Percutaneous mitral valve repair for secondary mitral valve regurgitation: A systematic review and meta-analysis

Percutaneous Mitral Valve Repair for Secondary Mitral Regurgitation: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis aimed to investigate whether percutaneous mitral valve repair (PMVr) using MitraClip was more effective than surgery or medical therapy for long-term morbidity and mortality. We searched MEDLINE, EMBASE, and CENTRAL (Cochrane Library) databases to identify relevant studies that recruited adult patients with functional or secondary mitral valve regurgitation who underwent PMVr with MitraClip implantation using appropriate search terms and Boolean operators. The odds ratios (ORs) were pooled using the random-effects model. A total of 14 studies recruiting 2,593 patients were included. Within 12 months of follow-up, patients who underwent PMVr did not maintain mitral valve regurgitation grade 2+ (OR 0.22, 95% confidence interval [CI] 0.12 to 0.41, p <0.0001, I2 = 0.0%, p = 0.52) or symptom-free heart failure (OR 0.47, 95% CI 0.29 to 0.77, p = 0.0028, I2 = 0.0%, p = 0.66) compared with their surgical counterparts. Patients were more likely to be rehospitalized for heart failure (OR 2.79, 95% CI 1.54 to 5.05, p = 0.0007, I2 = 0.0%, p = 0.51). However, there was no difference between the groups in terms of all-cause or cardiovascular mortality. Whereas, in comparison with medical therapy, PMVr significantly reduced all-cause mortality at 12 and ≥24 months of follow-up (OR 0.41, 95% CI 0.24, 0.69, p = 0.0009, I2 = 32%, p = 0.23 and OR 0.55, 95% CI 0.40, 0.75, p = 0.0002, I2 = 0.0%, p = 0.45, respectively). In conclusion, there was no difference in all-cause death at 12 or 24 months of follow-up between PMVr and the surgical approach, but the durability of valvular repair was inferior with PMVr. In comparison with medical therapy, there was a significant reduction in mortality with PMVr.

Mortality and Clinical Predictors After Percutaneous Mitral Valve Repair for Secondary Mitral Regurgitation: A Systematic Review and Meta-Regression Analysis

Background

Percutaneous mitral valve repair (PMVR) provides an available choice for patients suffering from secondary mitral regurgitation (SMR), especially those whose symptoms persist after optimal, conventional, heart-failure therapy. However, conflicting results from clinical trials have created a problem in identifying patients who will benefit the most from PMVR.

Objective

To pool mortality data and assess clinical predictors after PMVR among patients with SMR. To this end, subgroup and meta-regression analyses were additionally performed.

Methods

We searched PubMed, EMBASE, and Cochrane databases, and 13 studies were finally included for meta-analysis. Estimated mortality and 95% confidence intervals (CIs) were obtained using a random-effects proportional meta-analysis. We also carried out a meta-regression analysis to clarify the potential influence of important covariates on mortality.

Results

A total of 1,259 patients with SMR who had undergone PMVR were enrolled in our meta-analysis. The long-term estimated pooled mortality of PMVR was 19.3% (95% CI: 13.6–25.1). Meta-regression analysis showed that mortality was directly proportional to cardiac resynchronization therapy (CRT) (β = 0.009; 95% CI: 0.002–0.016; p = 0.009), an effective regurgitant orifice (ERO) (β = 0.009; 95% CI: 0.000–0.018; p = 0.047), and a mineralocorticoid receptor antagonist (MRA) use (β = −0.015; 95% CI: −0.023–−0.006; p < 0.001). Subgroup analysis indicated that patients with preexisting AF (β = −0.002; 95% CI: −0.005– −0.000; p = 0.018) were associated with decreased mortality if they received a mitral annuloplasty device. Among the edge-to-edge repair device group, a higher left ventricular (LV) ejection fraction, or lower LV end-systolic diameter, LV end-systolic volume, and LV end-diastolic volume were proportional to lower mortality.

