Percutaneous Repair of Secondary Mitral Regurgitation - A Tale of Two Trials

The evolution of technical prerequisites and local boundary conditions for optimization of mitral valve interventions-Emphasis on skills development and institutional risk performance

This viewpoint report describes how the evolution of transcatheter mitral valve intervention (TMVI) is influenced by lessons learned from three evolutionary tracks: (1) the development of treatment from mitral valve surgery (MVS) to transcutaneous procedures; (2) the evolution of biomedical engineering for research and development resulting in predictable and safe clinical use; (3) the adaptation to local conditions, impact of transcatheter aortic valve replacement (TAVR) experience and creation of infrastructure for skills development and risk management. Thanks to developments in computer science and biostatistics, an increasing number of reports regarding clinical safety and effectiveness is generated. A full toolbox of techniques, devices and support technology is now available, especially in surgery. There is no doubt that the injury associated with a minimally invasive access reduces perioperative risks, but it may affect the effectiveness of the treatment due to incomplete correction. Based on literature, solutions and performance standards are formulated with an emphasis in technology and positive outcome. Despite references to Heart Team decision making, boundary conditions such as hospital infrastructure, caseload, skills training and perioperative risk management remain underexposed. The role of Biomedical Engineering is exclusively defined by the Research and Development (R&D) cycle including the impact of human factor engineering (HFE). Feasibility studies generate estimations of strengths and safety limitations. Usability testing reveals user friendliness and safety margins of clinical use. Apart from a certification requirement, this information should have an impact on the definition of necessary skills levels and consequent required training. Physicians Preference Testing (PPT) and use of a biosimulator are recommended. The example of the interaction between two Amsterdam heart centers describes the evolution of a professional ecosystem that can facilitate innovation. Adaptation to local conditions in terms of infrastructure, referrals and reimbursement, appears essential for the evolution of a complete mitral valve disease management program. Efficacy of institutional risk management performance (IRMP) and sufficient team skills should be embedded in an appropriate infrastructure that enables scale and offers complete and safe solutions for mitral valve disease. The longstanding evolution of mitral valve therapies is the result of working devices embedded in an ecosystem focused on developing skills and effective risk management actions.

Thirty-day and one-year outcomes following transcatheter mitral valve edge-to-edge repair versus transapical mitral valve replacement in patients with left ventricular dysfunction

Background

A comparison of 30-day and 1-year clinical outcomes in patients with pre-existing left ventricular (LV) dysfunction undergoing transcatheter mitral valve edge-to-edge repair (TEER) or transcatheter transapical mitral valve replacement (TMVR) has not previously been reported.

Aims

We aimed to compare 30-day and 1-year rates of all-cause and cardiovascular mortality as well as rehospitalisation for heart failure (HFH).

Methods

All patients with severe (≥3+) symptomatic mitral regurgitation (MR) and an LV ejection fraction ≤50% who underwent TEER or TMVR over a 5-year period were evaluated.

Results

Ninety-six patients (50 TEER, age 80±9 years, 70% secondary MR and 46 TMVR, age 72±9 years, 91% secondary MR) were studied. Baseline demographic and transthoracic echocardiogram characteristics were well-matched, with the exception of age (TEER 80±9 vs TMVR 72±9; p=0.01). Successful device implantation occurred in 96% of TEER patients and 97.8% of TMVR patients. Ninety-two percent of TEER patients had ≤2+MR predischarge, whilst no TMVR patient had ≥1+MR (p<0.01). No significant difference in the combined endpoint of 30-day all-cause mortality or HFH was observed (p>0.05). At 1 year, freedom from all-cause mortality and HFH was 79.2% across the entire study population but was significantly higher in patients undergoing TEER (TEER: n=45 [90%] hazard ratio 11.26, 95% confidence interval [CI]: 10.59-11.93 vs TMVR: n=39 [67.4%] 95% CI: 10.09-11.33; p=0.008).

Conclusions

Despite comparable rates of successful device implantation, MR reduction, and 30-day all-cause mortality/HFH, TEER patients had lower all-cause mortality and HFH rates at 1 year.

CT Planning prior to Transcatheter Mitral Valve Replacement (TMVR)

BACKGROUND

 Transcatheter mitral valve replacement (TMVR) is a treatment option for patients with therapy refractory high-grade mitral valve regurgitation and a high perioperative risk.During TMVR, the mitral annulus cannot be visualized directly. Therefore, comprehensive pre-interventional planning and a precise visualization of the patient's specific mitral valve anatomy, outflow tract anatomy and projected anchoring of the device are necessary.Aim of this review-article is, to assess the role of pre-procedural computed tomography (CT) for TMVR-planning METHODS:  Screening and evaluation of relevant guidelines (European Society of Cardiology [ESC], American Heart Association [AHA/ACC]), meta-analyses and original research using the search terms "TVMR" or "TMVI" and "CT". In addition to this, the authors included insight from their own clinical experience.

