Transcatheter edge-to-edge repair for mitral regurgitation

Mitral valve transcatheter edge-to-edge repair (M-TEER) has emerged as a transformative therapy for mitral regurgitation (MR), addressing the unmet needs of patients unsuitable for surgery. Landmark trials such as EVEREST II, COAPT, and MITRA-FR have established the safety and efficacy of M-TEER, in both patients with primary (PMR) and secondary MR (SMR). Recent trials, including RESHAPE-HF2 and MATTERHORN, have expanded our understanding and refueled discussions regarding patient selection and appropriate treatment indications in SMR. These trials have also contributed to the discussion regarding SMR phenotypes most appropriate for M-TEER. This review summarizes the evidence from pivotal trials, discusses patient selection, device advancements, potential future directions, and outlines ongoing trials that may shape future clinical practice.

Association between the proportionality of functional mitral regurgitation and survival after mitral valve operation

Objective

The concept of proportionate and disproportionate functional mitral regurgitation suggests that transcatheter edge-to-edge mitral repair may benefit patients with a smaller left ventricle relative to a higher regurgitant burden. The clinical relevance of proportionality remains unknown in mitral operations for ischemic mitral regurgitation. We aimed to characterize the association between mitral regurgitation proportionality and outcomes after mitral valve operations.

Methods

By using the Cardiothoracic Surgery Trial Network's severe ischemic mitral regurgitation trial, we first identified the inflection point at which the risk of 2-year mortality changed along the spectrum of the mitral regurgitation proportionality (defined as effective regurgitant orifice area/left ventricular end-diastolic volume index) using a splined multivariable Cox proportional hazards model. Patients were dichotomized by the mitral regurgitation proportionality value. The Cox model evaluated the hazard of 2-year all-cause mortality between proportionate and disproportionate mitral regurgitation.

Results

Among the 240 patients, the median age was 69 years (interquartile range, 62-75), and 38% (n = 90) were women. Patients with effective regurgitant orifice/left ventricular end-diastolic volume index proportion greater than 0.40 (more disproportionate mitral regurgitation) had a higher hazard of death compared with those with more proportionate mitral regurgitation. The 90-day and 1-year mortality were higher in patients with disproportionate mitral regurgitation (13% vs 6.2% for 90 days and 19% vs 12% for 1 year). In a multivariable Cox model, the disproportionate mitral regurgitation group had a statistically significantly higher hazard of death compared with the proportionate mitral regurgitation group (hazard ratio, 2.15, 95% CI, 1.16-3.98, P = .015).

Conclusions

The clinical relevance of the proportionality of functional mitral regurgitation proposed in the transcatheter edge-to-edge mitral repair population may not generalize to surgical patient populations.

Regurgitant volume to LA volume ratio in patients with secondary MR: the COAPT trial

AIMS

The conceptual framework of proportionate vs. disproportionate mitral regurgitation (MR) translates poorly to individual patients with heart failure (HF) and secondary MR. A novel index, the ratio of MR severity to left atrial volume (LAV), may identify patients with 'disproportionate' MR and a higher risk of events. The objectives, therefore, were to investigate the prognostic impact of MR severity to LAV ratio on outcomes among HF patients with severe secondary MR randomized to transcatheter edge-to-edge repair (TEER) with the MitraClip™ device plus guideline-directed medical therapy (GDMT) vs. GDMT alone in the COAPT trial.

METHODS AND RESULTS

The ratio of pre-procedural regurgitant volume (RVol) to LAV was calculated from baseline transthoracic echocardiograms. The primary endpoint was 2-year covariate-adjusted rate of HF hospitalization (HFH). Among 567 patients, the median RVol/LAV was 0.67 (interquartile range 0.48-0.91). In patients randomized to GDMT alone, lower RVol/LAV was independently associated with an increased 2-year risk of HFH (adjHR: 1.77; 95% CI: 1.20-2.63). RVol/LAV was a stronger predictor of adverse outcomes than RVol or LAV alone. Treatment with TEER plus GDMT compared with GDMT alone was associated with lower 2-year rates of HFH both in patients with low and high RVol/LAV (Pinteraction = 0.28). Baseline RVol/LAV ratio was unrelated to 2-year mortality, health status, or functional capacity in either treatment group.

CONCLUSION

Low RVol/LAV ratio was an independent predictor of 2-year HFH in HF patients with severe MR treated with GDMT alone in the COAPT trial. TEER improved outcomes regardless of baseline RVol/LAV ratio.

CLINICAL TRIAL REGISTRATION

Trial Name: Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation (The COAPT Trial) (COAPT) ClinicalTrial.gov Identifier NCT01626079URL https://clinicaltrials.gov/ct2/show/NCT01626079.

Challenges and pitfalls in classification of disproportionate mitral regurgitation

