes were elevated at four weeks post MI, indicating elevated mechanotransduction. Genes related to extracellular matrix organization were downregulated at four weeks post MI when IMR occurred. Transcriptomic changes returned to baseline by eight weeks post MI. This multiscale study suggests that IMR induces plastic deformation of the MV with no functional damage to the collagen fibres, providing crucial information for computational simulations of the MV in IMR.

New developments in transcatheter therapy of mitral valve disease

Mitral valve regurgitation (MR) belongs to one of the most common acquired valve diseases in western countries with increasing prevalence in older age. For patients with high perioperative risk and older age prohibitive for valve surgery, the development of transcatheter mitral valve therapies offers new options. Assessment of the severity and etiology of MR and thorough imaging of the mitral valve anatomy and pathology are necessary prerequisites for appropriate decision making in the field of transcatheter mitral valve therapies. Different transcatheter repair and replacement techniques are on the market, most of them mimicking surgical techniques. With some techniques (e.g., the MitraClip device), there is good clinical experience (>80,000 devices implanted worldwide), and evidence (three randomized studies), whereas for newer procedures, safety and efficacy data are still very limited. Transcatheter mitral repair and replacement techniques have to be considered as complementary treatment options for high-risk patients indicated by the Heart Teams. The different techniques and devices will be introduced and discussed in the following paper.

A Unifying Concept for the Quantitative Assessment of Secondary Mitral Regurgitation

BACKGROUND

Diverging guideline definitions for the quantitative assessment of severe secondary mitral regurgitation (sMR) reflect the lacking link of the sMR spectrum to mortality and has introduced a source of uncertainty and continuing debate.

OBJECTIVES

The current study aimed to define improved risk-thresholds specifically tailored to the complex nature of sMR that provide a unifying solution to the ongoing guideline-controversy.

METHODS

This study enrolled 423 heart failure patients under guideline-directed medical therapy and assessed sMR by effective regurgitant orifice area (EROA), regurgitant volume (RegVol), and regurgitant fraction (RegFrac).

RESULTS

Measures of sMR severity were consistently associated with 5-year mortality with a hazard ratio of 1.42 for a 1-SD increase (95% confidence interval [CI]: 1.25 to 1.63; p < 0.001) for EROA, 1.37 (95% CI: 1.20 to 1.56; p < 0.001) for RegVol, and 1.50 (95% CI: 1.30 to 1.73; p < 0.001) for RegFrac. Results remained statistically significant after bootstrap- or clinical confounder-based adjustment. Spline-curve analyses showed a linearly increasing risk enabling the ability to stratify into low-risk (EROA <20 mm² and RegVol <30 ml), intermediate-risk (EROA 20 to 29 mm² and RegVol 30 to 44 ml), and high-risk (EROA ≥30 mm² and RegVol ≥45 ml) groups. In the intermediate-risk group, a RegFrac ≥50% as indicator for hemodynamic severe sMR was associated with poor outcome (p = 0.017). A unifying concept based on combined assessment of the EROA, the RegVol, and the RegFrac showed a significantly better discrimination compared with the currently established algorithms.

CONCLUSIONS

Risk-based thresholds tailored to the pathophysiological concept of sMR provide a unifying solution to the ongoing guideline controversy. An algorithm based on the combined assessment of the unifying cutoffs for EROA, RegVol, and RegFrac improves risk prediction compared with currently established grading.

Percutaneous mitral valve repair: the necessity to redefine secondary mitral regurgitation

Interest in percutaneous mitral valve repair has increased during recent years. This is mainly driven by the significant number of patients being declined for mitral valve surgery because of a high risk of surgery-related complications or death. In this subset of patients, percutaneous edge-to-edge repair using the MitraClip device (Abbott, Menlo Park, CA, USA) has become an established treatment option, proven to be safe, efficient and associated with improved functional status. In contrast to primary mitral regurgitation (MR), clinical outcomes after mitral valve surgery appear to be less favourable as regards secondary MR due to heart failure. In the MITRA-FR and COAPT trials, patients with moderate to severe and severe secondary MR with reduced left ventricular function received either medical treatment (control group) or MitraClip implantation plus medical treatment (device group). Results were conflicting, with only the COAPT trial showing better clinical outcomes in the device group. However, both trials are now seen as complementary and provide useful information especially regarding patient selection for MitraClip therapy. The goal of this review is to delineate which subset of patients with secondary MR will potentially benefit from percutaneous mitral valve repair.

Average pixel intensity method for prediction of outcome in secondary mitral regurgitation

Background

Echocardiographic grading of secondary mitral regurgitation (SMR) severity is challenging and involves multiple guideline-recommended parameters. We previously introduced the average pixel intensity (API) method for grading SMR. In this study, the clinical outcome in SMR based on the API method for grading MR was compared with conventional grading methods.

Methods

231 patients with systolic heart failure and reduced ejection fraction (ischaemic/non-ischaemic) and SMR were prospectively enrolled. MR was graded using all guideline-recommended parameters and the API method, which is based on the pixel intensity of the continuous wave Doppler signal. The primary outcome was MACE (major adverse cardiac event).