RESULTS

 CT allows for accurate measurement of the mitral annulus with high special and adequate temporal resolution in all cardiac phases. Therefore, CT represents a valuable method for accurate prosthesis-sizing.In addition to that, CT can provide information about the valvular- and outflow-tract-anatomy, mitral valve calcifications, configuration of the papillary muscles and of the left ventricle. Additionally, the interventional access-route may concomitantly be visualized.

CONCLUSION

 CT plays, in addition to echocardiographic imaging, a central role in pre-interventional assessment prior to TMVR. Especially the precise depiction of the left ventricular outflow tract (LVOT) provides relevant additional information, which is very difficult or not possible to be acquired in their entirety with other imaging modalities.

KEY POINTS

  · CT plays a central role in pre-interventional imaging for TMVR.. · CT-measurements allow for accurate prosthesis-sizing.. · CT provides valuable information about LVOT-anatomy, mitral calcifications and interventional access-route..

CITATION FORMAT

· Heiser L, Gohmann RF, Noack T et al. CT Planning prior to Transcatheter Mitral Valve Replacement (TMVR). Fortschr Röntgenstr 2022; DOI: 10.1055/a-1718-4182.

Exercise Hemodynamic Profiling Is Associated With Outcome in Patients Undergoing Percutaneous Mitral Valve Repair

BACKGROUND

Percutaneous mitral valve repair (PMVR) in high-risk patients is currently controversial, especially in those with secondary mitral regurgitation (MR). Exercise pulmonary hemodynamics may help to unmask cardiac dysfunction as well as the dynamic impact of MR. The present study sought to explore the clinical impact of preprocedural exercise right heart catheterization (RHC) for the selection of patients who could most benefit from PMVR.

METHODS

Sixty-eight patients with symptomatic primary and secondary MR and exercise RHC before PMVR were included in this retrospective analysis of the association of exercise RHC parameters with survival and improvement in New York Heart Association class within 12 months.

RESULTS

Median patient age was 77 years (±8.5), 37% were female, and 81% presented with New York Heart Association class III. A total of 65% of the patients had left ventricular ejection fraction <55%. MR was severe in 49% and moderate-to-severe in 51%. Twenty-two patients (32%) died within the follow-up period of 19 months (interquartile range, 9-32); they had a lower rise (Δ) in the V-wave on pulmonary artery wedge pressure tracings. Patients with ΔV-wave ≥17 mm Hg had a reduced risk of death after PMVR (hazard ratio, 0.11 [95% CI, 0.04-0.33], P<0.001), independent of age, frailty index, and workload during RHC. A higher ΔV-wave was also associated with New York Heart Association improvement (odds ratio, 1.14 [95% CI, 1.07-1.24]; P<0.001), and 79% of patients with ∆V-wave ≥15 mm Hg were in New York Heart Association class I or II at follow-up (<15 mm Hg: 28%). These results were for the most part confirmed in the subgroup of patients with secondary MR (65%).

CONCLUSIONS

In our cohort of patients with indication for PMVR, preprocedural exercise RHC was able to identify patients with an unfavorable outcome. Further studies with larger patient numbers are warranted before this approach can be implemented in a structured diagnostic workup of patients under evaluation for PMVR.

Transapical Transcatheter Mitral Valve Implantation in Heart Failure: Haemodynamic Challenges for a New Frontier

Secondary mitral regurgitation (MR) and heart failure are mutually dependent. Secondary MR occurs as a consequence of heart failure in patients with impaired left ventricular (LV) function, decreasing cardiac efficiency, accelerating a decline in contractility and worsening the already dismal prognosis of these patients. Advances in transcatheter techniques have now given promise to improved survival, outcomes, and quality of life for patients with advanced heart failure and secondary MR. Although transcatheter edge-to-edge repair is well established, transapical transcatheter mitral valve implantation (TMVI) may represent a more durable solution for correction of secondary MR without the need for cardiopulmonary bypass. Correction of MR, however, is thought to acutely increase LV afterload due to the elimination of low afterload regurgitant flow. In high-risk patients, this may cause acute decompensated heart failure. Off-pump TMVI on a beating heart poses a number of unique challenges, but also the opportunity to study invasive haemodynamic indices in high-risk heart failure patients for the first time. In the following discussion, we review the acute haemodynamic changes during off-pump TMVI in patients with heart failure in order to better guide optimal patient selection and management.

Outcomes of transcatheter mitral valve repair for secondary mitral regurgitation by severity of left ventricular dysfunction

BACKGROUND

In the COAPT trial, transcatheter mitral valve repair with the MitraClip plus maximally tolerated guideline-directed medical therapy (GDMT) improved clinical outcomes compared with GDMT alone in symptomatic patients with heart failure (HF) and 3+ or 4+ secondary mitral regurgitation (SMR) due to left ventricular (LV) dysfunction.

AIMS

In this COAPT substudy, we sought to evaluate two-year outcomes in HF patients with reduced LV ejection fraction (HFrEF; LVEF ≤40%) versus preserved LVEF (HFpEF; LVEF >40%) and in those with severe (LVEF ≤30%) versus moderate (LVEF >30%) LV dysfunction.