The concept of disproportionate mitral regurgitation (dispropMR) has been introduced to identify patients with functional mitral regurgitation (MR) who benefit from percutaneous treatment. We aimed to examine echocardiographic characteristics behind this entity. We retrospectively included 172 consecutive patients with reduced left ventricular ejection fraction (LVEF), and more than mild MR referred to clinically indicated echocardiography. According to the proportionality ratio (effective regurgitant orifice area (EROA)/left ventricular end-diastolic volume (LVEDV)) patients were divided into dispropMR and proportionate MR (propMR) group. Potential factors which might affect proportionality definition were analyzed. 55 patients (32%) had dispropMR. Discrepant grading of MR severity was observed when using regurgitant volume (RegVol) by proximal isovelocity surface area (PISA) method or volumetric method, with significant discordance only in dispropMR (p < 0.001). Patients with dispropMR had more frequently left ventricular foreshortened images for LVEDV calculation than patients with propMR (p = 0.003), resulting in smaller LVEDV in dispropMR group. DispropMR group had more substantial dynamic variation of regurgitant flow compared to propMR. Accordingly, EROA was consistently overestimated by standard single-point PISA method compared to serial PISA method. This was more pronounced in dispropMR (bias:10.5 ± 28.3 mm2) compared to propMR group (bias:6.4 ± 12.8 mm2). DispropMR may be found in roughly one third of clinically indicated echocardiographic studies in patients with reduced LVEF and more than mild MR. EROA overestimation due to dynamic variation of regurgitant flow and LVEDV underestimation due to LV foreshortening were more frequently found in dispropMR. Our results indicate that methodological limitations of echocardiographic MR grading could not be neglected in classifying the proportionality of MR.

Perspectives on Secondary Mitral Regurgitation in Heart Failure

PURPOSE OF THE REVIEW

This review focuses on broader perspectives of mitral regurgitation (MR) in patients with heart failure.

RECENT FINDINGS

The ratio of regurgitant volume to end-diastolic volume appears to help identify patients who may benefit from valve interventions. Secondary MR is not only attributed to geometric changes of the LV but also related to the structural changes in the mitral valve that include fibrosis of the mitral leaflets and changes in the extracellular matrix. The transition from mild to severe secondary MR can occur at different rates, from a slow LV remodeling process to a more abrupt process precipitated by an inciting event such as atrial fibrillation. Septal flash and apical rocking, two new visual markers of LV mechanical dyssynchrony, appear to be predictive of MR reduction following cardiac resynchronization therapy. Optimal guideline-directed medical therapy has been shown to decrease the severity of secondary MR effectively. A theoretical framework to characterize secondary MR as it relates to the onset of MR is proposed. Type A: Early onset of MR contemporaneous with myocardial injury. The maladaptive LV remodeling occurs in parallel with MR. Type B: LV remodeling proceeds without significant MR until the LV is moderately dilated, which coincides with or without inciting factors such as atrial fibrillation. Type C: LV remodeling proceeds after myocardial injury without significant MR until the LV is severely dilated. MR is a late manifestation of LV remodeling.

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

The causes of mitral regurgitation (MR) can be broadly divided into primary and secondary causes. Although primary MR is caused by degenerative alterations of the mitral valve and the mitral valve apparatus, secondary (functional) MR is multifactorial and related to dilation of the left ventricle and/or mitral annulus commonly resulting in concomitant restriction of the leaflets. Therefore, the treatment of secondary MR (SMR) is complex and includes guideline directed heart failure therapy along with surgical and transcatheter approaches that have shown effectiveness in certain subgroups. This review aims to provide insight into current advances in diagnosis and management of SMR.

MitraClip as a therapeutic strategy for post-myocardial infarction mitral regurgitation

Mitral regurgitation is a serious complication of post-myocardial infarction, with increasing mortality. Surgery as the primary treatment carries a high risk. MitraClip is a new therapeutic to treat post-myocardial infarction mitral regurgitation. In this case, a 62-year-old male patient suffered from severe heart failure symptoms after emergency coronary intervention and extracorporeal membrane oxygenation support. Based on cardiac echocardiography, severe mitral regurgitation was monitored in this patient. After MitraClip treatment, the patient's condition was gradually improved and discharged successfully. This case highlights that MitraClip is a safe and effective strategy for post-myocardial infarction mitral regurgitation.

[Clinical and echocardiographic parameters associated with the alteration of global longitudinal strain in secondary mitral regurgitation]

INTRODUCTION

Left ventricular systolic function may be overestimated in patients with secondary mitral regurgitation when using left ventricle ejection fraction. The Global longitudinal strain is a measure less dependent on left ventricle load. However, the clinical and echocardiographic parameters associated with the alteration of Global longitudinal strain in secondary mitral regurgitation have not been evaluated.

MATERIAL AND METHODS

A total of 96 patients (mean age 62.3 ± 12.1 years, 59.3% male) with secondary mitral regurgitation and low left ventricle ejection fraction < 50% were included. The study population was subdivided according to the Global longitudinal strain value with which an increased risk of all-cause mortality was associated (Global longitudinal strain < 7.0%, left ventricle systolic function impaired compared to Global longitudinal strain ≥ 7.0%, in absolute value). The clinical and echocardiographic endpoints are analysed in both groups of patients.

RESULTS

The strong and clear correlation between Global longitudinal strain (mean ± standard deviation: 7,2 ± 2,7) and parameters of systolic function (left ventricle ejection fraction mean ± standard deviation: 32,4 ± 8,0%) and contractility (dp/dt mean ± standard deviation: 682,5 ± 204,7 mmHg/s). the mean of left ventricle ejection fraction = 26.4 ± 5.3% in the Global longitudinal strain < 7 group, and the bivariate study using the 30% threshold shows that the Global longitudinal strain < 7 group presents a more altered left ventricle ejection fraction with odds ratio = 12, 5 (CI: 4.7-33.0) p < 0.001. In multivariate analysis of ultrasound parameters and linear regression shows a significant correlation between Global longitudinal strain and left ventricle ejection fraction (p < 0.001). The dp/dt analysis found a mean of 509.3 ± 99.1 mmHg/s in the Global longitudinal strain < 7 group and of 822.9 ± 154.1 in the Global longitudinal strain ≥ 7 group with significant difference (p < 0.001). In bivariate and multivariate analysis, the alteration of Global longitudinal strain is associated with a significantly lower dp / dt p < 0.001.

