Changes in dynamic mitral valve geometry during percutaneous edge-edge mitral valve repair with the MitraClip system

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.

Short-Term Effects of Different Transcatheter Edge-to-Edge Devices on Mitral Valve Geometry

Background Short-term effects on mitral valve (MV) anatomy after transcatheter edge-to-edge repair using the PASCAL system remain unknown. Precise quantification might allow for an advanced analysis of predictors for mean transmitral gradients. Methods and Results Consecutive patients undergoing transcatheter edge-to-edge repair for secondary mitral regurgitation using PASCAL or MitraClip systems were included. Quantification of short-term MV changes throughout the cardiac cycle was performed using peri-interventional 3-dimensional MV images. Predictors for mean transmitral gradients were identified in univariable and multivariable regression analysis. Long-term results were described during 1-year follow-up. A total of 100 patients undergoing transcatheter edge-to-edge repair using PASCAL (n=50) or MitraClip systems (n=50) were included. Significant reductions of anterior-posterior diameter, annular circumference, and area throughout the cardiac cycle were found in both cohorts (P<0.05 for all). Anatomic MV orifice area remained larger in the PASCAL cohort in mid (2.8±1.0 versus 2.4±0.9 cm2; P=0.049) and late diastole (2.7±1.1 versus 2.2±0.8 cm2; P=0.036) compared with the MitraClip cohort. Besides a device-specific profile of independent predictor of mean transmitral gradients, reduction of middiastolic anatomic MV orifice area was identified as an independent predictor in both the PASCAL (β=-0.410; P=0.001) and MitraClip cohorts (β=-0.318; P=0.028). At follow-up, reduction of mitral regurgitation grade to mild or less was more durable in the PASCAL cohort (90% versus 72%; P=0.035). Conclusions PASCAL and MitraClip showed comparable short-term effects on MV geometry. However, PASCAL might better preserve MV function and demonstrated more durable mitral regurgitation reduction during follow-up. Identification of independent predictors for mean transmitral gradients might potentially help to guide device selection in the future.

Transcatheter edge-to-edge-repair of functional mitral regurgitation induces significant remodeling of mitral annular geometry

Background

Mitral annular alterations in the context of heart failure often lead to severe functional mitral regurgitation (FMR), which should be treated with transcatheter edge-to-edge repair (M-TEER) according to current guidelines. M-TEER's effects on mitral valve (MV) annular remodeling have not been well elucidated.

Methods

141 consecutive patients undergoing M-TEER for treatment of FMR were included in this investigation. Comprehensive intraprocedural transesophageal echocardiography was used to assess the acute effects of M-TEER on annular geometry.

Results

Average patient age was 76.2 ± 9.6 years and 46.1% were female patients. LV ejection fraction was reduced (37.0% ± 13.7%) and all patients had mitral regurgitation (MR) grade ≥III. M-TEER achieved optimal MR reduction (MR ≤ I) in 78.6% of patients. Mitral annular anterior-posterior diameters (A-Pd) were reduced by -6.2% ± 9.5% on average, whereas anterolateral-posteromedial diameters increased (3.7% ± 8.9%). Overall, a reduction in MV annular areas was observed (2D: -1.8% ± 13.1%; 3D: -2.7% ± 13.7%), which strongly correlated with A-Pd reduction (2D: r = 0.6, p < 0.01; 3D: r = 0.65, p < 0.01). Patients that achieved A-Pd reduction above the median (≥6.3%) showed significantly lower rates of the composite endpoint rehospitalization for heart failure or all-cause mortality than those with less A-Pd reduction (9.9% vs. 28.6%, p = 0.037, log-rank p = 0.039). Furthermore, patients reaching the composite endpoint had an increase in annular area (2D: 3.0% ± 15.4%; 3D: 1.9% ± 15.3%), whereas those not reaching the endpoint showed a decrease (2D: -2.7% ± 12.4%; 3D: -3.6% ± 13.3%), although residual MR after M-TEER was similar between these groups (p = 0.57). In multivariate Cox regression adjusted for baseline MR, A-Pd reduction ≥6.3% remained a significant predictor of the combined endpoint (OR: 0.35, 95% CI: 0.14-0.85, p = 0.02).

Conclusion

Our findings indicate that effects of M-TEER in FMR are not limited to MR reduction, but also have significant impact on annular geometry. Moreover, A-Pd reduction, which mediates annular remodeling, has a significant impact on clinical outcome independent of residual MR.

Anatomical Changes after Transcatheter Edge-to-Edge Repair in Functional MR According to MitraClip Generation

BACKGROUND

The use of mitral transcatheter edge-to-edge repair (TEER) is rapidly increasing. Anatomical changes have been described after TEER with the MitraClip system in patients with functional mitral regurgitation (MR), although no study has yet evaluated such anatomical impacts in patients treated with the G4 MitraClip generation.