METHODS

The principal effectiveness outcome was the two-year rate of death from any cause or HF hospitalisations (HFH). Subgroup analysis with interaction testing was performed according to baseline LVEF; 472 patients (82.1%) had HFrEF (mean LVEF 28.0%±6.2%; range 12% to 40%) and 103 (17.9%) had HFpEF (mean LVEF 46.6%±4.9%; range 41% to 65%), while 292 (50.7%) had severely depressed LVEF (LVEF ≤30%; mean LVEF 23.9%±3.8%) and 283 (49.3%) had moderately depressed LVEF (LVEF >30%; mean LVEF 39.0%±6.8%).

RESULTS

The two-year rate of death or HFH was 56.7% in patients with HFrEF and 53.4% with HFpEF (HR 1.16, 95% CI: 0.86-1.57, p=0.32). MitraClip reduced the two-year rate of death or HFH in patients with HFrEF (HR 0.50, 95% CI: 0.39-0.65) and HFpEF (HR 0.60, 95% CI: 0.35-1.05), pint=0.55. MitraClip was consistently effective in reducing the individual endpoints of mortality and HFH, improving MR severity, quality of life, and six-minute walk distance in patients with HFrEF, HFpEF, LVEF ≤30%, and LVEF >30%.

CONCLUSIONS

In the COAPT trial, among patients with HF and 3+ or 4+ SMR who remained symptomatic despite maximally tolerated GDMT, the MitraClip was consistently effective in improving survival and health status in patients with severe and moderate LV dysfunction and those with preserved LVEF.

Safety, effectiveness and costs of percutaneous mitral valve repair: A real-world prospective study

Aims

Percutaneous mitral valve leaflet repair is a treatment option for some people with severe mitral valve regurgitation for whom conventional mitral valve surgery is clinically inappropriate. This study aimed to determine the safety, efficacy, and costs of percutaneous mitral valve leaflet repair, using the MitraClip device in a UK setting.

Methods and results

This was a prospective, single-armed registry with a follow-up of 2 years that reported a range of procedural, clinical and patient-orientated outcomes. Registry data were linked to routine data sources to allow for more comprehensive follow up concerning mortality and healthcare resource use. The registry received data for 199 mainly elective patients with mixed mitral regurgitation aetiology. A MitraClip device was implanted in 187 patients (94%), with a procedural success rate of 86%, with 8% of patients having a serious in-hospital adverse event (including 5% mortality). Percutaneous mitral valve leaflet repair reduced mitral regurgitation from 100% MR grade ≥ 3+ to 7% at discharge. There were corresponding improvements in New York Heart Association functional class, reducing from 92% (class ≥ 3) at baseline to 18% at 6 weeks. There were significant improvements in generic and disease specific quality of life indicators up to 2 years. The all-cause mortality rate was estimated to be 12.7% (95% CI 7.5 to 17.7%) at 1 year. Percutaneous mitral valve leaflet repair was associated with reduced hospital readmissions and potential cost-savings in post-procedural care.

Conclusion

This study shows that percutaneous mitral valve leaflet repair using MitraClip is a relatively safe and effective treatment in patients unable to tolerate surgery and has the potential to reduce ongoing healthcare costs in the UK.

Selection of the Optimal Candidate to MitraClip for Secondary Mitral Regurgitation: Beyond Mitral Valve Morphology

Secondary mitral regurgitation (MR) occurs despite structurally normal valve apparatus due to an underlying disease of the myocardium leading to disruption of the balance between tethering and closing forces with ensuing failure of leaflet coaptation. In patients with heart failure (HF) and left ventricular dysfunction, secondary MR is independently associated with poor outcome, yet prognostic benefits related to the correction of MR have remained elusive. Surgery is not recommended for the correction of secondary MR outside coronary artery bypass grafting. Percutaneous mitral valve repair (PMVR) with MitraClip implantation has recently evolved as a new transcatheter treatment option of inoperable or high-risk patients with severe MR, with promising results supporting the extension of guideline recommendations. MitraClip is highly effective in reducing secondary MR in HF patients. However, the derived clinical benefit is still controversial as two randomized trials directly comparing PMVR vs. optimal medical therapy in severe secondary MR yielded virtually opposite conclusions. We reviewed current evidence to identify predictors of PMVR-related outcomes in secondary MR useful to improve the timing and the selection of patients who would derive maximal benefit from MitraClip intervention. Beyond mitral valve anatomy, optimal candidate selection should rely on a comprehensive diagnostic workup and a fine-tuned risk stratification process aimed at (i) recognizing the substantial heterogeneity of secondary MR and its complex interaction with the myocardium, (ii) foreseeing hemodynamic consequences of PMVR, (iii) anticipating futility and (iv) improving symptoms, quality of life and overall survival.

2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the valvular heart disease guideline provides recommendations for clinicians to diagnose and manage valvular heart disease as well as supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from January 1, 2010, to March 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, Cochrane, Agency for Healthcare Research and Quality Reports, and other selected database relevant to this guideline. Structure: Many recommendations from the earlier valvular heart disease guidelines have been updated with new evidence and provides newer options for diagnosis and treatment of valvular heart disease. This summary includes only the recommendations from the full guideline which focus on diagnostic work-up, the timing and choice of surgical and catheter interventions, and recommendations for medical therapy. The reader is referred to the full guideline for graphical flow charts, text, and tables with additional details about the rationale for and implementation of each recommendation, and the evidence tables detailing the data considered in developing these guidelines.