CONCLUSION

A Global longitudinal strain < 7 (in absolute value) reflects a severe impairment of left ventricle function. In addition, several parameters were associated with this severe alteration of the Global longitudinal strain, namely a lower left ventricle ejection fraction, a lower dp/dt and more severe symptoms permitting to characterized this group of patients in addition to an integration in a multiparametric evaluation of the secondary mitral regurgitation.

Management of Heart Failure With Reduced Ejection Fraction

Heart failure with reduced ejection fraction (HFrEF) is a complex and progressive clinical condition characterized by dyspnea and functional impairment. HFrEF has a high burden of mortality and readmission rate making it one of the most significant public health challenges. Basic treatment strategies include diuretics for symptom relief and use of quadruple therapy (Angiotensin receptor blocker/neprilysin inhibitors, evidence-based beta-blockers, mineralocorticoid receptor antagonists, and sodium-glucose co-transporter 2 inhibitors) for reduction in hospitalizations, all-cause mortality, and cardiovascular mortality. Despite compelling evidence of clinical benefit, guideline directed medical therapy is vastly underutilized in the real-world clinical practice. Other medications such as intravenous iron, ivabradine, hydralazine/nitrates and vericiguat may also have a role in certain subgroup of HFrEF patients. Specific groups of patients with HFrEF may also be candidates for various device therapies such as implanted cardioverter defibrillators, cardiac resynchronization therapy and trans catheter mitral valve repair. This review provides a comprehensive overview of drug and device management approaches for patients with HFrEF, recommendations for initiation and titrations of therapies, and challenges associated with guideline directed medical therapy in the management of patients with HFrEF (Graphical abstract).

Impact of Left Ventricular Global Longitudinal Strain on Outcomes After Transcatheter Edge-to-Edge Repair in Secondary Mitral Regurgitation

Assessment of left ventricular (LV) systolic function is essential in patient selection for transcatheter edge-to-edge repair (TEER) in secondary mitral regurgitation (MR). Although LV ejection fraction (EF) is mostly used for assessing LV function, it represents the change of LV chamber size, but not myocardial contractility. LV global longitudinal strain (GLS) provides an alternative to assess LV systolic function in patients with secondary MR. This study included 380 patients with secondary MR (mean age 71.0 ± 13.0 years; 61.1% male) who underwent TEER. Patients were dichotomized based on baseline LV GLS (more impaired GLS [<7.0%] vs less impaired GLS [≥7%]) based on existing literature. The primary outcome was all-cause mortality, whereas the secondary outcome was the composite end point of all-cause mortality and heart failure hospitalization. The mean LV GLS was 8.1 ± 3.8%, and 162 patients had GLS <7%. Patients with more impaired GLS (<7%) were more likely to be male (68.5% vs 55.5%; p = 0.01) and have larger LV end-diastolic volume (110.5 ± 36.5 ml/m² vs 92.9 ± 34.3 ml/m²; p <0.001) and lower LVEF (22.2 ± 8.9% vs 36.4 ± 14.5%; p <0.001) than those with less impaired GLS (≥7%). The number of clips used and residual MR were similar between the 2 groups. Patients with more impaired LV GLS (<7%) had significantly higher 2-year event rates of the primary outcome (38.2% vs 25.9%; log-rank p = 0.003) and the secondary outcome (52.5% vs 36.3%; log-rank p <0.001). Multivariate analysis showed that LV GLS (<7%) was independently associated with the primary outcome (hazard ratio 1.65, 95% confidence interval 1.16 to 2.34, p = 0.005) and the secondary outcome (hazard ratio 1.54, 95% confidence interval 1.08 to 2.20, p = 0.016) whereas such associations were not observed with LVEF. In conclusion, LV GLS (<7%) was independently associated with a higher risk of adverse events in patients with secondary MR who underwent TEER.

Percutaneous Edge-to-Edge Mitral Valve Repair for Functional Mitral Regurgitation

The presence and severity of functional mitral regurgitation (FMR) is associated with worse outcomes in patients with heart failure and reduced ejection fraction. Prior to the availability of percutaneous mitral valve repair, management for FMR has been limited to medical therapy, cardiac resynchronization therapy for a specific subset of patients and surgery which has yet to demonstrate mortality benefits. Transcatheter edge-to-edge repair (TEER) of the mitral valve has emerged in the past decade as an invaluable member of the armamentarium against FMR with the 2 landmark randomized controlled trials providing deep insights on patient selection. In addition, TEER has spurred the rapid advancement in our understanding of FMR. This article seeks to provide an overview as well as our current understanding on the role of TEER in FMR.

Plausible Functional Diagnostics by Rational Echocardiography in the Assessment of Valvular Heart Disease - Role of Quantitative Echocardiography in the Assessment of Mitral Regurgitation

The echocardiographic assessment of valvular heart diseases is the basic analysis of valvular defects next to clinical investigation and stethoscopy. Severity of mitral regurgitation (MR) is usually estimated by an integrated approach using semi quantitative parameters and is still one of the biggest challenges of echocardiography. Quantitative echocardiographic analysis of MR severity often fails to describe comprehensible hemodynamic conditions. However, comprehensive echocardiography based on standardized image acquisition and proper image quality is required to properly assess hemodynamic parameter comparable to cardiac magnetic resonance tomography. This review focuses on the uncertainty of MR severity assessed by echocardiography in recent trials of interventional MR treatment. In addition, the necessity to provide plausible echocardiographic data for individual decision making is highlighted. In conclusion, plausible functional diagnostics by rational echocardiography is a prerequisite in patients with valvular heart diseases.