Conclusion and Relevance

The pooled mortality of PMVR was 19.3% (95% CI: 13.6–25.1). Further meta-regression indicated that AF was associated with a better outcome in conjunction with the use of a mitral annuloplasty device, while better LV functioning predicted a better outcome after the implantation of an edge-to-edge repair device.

Trends in Transcatheter Edge-to-Edge Mitral Valve Repair Over a Decade: Data From the MiTra ULM Registry

Objective

This study sought to determine the potential change in trends in the baseline characteristics of patients with symptomatic severe mitral regurgitation who underwent transcatheter edge-to-edge mitral valve repair (M-TEER) over the last decade in a high-volume center.

Methodology

The investigation included 942 symptomatic patients with moderate-to-severe and severe mitral regurgitation who underwent transcatheter edge-to-edge repair (TEER) at our institution between January 2010 and March 2021. Patients were divided into quintiles and compared separately.

Results

Patients treated in the last quintile had significantly lower surgical risk (Euro Score 7.2 ± 6.8% in the last quintile vs. 10.9 ± 9.4% in the first quintile, p < 0.001), better New York Heart Association (NYHA) status (NYHA IV 14% in the last quintile vs. 40% in the first quintile, p < 0.001), lower NT-pro-BNP, and smaller left ventricle diameter than patients who were treated in the first quintile. There was no difference in age between quintiles. However, an invasive hemodynamic assessment did not show significant changes over the last decade (sPAP 51.35 ± 16.2 mmHg in the first quintile vs. 51.02 ± 14.5 mmHg in the last quintile, p = 0.90, pulmonary capillary wedge V wave 30.7 ± 14.8 mmHg in the first quintile vs. 27.4 ± 10.3 mmHg in the last quintile, p = 0.40). There is a significant trend of a gradually increasing proportion of patients with degenerative mitral regurgitation (MR) over the last 10 years (p < 0.001). The experience gained in the M-TEER procedure brought a significant reduction in fluoroscopy time and hospitalization duration. Medical therapy significantly changed over the last decade in terms of higher use of angiotensin receptor blockers (ARBs), lower use of angiotensin-converting enzyme inhibitors (ACEIs), and the introduction of angiotensin receptor-neprilysin inhibitors (ARNIs).

Conclusion

Patients undergoing the M-TEER procedure nowadays have lower surgical risk and are treated before they develop a significant left ventricular (LV) remodeling than before. The increasing expertise on the procedure over the last decade led to a rising number of patients with complex degenerative pathology being treated.

Rest and exercise oxygen uptake and cardiac output changes 6 months after successful transcatheter mitral valve repair

Aims

Changes in peak exercise oxygen uptake (VO₂) and cardiac output (CO) 6 months after successful percutaneous edge‐to‐edge mitral valve repair (pMVR) in severe primary (PMR) and functional mitral regurgitation (FMR) patients are unknown.

The aim of the study was to assess the efficacy of pMVR at rest by echocardiography, VO₂ and CO (inert gas rebreathing) measurement and during cardiopulmonary exercise test with CO measurement.

Methods and results

We evaluated 145 and 115 patients at rest and 98 and 66 during exercise before and after pMVR, respectively.

After successful pMVR, significant reductions in MR and NYHA class were observed in FMR and PMR patients. Cardiac ultrasound showed reverse remodelling (left ventricular end‐diastolic volume from 158 ± 63 mL to 147 ± 64, P < 0.001; ejection fraction from 51 ± 15 to 48 ± 14, P < 0.001; pulmonary artery systolic pressure (PASP) from 43 ± 13 to 38 ± 8 mmHg, P < 0.001) in the entire population. These changes were significant in PMR (n = 62) and a trend in FMR (n = 53), except for PASP, which decreased in both groups. At rest, CO and stroke volume (SV) increased in FMR with a concomitant reduction in arteriovenous O₂ content difference [ΔC(a‐v)O₂]. Peak exercise, CO and SV increased significantly in both groups (CO from 5.5 ± 1.4 L/min to 6.3 ± 1.5 and from 6.2 ± 2.4 to 6.7 ± 2.0, SV from 57 ± 19 mL to 66 ± 20 and from 62 ± 20 to 69 ± 20, in FMR and PMR, respectively), whereas peak VO₂ was unchanged and ΔC(a‐v)O₂ decreased.