Percutaneous Mitral Valve Repair with the MitraClip System in the Current Clinical Practice

Severe mitral valve regurgitation (MR) carries a significant burden both in prognosis and quality of life of patients, as well as on healthcare systems, with high rates of hospitalization for heart failure. While mitral valve surgery constitutes the first-line treatment option for primary MR in suitable patients, surgical treatment for secondary severe MR remains controversial, with a substantial lack of evidence on a survival benefit. In recent decades, percutaneous mitral valve repair has emerged as an alternative treatment for patients deemed not suitable for surgery. Among several devices under development or evaluation, the MitraClip system is the most widespread and is supported by the strongest evidence. While the role of MitraClip in patients with chronic primary MR who are not deemed suitable for surgery is well established, with consistent data showing improvement in both prognosis and quality of life, MitraClip treatment in secondary MR is a rapidly evolving field. Two recent randomized clinical trials generated apparently controversial results but actually provided an interesting pathophysiologic frame that could help discerning patients who will benefit from the procedure versus patients who will not. In this review, we will discuss current treatment options for mitral regurgitation, focusing on percutaneous mitral valve repair with the MitraClip system.

Conflicting findings between the Mitra-Fr and the Coapt trials: Implications regarding the cost-effectiveness of percutaneous repair for heart failure patients with severe secondary mitral regurgitation

PURPOSE

Two randomized controlled trials (RCTs), Mitra-Fr and Coapt, evaluating the benefit of percutaneous repair (PR) for heart failure (HF) patients with severe mitral regurgitation, have led to conflicting results. We aimed to evaluate the impact of these trial results on the cost-effectiveness of PR using effectiveness inputs from the two RCTs.

METHODS

We developed a time varying Markov type model with three mutually exclusive health states: alive without HF hospitalisation, alive with HF hospitalisation, and dead. Clinically plausible extrapolations beyond observed data were obtained by developing parametric modelling for overall survival and HF hospitalisations using published data from each trial. We adopted the perspective of the French Health System and used a 30-year time horizon. Results were expressed as € / quality-adjusted life year (QALY) gained using utility inputs from literature.

FINDINGS

Results are presented using treatment efficacy measures from Mitra-F and Coapt trials respectively. With the Mitra-Fr data, after annual discounting, the base case model generated an incremental 0.00387 QALY at a cost of €25,010, yielding an incremental cost effectiveness ratio (ICER) of €6,467,032 / QALY. The model was sensitive to changes made to model inputs. There was no potential of PR being cost-effective. With the Coapt data, the model generated 1.19 QALY gain at a cost of €26,130 yielding an ICER of €21,918 / QALY and at a threshold of >€50,000/QALY PR had a probability of 1 of being cost-effective.

IMPLICATIONS

Cost effectiveness results were conflicting; reconciling differences between trials is a priority and could promote optimal cost effectiveness analyses and resource allocation.

Integration of a palliative approach into heart failure care: a European Society of Cardiology Heart Failure Association position paper

The Heart Failure Association of the European Society of Cardiology has published a previous position paper and various guidelines over the past decade recognizing the value of palliative care for those affected by this burdensome condition. Integrating palliative care into evidence-based heart failure management remains challenging for many professionals, as it includes the identification of palliative care needs, symptom control, adjustment of drug and device therapy, advance care planning, family and informal caregiver support, and trying to ensure a 'good death'. This new position paper aims to provide day-to-day practical clinical guidance on these topics, supporting the coordinated provision of palliation strategies as goals of care fluctuate along the heart failure disease trajectory. The specific components of palliative care for symptom alleviation, spiritual and psychosocial support, and the appropriate modification of guideline-directed treatment protocols, including drug deprescription and device deactivation, are described for the chronic, crisis and terminal phases of heart failure.

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).

Minimally Invasive Mitral Valve Repair for Standalone Secondary Mitral Regurgitation

BACKGROUND

Chronic secondary mitral valve regurgitation is associated with a poor prognosis. Yet, in contrast to primary mitral regurgitation, there is no clear evidence that a reduction in regurgitation improves survival. The limited availability of data regarding secondary mitral regurgitation has resulted in a low level of evidence for treatment recommendations. We evaluated the influence of minimally invasive mitral valve annuloplasty on survival, freedom from recurrent regurgitation, and other echocardiographic parameters in patients with "standalone" secondary mitral valve regurgitation.

METHODS

The analysis included patients with severe secondary mitral regurgitation, left ventricular function <40%, and persistent symptoms, despite optimal medical therapy. We excluded patients who were eligible for coronary artery revascularisation or cardiac resynchronisation therapy (i.e., not standalone mitral regurgitation). After discharge, patients were scheduled for outpatient clinic follow-up at 1, 3, 6, and 12 months.