Learning from Controversy and Revisiting the Randomized Trials of Secondary Mitral Regurgitation

Until recently, conventional mitral valve surgery has been the treatment of choice even in secondary mitral regurgitation. Recent evidence, however, advocates the use of transcatheter edge-to-edge mitral valve repair (TEER) of the mitral valve. This has been reflected by the change in guidelines of the American College of Cardiology/American Heart Association. We reviewed the literature to shed light on the risks and benefits of all interventions, surgical, transcatheter and guideline-directed medical therapy. Secondary mitral regurgitation occurs due to an imbalance between closing forces and tethering forces. Given the pathology extends beyond the valve alone, treatment should be directed at restoring the geometrical shape of the left ventricle alongside the valve. Myocardial revascularization plays a pivotal role in preventing recurrence. The role of papillary muscle approximation in addition to restrictive mitral annuloplasty should be considered in a select group of patients. We also reviewed the current literature on TEERs from the COAPT and Mitra-FR trials while highlighting the concept of proportionate/disproportionate MR which may help identify which patients benefit from mitral valve restoration. Treatment of this condition will require robust randomized trials alongside the use of state-of-the-art imaging technologies available with the full complement of the multidisciplinary team to ensure the best outcomes for each patient.

Disproportionate Mitral Regurgitation Determines Survival in Acute Heart Failure

Objectives: To assess the prevalence and impact of mitral regurgitation (MR) on survival in patients presenting to hospital in acute heart failure (AHF) using traditional echocardiographic assessment alongside more novel indices of proportionality.

Background: It remains unclear if the severity of MR plays a significant role in determining outcomes in AHF. There is also uncertainty as to the clinical relevance of indexing MR to left ventricular volumes. This concept of disproportionality has not been assessed in AHF.

Methods: A total of 418 consecutive patients presenting in AHF over 12 months were recruited and followed up for 2 years. MR was quantitatively assessed within 24 h of recruitment. Standard proximal isovelocity surface area (PISA) and a novel proportionality index of effective regurgitant orifice/left ventricular end-diastolic volume (ERO/LVEDV) >0.14 mm²/ml were used to identify severe and disproportionate MR.

Results: Every patient had MR. About 331/418 (78.9%) patients were quantifiable by PISA. About 165/418 (39.5%) patients displayed significant MR. A larger cohort displayed disproportionate MR defined by either a proportionality index using ERO/LVEDV > 0.14 mm²/ml or regurgitant volumes/LVEDV > 0.2 [217/331 (65.6%) and 222/345 (64.3%), respectively]. The LVEDV was enlarged in significant MR−129.5 ± 58.95 vs. 100.0 ± 49.91 ml in mild, [p < 0.0001], but remained within the normal range. Significant MR was associated with a greater mortality at 2 years {44.2 vs. 34.8% in mild MR [hazard ratio (HR) 1.39; 95% CI: 1.01–1.92, p = 0.04]}, which persisted with adjustment for comorbid conditions (HR; 1.43; 95% CI: 1.04–1.97, p = 0.03). Disproportionate MR defined by ERO/LVEDV >0.14 mm²/ml was also associated with worse outcome [42.4 vs. 28.3% (HR 1.62; 95% CI 1.12–2.34, p = 0.01)].

Conclusions: MR was a universal feature in AHF and determines outcome in significant cases. Furthermore, disproportionate MR, defined either by effective regurgitant orifice (ERO) or volumetrically, is associated with a worse prognosis despite the absence of adverse left ventricular (LV) remodeling. These findings outline the importance of adjusting acute volume overload to LV volumes and call for a review of the current standards of MR assessment.

Clinical Trial Registration:https://clinicaltrials.gov/ct2/show/NCT02728739, identifier NCT02728739.

Outcomes Stratified by Adapted Inclusion Criteria After Mitral Edge-to-Edge Repair

BACKGROUND

Although mitral valve transcatheter edge-to-edge repair (M-TEER) achieves symptomatic benefit for a broad spectrum of patients with relevant secondary mitral regurgitation, conflicting data exist on its prognostic impact.

OBJECTIVES

Adapted enrollment criteria approaching those used in the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation) and MITRA-FR (Percutaneous Repair or Medical Treatment for Secondary Mitral Regurgitation) trials were retrospectively applied to a European real-world registry to evaluate the influence of the respective criteria on outcomes.

METHODS

A total of 1,022 patients included in the EuroSMR (European Registry of Transcatheter Repair for Secondary Mitral Regurgitation) registry and treated with M-TEER (November 2008 to September 2019) were stratified into COAPT-eligible (n = 353 [34.5%]) and COAPT-ineligible (n = 669 [65.5%]) as well as MITRA-FR-eligible (n = 408 [48.3%]) and MITRA-FR-ineligible (n = 437 [51.7%]) groups.

RESULTS

Although the stratification of patients according to adapted MITRA-FR criteria led to comparable outcomes regarding all-cause mortality (P = 0.19), the application of adapted COAPT enrollment criteria demonstrated lower mortality rates in COAPT-eligible compared with COAPT-ineligible patients (P < 0.001). Multivariable Cox regression analysis identified New York Heart Association functional class IV (hazard ratio [HR]: 2.29; 95% confidence interval [CI]: 1.53-3.42; P < 0.001), logarithmic N-terminal pro-brain natriuretic peptide (HR: 1.47; 95% CI: 1.24-1.75; P < 0.001), and right ventricular-to-pulmonary arterial coupling (HR: 0.10; 95% CI: 0.02-0.57; P = 0.009) as independent predictors of outcome. Yet improvement of functional outcome was demonstrated in a subset of patients irrespective of COAPT eligibility status.

