MitraClip Treatment of Moderate-to-Severe and Severe Mitral Regurgitation in High Surgical Risk Patients - Real-World 1-Year Outcomes From Japan

Impact of the MitraClip G4 System on Routine Practice and Outcomes in Patients With Secondary Mitral Regurgitation

BACKGROUND

The MitraClip G4 system is a new iteration of the transcatheter edge-to-edge repair system. We assessed the impact of the G4 system on routine practice and outcomes in secondary mitral regurgitation (2°MR).Methods and Results: Consecutive patients with 2°MR treated with either the MitraClip G2 (n=89) or G4 (n=63) system between 2018 and 2021 were included. Baseline characteristics, procedures, and outcomes were compared. Inverse probability of treatment weighting and Cox regression were used to adjust for baseline differences. Baseline characteristics were similar, except for a lower surgical risk in the G4 group (Society of Thoracic Surgeons Predicted Risk of Mortality ≥8: 38.1% vs. 56.2%; P=0.03). In the G4 group, more patients had short (≤2 mm) coaptation length (83.7% vs. 54.0%; P<0.001) and fewer clips were used (17.5% vs. 36.0%; P=0.02). Acceptable MR reduction was observed in nearly all patients, with no difference between the G4 and G2 groups (100% vs. 97.8%, respectively; P=0.51). The G4 group had fewer patients with high transmitral gradients (>5mmHg; 3.3% vs. 13.6%; P=0.03). At 1 year, there was no significant difference between groups in the composite endpoint (death or heart failure rehospitalization) after baseline adjustment (10.5% vs. 20.2%; hazard ratio 0.39; 95% confidence interval 0.11-1.32; P=0.13).

CONCLUSIONS

The G4 system achieved comparable device outcomes to the early-generation G2, despite treating more challenging 2°MR with fewer clips.

Two-Year Clinical Outcome of MitraClip Transcatheter Edge-to-Edge Repair From the J-MITRA Registry Data

BACKGROUND

The introduction of transcatheter edge-to-edge repair for moderate-to-severe or severe mitral regurgitation (MR) utilizing the MitraClip system became reimbursed and clinically accessible in Japan in April 2018. This study presents the 2-year clinical outcomes of all consecutively treated patients who underwent MitraClip implantation in Japan and were prospectively enrolled in the Japanese Circulation Society-oriented J-MITRA registry.Methods and Results: Analysis encompassed 2,739 consecutive patients enrolled in the J-MITRA registry with informed consent (mean age: 78.3±9.6 years, 1,550 males, STS risk score 11.7±8.9), comprising 1,999 cases of functional MR, 644 of degenerative MR and 96 in a mixed group (DMR and FMR). The acute procedure success rate was 88.9%. After MitraClip implantation, >80% exhibited an MR grade ≤2+ and the trend was sustained over the 2 years. Within this observation period, the mortality rate was 19.3% and the rate of heart failure readmissions was 20.6%. The primary composite endpoint, inclusive of cardiovascular death and heart failure readmission, was significantly higher in patients with functional MR than in with degenerative MR (32.0% vs. 17.5%, P<0.001).

CONCLUSIONS

The 2-year clinical outcomes after MitraClip implantation were deduced from comprehensive data within an all-Japan registry.

Mechanical Support Strategies for High-Risk Procedures in the Invasive Cardiac Catheterization Laboratory: A State-of-the-Art Review

Thanks to advancements in percutaneous cardiac interventions, an expanding patient population now qualifies for treatment through percutaneous endovascular procedures. High-risk interventions far exceed coronary interventions and include transcatheter aortic valve replacement, endovascular management of acute pulmonary embolism and ventricular tachycardia ablation. Given the frequent impairment of ventricular function in these patients, frequently deteriorating during percutaneous interventions, it is hypothesized that mechanical ventricular support may improve periprocedural survival and subsequently patient outcome. In this narrative review, we aimed to provide the relevant evidence found for the clinical use of percutaneous mechanical circulatory support (pMCS). We searched the Pubmed database for articles related to pMCS and to pMCS and invasive cath lab procedures. The articles and their references were evaluated for relevance. We provide an overview of the clinically relevant evidence for intra-aortic balloon pump, Impella, TandemHeart and ECMO and their role as pMCS in high-risk percutaneous coronary intervention, transcatheter valvular procedures, ablations and high-risk pulmonary embolism. We found that the right choice of periprocedural pMCS could provide a solution for the hemodynamic challenges during these procedures. However, to enhance the understanding of the safety and effectiveness of pMCS devices in an often high-risk population, more randomized research is needed.

One-Year Outcomes and Their Relationship to Residual Mitral Regurgitation After Transcatheter Edge-to-Edge Repair With MitraClip Device: Insights From the OCEAN-Mitral Registry