RESULTS

From 2012 to 2018, 54 consecutive patients underwent minimally invasive mitral valve annuloplasty for severe standalone secondary mitral regurgitation. All patients were discharged with no or trivial residual regurgitation. The mean duration of follow-up was 33.5±16.8 months. Overall survival was 90% at 4 years postprocedure. Freedom from moderate regurgitation or reintervention was 89% at the 4-year follow-up. There was a low incidence of readmission for heart failure and patients showed consistent improvements in left ventricular function and symptoms.

CONCLUSIONS

Mitral valve repair with reduction and stabilisation of the annulus may be beneficial for symptomatic patients with secondary stand-alone mitral regurgitation.

Impact of chronic kidney disease on in-hospital outcomes and readmission rate after edge-to-edge transcatheter mitral valve repair

BACKGROUND

Transcatheter mitral valve repair (TMVR) is a treatment option for patients with 3+ or greater mitral regurgitation who cannot undergo mitral valve surgery. Outcomes in patients with chronic kidney disease (CKD) and end stage renal disease (ESRD) are unclear. We sought to evaluate the TMVR in-hospital outcomes, readmission rates and its impact on kidney function.

METHODS

Data from 2016 National Readmission Database was used to obtain all patients who underwent TMVR. Patients were classified by their CKD status: no CKD, CKD, or ESRD. The primary outcomes were: in-hospital mortality, 30- and 90-day readmission rate, and change in CKD status on readmission. Multivariable logistic regression analysis was used to assess in-hospital, readmission outcomes and kidney function stage.

RESULTS

A total of 4,645 patients were assessed (mean age 78.5 ± 10.3 years). In-hospital mortality was higher in patients with CKD (4.0%, odds ratio [OR]:2.01 [95% CI, confidence interval: 1.27-3.18]) and ESRD (6.6%, OR: 6.38 [95% CI: 1.49-27.36]) compared with non-CKD (2.4%). 30-day readmission rate was higher in ESRD versus non-CKD patients (17.8% vs. 10.4%, OR: 2.24 [95% CI: 1.30-3.87]) as was 90-day readmission (41.2% vs. 21% OR: 2.51 [95% CI:1.70-3.72]). Kidney function improved in 25% of patients with CKD stage 3 and in 50% with CKD stage 4-5 at 30-and 90-day readmission. Incidence of AKI, major bleeding, and respiratory failure were higher in CKD group.

CONCLUSIONS

Patients with CKD and ESRD have worse outcomes and higher readmission rate after TMVR. In patients who were readmitted after TMVR, renal function improved in some patients, suggesting that TMVR could potentially improve CKD stage.

Clinical Trial Perspective: Cost-effectiveness of Transcatheter Mitral Valve Repair Versus Medical Therapy in Patients with Heart Failure and Secondary Mitral Regurgitation. Results From the COAPT Trial

Treatment of secondary (or functional) mitral regurgitation had traditionally been limited to optimal medical therapy because studies have failed to show a survival benefit with mitral valve surgery for this condition. However, recently the Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation (COAPT) trial demonstrated a significant decrease in heart failure hospitalizations and mortality in patients with severe secondary mitral regurgitation treated with percutaneous edge-to-edge mitral valve repair (TMVr) using the MitraClip device compared with medical therapy. Based o the results of the COAPT trial, the Food and Drug Administration granted approval for MitraClip treatment of patients with severe secondary mitral regurgitation in March 2019. In an attempt to understand the economic impact of treating this patient population with TMVr using the MitraClip device, a formal cost-effectiveness analysis was performed alongside the COAPT trial. This review summarizes the methods and results of the economic substudy of the COAPT trial and discusses the value of the MitraClip device from the perspective of the US healthcare system in the treatment of patients with symptomatic heart failure and secondary mitral regurgitation.

Percutaneous Interventions for Secondary Mitral Regurgitation

Mitral regurgitation is frequently associated with ventricular dysfunction and carries a high mortality. Guideline-directed medical therapy, surgical mitral valve repair or replacement, and, in the setting of advanced heart failure, heart transplant and left ventricular assist devices have been the mainstay of treatment. However, rapid advancement in the field has resulted in approval of edge-to-edge mitral valve repair with the MitraClip, and there are several novel catheter-based percutaneous options in clinical trials. Percutaneous options, while promising, must be deployed in patients who are most likely to benefit, and thus, understanding the pathophysiology of specific subgroups of patients with functional mitral regurgitation (eg, disproportionate versus proportionate mitral regurgitation) is key to the success of new devices. We review the pathophysiology, percutaneous therapeutic treatment options, and ongoing clinical trials for functional mitral regurgitation.

Underweight is associated with inferior short and long-term outcomes after MitraClip implantation: Results from the German TRAnscatheter mitral valve interventions (TRAMI) registry

BACKGROUND

Underweight and obesity represent classical risk factors for adverse outcome in patients treated for cardiovascular disease.

AIMS

The current analysis examines the impact of underweight, overweight and obesity on intra-hospital, short and long-term outcomes in patients treated by MitraClip therapy.