METHODS

This research constituted a prospective, single-center, observational study including consecutive patients with functional MR. Mitral three-dimensional images were obtained transesophageally with echocardiography before and immediately after TEER. Patients receiving the late-generation (G4) system were compared to those receiving early-generation systems.

RESULTS

A total of 116 functional MR patients were evaluated, and 40 (34.5%) and 76 (65.5%) received a late-generation (G4) or early-generation device system, respectively. The baseline clinical and echocardiographic features were well-balanced between the groups. Overall, there was a significant reduction in mitral annular size after the intervention, and greater reductions in the anteroposterior diameter (4 mm vs. 3.54 mm, p = 0.03), annular perimeter (11.07 mm vs. 5.29 mm for 3D-perimeter, p = 0.001), and annular area (1.29 cm2 vs. 1.03 cm2, p = 0.002) were found for patients receiving the late G4 device generation compared to the early-generation systems.

CONCLUSIONS

In patients with functional MR, we observed significant changes in mitral valve anatomy with a reduction in anteroposterior diameter, valve perimeter, and area. In our cohort, the extent of those changes was greater with the use of the new-generation G4 MitraClip system compared to prior device generations.

Surgical Management for Systolic Anterior Motion (SAM) of the Mitral Valve in Obstructive Hypertrophic Myopathy

In patients with obstructive hypertrophic cardiomyopathy, left ventricular outflow tract (LVOT) obstruction can be created by the hypertrophic interventricular septum (IVS) as well as systolic anterior motion (SAM) of the anterior mitral leaflet (AML). Sufficient septal myectomy is a fundamental surgical technique to treat LVOT obstruction, however, direct surgical management for SAM is another key aspect. Besides the hypertrophic IVS, mitral valve, subvalvular apparatus, and papillary muscle may play important role for SAM and several surgical techniques have been proposed to treat SAM in literature. In this review, each surgical technique is classified by the anatomical structure on which the surgical procedure is applied. The AML is the main surgical site and is applied with plication (vertical plication, resection–plication–release strategy), extension (the AML extension, transverse incision of the AML), sutured (edge-to-edge repair, anterior leaflet retention plasty), or traction (floating stitch, papillary muscle-to-anterior annulus stitches, paradoxical stitches, transposition of a directed chorda tendinea to the AML). Height reduction of the posterior mitral valve leaflet and papillary muscle reorientation are other techniques. We should understand theoretical aspects of each technique on correction of anatomical and functional abnormalities of the structure and should apply them under proper indication.

The impact of transcatheter edge-to-edge repair on mitral valve annular geometry

PURPOSE OF REVIEW

Mitral valve transcatheter edge-to-edge repair (TEER) is becoming increasingly common to treat severe mitral regurgitation. However, the lack of concomitant annuloplasty raises concerns regarding its durability. As a result, there is an emerging body of literature evaluating the impacts of TEER on mitral annular geometry. In this review, we summarize the most recent literature evaluating the impacts of TEER on annular geometry in the acute, intermediate and long-term. We also review the relationship between changes in annular geometry and clinical endpoints.

RECENT FINDINGS

Current evidence suggests that TEER acutely induces favourable changes in mitral annular size and shape, which may persist for at least up to 1 year. Few studies suggest that TEER-induced annular remodelling is associated with positive clinical outcomes.

SUMMARY

The current body of literature is sparse and limited to primarily small case series. Data from the surgical literature suggest that ringless edge-to-edge repair is associated with eventual failure. Unfortunately, few studies evaluate TEER-induced annular changes beyond the acute postprocedural phase. Future research needs to focus on and evaluate the significance of TEER-induced changes in annular dimensions in the long-term.

Three-dimensional echocardiography for predicting mitral stenosis after MitraClip for functional mitral regurgitation

BACKGROUND

Postprocedural mitral stenosis (MS), or increased transmitral mean pressure gradient (TMPG), is one of the limitations of transcatheter edge-to-edge mitral valve repair using MitraClip (Abbott Vascular Inc., Santa Clara, USA); however, the usefulness of three-dimensional transesophageal echocardiography (3D-TEE) for predicting postprocedural MS in functional mitral regurgitation (MR) has not been fully elucidated.

METHODS

Eighty-two consecutive functional MR patients who underwent transcatheter mitral valve repair using MitraClip were retrospectively studied. Postprocedural MS was defined as TMPG ≥ 5 mmHg by echocardiography.