Background Limited data are available about clinical outcomes and residual mitral regurgitation (MR) after transcatheter edge-to-edge repair in the large Asian-Pacific cohort. Methods and Results From the Optimized Catheter Valvular Intervention (OCEAN-Mitral) registry, a total of 2150 patients (primary cause of 34.6%) undergoing transcatheter edge-to-edge repair were analyzed and classified into 3 groups according to the residual MR severity at discharge: MR 0+/1+, 2+, and 3+/4+. The mortality and heart failure hospitalization rates at 1 year were 12.3% and 15.0%, respectively. Both MR and symptomatic improvement were sustained at 1 year with MR ≤2+ in 94.1% of patients and New York Heart Association functional class I/II in 95.0% of patients. Compared with residual MR 0+/1+ (20.4%) at discharge, both residual MR 2+ (30.2%; P < 0.001) and 3+/4+ (32.4%; P = 0.007) were associated with the higher incidence of death or heart failure hospitalization (adjusted hazard ratio [HR], 1.59; P < 0.001, and adjusted HR, 1.73; P = 0.008). New York Heart Association class III/IV at 1 year was more common in the MR 3+/4+ group (20.0%) than in the MR 0+/1+ (4.6%; P < 0.001) and MR 2+ (6.4%; P < 0.001) groups, and the proportion of New York Heart Association class I is significantly higher in the MR 1+ group (57.8%) than in the MR 2+ group (48.3%; P = 0.02). Conclusions The OCEAN-Mitral registry demonstrated favorable clinical outcomes and sustained MR reduction at 1 year in patients undergoing transcatheter edge-to-edge repair. Both residual MR 2+ and 3+/4+ after transcatheter edge-to-edge repair at discharge were associated with worse clinical outcomes compared with residual MR 0+/1+. Registration Information https://upload.umin.ac.jp. Identifier: UMIN000023653.

Appropriate Use Criteria for the Management of Aortic Stenosis: Insight From the Japanese Expert Panel

Background

The indication for transcatheter aortic valve replacement (TAVR) for aortic stenosis (AS) significantly varies among physicians and institutions.

Objectives

This study aims to develop a set of appropriate use criteria for AS management to assist physicians in decision-making.

Methods

The RAND-modified Delphi panel method was used. A total of >250 common clinical scenarios were identified in terms of whether to perform the intervention for AS and the mode of intervention (surgical aortic valve replacement vs TAVR). Eleven nationally representative expert panelists independently rated the clinical scenario appropriateness on a scale of 1-9, as "appropriate" (7-9), "may be appropriate" (4-6), or "rarely appropriate" (1-3); the median score of the 11 experts was then assigned to an appropriate-use category.

Results

The panel identified 3 factors that were associated with a rarely appropriate rating in terms of performing the intervention: 1) limited life expectancy; 2) frailty; and 3) pseudo-severe AS on dobutamine stress echocardiography. Clinical scenarios that were deemed rarely appropriate for TAVR were also identified: 1) patients with low surgical risk and high TAVR procedural risk; 2) patients with coexistent severe primary mitral regurgitation or rheumatic mitral stenosis; and 3) bicuspid aortic valve that was not suitable for TAVR. Importantly, any TAVRs for patients who were older than 75 years of age were not rated as rarely appropriate.

Conclusions

These appropriate use criteria provide a practical guide for physicians regarding clinical situations commonly encountered in daily practice and elucidates scenarios deemed rarely appropriate that are clinical challenges for TAVR.

MitraClip: a review of its current status and future perspectives

Mitral regurgitation (MR), among the most common valvular heart diseases, is closely associated with heart failure and worse clinical outcomes. Surgical repair or replacement as an intervention for MR is deemed too high risk in patients who are elderly or have multiple comorbidities; thus, nearly half of all patients with severe symptomatic MR are not referred for surgical therapy. MitraClip, a transcatheter mitral valve repair system for MR that mimics the Alfieri surgical edge-to-edge technique for mitral valve repair, was developed in the late 1990s. After clinical trials demonstrated its safety and efficacy, it received approval for clinical use, particularly for aging and inoperable or high-risk patients for heart surgery in Europe, the US, and Japan. Since the start of its clinical use, randomized clinical trials (RCTs) have optimized patient selection, and the latest generation MitraClip can increase procedural success, even in patients with challenging mitral valve anatomy. Therefore, here, we review evidence from clinical trials and RCTs and discuss optical patient selection and future perspectives for the MitraClip.

Outcomes of Transcatheter Edge-to-Edge Repair in Degenerative vs. Functional Mitral Regurgitation

Current guidelines support the use of transcatheter edge-to-edge repair (TEER) for patients with both primary and secondary mitral regurgitation. We aimed to compare the prognoses of TEER in degenerative mitral regurgitation (DMR) vs. functional mitral regurgitation (FMR). A total of 208 consecutive patients who underwent TEER over a ten-year period were analyzed. Primary endpoints included rates of all-cause death and major adverse cardiac events (MACE: composite of all-cause death, hospitalizations for heart failure, mitral valve surgery, or TEER re-intervention). A total of 148 (71%) patients were identified with FMR, while 60 (29%) were identified with DMR. Patients in the FMR group were younger (77.2 ± 8.4 vs. 80.2 ± 7.2, p = 0.02), suffered more frequently from coronary artery disease (54.1% vs. 10.0%, p = 0.02), and atrial fibrillation/flutter (70.9% vs. 38.3%, p = 0.02). Rates of 1-year death (21.6% vs. 10.0%, p = 0.03) and MACE (41.2% vs. 21.7%, p = 0.02) were higher for the FMR group, as compared to the DMR group. After correcting for variables, FMR independently predicted rates of MACE (HR-1.78, 95% CI 1.23–2.48, p = 0.04) and had a non-significant effect on one-year mortality (HR-1.67, 95%CI 0.98–3.74, p = 0.07). In our experience, worse overall 1-year composite MACE outcomes were observed after TEER in patients with FMR as compared to patients with DMR.