Results

The API method was applicable in 98% of patients with SMR (n=227). During a median follow-up of 24 months, 98 patients (43%) had a MACE (cardiovascular mortality (n=50, 22%), heart failure hospitalisation (n=44, 19%), mitral valve surgery (n=11, 5%), percutaneous mitral intervention (n=12, 5%), heart transplantation (n=5, 2%)). On log-rank test, the API method was highly significant in predicting clinical outcome. On multivariable Cox proportional hazard analysis, SMR grading with the API method was an independent predictor of clinical outcome (along with NYHA class and right ventricular systolic pressure; p<0.001), increasing the event risk by 9% per 10 au API rise (p=0.001). In the same multivariable analysis, proximal isovelocity surface area (PISA)-effective regurgitant orifice area or PISA-regurgitant volume were not independent predictors of events (p=0.18 and 0.26, respectively).

Conclusion

SMR grading with the API method is an independent predictor of clinical outcome and provides prognostic information in addition to clinical and other echocardiographic variables.

Initial Feasibility Study of a New Transcatheter Mitral Prosthesis: The First 100 Patients

BACKGROUND

Transcatheter mitral valve replacement (TMVR) is a rapidly evolving therapy. Follow-up of TMVR patients remains limited in duration and number treated.

OBJECTIVES

The purpose of this study was to examine outcomes with expanded follow-up for the first 100 patients who underwent TMVR with the prosthesis.

METHODS

The Global Feasibility Study enrolled symptomatic patients with either primary or secondary mitral regurgitation (MR) who were at high or prohibitive surgical risk. The present investigation examines the first 100 patients treated in this study. Clinical outcomes through last clinical follow-up were adjudicated independently.

RESULTS

In the cohort (mean age 75.4 ± 8.1 years; 69% men), there was a high prevalence of severe heart failure symptoms (66%), left ventricular dysfunction (mean ejection fraction 46.4 ± 9.6%), and morbidities (Society of Thoracic Surgeons Predicted Risk of Mortality, 7.8 ± 5.7%). There were no intraprocedural deaths, 1 instance of major apical bleeding, and no acute conversion to surgery or need for cardiopulmonary bypass. Technical success was 96%. The 30-day rates of mortality and stroke were 6% and 2%, respectively. The 1-year survival free of all-cause mortality was 72.4% (95% confidence interval: 62.1% to 80.4%), with 84.6% of deaths due to cardiac causes. Among survivors at 1 year, 88.5% were New York Heart Association function class I/II, and improvements in 6-min walk distance (p < 0.0001) and quality-of-life measurements occurred (p = 0.011). In 73.4% of survivors, the Kansas City Cardiomyopathy Questionnaire score improved by ≥10 points.

CONCLUSIONS

In this study of TMVR, which is the largest experience to date, the prosthesis was highly effective in relieving MR and improving symptoms, with an acceptable safety profile. Further study to optimize the impact on long-term survival is needed.

Restrictive mitral valve annuloplasty for chronic ischaemic mitral regurgitation: outcomes of flexible versus semi-rigid rings

Background

Restrictive mitral annuloplasty is the mainstay of surgical correction of chronic ischaemic mitral regurgitation (CIMR). Long-term data on the various types of annuloplasty rings is limited. The aim of this study was to investigate the clinical and echocardiographic outcomes of restrictive mitral annuloplasty in patients with CIMR, comparing the use of flexible versus semi-rigid annuloplasty rings.

Methods

A retrospective review was conducted for 133 patients with CIMR who underwent restrictive mitral annuloplasty at our institution between 1999 and 2015. Patient demographics and postoperative outcomes were analyzed.

Results

Mean age was 61.9±9.2 years and 103 patients (77.4%) were male. All patients underwent coronary artery bypass grafting, with a mean of 3.3±0.8 grafts. Flexible rings was implanted in 39 patients (29.3%, group F) and semi-rigid rings in 94 (70.7%, group R). Preoperative New York Heart Association class was III/IV in 104 patients (78.2%). Mean preoperative left ventricular ejection fraction was 28.8%±10.2%. Preoperative mitral regurgitation was moderate in 51 patients (38.3%) and severe in 82 (61.7%). In-hospital mortality occurred in 11 patients (8.3%). Overall survival at 1, 5 and 10 years were, respectively, 86.4%, 69.7% and 45.9%. At 10 years, overall survival (group F 53.1%, group R 40.0%, P=0.330) and freedom from moderate to severe MR (group F 53.1%, group R 53.8%, P=0.725) did not differ significantly. Freedom from hospitalization for heart failure was 59.3%. Left ventricular reverse remodelling, defined as a reduction of left ventricular end-systolic volume index >15%, occurred more commonly in Group R (51.1%) compared to Group F (23.1%), P=0.003.

Conclusions

Restrictive mitral annuloplasty was associated with an operative mortality of 8.3%. Heart failure symptoms and significant MR recur in approximately 40% of patients after 10 years. Survival remained suboptimal and was not influenced by the type of annuloplasty ring.

Image Guided Mitral Valve Replacement: Registration of 3D Ultrasound and 2D X-ray Images

Mitral valve repair or replacement is important in the treatment of mitral regurgitation. For valve replacement, a transcatheter approach had the possibility of decrease the invasiveness of the procedure while retaining the benefit of replacement over repair. However, fluoroscopy images acquired during the procedure provide no anatomical information regarding the placement of the probe tip once the catheter has entered a cardiac chamber. By using 3D ultrasound and registering the 3D ultrasound images to the fluoroscopy images, a physician can gain a greater understanding of the mitral valve region during transcatheter mitral valve replacement surgery. In this work, we present a graphical user interface which allows the registration of two co-planar X-ray images with 3D ultrasound during mitral valve replacement surgery.