RESULTS

Ten patients had postprocedural MS, and 3D-TEE showed that patients with postprocedural MS had smaller preprocedural mitral valve orifice area (MVOA), anteroposterior and mediolateral diameter, leaflet area, and annulus area. Receiver operating characteristic analysis showed that leaflet area (area under the curve (AUC) 0.829), annulus area (AUC 0.813), anteroposterior diameter (AUC 0.797) and mediolateral diameter (AUC 0.803) evaluated using 3D-TEE were predictors of postprocedural MS, and their predictive abilities were higher than those of preprocedural MVOA (AUC 0.756) and preprocedural TMPG (AUC 0.716). Adding leaflet area to TMPG and MVOA resulted in higher C-statistics for predicting postprocedural MS (from 0.716 to 0.845 and from 0.756 to 0.853, respectively).

CONCLUSIONS

In functional MR patients treated with MitraClip, leaflet area and annulus area evaluated using 3D-TEE had high predictive values for postprocedural MS, and their predictive abilities were higher than those of preprocedural TMPG or MVOA.

Acute changes in mitral valve geometry after percutaneous valve repair with MitraClip XTR by three-dimensional echocardiography

BACKGROUND

Mitral valve (MV) repair with MitraClip system is a safe treatment option for high-risk patients with significant mitral regurgitation (MR). We aimed to characterize, by three-dimensional echocardiography (3D-E), changes occurring in MV after implantation of third generation MitraClip XT_R device, with specific reference to the underlying MR mechanism (functional vs degenerative, FMR vs DMR).

METHODS

We prospectively enrolled 59 patients, who underwent intra-procedural 3D-E before and after device deployment. Three-D datasets were analyzed off-line, using a dedicated semiautomatic software, to obtain parametric quantification of mitral anatomy.

RESULTS

Post-procedural MR of mild or lesser degree was achieved in 40 patients (68%), with no differences between FMR and DMR (p 0.9). After MitraClip XT_R implantation, the FMR group experienced an immediate annular resizing, with reduction of antero-posterior diameter (p 0.024) and sphericity index (p 0.017), next to a recovery of physiological saddle-shape, defined by lower non-planar angle (p ≤0.001) and higher annulus height to commissural width ratio (p ≤0.001). On the opposite, the DMR group revealed a significant decrease of maximum annular velocity (p 0.027), addressing a mechanic effect of the device deployment. Finally, baseline anterior mitral leaflet angle was found as an independent predictor of acute procedural result (OR 6.7, [CI 1.01-44.33], p 0.049).

CONCLUSIONS

MitraClip XT_R implantation acts in restoring the original mitral geometry, with distinctive effects according to MR mechanism. Three-D parametric quantification of MV sheds new light on changes occurring in the valvular apparatus, and helps identifying possible new predictors of acute procedural success.

Relations of Augmented Systolic Annular Expansion and Leaflet/Papillary Muscle Dynamics in Late-Systolic Mitral Valve Prolapse Evaluated by Echocardiography with a Speckle Tracking Analysis

The mechanism of systolic annular expansion in mitral valve prolapse (MVP) is not clarified. Since annular expansion is systolic outward shift of MV leaflet/chorda tissue complex at superior and outer ends, annular expansion could be related to inward (superior) shift of the complex at another inferior and inner end of the papillary muscle (PM) tip and/or systolic lengthening of the tissue complex, especially MV leaflets.MV annulus systolic expansion, PMs' systolic superior shift, and MV leaflets' systolic lengthening were evaluated by echocardiography with a speckle tracking analysis in 25 normal subjects, 25 subjects with holo-systolic MVP and 20 subjects with late-systolic MVP.PMs' superior shift, MV leaflets' lengthening, MV annular area at the onset of systole and subsequent MV annulus expansion were significantly greater in late-systolic MVP than in holo-systolic MVP (4.6 ± 1.6 versus 1.5 ± 0.7 mm/m², 2.5 ± 1.4 versus 0.6 ± 2.0 mm/m², 6.8 ± 2.5 versus 5.7 ± 1.0 cm²/m² and 1.6 ± 0.8 versus 0.1 ± 0.5 cm²/m², P < 0.001, respectively). Multivariate analysis identified MV leaflets' lengthening and PMs' superior shift as independent factors associated with MV annular expansion.Conclusions: These results suggest that systolic MV annular expansion in MVP is related to abnormal MV leaflets' lengthening and PMs' superior shift.

Functional mitral regurgitation: structural modifications with percutaneous valve repair with MitraClip

Background

Mitral regurgitation (MR) is one of the most prevalent valvular diseases in our society. Transcatheter mitral valve repair (TMVR) with the MitraClip^® system is increasingly used for treating this condition. The aim of our study is to analyse morphological mitral valve changes related to the procedure and its correlation with the degree of regurgitation at mid-term follow-up and with the combined endpoint of heart failure and all-cause mortality.

