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

Outcomes of mitral valve transcatheter edge-to-edge repair for patients with hemodynamic instability: A systematic review and meta-analysis

BACKGROUND

The outcomes after mitral valve transcatheter edge-to-edge repair (M-TEER) for the patients with severe mitral regurgitation (MR) in hemodynamically unstable conditions, such as cardiogenic shock, still remain unclear. We aimed to integrate previous publications regarding M-TEER indicated for life-threatening conditions and indirectly particularly compared the short-term outcomes thereof, with that of other treatments.

METHODS

We systematically searched the PubMed, Cochrane, and MEDLINE databases for studies from inception to June 2023, regarding M-TEER in patients with hemodynamic instability and severe MR. The primary outcomes analyzed included the in-hospital and 30-day mortality rates, and peri-procedural complications.

RESULTS

Of the initial 820 publications, we conducted a meta-analysis of a total of 25 studies. The relative risk of moderate-to-severe or severe MR was 0.13 (95 % confidence interval [CI]: 0.10-0.18, I2 = 45.2 %). The pooled in-hospital and 30-day mortality rates were 11.8 % (95 % CI: 8.7-15.9, I2 = 96.4 %) and 14.1 % (95 % CI: 10.9-18.3, I2 = 35.5 %), respectively. The 30-day mortality rate was statistically significantly correlated with the residual moderate-to-severe or severe MR, as per the meta-regression analysis (coefficient β = 3.48 [95 % CI: 0.99-5.97], p = 0.006). Regarding peri-procedural complications, the pooled rates of a stroke or transient ischemic attack, life-threatening or major bleeding, acute kidney injury, and peri-procedural mitral valve surgery were 2.3 % (95 % CI: 1.9-2.6), 7.6 % (95 % CI: 6.8-8.5), 32.9 % (95 % CI: 31.6-34.3), and 1.0 % (95 % CI: 0.8-1.3), respectively.

CONCLUSIONS

This meta-analysis demonstrates that the relatively higher rates of procedural complications were observed, nevertheless, M-TEER can potentially provide favorable short-term outcomes even in hemodynamically unstable patients.

PROSPERO REGISTRATION NUMBER

CRD42023468946.

Evolving indications for transcatheter mitral edge-to-edge repair

Transcatheter mitral edge-to-edge repair (TEER) is an established procedure for managing mitral regurgitation (MR) in high-risk patients. It is effective in treating both primary and secondary MR, as reported in the surgical and interventional literature. Over time, TEER has gained popularity and achieved procedural success in various anatomies. The less invasive nature of TEER, along with its high safety profile and immediate haemodynamic improvement suggest potential benefits in high-risk populations who are not normally included in major trials. These patients, often deemed unsuitable for surgical intervention, are typically managed conservatively, despite accumulating evidence suggesting the potential of clinical improvement by reducing MR through TEER. Examples include post-myocardial infarction MR, patients with hypertrophic obstructive cardiomyopathy and patients experiencing recurrent MR after surgical intervention. This review discusses the utilisation of TEER beyond recognised indications, examining outcomes and limitations in diverse patient populations. Further studies are warranted to evaluate the benefits of TEER in clinical scenarios beyond the current indications.

Bileaflet Tethering With Preserved LV Geometry and Function: An Unusual Mechanism of Functional Mitral Regurgitation

An 81-year-old woman presented with acute pulmonary edema. Echocardiography revealed severe functional mitral regurgitation, the mechanism of which was unusual. An atypical bileaflet tethering caused by disharmonic annular remodeling, concomitant aortic dilatation, and reduced aorto-mitral angle without left ventricular dysfunction or dilatation was found. A transcatheter edge-to-edge repair was nonetheless successfully performed.

Transcatheter edge-to-edge repair for chronic functional mitral regurgitation in patients with very severe left ventricular dysfunction

BACKGROUND

There is scarce data on transcatheter edge-to-edge repair (TEER) for chronic functional mitral regurgitation (FMR) in the setting of very severe left ventricular dysfunction (LVD), defined by a left ventricular ejection fraction (LVEF) of <20%.

METHODS

We retrospectively explored periprocedural characteristics and one-year clinical and echocardiographic outcomes of consecutive patients with chronic FMR and very severe LVD who underwent an isolated, first-time TEER. The composite of all-cause mortality or heart failure hospitalizations constituted the primary outcome.