Prognostic Impact of Ischemic Mitral Regurgitation Severity and Myocardial Infarct Quantification by Cardiovascular Magnetic Resonance

OBJECTIVES

This study sought to evaluate the role of cardiac magnetic resonance (CMR) for the quantification of ischemic mitral regurgitation (IMR) and myocardial infarct size (MIS) in patients with ischemic cardiomyopathy (ICM). This study also sought to explore the interaction between IMR severity and MIS and its association with outcomes in patients with ICM.

BACKGROUND

IMR occurs secondary to a disease of the left ventricle and is associated with poor outcomes. The role of CMR for the evaluation and risk stratification of patients with ICM and IMR remains uncertain.

METHODS

Consecutive patients with ICM who underwent baseline CMR were included. MIS was quantified on late gadolinium enhancement imaging as the proportion of left ventricular mass. IMR was quantified with CMR by calculating the mitral regurgitant fraction (MRFraction). Cox proportional hazards models were built to assess the association of IMR and MIS quantification with the combined endpoint of all-cause death or heart transplant.

RESULTS

We evaluated 578 patients (mean age: 62 ± 11 years, 76% males). The mean left ventricular ejection fraction was 25 ± 11%, with an MIS of 24 ± 16% and MRFraction of 18 ± 17%. Over a median follow-up time of 4.9 years, 198 (34%) patients experienced death or cardiac transplant. On multivariable analysis, after comprehensive medical risk score, subsequent revascularization, implantable cardioverter-defibrillator insertion, and surgical mitral valve intervention were controlled for, the interaction of IMR severity and MIS emerged as a powerful predictor of adverse outcomes (p = 0.008). For patients with significant IMR (MRFraction: ≥35%), the hazard ratio comparing moderate MIS (15% to 29%) versus small MIS (<15%) was 1.51 (0.57 to 3.98), and the hazard ratio comparing large MIS (≥30%) versus small MIS was 5.41 (2.34 to 12.7).

CONCLUSIONS

Risk associated with IMR is more comprehensively described as an interaction between IMR severity and MIS. Further studies in patients IMR using comprehensive CMR evaluation are needed to verify whether this approach can improve patient selection and procedural outcomes to address IMR.

[Evaluation of mitral regurgitation : How much quantification do we need?]

Severe mitral regurgitation (MR) is associated with increased morbidity and mortality. Thus, the correct evaluation of the underlying etiology, pathomechanism and severity is crucial for optimal treatment. Echocardiography is the predominant diagnostic modality in the clinical routine as it enables grading of mitral regurgitation, which can frequently be achieved by readily available qualitative parameters. Additionally, echocardiography provides several methods to quantify the hemodynamic significance of MR. The effective regurgitation orifice area (EROA) is the quantitative parameter best correlated with clinical events. American and European imaging guidelines both recommend the use of quantitative parameters even though they disagree on the cut-off values for secondary MR. The evaluation of MR should always include an assessment of the adjacent heart chambers in order to be able to assess the impact of volume overload on size and function of the left ventricle and left atrium. The final interpretation of the quantitative parameters requires knowledge of left ventricular volume and ejection fraction. Newer 3D-echocardiographic approaches to quantify MR are less dependent on mathematical assumptions and have shown convincing results in several studies but still lack sufficient clinical validation. As an alternative to echocardiography, for specific indications cardiac magnetic resonance imaging (MRI) has proven to be a systematic and observer-independent method for quantification of MR.

Impact of posteromedial papillary muscle infarction on mitral regurgitation during ST-segment elevation myocardial infarction

The exact role of papillary muscle infarction (PMI) during the acute phase of acute ST-segment elevation myocardial infarction (STEMI) is not well understood, as existing data on the impact of PMI location is conflicting. We hypothesized that infarction of the posteromedial papillary muscle (PM-PMI) as determined by cardiac magnetic resonance imaging might be associated with an increased incidence of mitral valve regurgitation in the first week after STEMI. 242 patients with first STEMI underwent a late-enhancement (LGE-) cardiac magnetic resonance imaging within a median of 2 (IQR 2-5) days and echocardiography within 3 (IQR 2-5) days after primary angioplasty for the index event. PMI was scored based on short axis slices (AL-PMI: anterolateral PMI, PM-PMI, AL/PM-PMI: AL- and PM-PMI). Patients with PM-PMI had significantly higher odds (OR 2.62, p < 0.01) for the occurrence of mitral regurgitation than patients with no-PMI, AL-PMI or AL/PM-PMI. Furthermore, advanced age, non-anterior infarct location and longer pain-to-balloon time were identified as risk factors for the occurrence of mitral regurgitation. Binary logistic regression analysis revealed that PM-PMI is a predictor of mitral regurgitation independent of infarct location and age (OR 2.229, CI 1.078-4.903, p = 0.031). PM-PMI as determined by cardiac magnetic resonance imaging is an independent predictor of mitral regurgitation in the setting of acute STEMI. Our data might improve our understanding of the dynamic nature of functional mitral regurgitation.

Predictors and prognostic impact of secondary mitral regurgitation in myocardial infarction with preserved ejection fraction

BACKGROUND

Secondary or functional mitral regurgitation (FMR) has been reported associated with poor prognosis in patients with ischemic or non-ischemic cardiomyopathy. Prognostic impact of the FMR in myocardial infarction with preserved ejection fraction (MIpEF) is unknown. The aim of this study was to investigate predictors and prognostic impact of FMR in MIpEF.