Methods

A single-centre, prospective and observational study including consecutive patients admitted between October 2015 and October 2019 for TMVR was designed. The mitral valve annulus (MVA) was analyzed using the three-dimensional MVQ QLAB mitral valve quantification software (Philips; Amsterdam, The Netherlands). Clinical data was collected retrospectively.

Results

Eighty-two MitraClip^® were implanted. Control echocardiograms showed a significant decrease in the three measures: annular diameters, perimeter and area. Patients with functional MR had greater left ventricular and mitral annular dimensions and experienced greater reductions in anteroposterior diameter and mitral valve area compared with organic MR patients. The anteroposterior diameter reduction (OR 0.90; 95% CI: 0.82–0.99), as well as posterior leaflet grasping (OR 0.94; 95% CI: 0.89–0.99) were associated with the probability of significant MR recurrence. Posterior leaflet grasping and left ventricle ejection fraction were associated with the combined endpoint of heart failure and any cause death.

Conclusions

MitraClip^® implantation results in secondary changes in the mitral annular morphology. The magnitude of these morphological changes varies depending on the etiology of the mitral valve regurgitation. Posterior leaflet grasping and anteroposterior diameter reduction after clip are factors associated with relevant clinical and echocardiographic endpoints.

Decreased Mortality with Beta-Blocker Therapy in HFpEF Patients Associated with Atrial Fibrillation

BACKGROUND

There are no proven effective treatments that can reduce the mortality in heart failure with preserved ejection fraction (HFpEF), probably due to its heterogeneous nature which will weaken the effect of therapy in clinical studies. We evaluated the effect of beta-blocker treatment in HFpEF patients associated with atrial fibrillation (AF), which is a homogeneous syndrome and has seldom been discussed.

METHODS

This retrospective cohort study screened 955 patients diagnosed with AF and HFpEF. Patients with a range of underlying heart diseases or severe comorbidities were excluded; 191 patients were included and classified as with or without beta-blocker treatment at baseline. The primary outcome was all-cause mortality and rehospitalization due to heart failure. Kaplan-Meier curves and multivariable Cox proportional-hazards models were used to evaluate the differences in outcomes.

RESULTS

The mean follow-up was 49 months. After adjustment for multiple clinical risk factors and biomarkers for prognosis in heart failure, patients with beta-blocker treatment were associated with significantly lower all-cause mortality (hazard ratio (HR) = 0.405, 95% confidence interval (CI) = 0.233-0.701, p=0.001) compared with those without beta-blocker treatment. However, the risk of rehospitalization due to heart failure was increased in the beta-blocker treatment group (HR = 1.740, 95% CI = 1.085-2.789, p=0.022). There was no significant difference in all-cause rehospitalization between the two groups (HR = 1.137, 95% CI = 0.803-1.610, p=0.470).

CONCLUSIONS

In HFpEF patients associated with AF, beta-blocker treatment is associated with significantly lower all-cause mortality, but it increased the risk of rehospitalization due to heart failure.

A Comprehensive Engineering Analysis of Left Heart Dynamics After MitraClip in a Functional Mitral Regurgitation Patient

Percutaneous edge-to-edge mitral valve (MV) repair using MitraClip has been recently established as a treatment option for patients with heart failure and functional mitral regurgitation (MR), which significantly expands the number of patients that can be treated with this device. This study aimed to quantify the morphologic, hemodynamic and structural changes, and evaluate the biomechanical interaction between the MitraClip and the left heart (LH) complex of a heart failure patient with functional MR using a fluid-structure interaction (FSI) modeling framework. MitraClip implantation using lateral, central and double clip positions, as well as combined annuloplasty procedures were simulated in a patient-specific LH model that integrates detailed anatomic structures, incorporates age- and gender-matched non-linear elastic material properties, and accounts for mitral chordae tethering. Our results showed that antero-posterior distance, mitral annulus spherecity index, anatomic regurgitant orifice area, and anatomic opening orifice area decreased by up to 28, 39, 52, and 71%, respectively, when compared to the pre-clip model. MitraClip implantation immediately decreased the MR severity and improved the hemodynamic profile, but imposed a non-physiologic configuration and loading on the mitral apparatus, with anterior and posterior leaflet stress significantly increasing up to 210 and 145% during diastole, respectively. For this patient case, while implanting a combined central clip and ring resulted in the highest reduction in the regurgitant volume (46%), this configuration also led to mitral stenosis. Patient-specific computer simulations as used here can be a powerful tool to examine the complex device-host biomechanical interaction, and may be useful to guide device positioning for potential favorable clinical outcomes.