METHODS AND RESULTS

From August 2010 until July 2013, 799 patients (age 75.3 ± 8.6 years, male gender 60.7%, median logistic EuroSCORE 20% [12; 31], functional mitral regurgitation (MR): 69.3%) were prospectively enrolled into the multicenter German Transcatheter Mitral Valve Interventions registry. Patients were stratified according to body mass index (BMI) into 4 groups: BMI <20 kg/m² (underweight), BMI 20.0 to <25.0 kg/m² (normal weight, reference group), BMI 25.0 to <30.0 kg/m² (overweight) and BMI ≥30 kg/m² (obese). Significant increased rates of procedural failure, transfusion/bleeding, sepsis or multiorgan failure and low cardiac output failure were found for underweight patients only. Kaplan-Meier survival curves demonstrated inferior survival for underweight patients, but comparable outcomes for all other patients (global log rank test, P < .01). Multivariable Cox-regression analysis (adjusted for age, gender, creatinine ≥1.5 mg/dL, diabetes, left ventricular ejection fraction <30% and chronic obstructive pulmonary disease) confirmed underweight (as compared to normal weight) as an independent risk factor of death (hazard ratio [HR]: 1.58, 95% confidence interval (CI): 1.01-2.46, P = .044) and overweight as protective against death (HR: 0.71; 95%-CI: 0.55-0.93; P = .011).

CONCLUSIONS

Compared to other weight groups, underweight patients undergoing MitraClip implantation are exposed to increased rates of procedural failure, bleeding and low cardiac output as well as increased short- and long-term mortality rates and should therefore be carefully discussed in the heart-team.

Transcatheter mitral valve repair for functional mitral regurgitation: Evaluating the evidence

OBJECTIVES

Two trials (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation Trial and Percutaneous Repair with the MitraClip Device for Severe Functional/Secondary Mitral Regurgitation Trial) were published in 2018 evaluating the effectiveness and safety of transcatheter repair for patients with heart failure with significant functional mitral regurgitation, which yielded different results. This article reviews the strength of the evidence, differences in trial designs, ethical and implementation implications, and delineates future research needs to help guide the appropriate dissemination of transcatheter repair for functional patients with mitral regurgitation.

METHODS

The National Heart, Lung, and Blood Institute convened a workshop of interdisciplinary experts to address these objectives.

RESULTS

Transcatheter repair of functional mitral regurgitation can provide significant benefits in terms of heart failure hospitalizations, survival, and quality of life when appropriate heart failure candidates with moderate to severe or severe mitral regurgitation while on optimal guideline-directed medical therapy can be identified. Key ingredients for success are preoperative evaluation and management and postoperative care by an interdisciplinary heart team.

CONCLUSIONS

Given the discordance observed between trials, ongoing innovation in patient management, and potential expansion of indications for use, the evidence base must be expanded to optimize appropriate implementation of this complex therapy. This will require more complete capture of outcome data in real-world settings for all eligible candidates whether or not they receive this therapy. Inevitably, the indications for use of this therapy will expand, as will the devices and therapeutic approaches for this population, necessitating the study of comparative effectiveness through randomized trials or observational studies. Moreover, given the substantial variations in care delivery, conducting implementation research to delineate characteristics of the optimal care model would be of benefit.

Transcatheter Mitral Valve Repair and Replacement: Current Evidence for Intervention and the Role of CT in Preprocedural Planning-A Review for Radiologists and Cardiologists Alike

The mitral valve is a complex structure with a three-dimensional saddle shape annulus. Mitral regurgitation occurs from leaflet coaptation failure that is either primary (a problem with the leaflets) or secondary (chamber dilatation in the setting of cardiomyopathy). There has been an increase in focus on transcatheter mitral valve interventions, for both mitral repair and replacement. These technologies have rapidly developed to provide treatment for a substantial number of patients with severe symptomatic mitral regurgitation who are at too high of a risk to undergo open heart surgery. CT assessment of the mitral valve has developed with equal rapidity, with regard to preprocedural planning for transcatheter therapies. This review will provide an overview of mitral valve anatomy, an update on the current transcatheter repair and replacement therapies, as well as a focused overview of the role of multislice CT in mitral assessment prior to intervention. © RSNA, 2020.

To Clip or Not to Clip: The Use of MitraClip Therapy for Functional Mitral Regurgitation

Percutaneous edge-to-edge repair of the mitral valve with the MitraClip device has been shown to serve as a safe and effective treatment for severe mitral regurgitation in the high-risk surgical population. Although the device originally was designed for the reduction of degenerative mitral regurgitation resulting from primary leaflet abnormalities, numerous studies have included patients with functional mitral regurgitation from annular or ventricular distortion. Two recent landmark studies examined the use of the MitraClip device for functional mitral regurgitation treatment and found drastically opposing results. Data reconciliation by others has suggested only a subset of those with functional mitral regurgitation may benefit from this treatment. Herein 2 seemingly similar cases to illustrate the subtle differences in patient selection that eventually may change the clinical outcome for this procedure are presented.

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.