METHODS

A total of 556 patients with MIpEF were selected from the Bell Land General Hospital MI (BELAMI) registry (n = 953). Patients were grouped according to the presence or absence of severe FMR. Clinical endpoint was all-cause death.

RESULTS

Severe FMR was present in 26 patients (4.7%) (FMR group) and absent in 530 patients (control). FMR group was older (77.5 ± 7.2 vs. 67.3 ± 11.3 years, P < 0.01) and had more female gender (54% vs. 28%, P < 0.01). By echocardiography, FMR group had larger left atrial diameter and left ventricular end-systolic volume. E and E/e' were significantly higher and deceleration time of E was significantly shorter in FMR group. By Kaplan-Meier analysis, survival was significantly lower in FMR group than in control (log-rank, P = 0.004).

CONCLUSION

Severe FMR is rare in MI patients with preserved EF but is associated with poor long-term prognosis.

Injectable Shear-Thinning Hydrogels Prevent Ischemic Mitral Regurgitation and Normalize Ventricular Flow Dynamics

Injectable hydrogels are known to attenuate left-ventricular (LV) remodeling following myocardial infarction (MI), dependent on material mechanical properties. The effect of hydrogel injection on ischemic mitral regurgitation (IMR) resultant from LV remodeling remains relatively unexplored. This study uses multiple imaging methods to evaluate the efficacy of injectable hydrogels with tunable modulus to prevent post-MI development of IMR. Posterolateral MI was induced in 20 sheep with subsequent epicardial injection of saline (control (MI); n = 7), soft hydrogel (guest-host crosslinking, modulus <1 kPa, n = 7), or stiff hydrogel (dual-crosslinking, modulus = 41.4 ± 4.3 kPa, n = 6) within the infarct region and 8-week follow-up. IMR and valve geometry were assessed by echocardiography. LV geometry (long-axis dimension, posterior chordae length) and ventricular flow dynamics were assessed by magnetic resonance imaging. IMR developed in MI controls at 8 weeks and was attenuated with hydrogel treatment (IMR grade for MI: 1.86 ± 0.69; guest-host crosslinking: 1.29 ± 1.11; dual-crosslinking: 0.50 ± 0.55, P = 0.02 vs MI). Tethering of the posterior leaflet increased in MI controls, but not with stiff hydrogel treatment. Across cohorts, IMR was correlated with changes in the long-axis dimension (Spearman R = 0.77) and posterior chordae length (Spearman R = 0.64). Intraventricular flow dynamics were highly disturbed in MI controls, but stiff hydrogel treatment normalized flow patterns and reduced the prevalence of large (≥2+ MR, >5 mL) regurgitant volumes. Injectable hydrogels attenuated subvalvular remodeling and leaflet tethering, preventing IMR development and normalizing LV flow dynamics. Hydrogels with a supraphysiological modulus yielded best outcomes.

Quantitative assessment of effective regurgitant orifice: impact on risk stratification, and cut-off for severe and torrential tricuspid regurgitation grade

Aims 

Asses the added value of quantitative evaluation of tricuspid regurgitation (TR), the proper cut-off value for severe TR and ‘torrential TR’ based on outcome data. The added value of quantitative evaluation of TR, and the cut-off values associated with increased mortality are unknown.

Methods and results

In patients with all-cause TR assessed both qualitatively and quantitatively by proximal iso-velocity surface area method, long-term and 1-year outcome analysis was conducted. Thresholds for excess mortality were assessed using spline curves, receiver-operating characteristic curves, and minimum P-value analysis. The study involved 676 patients with all-cause TR (age 73.9 ± 14 years, male 45%, ejection fraction 52.9 ± 14%). Effective regurgitant orifice (ERO) was strongly associated with decreased survival in unadjusted [hazard ratio (HR) 2.38 (1.79–3.01), P &lt; 0.0001 per 0.1 cm2 increment] and adjusted [2.6 (1.25–5.0), P = 0.01] analyses. Quantitative grading was superior to qualitative grading in prediction of outcome (P &lt; 0.01). The optimal cut-off value for the best separation in survival between groups of patients with severe vs. lesser degree of TR was 0.35 cm2 [P &lt; 0.0001, HR =2.0 (1.5–2.7)]. ERO negatively impacted survival, even when including only the subgroup of patients with severe TR [HR 1.5 (1.01–2.3); P = 0.04]. The optimal threshold corresponding for the best separation for survival between groups of patients with severe vs. ‘torrential’ TR was 0.7 cm2 [P = 0.005, HR =2.6 (1.2–5.1)].

Conclusion 

TR can be severe and even ‘torrential’ and is associated with excess mortality. Quantitative assessment of TR by ERO measurement is a powerful independent predictor of outcome, superior to standard qualitative assessment. The optimal cut-off above which mortality is increased is 0.35 cm2, similar albeit slightly lower than suggested in recent guidelines. Torrential TR &gt;0.7 cm2 is associated with poorer survival compared to patients with severe TR (ERO &gt; 0.4 cm2 and &lt;0.7 cm2).

