Echocardiographic Variables Associated with Transvalvular Gradient After a Transcatheter Edge-To-Edge Mitral Valve Repair

The Clinical Impact of Mitral Gradient Post Transcatheter Edge-To-Edge Repair: A Systematic Review and Meta-Analysis

BACKGROUND

Mitral transcatheter edge-to-edge repair (TEER) is a minimally invasive therapy for severe mitral regurgitation (MR) in patients with high surgical risk. TEER results in a tissue bridge that decreases mitral valve area, potentially leading to elevated mean gradient. The clinical impact of elevated gradient on outcomes is unclear.

METHODS

This systematic review and meta-analysis was based on a comprehensive search of five databases. We included studies that evaluated post mitral TEER gradient on one of the following outcomes: all-cause mortality, combined endpoints, symptoms, hospitalizations, and mitral valve re-intervention. Meta-analysis was conducted using the random-effects model.

RESULTS

Out of 6458 citations, 17 studies were included (2017-2024) reporting on 7748 patients. There was significant heterogeneity between studies related to the cutoff used to define elevated gradient, etiology of MR, and outcomes. Elevated mitral gradient post TEER (4, 4.5, 5 mmHg) was associated with worse combined endpoint (HR = 1.35, 95% CI 1.07-1.71; I2 64%), but not all-cause mortality (HR = 1.25, 95% CI 0.97-1.59; I2 45%) or risk of hospitalization. For the combined endpoint, this association was mainly significant in patients who had mitral gradient assessed using discharge echocardiogram (HR = 1.39, 95% CI 1.07-1.81; I2 62%) for all patients and for those with degenerative MR.

CONCLUSION

Despite the heterogeneity between studies, the current analysis suggests that patients with elevated mitral gradient post TEER are at risk of worse clinical outcomes, particularly in patients who had mitral gradient assessed using discharge transthoracic echocardiogram.

Iatrogenic atrial septal closure for mitral stenosis after transcatheter edge-to-edge repair: A case report

Interventions for structural heart disease requiring a transvenous and transseptal approach, such as transcatheter edge-to-edge repair (TEER), cause iatrogenic atrial septal defect (IASD) after treatment. Its clinical impact remains uncertain. We present the case of an 84-year-old female patient with heart failure with preserved ejection fraction and stress-induced mitral regurgitation (MR), who was repeatedly hospitalized for acute pulmonary edema. Exercise stress echocardiography reproduced worsening MR. Intervention for MR by TEER was considered, while small mitral valve area was a concern. Mitral stenosis (MS) occurred at the time of TEER, but the clip was eventually implanted to prioritize improvement of regurgitation. IASD was subsequently a concern, as the volume of the left-to-right shunt was increasing, and cardiac output was decreasing. We decided to perform a percutaneous IASD closure, which successfully elevated her blood pressure and allowed her to be discharged home on foot. The coexistence of MS, as in the present case, may increase the negative hemodynamic impact of IASD. Percutaneous IASD closure may be a promising therapeutic strategy to stabilize hemodynamics in carefully selected cases.

Learning objective

Iatrogenic atrial septal defect (IASD) closure is rarely necessary after transcatheter edge-to-edge repair (TEER). Excessively narrowing mitral valve area after TEER can increase the hemodynamic impact of left-to-right shunt flow through IASD. IASD closure may increase cardiac output, but the indication should be carefully determined after confirming the hemodynamic impact, e.g. balloon closure studies.

Long-Term Impact of Small Mitral Valve Orifice Area after Transcatheter Edge-to-Edge Mitral Valve Repair on Clinical Outcome: A Three-Dimensional Echocardiography Study

BACKGROUND

Iatrogenic mitral stenosis is a complication associated with transcatheter edge-to-edge mitral valve repair. Some reports revealed the impact of mean transmitral pressure gradient after procedure on long-term clinical outcomes. However, the association between prognosis and mitral valve orifice area (MVA) after the procedure has been poorly studied. This study aimed to investigate the association between postprocedural small MVA, derived from three-dimensional (3D) transesophageal echocardiography (TEE), and long-term clinical outcomes in 2 cohorts: the degenerative mitral regurgitation (MR) cohort and the functional MR cohort.

METHODS

This retrospective study assessed 279 consecutive patients with 3D TEE data during transcatheter edge-to-edge mitral valve repair between January 2010 and December 2016. Mitral valve orifice area after device implantation was measured by 3D planimetry. The patients with degenerative and functional MR were stratified separately into 2 groups according to postprocedural MVA: normal MVA (MVA > 1.5 cm2) group and small MVA (MVA ≤ 1.5 cm2) group.

RESULTS

Of the 279 patients, 142 (51%) had degenerative MR and 137 (49%) had functional MR. The number of degenerative MR patients with small MVA was 38, whereas 42 patients were in the functional MR cohort. Patients with small MVA had higher rate of all-cause mortality in the degenerative MR group (log-rank test: P = .01) but not in the functional MR group (log-rank test: P = .52). In multivariate analysis small MVA was independently associated with all-cause mortality but not postprocedural transmitral pressure gradient. Neither small MVA nor transmitral pressure gradient was associated with all-cause mortality in patients with functional MR.

CONCLUSION

Small MVA measured by 3D TEE after transcatheter mitral edge-to-edge repair was associated with poor prognosis in patients with degenerative MR.