Cost-effectiveness analysis of percutaneous mitral valve repair with the MitraClip delivery system for patients with mitral regurgitation in Japan

Aims: The objective of the study is to evaluate the cost-effectiveness of percutaneous mitral valve repair (TMVr) with the MitraClip NT system (MitraClip procedure) for patients with symptomatic severe mitral regurgitation (MR) at high surgical risk in line with the methodological guideline for cost-effectiveness evaluation by the Ministry of Health, Labour and Welfare.Material and Methods: The cost-effectiveness of MitraClip procedure was evaluated using a Markov model. Patients are classified into four New York Heart Association classes in each cycle. The model considered MitraClip complication ("major vascular complication", "major bleeding complication", "non-cerebral thromboembolism"), adverse events, re-implantation with MitraClip device, mitral valve surgery, and congestive heart failure hospitalization. For the evidence on additional benefits, a study compared with propensity score-matched medical therapy group was used in the analysis. The analysis was conducted from the perspective of a public healthcare payer with a discount rate of 2% for both cost and effectiveness.Results: In the base-case analysis, total cost and quality-adjusted life year (QALY) gained (Life year (LY) gained) were 7,541,151 JPY and 3.23 QALYs (3.85 LYs) for MitraClip group, and 4,699,692 JPY and 1.79 QALYs (2.43 LYs) for medical therapy group, respectively. The incremental cost-effectiveness ratio (ICER) of MitraClip procedure versus medical therapy was 1.97 million JPY/QALY (US$18,570/QALY, US$1 = 106 JPY), which was evaluated to be cost-effective. The probability of ICER of MitraClip procedure versus medical therapy being 5 million JPY/QALY was 96.7%.Limitations: There are two limitations. Firstly, the parameters for the comparators were based on some assumptions. However, it was a conservative setting against MitraClip group. Secondary, the mortality rate and adverse events of MitraClip group in a lifetime were estimated from data during a year after the procedure.Conclusions: MitraClip procedure improved life-years and quality of life in patients at high surgical risk and it was also a cost-effective treatment option.

Percutaneous repair or medical treatment for secondary mitral regurgitation: outcomes at 2 years

AIMS

The MITRA-FR trial showed that among symptomatic patients with severe secondary mitral regurgitation, percutaneous repair did not reduce the risk of death or hospitalization for heart failure at 12 months compared with guideline-directed medical treatment alone. We report the 24-month outcome from this trial.

METHODS AND RESULTS

At 37 centres, we randomly assigned 304 symptomatic heart failure patients with severe secondary mitral regurgitation (effective regurgitant orifice area >20 mm² or regurgitant volume >30 mL), and left ventricular ejection fraction between 15% and 40% to undergo percutaneous valve repair plus medical treatment (intervention group, n = 152) or medical treatment alone (control group, n = 152). The primary efficacy outcome was the composite of all-cause death and unplanned hospitalization for heart failure at 12 months. At 24 months, all-cause death and unplanned hospitalization for heart failure occurred in 63.8% of patients (97/152) in the intervention group and 67.1% (102/152) in the control group [hazard ratio (HR) 1.01, 95% confidence interval (CI) 0.77-1.34]. All-cause mortality occurred in 34.9% of patients (53/152) in the intervention group and 34.2% (52/152) in the control group (HR 1.02, 95% CI 0.70-1.50). Unplanned hospitalization for heart failure occurred in 55.9% of patients (85/152) in the intervention group and 61.8% (94/152) in the control group (HR 0.97, 95% CI 0.72-1.30).

CONCLUSIONS

In patients with severe secondary mitral regurgitation, percutaneous repair added to medical treatment did not significantly reduce the risk of death or hospitalization for heart failure at 2 years compared with medical treatment alone.

Left Ventricular Size Predicts Clinical Benefit After Percutaneous Mitral Valve Repair for Secondary Mitral Regurgitation: A Systematic Review and Meta-Regression Analysis

BACKGROUND

The benefit of percutaneous mitral valve repair (PMVR) in patients with secondary MR is still debated. We aimed to compare the outcome of PMVR with optimal medical therapy (OMT) versus OMT alone in patients with secondary mitral regurgitation (MR) and to assess the role of potential effect modifiers.

METHODS

We performed a systematic review and meta-analysis of 2 randomized clinical trials (RCT) and 7 non-randomized observational studies (nROS). Hazard ratios (HR) and 95% confidence intervals (CI) were pooled through inverse variance random-effects model to compute the summary effect size for all-cause death, cardiovascular death and cardiac-related hospitalization. Subgroup and meta-regression analysis were also performed.

RESULTS

An overall population of 3118 individuals (67% men; mean age, 73 years) was included: 1775 PMVR+OMT and 1343 OMT patients, with mean follow-up of 24 ± 15 months. PMVR+OMT was associated with a lower risk of all-cause death (HR: 0.77; 95% CI: 0.68-0.87), cardiovascular death (HR: 0.55; 95% CI: 0.34-0.89) and cardiac-related hospitalization (HR:0.77; 95% CI: 0.64-0.92). Meta-regression analysis showed that larger left ventricular end-diastolic volume index (LVEDVI) portends higher risk of all-cause death, cardiovascular death and cardiac-related hospitalization after PMVR (p < 0.001 for all).