CONCLUSIONS

In this real-world cohort of patients with secondary mitral regurgitation undergoing M-TEER, the retrospective application of adapted COAPT enrollment criteria successfully identified a specific phenotype demonstrating lower mortality rates. On the contrary, stratification according to adapted MITRA-FR criteria resulted in comparable outcomes.

From secondary to tertiary mitral regurgitation: the paradigm shifts, but uncertainties remain

Secondary mitral regurgitation (MR) is the most common and undertreated form of MR, whose contribution to poor prognosis and indications to correction remains under discussion. MR has been characterized into 'proportionate' or 'disproportionate', based on left ventricle (LV) and regurgitant volumes, whereas 'tertiary' MR identifies conditions, in which regurgitation is pathologic per se and actively contributes to LV dysfunction. Echocardiographic and anatomo-pathological studies revealed that secondary MR prompts subtle leaflet maladaptive changes, actively contributing to the dynamic progression of secondary MR. We critically discuss the paradigm shift from secondary to tertiary MR and question the notion that MV leaflets play a passive role in secondary MR. We also review the role of standard transthoracic echocardiography for appraising and quantifying maladaptive MV leaflet changes and LV volumes and call for a more sophisticated and comprehensive imaging framework for classifying MR in future interventional studies.

Implantation of one, two or multiple MitraClips for transcatheter mitral valve repair: insights from a 1824-patient multicenter study

BACKGROUND

Transcatheter mitral valve repair (TMVR) with the MitraClip device is an established treatment for mitral regurgitation (MR). More than one MitraClip may be implanted if a single one does not reduce MR adequately. We aimed at appraising the outlook of patients undergoing implantation of one, two or multiple MitraClips for TMVR.

METHODS

Exploiting the ongoing prospective GIse registry Of Transcatheter treatment of mitral valve regurgitaTiOn (GIOTTO) Study dataset, we compared patients, procedural details and outcomes distinguishing those receiving one, two or multiple MitraClips. The primary endpoint was the composite of 1-year cardiac death or rehospitalization for heart failure. Additional endpoints included all cause death, surgical mitral repair, and functional class. Multivariable adjusted Cox proportional hazard analysis was used for confirmatory purposes.

RESULTS

As many as 1824 patients were included: 718 (39.4%) treated with a single MitraClip, and 940 (51.5%) receiving two MitraClips, and 166 (9.1%) receiving three or more. Significant differences were found for baseline features, including age, female gender, diabetes mellitus, hypertension, chronic obstructive pulmonary disease, prior myocardial infarction, atrial fibrillation, permanent pacemaker, cardiac resynchronization therapy, implantable cardioverter defibrillator, and prior mitral valve repair (all p<0.05). Several imaging features were also different, including left ventricular dimensions, MR severity and proportionality, mitral valve area, flail leaflet, and pulmonary vein flow (all p<0.05). Among procedural features, significant differences were found for anesthesia type, MitraClip type, fluoroscopy, device, and operating room times, postprocedural mitral gradient, residual MR, smoke-like effect, device success partial detachment and surgical conversion (all p<0.05). In-hospital death occurred more frequently in patients receiving multiple MitraClips, and the same applied severe residual MR (all p<0.05). Mid-term follow-up (15±13 months) showed significant difference in the risk of death, cardiac death, rehospitalization for heart failure, and their composites, mainly, but not solely, associated with multiple MitraClips (all p<0.05). Adjusted analysis confirmed the significantly increased risk of composite adverse events when comparing the multiple vs single MitraClip groups (p=0.014 for death and rehospitalization, p=0.013 for cardiac death or rehospitalization).

CONCLUSIONS

Implantation of one or two MitraClips is associated with favorable clinical outcomes. Conversely, bail-out implantation of three or more MitraClips may portend a worse long-term prognosis.

Mitral Regurgitation International Database (MIDA) Score Predicts Outcome in Patients With Heart Failure Undergoing Transcatheter Edge-to-Edge Mitral Valve Repair

Background Optimizing risk stratification in patients undergoing transcatheter mitral valve repair is an ongoing challenge. The Mitral Regurgitation International Database (MIDA) score represents a user-friendly mortality risk stratification tool that is validated on a large-scale registry of patients with degenerative mitral regurgitation (MR). We here assessed the potential benefit of the MIDA risk score for patients with functional or degenerative MR undergoing transcatheter mitral valve repair. Methods and Results In total, 680 patients undergoing MitraClip implantation were stratified according to MIDA score tertiles into a low (0-7), intermediate (8-9), and a high (10-12) MIDA score group. MR was assessed in follow-up echocardiograms in 416 patients at 323±169 days after transcatheter mitral valve repair. During 2-year follow-up, 8.2% (15/182) of patients with low, 21.3% (64/300) with intermediate, and 26.3% (52/198) with high MIDA score died (log-rank test P<0.001). Hazard of all-cause mortality increased by 13% (95% CI, 3%-25%) with every additional point of the MIDA score. Subanalysis of 431 patients with functional MR showed similar results. Furthermore, rates of a combined end point of mortality and hospitalization for heart failure were higher with increasing MIDA score (30% [54/182], 38% [113/300] and 48% [94/198], respectively, log-rank test P=0.001). Frequency of residual MR ≥II at follow-up increased with increasing MIDA score group (33%, 44%, and 59%, respectively, P<0.001). Conclusions The MIDA mortality risk score maintains its predictive utility in patients undergoing transcatheter mitral valve repair, regardless of MR cause. Moreover, it was predictive of worse event-free survival regarding a combined end point of mortality and hospitalization for heart failure, and was associated with postprocedural residual MR ≥II and MR recurrence.