RESULTS

Ninety-six patients (median age 69 [IQR, 55-76] years, 64 (66.7%) males, median LVEF 15 [IQR, 12-17] %) were included. In 47 (49.0%), TEER was performed urgently or in the setting of hemodynamic instability. Almost all procedures (98.0%) were technically successful, leading to ≤moderate MR in 94.7% and 90.7% of cases by 1-month and 1-year, respectively. New York Heart Association class ≤II was maintained in 60.0% of patients. One-year survival and freedom from the primary outcome were 74.0% and 50.0%, respectively. Functional and echocardiographic improvement compared to baseline was independent of procedural urgency, hemodynamic stability, and downstream left ventricular assist device implantation / heart transplantation (n = 12). Mortality was not predicted by COAPT exclusion criteria, nor was the primary outcome discriminated by published risk models.

CONCLUSION

TEER for chronic FMR is feasible, safe, and efficacious in selected patients with very severe LVD. Preprocedural risk stratification in this population may be optimized.

Cardiac rehabilitation in a heart-failure patient using customized "cardiac support net" treatment: a case report

At our hospital, we are conducting the "Clinical Study of a Patient-Specific Cardiac Support Net for Dilated Cardiomyopathy (jRCTs042180025)", a multi-facility clinical study of a customized cardiac support net (CSN). Here, we describe the cardiac rehabilitation (CR) of a heart failure (HF) patient after CSN treatment. The patient was a 65-year-old man who exhibited dilated cardiomyopathy (DCM) because of left ventricular non-compaction; his New York Heart Association status was class III. In November 2019, he received CSN treatment. The early CR program was adapted for this patient, and his postoperative course was uneventful. Functional measurements showed improved leg-muscle strength (before treatment: 61.4% BW; at discharge: 77.3% BW). During long-term follow-up, the patient's exercise tolerance increased, as shown by 6-minute walk distance (before treatment: 576 m; long-term follow-up: 600 m) and peak oxygen uptake (before treatment: 12.5 mL/kg/min; long-term follow-up: 13.3 mL/kg/min). In the 2 years since discharge, the patient has not been hospitalized for HF. This report is the first to show that the CSN can be used to perform a CR program in a DCM patient without significant functional decline.

Global Longitudinal Strain Predicts Outcomes in Patients with Reduced Left Ventricular Function Undergoing Transcatheter Edge-to-Edge Mitral Repair

BACKGROUND

The timing and selection of optimal candidates for mitral transcatheter edge-to-edge valve repair remains to be fully determined, especially in cases with severely depressed left ventricular ejection fraction (LVEF). The objective of this study is to evaluate the prognostic value of myocardial strain (LVGLS) in this setting.

METHODS

Retrospectively, 172 consecutive patients with LVEF ≤40% and severe MR treated with MitraClip were included. Four groups were generated according to the LVEF (<30% or ≥30%) and median LVGLS. The primary end-point was cardiovascular mortality.

RESULTS

Procedural success was high (96.5%) and complications were rare. At one-year follow-up, 82.5% of patients maintained MR grade ≤2, 79.2% were at a NYHA class ≤II and a reduction of 80% in heart failure admissions was observed in all groups. Interestingly, among patients with a more depressed LVEF, LVGLS was found to be an independent predictor for cardiovascular mortality (HR: 3.3; 95% CI: 1.1-10, p = 0.023).

CONCLUSIONS

Mitral valve repair with MitraClip is safe and it improves the mid-term functional class of patients regardless of LVEF. LVGLS can help in the selection of optimal candidates and timing for this procedure, as well as in the recognition of those patients with worse prognoses.

Prediction of mortality and heart failure hospitalisations in patients undergoing M-TEER: external validation of the COAPT risk score

BACKGROUND

A risk score was recently derived from the Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation (COAPT) Trial. However, external validation of this score is still lacking.

AIMS

We aimed to validate the COAPT risk score in a large multicentre population undergoing mitral transcatheter edge-to-edge repair (M-TEER) for secondary mitral regurgitation (SMR).