CONCLUSIONS

This study-level meta-analysis shows that PMVR+OMT is associated with reduced all-cause death, cardiovascular death and cardiac-related hospitalization when compared with OMT alone in secondary MR. LVEDVI is a predictive marker of efficacy, as patients with smaller LVEDVI have been shown to derive the largest benefit from PMVR.

The Year in Cardiothoracic and Vascular Anesthesia: Selected Highlights from 2019

This highlights in our specialty for 2019 begin with the ongoing major developments in transcatheter valve interventions. Thereafter, the advances in left ventricular assist devices are reviewed. The recent focus on conduit selection and robotic options in coronary artery bypass surgery are then explored. Finally, this special articles closes with a discussion of pulmonary hypertension in noncardiac surgery, anesthetic technique in cardiac surgery, as well as postoperative pneumonia and its outcome consequences.

One more option in heart failure: correction of mitral regurgitation with MitraClip®

Degenerative mitral regurgitation in elderly patients and functional mitral regurgitation secondary to severe left ventricular dysfunction are not easy options for conventional surgery. Recently, a new percutaneous approach has been proposed with the MitraClip^®, based on the Alfieri edge-to-edge repair technique. The aim of the study is to report, compare and discuss the results of two multicenter randomized trials: MITRA.FR and COAPT in light of the current practice. In both trials patients with functional mitral regurgitation grade 3/4+ or 4/4+ were randomly assigned, in 1:1 ratio, to undergo percutaneous repair and optimal medical therapy or optimal medical therapy alone. Other baseline characteristics reflecting severity of mitral regurgitation and of left ventricular impairment were statistically different, such as the effective regurgitant orifice area (0.31 cm² in MITRA.FR vs 0.41 cm² in COAPT) and the indexed LVEDV (135 ± 37 ml/m² in MITRA.FR vs 101 ± 34 ml/m² in COAPT). A 24 months follow-up and a 12 months follow-up have been completed, respectively, in COAPT and MITRA.FR. Out of the 307 patients enrolled in the MITRA.FR, 152 were randomized to percutaneous treatment but only in 138 (95.8%) the MitraClip^® was actually implanted. At the end of the follow-up a residual mitral regurgitation of at least grade 3+ has been observed in 17% of the patients. A composite of death from any cause or unplanned hospitalizations for heart failure at 12 months respectively occurred in 83 patients (54.6%) treated percutaneously and 78 patients (51.3%) treated with medical therapy only. A total of 614 patients have been enrolled in the COAPT and 293 underwent transcatheter treatment. A successful implantation of the MitraClip^® was achieved in 287 patients (98.0%). Hospitalization for heart failure at 24 months occurred in 160 patients in the device group and in 283 in the control group, with an annualized ratio of 35.8% and 67.9%, respectively (p > 0.001). The conflicting results of the two trials may have many explanations, but probably the main cause is the most stringent inclusion criteria in COAPT. The effective reduction of mitral regurgitation and improvement in exercise capacity already observed in registries including more than 70,000 patients was confirmed in a randomized trial with improvement observed in hard end-points. This has already led to an extension of FDA approval to functional regurgitation and a more liberal use across the world.

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.

Transcatheter Mitral Valve Implantation with the Medtronic Intrepid™ Transcatheter Mitral Valve Replacement System

Mitral regurgitation is the most prevalent yet undertreated valvulopathy despite its adverse prognosis. With the emergence of transcatheter mitral interventions, the potential for this huge unmet disease burden to be addressed may finally be realized. Medtronic Intrepid™ Transcatheter Mitral Valve Replacement System represents one of several novel solutions. Based on early data from the pilot study, its efficacy and clinical utility is currently being tested against the mainstay treatment of surgical mitral valve replacement in a randomized trial. While there remain significant challenges before transcatheter mitral intervention can become part of the routine treatment algorithm, the authors are optimistic that transcatheter mitral valve repair and intervention have the potential in revolutionizing the management of severe symptomatic mitral regurgitation.

Nine contemporary therapeutic directions in heart failure

The global burden of heart failure has continued to increase dramatically with 26 million people affected and an estimated health expenditure of $31 billion worldwide. Several practice-influencing studies were reported recently, bringing advances along many frontiers in heart failure, particularly heart failure with reduced ejection fraction. In this article, we discuss nine distinct therapeutic areas that were significantly influenced by this scientific progress. These distinct areas include the emergence of sodium-glucose cotransporter-2 inhibitors, broadening the application of angiotensin-neprilysin inhibition, clinical considerations in therapy withdrawal in those patients with heart failure that 'recover' myocardial function, benefits of low-dose direct oral anticoagulants in sinus rhythm, targeted therapy for treating cardiac amyloidosis, usefulness of mitral valve repair in heart failure, the advent of newer left ventricular assist devices for advanced heart failure, the role of ablation in atrial fibrillation in heart failure, and finally the use of wearable defibrillators to address sudden death.