Impact of the introduction of percutaneous edge-to-edge mitral valve reconstruction on clinical practice in Germany compared to surgical valve repair

BACKGROUND

The introduction of percutaneous mitral valve (MV) repair had an effect on clinical practice in comparison with surgical MV repair. Complete nationwide data are useful in examining how the introduction of a new technique influences clinical practice.

METHODS

We analyzed procedural numbers, patient characteristics, and in-hospital outcomes for all percutaneous edge-to-edge and surgical MV reconstruction procedures performed in Germany between 2009 and 2015.

RESULTS

12,664 percutaneous edge-to-edge and 22,825 surgical MV reconstructions were recorded. Numbers increased steadily, albeit more rapidly in the percutaneous edge-to-edge group (108-4079 vs. 2923-3603 with surgical MV reconstruction). Patients with percutaneous edge-to-edge MV reconstruction were older (75.6 ± 8.8 vs 61.6 ± 13.4 years, P < 0.001) and at higher operative risk (estimated logistic EuroSCORE 13.2% vs. 4.7%, P < 0.001) compared to those undergoing surgery. However, in-hospital mortality did not differ (2.9% vs. 2.8%; P = 0.395). This was also true for the subset of 2103 patients at intermediate operative risk as defined by a logistic EuroSCORE ≥ 4% and ≤ 9%. Of note, complication rates (except acute kidney injury) were more favorable in patients undergoing percutaneous edge-to-edge reconstruction.

CONCLUSIONS

Percutaneous edge-to-edge MV reconstruction has markedly changed clinical practice of MR therapy in Germany. Annual overall procedural numbers more than doubled, with a massive increase in percutaneous edge-to-edge procedures. Our data demonstrate its use mainly in high-risk patients and prove the favorable safety profile of this novel technique, with low in-hospital mortality and complication rates.

Echocardiographic assessment of mitral regurgitation: discussion of practical and methodologic aspects of severity quantification to improve diagnostic conclusiveness

The echocardiographic assessment of mitral valve regurgitation (MR) by characterizing specific morphological features and grading its severity is still challenging. Analysis of MR etiology is necessary to clarify the underlying pathological mechanism of the valvular defect. Severity of mitral regurgitation is often quantified based on semi-quantitative parameters. However, incongruent findings and/or interpretations of regurgitation severity are frequently observed. This proposal seeks to offer practical support to overcome these obstacles by offering a standardized workflow, an easy means to identify non-severe mitral regurgitation, and by focusing on the quantitative approach with calculation of the individual regurgitant fraction. This work also indicates main methodological problems of semi-quantitative parameters when evaluating MR severity and offers appropriateness criteria for their use. It addresses the diagnostic importance of left-ventricular wall thickness, left-ventricular and left atrial volumes in relation to disease progression, and disease-related complaints to improve interpretation of echocardiographic findings. Finally, it highlights the conditions influencing the MR dynamics during echocardiographic examination. These considerations allow a reproducible, verifiable, and transparent in-depth echocardiographic evaluation of MR patients ensuring consistent haemodynamic plausibility of echocardiographic results.

Association of Effective Regurgitation Orifice Area to Left Ventricular End-Diastolic Volume Ratio With Transcatheter Mitral Valve Repair Outcomes: A Secondary Analysis of the COAPT Trial

Importance

Transcatheter mitral valve repair (TMVr) plus maximally tolerated guideline-directed medical therapy (GDMT) reduced heart failure (HF) hospitalizations (HFHs) and all-cause mortality (ACM) in symptomatic patients with HF and secondary mitral regurgitation (SMR) compared with GDMT alone in the Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation (COAPT) trial but not in a similar trial, Multicenter Study of Percutaneous Mitral Valve Repair MitraClip Device in Patients With Severe Secondary Mitral Regurgitation (MITRA-FR), possibly because the degree of SMR relative to the left ventricular end-diastolic volume index (LVEDVi) was substantially lower.

Objective

To explore contributions of the degree of SMR using the effective regurgitation orifice area (EROA), regurgitant volume (RV), and LVEDVi to the benefit of TMVr in the COAPT trial.

Design, Setting, and Participants

This post hoc secondary analysis of the COAPT randomized clinical trial performed December 27, 2012, to June 23, 2017, evaluated a subgroup of COAPT patients (group 1) with characteristics consistent with patients enrolled in MITRA-FR (n = 56) (HF with grade 3+ to 4+ SMR, left ventricular ejection fraction of 20%-50%, and New York Heart Association function class II-IV) compared with remaining (group 2) COAPT patients (n = 492) using the end point of ACM or HFH at 24 months, components of the primary end point, and quality of life (QOL) (per the Kansas City Cardiomyopathy Questionnaire overall summary score) and 6-minute walk distance (6MWD). The same end points were evaluated in 6 subgroups of COAPT by combinations of EROA and LVEDVi and of RV relative to LVEDVi.

Interventions

Interventions were TMVr plus GDMT vs GDMT alone.