METHODS

The Italian Society of Interventional Cardiology (GIse) Registry of Transcatheter Treatment of Mitral Valve RegurgitaTiOn (GIOTTO) population was stratified according to COAPT score quartiles. The performance of the COAPT score for 2-year all-cause death or heart failure (HF) hospitalisation was evaluated in the overall population and in patients with or without a COAPT-like profile.

RESULTS

Among the 1,659 patients included in the GIOTTO registry, 934 had SMR and complete data for a COAPT risk score calculation. The incidence of 2-year all-cause death or HF hospitalisation progressively increased through the COAPT score quartiles in the overall population (26.4% vs 44.5% vs 49.4% vs 59.7%; log-rank p<0.001) and COAPT-like patients (24.7% vs 32.4% vs 52.3% vs. 53.4%; log-rank p=0.004), but not in those with a non-COAPT-like profile. The COAPT risk score had poor discrimination and good calibration in the overall population, moderate discrimination and good calibration in COAPT-like patients and very poor discrimination and poor calibration in non-COAPT-like patients.

CONCLUSIONS

The COAPT risk score has a poor performance in the prognostic stratification of real-world patients undergoing M-TEER. However, after application to patients with a COAPT-like profile, moderate discrimination and good calibration were observed.

Mitral valve transcatheter edge-to-edge repair

Mitral regurgitation (MR) is the most prevalent valvular heart disease and, when left untreated, results in reduced quality of life, heart failure, and increased mortality. Mitral valve transcatheter edge-to-edge repair (M-TEER) has matured considerably as a non-surgical treatment option since its commercial introduction in Europe in 2008. As a result of major device and interventional improvements, as well as the accumulation of experience by the interventional cardiologists, M-TEER has emerged as an important therapeutic strategy for patients with severe and symptomatic MR in the current European and American guidelines. Herein, we provide a comprehensive up-do-date overview of M-TEER. We define preprocedural patient evaluation and highlight key aspects for decision-making. We describe the currently available M-TEER systems and summarise the evidence for M-TEER in both primary mitral regurgitation (PMR) and secondary mitral regurgitation (SMR). In addition, we provide recommendations for device selection, intraprocedural imaging and guiding, M-TEER optimisation and management of recurrent MR. Finally, we provide information on major unsolved questions and "grey areas" in M-TEER.

[The "Mickey Mouse Heart"]

The "Mickey Mouse Heart" Abstract. The "Mickey Mouse Heart" describes patients with a combination of HFpEF, massive biatrial dilatation and dilatation of the mitral- and tricuspid annulus, atrial fibrillation and severe mitral- and tricuspid regurgitation. Most frequently elderly patients with HFpEF are affected by this syndrome. The underlying molecular mechanisms or risk factors for the typical biatrial dilatation are unknown. The guideline-directed heart failure therapy as well as the evaluation of early rhythm control for atrial fibrillation and the treatment of mitral- and tricuspid regurgitation are recommended.

Transcatheter Edge-To-Edge Repair in COAPT-ineligible Patients: Incidence and Predictors of 2-year Good Outcome

BACKGROUND

COAPT trial entry criteria are useful to identify patients with better outcomes after transcatheter edge-to-edge repair (TEER). However, up to half of real-world patients with secondary mitral regurgitation (SMR) undergoing TEER do not meet these highly selective criteria and no study has formally investigated them. The aim of this study was to evaluate the predictors of good outcome after TEER in COAPT-ineligible patients.

METHODS

All consecutive patients with SMR and heart failure (HF) treated with MitraClip at 3 European centers were retrospectively screened. The presence of at least one COAPT exclusion criterion was used to define a COAPT-ineligible profile, allowing the inclusion in the study population. Freedom from all-cause death or HF hospitalization was evaluated at 2-year follow-up (primary endpoint).

RESULTS

A total of 305 (47%) patients had a COAPT-ineligible profile. An overall 58% rate of all-cause death or HF hospitalization was detected at 2-years. Patients with a single COAPT exclusion criterion showed less adverse events than those with multiple criteria (55% vs. 69%). At multivariable Cox-regression analysis, NYHA-class II, younger age (<75 years), lower serum creatinine (<2 mg/dl), lower left ventricle end-diastolic volume (<240 ml), and the absence of hemodynamic instability, atrial fibrillation, and chronic obstructive pulmonary disease, were independently associated with good outcome.