One-Year Outcomes After MitraClip for Functional Mitral Regurgitation

BACKGROUND

Secondary mitral regurgitation (SMR) occurs in the absence of organic mitral valve disease and may develop as the left ventricle dilates or remodels or as a result of leaflet tethering with impaired coaptation, most commonly from apical and lateral distraction of the subvalvular apparatus, with late annular dilatation. The optimal therapy for SMR is unclear. This study sought to evaluate the 1-year adjudicated outcomes of all patients with SMR undergoing the MitraClip procedure in the EVEREST II (Endovascular Valve Edge-to-Edge Repair Study) Investigational Device Exemption program, which is comprised of the randomized clinical trial, the prospective High-Risk Registry, and the REALISM Continued Access Registry (Multicenter Study of the MitraClip System).

METHODS

Patients with 3+/4+ SMR enrolled in EVEREST II were stratified by non-high surgical risk (non-HR) and high surgical risk (HR) status (defined as Society of Thoracic Surgeons risk of mortality ≥12% or predefined risk factors). Clinical, echocardiographic, and functional outcomes at 1 year were evaluated.

RESULTS

A total of 616 patients (482 HR, 134 non-HR; mean age, 73.3±10.5 years; Society of Thoracic Surgeons risk, 10.2±6.9%) with SMR underwent the MitraClip procedure. At baseline, 80.5% of patients were in New York Heart Association class III/IV. Major adverse events at 30 days included death (3.6%), stroke (2.3%), and renal failure (1.5%). At discharge, 88.8% had MR ≤2+. At 1 year, there were 139 deaths, and the Kaplan-Meier estimate of freedom from mortality was 76.8%. The majority of surviving patients (84.7%) remained with MR ≤2+ and New York Heart Association class I/II (83.0%). Kaplan-Meier survival at 1 year was 74.1% in HR patients and 86.4% in non-HR patients ( P=0.0175). At 1 year, both groups achieved comparable MR reduction (MR ≤2+, 84.0% versus 87.0%) and improvement in left ventricular end-diastolic volume (-8.0 mL versus -12.7 mL), whereas New York Heart Association class I/II was found in 80.1% versus 91.8% ( P=0.008) of HR and non-HR patients, respectively. In HR patients, the annualized rate of heart failure hospitalizations decreased from 0.68 to 0.46 in the 12 months before to 12 months after the procedure ( P<0.0001).

CONCLUSIONS

Transcatheter mitral valve repair with the MitraClip in patients with secondary MR is associated with acceptable safety, reduction of MR severity, symptom improvement, and positive ventricular remodeling.

CLINICAL TRIAL REGISTRATION

https://www.clinicaltrials.gov . Unique identifiers: NCT00209274, NCT01940120, and NCT01931956.

Refining the prognostic impact of functional mitral regurgitation in chronic heart failure

Aims

Significant efforts are currently undertaken to reduce functional mitral regurgitation (FMR) in patients with chronic heart failure in the hope to improve prognosis. We aimed to assess the prognostic impact of FMR in heart failure with reduced ejection fraction (HFrEF) under optimal medical therapy (OMT) and various conditions of HFrEF. We further intended to identify a heart failure phenotype, where FMR is most likely a driving force and not a mere bystander of the disease.

Methods and results

We prospectively included 576 consecutive HFrEF patients into our long-term observational study. Functional [i.e. New York Heart Association (NYHA) class], echocardiographic, invasive haemodynamic, and biochemical (i.e. NT-proBNP, MR-proANP, MR-proADM, CT-proET-1, copeptin) measurements were performed at baseline. During a median follow-up of 62 months (interquartile range 52-76), 47% of patients died. Severe FMR was a significant predictor of mortality [hazard ratio (HR) 1.76, 95% confidence interval (CI) 1.34-2.30; P < 0.001], independent of clinical (adjusted HR 1.61, 95% CI 1.22-2.12; P = 0.001), and echocardiographic (adjusted HR 1.46, 95% CI 1.09-1.94; P = 0.01) confounders, OMT (adjusted HR 1.81, 95% CI 1.25-2.63; P = 0.002), and neurohumoral activation (adjusted HR 1.38, 95% CI 1.03-1.84; P = 0.03). Subanalysis revealed that severe FMR was associated with poor outcome in an intermediate-failure phenotype of HFrEF i.e. patients with NYHA class II (adjusted HR 2.17, 95% CI 1.07-4.44; P = 0.03) and III (adjusted HR 1.80, 95% CI 1.17-2.77; P = 0.008), moderately reduced left ventricular function (adjusted HR 2.37, 95% CI 1.36-4.12; P = 0.002), and within the second quartile (871-2360 pg/mL) of NT-proBNP (adjusted HR 2.16, 95% CI 1.22-3.86; P = 0.009).

Conclusion

In a patient cohort under OMT, the adverse prognostic impact of FMR is given predominantly in a sub-cohort of a specific intermediate-failure phenotype-well-defined functionally, haemodynamically, biochemically, and morphologically.

Percutaneous Mitral Edge-to-Edge Repair: State of the Art and a Glimpse to the Future

Patients with severe symptomatic mitral regurgitation have a poor prognosis if left untreated. In those patients who are not eligible for mitral valve surgery, percutaneous edge-to-edge repair may improve clinical outcomes. Recent clinical trials have added to our knowledge and provide interesting insights into the management of such patients. With an increasingly aging global population, these technologies are likely to represent an important treatment option. This mini-review will examine the technology, the evidence and the latest developments in percutaneous mitral edge-to-edge repair.