Results

A total of 548 participants (mean [SD] age, 71.9 [11.2] years; 351 [64%] male) were included. In group 1, no significant difference was found in the composite rate of ACM or HFH between TMVr plus GDMT vs GDMT alone at 24 months (27.8% vs 33.1%, P = .83) compared with a significant difference at 24 months (31.5% vs 50.2%, P < .001) in group 2. However, patients randomized to receive TMVr vs those treated with GDMT alone had significantly greater improvement in QOL at 12 months (mean [SD] Kansas City Cardiomyopathy Questionnaire summary scores: group 1: 18.36 [5.38] vs 0.43 [4.00] points; P = .01; group 2: 16.54 [1.57] vs 5.78 [1.82] points; P < .001). Group 1 TMVr-randomized patients vs those treated with GDMT alone also had significantly greater improvement in 6MWD at 12 months (mean [SD] paired improvement: 39.0 [28.6] vs -48.0 [18.6] m; P = .02). Group 2 TMVr-randomized patients vs those treated with GDMT alone tended to have greater improvement in 6MWD at 12 months, but the difference did not reach statistical significance (mean [SD] paired improvement: 35.0 [7.7] vs 16.0 [9.1] m; P = .11).

Conclusions and Relevance

A small subgroup of COAPT-resembling patients enrolled in MITRA-FR did not achieve improvement in ACM or HFH at 24 months but had a significant benefit on patient-centered outcomes (eg, QOL and 6MWD). Further subgroup analyses with 24-month follow-up suggest that the benefit of TMVr is not fully supported by the proportionate-disproportionate hypothesis.

Trial Registration

ClinicalTrials.gov Identifier: NCT01626079.

3-Year Outcomes of Transcatheter Mitral Valve Repair in Patients With Heart Failure

BACKGROUND

In the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) trial, transcatheter mitral valve repair (TMVr) resulted in fewer heart failure hospitalizations (HFHs) and lower mortality at 24 months in patients with heart failure (HF) with mitral regurgitation (MR) secondary to left ventricular dysfunction compared with guideline-directed medical therapy (GDMT) alone.

OBJECTIVES

This study determined if these benefits persisted to 36 months and if control subjects who were allowed to cross over at 24 months derived similar benefit.

METHODS

This study randomized 614 patients with HF with moderate-to-severe or severe secondary MR, who remained symptomatic despite maximally tolerated GDMT, to TMVr plus GDMT versus GDMT alone. The primary effectiveness endpoint was all HFHs through 24-month follow-up. Patients have now been followed for 36 months.

RESULTS

The annualized rates of HFHs per patient-year were 35.5% with TMVr and 68.8% with GDMT alone (hazard ratio [HR]: 0.49; 95% confidence interval [CI]: 0.37 to 0.63; p < 0.001; number needed to treat (NNT) = 3.0; 95% CI: 2.4 to 4.0). Mortality occurred in 42.8% of the device group versus 55.5% of control group (HR: 0.67; 95% CI: 0.52 to 0.85; p = 0.001; NNT = 7.9; 95% CI: 4.6 to 26.1). Patients who underwent TMVr also had sustained 3-year improvements in MR severity, quality-of-life measures, and functional capacity. Among 58 patients assigned to GDMT alone who crossed over and were treated with TMVr, the subsequent composite rate of mortality or HFH was reduced compared with those who continued on GDMT alone (adjusted HR: 0.43; 95% CI: 0.24 to 0.78; p = 0.006).

CONCLUSIONS

Among patients with HF and moderate-to-severe or severe secondary MR who remained symptomatic despite GDMT, TMVr was safe, provided a durable reduction in MR, reduced the rate of HFH, and improved survival, quality of life, and functional capacity compared with GDMT alone through 36 months. Surviving patients who crossed over to device treatment had a prognosis comparable to those originally assigned to transcatheter therapy. (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation [COAPT]; NCT01626079).

Innovative transcatheter procedures for the treatment of heart failure

The prevalence of heart failure (HF) continues to rise over time, with aging of the population and increased survival of incident cases. Major improvements occurred in drug therapy but morbidity and mortality of HF patients remain high. Some non-pharmacologic approaches to HF are already part of standard treatment for HF, including implantable cardioverter-defibrillators, cardiac resynchronization therapy (CRT) and left ventricular assist devices (LVADs). A number of transcatheter treatments and devices have been developed to improve management of valvular heart diseases (VHD), and some of them are being used or tested in specific HF conditions. For example, transcatheter aortic valve implantation (TAVI) to unload the left ventricle in patients with moderate aortic stenosis (AS) and HF or TAVI for severe aortic regurgitation (AR) in patients with LVADs. Similarly, percutaneous mitral valve repair can be used to improve prognosis and quality of life in patients with functional mitral valve regurgitation, and has been proposed as a bridge-to-LVAD or to heart transplant in selected patients. Other devices have been specifically developed for the treatment of chronic HF. In this review we describe the main devices used in the treatment of HF associated with aortic and mitral valve disease, as well as novel transcatheter interventions for chronic HF with different pathophysiologic targets.

Impact of Mitral Regurgitation Severity and Left Ventricular Remodeling on Outcome After MitraClip Implantation: Results From the Mitra-FR Trial

OBJECTIVES

This study aimed to identify a subset of patients based on echocardiographic parameters who might have benefited from transcatheter correction using the MitraClip system in the MITRA-FR (Percutaneous Repair with the MitraClip Device for Severe Functional/Secondary Mitral Regurgitation) trial.

BACKGROUND

It has been suggested that differences in the degree of mitral regurgitation (MR) and left ventricular (LV) remodeling may explain the conflicting results between the MITRA-FR and the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) trials.

METHODS

In a post hoc analysis, we evaluated the interaction between the intervention and subsets of patients defined based on MR severity (effective regurgitant orifice [ERO], regurgitant volume [RVOL] and regurgitant fraction [RF]), LV remodeling (end-diastolic and end-systolic diameters and volumes) and combination of these parameters with respect to the composite of death from any cause or unplanned hospitalization for heart failure at 24 months.