Prognosis of Elevated Mitral Valve Pressure Gradient After Transcatheter Edge-to-Edge Repair: Systematic Review and Meta-Analysis

Elevation in mitral valve pressure gradient (MVPG) after mitral valve transcatheter edge-to-edge repair (M-TEER) is common, however, evidence on its prognosis is scarce and debatable. Thus, this study aims to investigate the impact of increased MVPG after M-TEER on outcomes. Studies reporting the associations between the elevated MVPG after M-TEER and outcomes were identified in a systematic search of published literatures. Associations were pooled by meta-analysis using a random-effects model. The primary outcome was the composite of all-cause mortality and heart failure (HF) hospitalization. Seven observational studies with 2,730 patients (mean age, 77.7 ± 9.3 years; male, 64.4%; functional mitral regurgitation [MR], 65.2%) were eligible for the present analysis. M-TEER was performed entirely using the MitraClip system (Abbott), followed by 29.7% of patients having increased MVPG. Elevated postprocedural MVPG was not associated with a higher risk of the primary outcome, compared to low MVPG [hazard ratio (HR) = 1.22; 95% confidence interval (CI) 0.95-1.58; p = 0.12; I2 = 53.5%). However, the prognosis of elevated MVPG was observed in degenerative MR patients (HR = 1.37; 95% CI 1.03-1.84; p = 0.03; I2 = 0%), whereas not in functional MR patients. Patients with low MVPG + high residual MR had a higher risk of the primary outcome than those with high MVPG + low residual MR after M-TEER (HR = 1.50; 95% CI 1.10-2.03; p = 0.01; I2 = 13%). In conclusion, elevated MVPG seems to predict adverse outcomes mainly in patients with degenerative MR. Future studies are needed to prove these findings.

The effect of a smaller spacer in the PASCAL Ace on residual mitral valve orifice area

BACKGROUND

Mitral transcatheter edge-to-edge repair (M-TEER) is an established treatment for functional mitral regurgitation (FMR) associated with a risk of creating iatrogenic stenosis.

OBJECTIVES

To investigate the impact of the P10 and its larger spacer compared to the narrower Ace and its smaller spacer on reduction of mitral valve orifice area (MVOA) during M-TEER.

METHODS

Consecutive patients undergoing M-TEER for treatment of severe FMR were screened retrospectively. Patients with a single PASCAL device implantation within the central segments of the MV leaflets, non-complex anatomy, and baseline MVOA ≥ 3.5cm2 were selected. Intraprocedural transesophageal echocardiography was used to compare MVOA reduction with 3D multiplanar reconstruction and direct planimetry. Device selection did not follow a prespecified MVOA threshold.

RESULTS

Seventy-two patients (81.0 years, IQR {74.3-85.0}) were included. In 32 patients, the P10 was implanted (44.4%). MR severity (p = 0.66), MR reduction (p = 0.73), and body surface area (p = 0.56) were comparable. Baseline MVOA tended to be smaller in P10 patients with the larger spacer (5.0 ± 1.1 vs. 5.4 ± 1.3cm2, p = 0.18), however, residual MVOA was larger in these patients (2.7 ± 0.7 vs. 2.3 ± 0.6cm2, p = 0.03). Accordingly, relative MVOA reduction was significantly less in P10 patients (- 45.9 ± 7.6 vs. - 56.3 ± 7.0%, p < 0.01). Indirect annuloplasty was more pronounced in Ace patients whereas mean transmitral gradients were similar.

CONCLUSION

In FMR patients with non-complex anatomy, the larger spacer of the P10 maintains greater MVOA with similar MR reduction. Hence, the use of the PASCAL Ace device in patients with small MVOAs might correlate with a risk of both clinically relevant orifice reduction and even iatrogenic stenosis.

Transcatheter edge-to-edge mitral valve repair with extended clip arms for ventricular functional mitral regurgitation

BACKGROUND

The new sizing options of the MitraClip system (Abbott Vascular, Abbott Park, IL, USA) with extended clip arms were recently developed. Its applicability and effectiveness for ventricular functional mitral regurgitation (VFMR) are yet to be investigated.

METHODS

We retrospectively reviewed consecutive patients with symptomatic VFMR who underwent transcatheter edge-to-edge repair between 2018 and 2022 at the Sakakibara Heart Institute. Pre- and post-procedural mitral valve morphologies were assessed using three-dimensional transesophageal echocardiography.

RESULTS

In a total of 104 VFMR patients, the posterior mitral leaflet length was 12.8 ± 2.8 mm and 92 % was indicative of the extended arm (≥9 mm). Although baseline VFMR was more severe in the patients treated with the extended arms (n = 35, XT group) than the patients treated with the standard arms (n = 69, NT group), the decrease in VFMR was greater in the XT group (delta three-dimensional vena contracta area - 43 ± 33 mm2 vs. -31 ± 22 mm2, p = 0.030) and residual VFMR was similar between the groups, with a significantly greater reduction in the mitral annulus anterior-posterior diameter (-4.9 ± 2.2 mm vs -3.1 ± 2.1 mm, p < 0.001) and mitral annulus area in the XT group. The use of extended arms was independently associated with shorter procedure time (81 ± 26 min vs 108 ± 41 min) after adjustment for device generation and the number of clips (p = 0.017).

CONCLUSIONS

Most VFMR patients had enough leaflet lengths for transcatheter edge-to-edge repair using the MitraClip with the extended arms, which was associated with shorter procedure time and a greater decrease in the mitral annular size.