Diagnosis and Management of Ischemic Mitral Regurgitation: Evidence-Based Clinical Decision Making at the Point of Care

Anatomical, functional, and pathophysiologic mechanisms of ischemic mitral regurgitation (IMR) are markedly different from the primary mitral regurgitation. The older and ubiquitous cutoff of EROA (effective regurgitant orifice area) and Rvol (regurgitant volume) for IMR has been reinstated in the new guideline after a brief hiatus. There had always been a lack of good-quality evidence for its introduction for guiding IMR severity in the previous guideline, and we still do not have quality evidences that could justify its reintroduction. Unlike primary MR, IMR is usually associated with reduced ejection fraction. Therefore, it appears unrealistic to keep the similar cutoff for primary MR and IMR. The cutoff of severity can be modified according to projected values of Rvol normalized to ejection fraction and EROA normalized to Rvol. In addition, the treatment outcome in these patients is determined by factors (left ventricular dyssynchrony, annular dilatation, tenting area, tenting height, tenting volume, and myocardial viability) other than the simple grading. In this review article, a series of graph have been constructed from the numerical data derived from the literatures on IMR to depict the relationship between EROA, Rvol, left ventricular end diastolic volume, and ejection fraction in order to obtain a reasonable projection formula for EROA and Rvol. Furthermore, a management algorithm has been proposed for patients with IMR undergoing coronary artery bypass grafting based on echocardiographic predictors that influence the postoperative outcome.

Mitral regurgitation worsens cardiac remodeling in ischemic cardiomyopathy in an experimental model

OBJECTIVE

Mitral regurgitation (MR) developing concomitant with ischemic cardiomyopathy is a frequently diagnosed valvular lesion, for which an optimal therapeutic strategy is unknown. The contribution of MR to the ongoing cardiac remodeling from myocardial infarction (MI) remains controversial. We have developed a novel experimental model in which MI and severe MR can be independently introduced, to study the role of MR in chronic remodeling of the ischemic heart.

METHODS

A total of 98 rats were induced with MI+MR (group 1), MI (group 2), MR (group 3), or sham surgery (group 4). MR was induced by inserting a needle into the anterior mitral leaflet via the ventricular apex in a beating heart. MI was induced by ligating the left coronary artery. Biweekly ultrasound examinations were performed after surgery, and invasive hemodynamic assessments were performed in some rats at 2, 10, and 20 weeks.

RESULTS

At 2 weeks postsurgery, the mean end-diastolic volume was 432 ± 103 μL in ischemic hearts with MR, compared with 390 ± 76.3 μL in ischemic hearts without MR (a 10.76% difference). By 20 weeks, the mean volume was significantly greater in the former group (767 ± 246 μL vs 580 ± 85 μL; a 32.24% difference). At 2 weeks, mean end-systolic volume was 147 ± 46.8 μL in the ischemic hearts with MR and 147 ± 45.7 μL in those without MR. By 20 weeks, the mean volumes had increased to 357 ± 136.4 μL and 271 ± 82.3 μL, respectively (a 31.73% difference).

CONCLUSIONS

MR in ischemic hearts significantly increased end-diastolic and end-systolic volumes of the left ventricle, indicating adverse cardiac remodeling and worse systolic function.

Echocardiographic assessment of mitral regurgitation

Mitral regurgitation (MR) is one of the most frequent indications for valve surgery in developed countries, and echocardiographic assessment is an essential tool to evaluate its etiologies, severity, and therapeutic indications. The mitral valve apparatus is a complex structure composed of several parts: apart from the mitral valve leaflets and annulus, it also includes the chordae tendineae, papillary muscles, and left ventricular (LV) wall. MR can be caused not only by organic changes of the mitral valve leaflets or chordae (primary MR) but also by extreme mitral annular enlargement or mitral leaflet tethering due to displacement and malfunction of papillary muscles and LV wall (secondary MR). In secondary MR with LV dysfunction, a milder degree of MR can be associated with adverse outcomes compared with primary MR. Grading the severity is the first step in evaluation of indication for surgical/transcatheter interventions. As such, there are several techniques to assess the severity of MR using echocardiography. However, none of the techniques is reliable enough by itself, and it is always recommended to integrate multiple methods. In cases where echocardiographic assessment of MR severity is inconclusive, magnetic resonance may be helpful. In addition to the severity, anatomical information, such as localization in primary MR due to mitral valve prolapse and LV size in secondary MR due to LV dilatation/dysfunction, is an important concern in presurgical echocardiography. Transesophageal echocardiography and three-dimensional echocardiography are key techniques for anatomical evaluation including mitral valve and LV volumes. In transcatheter intervention for MR, echocardiography plays a pivotal role as a guide for procedures and endpoints. In this review article, the authors provide a comprehensive summary of current standards of echocardiographic assessment of MR.

[Clinical Course and Predictors of Ischemic Mitral Regurgitation in Patients with Myocardial Infarctions of Different Localizations]

PURPOSE

to assess the clinical course of ischemic mitral regurgitation (IMR) in patients with myocardial infarction of different localizations and reveal its mechanisms and predictors.

MATERIALS AND METHODS

We enrolled in this study patients with first inferoposterior myocardial infarction (IPMI) (n=77), and anteroseptal MI (ASMI) (n=79) revascularized within 12 hours after symptoms onset, as well as age, sex and weight matched healthy control subjects (n=50). Parameters of mitral structures and mitral annulus areas (MAA), left ventricular (LV) volumes (LVV) and sphericity index (SI), global (G) and segmental (S) longitudinal LV strain (GLS, SLS), papillary muscles (PM) LS (PMLS) and PM systolic dyssynchrony (PMSD) were measured by echocardiography on the 7th and 180th days of follow up.