Conclusions

These data confirm pMVR‐induced clinical improvement and reverse ventricular remodelling at a 6‐month analysis and show, in spite of an increase in CO, an unchanged exercise performance, which is achieved through a ‘more physiological’ blood flow distribution and O₂ extraction behaviour. Direct rest and exercise CO should be measured to assess pMVR efficacy.

Transcatheter mitral valve repair and replacement: the next frontier of transcatheter valve intervention

PURPOSE OF REVIEW

We summarize the recent developments in transcatheter mitral valve repair (TMVr) and replacement (TMVR), discuss determinants of MitraClip outcomes in various mitral regurgitation causes, and highlight newly emerging devices and randomized trials.

RECENT FINDINGS

The discordant results published in the two recent randomized trials for MitraClip, the COAPT and the MITRA-FR trial have led to the emergence of a new conceptual framework such as the proportionate versus disproportionate mitral regurgitation and hemodynamics assessment tools like the real-time continuous left atrial pressure monitoring. Learning curve and volume-outcome analyses and studies examining the MitraClip usage in patients with degenerative mitral regurgitation are recent developments that have influenced MitraClip regulation and coverage. Several trials for TMVr devices that take an alternative approach to the edge-to-edge repair are underway and advancements in the TMVR technologies are continuing to progress to fill the unmet needs of treating high surgical risk patients whose complex valve anatomy make TMVr unfeasible.

SUMMARY

Evidence supports careful analysis of the valve area and left ventricular function in addition to the left atrial hemodynamics will improve the MitraClip outcome. Operator experience plays a greater effect when achieving excellent results with 1+ or less residual mitral regurgitation whereas surgical MVr volume did not influence TMVr outcome. Interventions on the complex primary mitral regurgitation remain under the surgical domain, but MITRA high risk (HR) and REPAIR mitral regurgitation trials are underway to evaluate the role of MitraClip in high to intermediate surgical risk patients with primary mitral regurgitation. Despite the slow developments in TMVR, the results of the early trials of its devices are promising.

Transcatheter Mitral Repair for Functional Mitral Regurgitation According to Left Ventricular Function: A Real-Life Propensity-Score Matched Study

BACKGROUND

Transcatheter mitral valve repair (TMVR) could improve survival in functional mitral regurgitation (FMR), but it is necessary to consider the influence of left ventricular ejection fraction (LVEF). Therefore, we compare the outcomes after TMVR with Mitraclip® between two groups according to LVEF.

METHODS

In an observational registry study, we compared the outcomes in patients with FMR who underwent TMVR with and without LVEF <30%. The primary endpoint was the combined one-year all-cause mortality and unplanned hospital readmissions due to HF. The secondary end-points were New York Heart Association (NYHA) functional class and mitral regurgitation (MR) severity. Propensity-score matching was used to create two groups with the same baseline characteristics, except for baseline LVEF.

RESULTS

Among 535 FMR eligible patients, 144 patients with LVEF <30% (group 1) and 144 with LVEF >30% (group 2) had similar propensity scores and were included in the analyses. The primary study endpoint was significantlly higher in group 1 (33.3% vs. 9.4%, p = 0.002). There was a maintained improvement in secondary endpoints without significant differences among groups.

CONCLUSION

FMR patients with LVEF <30% treated with MitraClip® had higher mortality and readmissions than patients with LVEF ≥30% treated with the same device. However, both groups improved the NYHA functional class and MR severity.