RESULTS

We observed a neutral impact of the intervention in subsets with the highest MR degree (ERO ≥30 mm², RVOL ≥45 ml or RF ≥50%) as in patients with milder MR degree. The same was seen in subsets with the milder LV remodeling using either diastolic or systolic diameters or volumes. When parameters of MR severity and LV remodeling were combined, there was still no benefit of the intervention including in the subset of patients with an ERO/end-diastolic volume ratio ≥ 0.15 despite similar ERO and LV end-diastolic volume compared with COAPT patients.

CONCLUSIONS

In the MITRA-FR trial, we could not identify a subset of patients defined based on the degree of the regurgitation, LV remodeling or on their combination, including those deemed as having disproportionate MR, that might have benefited from transcatheter correction using the MitraClip system. (Multicentre Study of Percutaneous Mitral Valve Repair MitraClip Device in Patients With Severe Secondary Mitral Regurgitation [MITRA-FR]; NCT01920698).

Disproportionate mitral regurgitation: another myth? A critical appraisal of echocardiographic assessment of functional mitral regurgitation

The contradictory findings of recent prospective randomized controlled trials assessing the impact of percutaneous edge-to-edge repair in patients with functional or secondary mitral regurgitation have triggered a lively discussion about an “integrated” echocardiographic approach for grading severity of mitral regurgitation. In the MITRA-FR trial, the COAPT trial and the REDUCE-FMR trial echocardiographic assessment of the severity of mitral regurgitation was consistent with principles set forth by the current echocardiographic guidelines and analysed in its best settings by expert international leaders in the field of echocardiography. However, serious inconsistencies appeared in the presented echocardiographic assessments regarding cardiac output and regurgitant fraction. A new term “disproportionate functional mitral regurgitation” was introduced describing a situation where the increase of effective regurgitant orifice area exceeds the enlargement of the left ventricular end-diastolic volumes. Further discussion resulted in the idea of a “new conceptional framework” for distinguishing “proportionate” and “disproportionate” functional mitral regurgitation. The aim of this viewpoint is to dispute conclusions based on the term “disproportionate” mitral regurgitation. A “disproportionate” FMR is highly questionable because disproportionateness of flow in communication vessels cannot exist. In addition, a proposal of echocardiographic assessment based on a conventional comprehensive transthoracic echocardiography is given to avoid obvious hemodynamic contradictions.

Heart Failure With Reduced Ejection Fraction: A Review

IMPORTANCE

Worldwide, the burden of heart failure has increased to an estimated 23 million people, and approximately 50% of cases are HF with reduced ejection fraction (HFrEF).

OBSERVATIONS

Heart failure is a clinical syndrome characterized by dyspnea or exertional limitation due to impairment of ventricular filling or ejection of blood or both. HFrEF occurs when the left ventricular ejection fraction (LVEF) is 40% or less and is accompanied by progressive left ventricular dilatation and adverse cardiac remodeling. Assessment for heart failure begins with obtaining a medical history and physical examination. Also central to diagnosis are elevated natriuretic peptides above age- and context-specific thresholds and identification of left ventricular systolic dysfunction with LVEF of 40% or less as measured by echocardiography. Treatment strategies include the use of diuretics to relieve symptoms and application of an expanding armamentarium of disease-modifying drug and device therapies. Unless there are specific contraindications, patients with HFrEF should be treated with a β-blocker and one of an angiotensin receptor-neprilysin inhibitor, angiotensin-converting enzyme inhibitor, or angiotensin receptor blocker as foundational therapy, with addition of a mineralocorticoid receptor antagonist in patients with persistent symptoms. Ivabradine and hydralazine/isosorbide dinitrate also have a role in the care of certain patients with HFrEF. More recently, sodium-glucose cotransporter 2 (SGLT2) inhibitors have further improved disease outcomes, significantly reducing cardiovascular and all-cause mortality irrespective of diabetes status, and vericiguat, a soluble guanylate cyclase stimulator, reduces heart failure hospitalization in high-risk patients with HFrEF. Device therapies may be beneficial in specific subpopulations, such as cardiac resynchronization therapy in patients with interventricular dyssynchrony, transcatheter mitral valve repair in patients with severe secondary mitral regurgitation, and implantable cardiac defibrillators in patients with more severe left ventricular dysfunction particularly of ischemic etiology.

CONCLUSIONS AND RELEVANCE

HFrEF is a major public health concern with substantial morbidity and mortality. The management of HFrEF has seen significant scientific breakthrough in recent decades, and the ability to alter the natural history of the disease has never been better. Recent developments include SGLT2 inhibitors, vericiguat, and transcatheter mitral valve repair, all of which incrementally improve prognosis beyond foundational neurohormonal therapies. Disease morbidity and mortality remain high, with a 5-year survival rate of 25% after hospitalization for HFrEF.

Proportionate or disproportionate secondary mitral regurgitation: how to untangle the Gordian knot?

Recent randomised percutaneous mitral intervention trials in patients with heart failure with secondary mitral regurgitation (SMR) have yielded contrasting results. A 'relative load' or 'proportionality' conceptual framework for SMR has been proposed to partly explain the disparate results. The rationale behind the framework is that SMR depends on the left ventricular dimension and not vice versa. In this review, we provide an in-depth analysis of the proportionality parameters used in this framework and also discuss the regurgitant fraction. We also consider haemodynamic observations in SMR that may affect the interpretation and comparisons among proportionality parameters. The conclusion is that the proportionality concept remains hypothetical and requires prospective validation before envisaging its use at individual patient level for risk stratification or therapeutic decision-making.