RESULTS

On the 7th day of follow up IMR was diagnosed more frequently in IPMI vs. ASMI (42 vs. 28%, р&lt;0.001). In both groups patients with TIMI 0 flow before angioplasty had highest, while those with TIMI 3 flow - lowest incidence of IMR. Presence of IMR depended on collateral flow availability in vascular bed of infarct related artery. Wall motion abnormalities (WMA) of infarcted segments, MAA, posteromedial PM posterior displacement (PPMPD), SLS, PMLS, PMSD correlated with IMR in patients with IPMI on the 7th day of follow up. VLV, GLS and MAA correlated with IMR in patients with ASMI on the 7th day follow up. Patients with IPMI without IMR in 7th day did not develop IMR for 180 days of follow up while IMR developed in 19.3% of patients with ASMI without IMR at initial examination. Among patients with IPMI and ASMI 37.5% and 45.5%, respectively, of those with IMR at initial examination had no IMR after 180 days of follow up. Patients with IPMI more frequently had eccentric IMR than patients with ASMI (78 and 24%, respectively, p&lt;0.002). At examination after 6 months WMA, MAA, PMSD, PPMPD, SLS, PMLS, PMSD correlated with IMR in patients with IPMI, while VLV, AMA, PM apical displacement (PMAD), GLS and PMSD correlated with IMR in patients with ASMI. AMA, PMAD and PMSD were predictors of IMR in patients with MI of both localizations. In addition, in patients with ASMI VLV and SI were also predictors of IMR.

Risk of Ischemic Mitral Regurgitation Recurrence After Combined Valvular and Subvalvular Repair

BACKGROUND

Mitral valve repair (MVr) combined with papillary muscle approximation (PMA) may improve repair durability in severe ischemic mitral regurgitation (MR), when compared with MVr alone. We sought to identify preoperative transthoracic echocardiographic markers associated with MR recurrence after MVr with PMA.

METHODS

A post-hoc analysis was performed on patients with severe ischemic MR who underwent coronary artery bypass graft surgery with MVr with PMA in the papillary muscle approximation randomized trial. The PMA was performed utilizing a 4-mm polytetrafluoroethylene graft placed around the papillary muscles. Linear regression analyses and receiver-operating characteristic curves were used to identify echocardiographic variables and diagnostic models associated with recurrent MR.

RESULTS

There were 48 patients with a mean age of 63 ± 7 years, a left ventricular ejection fraction of 35% ± 5%, and a left ventricular end-diastolic diameter of 63 ± 3 mm. Of these, 37 patients had baseline and 5-year follow-up echocardiograms, with moderate-to-severe MR recurring in 27%. Linear regression analyses revealed associations between preoperative pulmonary artery systolic pressure (standardized beta coefficient, β = 0.49/mm Hg, p = 0.002), MV tenting area (β = 0.47/cm2, p = 0.004), a symmetric MV tethering pattern (β = 0.44, p = 0.007), and left ventricular end-diastolic diameter (β = 0.37/mm, p = 0.02) with follow-up MR grade. The presence of both MV tenting area 3.1 cm2 or greater (area under the curve 0.822) and left ventricular end-diastolic diameter of 64 mm or greater (area under the curve 0.801) was the most robust discriminative model for moderate-to-severe MR recurrence (specificity 92%, sensitivity 69%, area under the curve 0.804, p = 0.003).

CONCLUSIONS

In patients undergoing coronary artery bypass graft surgery with MVr plus PMA, the extent of baseline MV apparatus and left ventricle geometric remodeling identifies patients at increased risk for MR recurrence.

The effects of cardiac resynchronization therapy on left ventricular and mitral valve geometry and secondary mitral regurgitation in patients with left bundle branch block

BACKGROUND

Secondary mitral regurgitation (MR) is common in patients with left bundle branch block (LBBB) undergoing cardiac resynchronization therapy (CRT). We aimed to define CRT effects on left ventricular (LV) and mitral valve (MV) geometry, and their correlation with MR severity.

METHODS

Forty-one patients with LBBB and ≥mild secondary MR underwent CRT between 2009 and 2012, and had baseline and follow-up echocardiograms available. Repeated measure and linear regression analyses were performed to assess for changes in MV and LV geometry and MR severity, and associations with follow-up MR grade.

RESULTS

The mean age and baseline QRS duration were 65.5 ± 14.9 years and 160 ± 24 ms. At a mean follow-up of 2.6 ± 1.8 years, there was an increase in LV ejection fraction and reductions in LV end-systolic volume index, MR grade, and end-systolic interpapillary muscle distance (P < .05 for all). Linear correlations were observed between follow-up MR grade and baseline MV tenting height (r = .44), left atrial volume index (r = .41), LV end-systolic volume index (r = .4), MV tenting area (r = .38), LV ejection fraction (r = -.34), and end-systolic interpapillary muscle distance (r = .34) (P < .05 for all). Multiple regression analysis revealed associations between follow-up MR grade and baseline MV tenting height (β/mm = 0.42, P = .006) and left atrial volume index (β/mL/m2  = 0.4, P = .008), independent of QRS duration (β/ms=-0.07; P = 0.6) and nonischemic cardiomyopathy (β = -0.34, P = .02).

