Short-term and 1-year outcomes after MitraClip therapy in functional versus degenerative mitral regurgitation patients: a systematic review and meta-analysis

The Usefulness of Cardiopulmonary Exercise Testing to Detect Functional Improvement after Transcatheter Valve Procedures: What Do We Know So Far?

Transcatheter valve procedures have become a cornerstone in the management of patients with valvular heart disease and high surgical risk, especially for aortic stenosis and mitral and tricuspid regurgitation. Cardiopulmonary exercise testing (CPET) is generally considered the gold standard for objectively quantifying functional capacity, providing a comprehensive evaluation of the human body's performance, particularly in patients with heart failure (HF). Its accurate assessment is valuable for exploring the pathogenetic mechanisms implicated in HF-related functional impairment. It is also useful for objectively staging the clinical severity and the prognosis of the disease. The improvement in functional capacity after transcatheter valve procedures may be clinically relevant and may provide prognostic information, even in this setting. However, it remains to be fully determined as data on the topic are limited. This review aims to summarize the available evidence on the usefulness of CPET to assess functional improvement in patients undergoing transcatheter valve procedures.

Mitral Valve Transcatheter Edge-to-Edge Repair Using MitraClip or PASCAL: A Multicenter Propensity Score-Matched Comparison

BACKGROUND

Since its introduction in 2003, Abbott's MitraClip (MC) has become the most established catheter-based treatment for mitral regurgitation (MR). Recent approval of Edwards Lifescience's PASCAL device has extended the field of TEER.

OBJECTIVES

The aim of this retrospective multicenter study was to compare the PASCAL and MC regarding procedural results and short- and long-term outcomes after mitral valve transcatheter edge-to-edge repair (TEER).

METHODS

Data from 3 high-volume centers were analyzed. The primary endpoint was residual MR at discharge. Secondary endpoints were technical success, MR reduction, and 30-day mortality. After 1 year, all-cause mortality and residual MR were reported.

RESULTS

A total of 412 patients (216 MC, 196 PASCAL) treated between 2018 and 2020 were included. A total of 184 patients (92 in each treatment group) remained after propensity score matching. The rate of baseline MR ≥3 was 98.9% in both groups (P = 1.00). Both TEER systems achieved equally high technical success rates (97.8%; P = 1.00), resulting in residual MR ≤1 in 69.6% vs 77.1% of patients (P = 0.24) and MR reduction by ≥2 grades in 83.7% vs 92.4% of patients (P = 0.13) using the MC and PASCAL, respectively. Thirty-day mortality was 1.1% in both cohorts (P = 0.98), and 1-year follow-up showed similar MR reductions (residual MR ≤1, 78.0% with MC vs 82.3% with PASCAL; P = 0.70) and comparable all-cause mortality (14.1% with MC vs 6.5% with PASCAL; P = 0.14). In multivariate regression analysis, Society of Thoracic Surgeons score independently correlated with an optimal result (MR ≤1), while device choice did not show a significant impact.

CONCLUSIONS

In this retrospective multicenter study, the established MC and the novel PASCAL mitral valve TEER systems were safe and offered excellent performance with comparable short- and long-term outcomes.

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.

Epidemiological Trends in Patients Undergoing Mitral Valve Transcatheter Edge-to-Edge Repair over the Last Decade: Functional vs. Structural Mitral Regurgitation

OBJECTIVE

We aimed to investigate the demographic, clinical and hemodynamic characteristics of patients who underwent percutaneous mitral valve (MV) repair over the last decade, as well as to determine the potential changes in trends of these parameters among patients with structural and functional MR (SMR and FMR).

METHODOLOGY

We analyzed all patients who underwent interventional MV repair in our institution between January 2010 and March 2021. Our study included both SMR and FMR patients. All data were obtained from a local registry.

RESULTS

Nine hundred and seventeen patients (357 SMR patients and 563 FMR patients) were involved in this study. We did not find significant differences in demographical, clinical and hemodynamic characteristics among SMR and FMR patients. Left ventricular remodeling and systolic dysfunction were more pronounced in FMR patients. Systemic vascular resistance was the only hemodynamic parameter that differed between SMR and FMR patients; it was higher in SMR group. An evaluation of the trend between the first and last five years of our experience revealed that the number of patients treated with this technique is constantly increasing, but that this is more pronounced in SMR patients. It was also found that the operative risk of SMR and FMR patients was significantly higher in the first five years. Additionally, our results showed change in medical therapy in MR patients over the last decade in terms of increased use of angiotensin II receptor blockers and the introduction of angiotensin receptor II blocker-neprilysin inhibitor.

CONCLUSION

SMR and FMR patients who underwent interventional MV repair have similar clinical and hemodynamic characteristics. The percentage of SMR patients increased more significantly than FMR patients over the last five years.

Clinical and echocardiographic outcomes of transcatheter mitral valve repair in atrial functional mitral regurgitation

BACKGROUND

Isolated atrial fibrillation can cause mitral regurgitation (MR) in patients with normal left ventricular systolic function and no organic disease of the mitral valve. Little information is available regarding outcomes of Mitraclip in patients with atrial functional mitral regurgitation (AFMR). We aimed to evaluate 12-month clinical and echocardiographic outcomes of transcatheter mitral valve repair (TMVR) with MitraClip in patients with AFMR compared to those with ventricular functional or degenerative/mixed MR.

METHODS

Registry-based analysis of all consecutive patients who underwent TMVR and were included in the Spanish Registry of Mitraclip. Changes in MR and NYHA functional class, and a combined endpoint including all-cause mortality and hospitalizations due to heart failure were the main outcomes.

RESULTS

Overall, 1074 (69.1% male, 73.3 ± 10.2 years-old) patients were analyzed in this report. 48 patients (4.5%) presented AFMR. AFMR was significantly reduced after TMVR, with a procedural success rate of 91.7%, and this reduction persisted at 12-month (p < 0.001). Patients with AFMR showed a significant functional improvement at 6- and 12-month follow-up in our series (baseline: NYHA III 70.8% IV 18.8% vs. 1-year: NYHA III 21.7% IV 0%; p < 0.001). The probability of survival free of readmission for heart failure and all-cause mortality within the first year after TMVR was 74.9%. Procedural and clinical outcomes, as well as recurrent rates of MR were similar acutely and at 1-year compared to other etiologies.

CONCLUSION

TMVR in patients with AFMR showed no significant differences compared to ventricular functional or degenerative/mixed MR regarding MR reduction or clinical outcomes.

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.