CONCLUSIONS

In this real-world series of patients with SMR undergoing TEER, a COAPT-ineligible profile was common. The presence of only one COAPT exclusion criterion or the absence of hemodynamic instability were associated with the most favorable outcomes.

Transcatheter edge-to-edge mitral valve repair in atrial functional mitral regurgitation: insights from the multi-center MITRA-TUNE registry

BACKGROUND

A-FMR is considered a specific sub-type of secondary MR in patients with atrial fibrillation (AF) and preserved left ventricle ejection fraction (LVEF). Aim of the study was to investigate the acute and mid-term outcomes of transcatheter edge-to-edge mitral valve repair (TMVr) with the MitraClip in atrial functional mitral regurgitation (A-FMR).

METHODS

The study included patients with A-FMR and concomitant AF who underwent to the MitraClip at 7 Italian Centers. Aim of the study was to assess the safety, efficacy and mid-term cardiovascular outcomes.

RESULTS

After reviewing 1153 patients with FMR treated with TMVr from 2009 to 2021, 87 patients (median age 81 years, 61% female) with A-FMR were identified. Technical success was achieved in 97%, 30-day device success in 83% and 30-day procedural success in 80%. All-cause death at 30-day was 5%. Estimated two-year freedom from all-cause death and cardiac death was 60% and 77%, respectively, whereas freedom from all-cause death/heart failure hospitalization was 55%. Residual MR ≤ 2+ was encountered in 89% (n = 47/53) and improvement in NYHA class I/II in 79% (n = 48/61). Post-procedural MR ≥ 2+ (HR 5.400, CI 1.371-21.268) and inter-commissural annular diameter ≥ 35 mm (HR 4.159, CI 1.057-16.363) were independent predictors of all-cause death/heart failure hospitalization during the follow-up. Positive reverse remodeling of left atrium and mitral annular dimensions occurred after TMVr during the follow-up.

CONCLUSIONS

MitraClip resulted to be a safe and effective option to treat A-FMR in elderly patients.

2-Year Outcomes of Transcatheter Mitral Valve Replacement in Patients With Severe Symptomatic Mitral Regurgitation

BACKGROUND

Transcatheter mitral valve replacement (TMVR) is feasible for selected patients with severe mitral regurgitation (MR) who are poor candidates for valve surgery. Intermediate-term to long-term TMVR outcomes have not been reported.

OBJECTIVES

This study sought to evaluate the safety and effectiveness through 2-year follow-up of TMVR in high-surgical-risk patients with severe MR.

METHODS

The first 100 patients enrolled in the Expanded Clinical Study of the Tendyne Mitral Valve System, an open-label, nonrandomized, prospective study of transapical TMVR, were followed for 2 years.

RESULTS

The patients (aged 74.7 ± 8.0 years, 69.0% male) had symptomatic (66.0% New York Heart Association [NYHA] functional class III or IV) grade 3+ or 4+ MR that was secondary or mixed in 89 (89.0%). Prostheses were successfully implanted in 97 (97.0%) patients. At 2 years, all-cause mortality was 39.0%; 17 (43.6%) of 39 deaths occurred during the first 90 days. Heart failure hospitalization (HFH) fell from 1.30 events per year preprocedure to 0.51 per year in the 2 years post-TMVR (P < 0.0001). At 2 years, 93.2% of surviving patients had no MR. No patient had >1+ MR. The improvement in symptoms at 1 year (88.5% NYHA functional class I or II) was sustained to 2 years (81.6% NYHA functional class I or II). Among survivors, the left ventricular ejection fraction was 45.6 ± 9.4% at baseline and 39.8 ± 9.5% at 2 years (P = 0.0012). Estimated right ventricular systolic pressure decreased from 47.6 ± 8.6 mm Hg to 32.5 ± 10.4 mm Hg (P < 0.005).

CONCLUSIONS

In this study, the impact of TMVR on severity of MR, reduction in HFH rate, and improvement in symptoms was sustained through 2 years. All-cause mortality and the need for HFH was highest in the first 3 months postprocedure. (Expanded Clinical Study of the Tendyne Mitral Valve System; NCT02321514).