CONCLUSIONS

Cardiac resynchronization therapy in patients with LBBB and secondary MR results in LV and MV geometric reverse remodeling and decreases MR severity. Extent of baseline MV tethering is independently associated with persistent MR at follow-up.

Valvular Heart Disease in Patients ≥80 Years of Age

In the United States, the octogenarian population is projected to triple by 2050. With this aging population, the prevalence of valvular heart disease (VHD) is on the rise. The etiology, approach to treatment, and expected outcomes of VHD are different in the elderly compared with younger patients. Both stenotic and regurgitant lesions are associated with unfavorable outcomes if left untreated. Surgical mortality remains high due to multiple co-morbidities, and long-term survival benefit is dependent on many variables including valvular pathology. Quality of life is an important consideration in treatment decisions in this age group. Increasingly, octogenarian patients are receiving transcatheter therapies, with transcatheter aortic valve replacement having the greatest momentum. Numerous transcatheter devices for management of other valve lesions are currently in early clinical trials. This review will describe the epidemiology, etiology, diagnosis, and therapeutic options for VHD in the oldest old, with a focus on transcatheter technologies.

Echocardiographic assessment of functional mitral regurgitation: opening Pandora's box?

Two recent trials of transcatheter mitral-valve repair in patients with functional mitral regurgitation (FMR) presented opposing results for the MitraClip® compared to medical therapy alone. The conflicting results gave rise to intensive discussions about assessment of mitral valve regurgitation (MR). A recent editorial viewpoint provided a potential explanation presenting a new pathophysiologic concept. However, the echocardiographic characterization of both trials' patients is inconsistent and the discussed concepts appear to suffer from plausibility weaknesses. It is well conceivable that limitations in the echocardiographic assessment of the trial patients introduced a bias regarding the selection of patients with severe (or less severe) MR that may be a more plausible explanation for the differences in outcome. We here illustrate our viewpoint regarding the two MitraClip trials and also illustrate the difficulties in assessing functional MR properly. It may indeed be "opening Pandora's box", but we will also make an attempt to provide a solution.

Percutaneous Mitral Valve Interventions (Repair): Current Indications and Future Perspectives

Mitral valve regurgitation (MR) is the commonest valvular abnormality encountered among adult patients with cardiac valvular disease and conveys significant morbidity and mortality. The mitral valve is a complex anatomical structure and etiology for regurgitation is classified as either primary or secondary MR. Identification of the etiology in severe MR is critical in determining the appropriate treatment strategy. Transcatheter mitral valve repair (TMVR) is a minimally invasive technique for treatment of selected patients with symptomatic chronic moderate-severe or severe (3 to 4+) MR. While surgery remains the mainstay for treatment in primary MR, several technological advances within the last decade have made transcatheter mitral valve intervention increasingly feasible and safe in clinical practice. Use of TMVR in patients with severe MR has successfully reduced patient symptoms, disease morbidity, improved quality of life, and facilitated reverse remodeling with potential for a survival advantage among certain patients with secondary MR. Recent randomized controlled trials on MitraClip use in secondary MR have reinvigorated interest in this disease and refocused our attention on optimizing patient selection and timing of intervention to maximize benefit from using such percutaneous devices. In our review, we discuss etiologies and pathophysiology in both acute MR and development of chronic severe MR. We discuss management strategies for MR among patients based on etiology, particularly percutaneous mitral valve interventional therapies. We perform an extensive review comparing and contrasting existing data on safety, efficacy, durability, and appropriate patient selection related to MitraClip implantation in both primary and secondary MR. Lastly, we explore percutaneous MV therapies beyond the MitraClip as we await larger scale trials on these devices prior to them making way into day-to-day practice.

Early and long-term results of surgery for secondary mitral regurgitation with a damaged heart

BACKGROUND

Surgery for secondary mitral regurgitation is still controversial, especially when the left ventricle is damaged. The Mitra Clip has been shown to be safe and effective for certain patient groups but does not offer superior control of mitral regurgitation compared with the surgery. If performed safely, the surgery can provide greater benefits over the long-term. The objective of this study was to retrospectively investigate the early and long-term results of mitral valve surgery for secondary mitral valve regurgitation with a damaged, dilated left ventricle.

METHODS

Patients with ejection fraction <40% and left ventricular end-diastolic/systolic diameter >50/40 mm who underwent mitral valve surgery for secondary mitral regurgitation were investigated retrospectively.

RESULTS

The mean age of the 80 identified cases was 65.7 years, and 63 patients were male. Preoperative echocardiograms showed a mean ejection fraction of 25.2% and mean left ventricular diameters in diastole/systole of 64.5/56.9 mm, respectively. Mitral valve replacement was performed in 39 cases, and mitral valve plasty in 41 cases. The most common concomitant procedures were coronary artery bypass grafting and tricuspid valve surgery (41.3% each). Mitral regurgitation improved significantly from 3.5 to 0.83, and no operative or in-hospital deaths were encountered. Long-term results showed actual 1-, 3- and 5-year survival rates of 93.1%, 80.0%, and 64.7%, respectively (mean follow-up, 1264 days).

CONCLUSIONS

Early results of this study were good and long-term results were acceptable. Our results suggest that mitral valve surgery is feasible for secondary mitral valve regurgitation even in dilated, damaged hearts.