Quantification of Mitral Regurgitation by Real Time Three-Dimensional Color Doppler Flow Echocardiography Pre- and Post-Percutaneous Mitral Valve Repair

Use of Pleth Variability Index as a Non-invasive, Dynamic Indicator of Left Atrial Pressure Change During MitraClip: Transcatheter Mitral Valve Repair

BACKGROUND

Transcatheter edge-to-edge repair (TEER) with MitraClip is a safe and effective alternative to surgical mitral valve repair/replacement in patients with high operative risk. Pleth Variability Index (PVI) is a non-invasive, dynamic index based on analysis of the respiratory variations in the plethysmographic waveform recorded transcutaneously by the pulse oximeter.

OBJECTIVES

The objective of the study was to evaluate if the hemodynamic effect of improved left-sided output after successful transcatheter mitral valve repair would lead to a significant change in PVI, and if it would correlate with the decrease in left atrial pressure (LAP).

DESIGN

Prospective, observational cohort study (ClinicalTrials.gov NCT03993938).

SETTING

Single academic hospital in Detroit, Michigan (USA), from October 2019 to February 2021.

PARTICIPANTS

The authors included adult patients with severe mitral regurgitation who underwent successful MitraClip placement.

MEASUREMENTS AND MAIN RESULTS

Of 30 patients, all components of the LAP (a wave, v wave, and mean) decreased significantly after successful MitraClip placement (P < .01). The median (IQR) PVI increased from 21 (11-35) to 23 (13-38) after clip placement; however, this change was not statistically significant (P = .275). No significant correlation between change in PVI and change in LAP was observed (P = .235).

CONCLUSIONS

In patients with severe mitral regurgitation, successful MitraClip resulted in a significant reduction in LAP without a significant change in PVI. A larger sample size may provide more insight on the utility of using PVI as an indicator of LAP change in patients with mitral regurgitation.

Quantification of mitral regurgitation after transcatheter edge-to-edge repair: Comparison of echocardiography and patient-specific in silico models

BACKGROUND

Doppler echocardiographic (echo) assessment of residual mitral regurgitation (MR) after transcatheter edge-to-edge repair (TEER) is challenging and often subjective. This study aimed to evaluate the accuracy and feasibility of standardized quantitative echo methods for assessment of MR severity after MitraClip repair by comparing measurements against a reference MR severity obtained from patient-specific in silico models.

METHODS

Post-procedure hemodynamics were simulated under five different MitraClip configurations in previously validated patient-specific in silico models for the treatment of functional MR. The residual regurgitant volume was calculated as in clinical practice using four quantitative virtual echo methods: pulsed Doppler, volumetric, proximal isovelocity surface area (PISA) and vena contracta area (VCA). Multiple permutations were performed for each method. Virtual echo MR results were evaluated against reference MR values directly extracted from the 5 patient-specific in silico models.

RESULTS

The echo methods with the greatest accuracy were the three-dimensional (3D) volumetric method (r = 0.957, bias -0.8 ± 1.2 ml, p = 0.01), the 3D VCA method wherein velocity time integrals were evaluated for each jet assessed (r = 0.919, bias -1.5 ± 1.7 ml, p = 0.03), and the 3D PISA method integrating surface areas throughout systole (r = 0.98, bias -2.0 ± 0.9 ml, p = 0.003). The pulsed Doppler and 2D volumetric methods had technical limitations that may result in a high underestimation or overestimation of the MR severity after TEER. In the case of multiple regurgitant jets, a more accurate MR assessment was obtained when all significant jets were evaluated.

CONCLUSIONS

Clinically, the 3D volumetric, 3D VCA and 3D PISA methods gave the most accurate MR quantification after TEER. Three-dimensional echo technologies harbor the potential of becoming the non-invasive imaging tool of choice for MR quantification after complex transcatheter mitral interventions.

Head to Head Comparison between Different 3-Dimensional Echocardiographic Rendering Tools in the Imaging of Percutaneous Edge-to-Edge Mitral Valve Repair

MitraClip (MC) is the most common percutaneous treatment for severe mitral regurgitation (MR). An accurate two-dimensional and three-dimensional echocardiographic (3DTEE) imaging is mandatory for the optimal procedural result. Recently transillumination 3DTEE rendering (3DTr) has been introduced integrating a virtual light source into the dataset and with the addition of glass effect (3DGl) allows to adjust tissue transparency improving depth perception and anatomical structure delineation in comparison with the standard 3DTEE (3DSt). The aim of this retrospective study in 30 patients undergoing MC, was to compare 3DSt, 3DTr, and 3DGl in mitral valve (MV) evaluation and procedural result assessment. 3DTEE acquisitions obtained before and after MC were processed with 3DSt, 3DTr, and 3DGl rendering. Each reconstruction was scored for quality and for ability to recognize MV anatomy, MR origin, clip position, dimension and grasping. Imaging quality was judged good or optimal in 52%, 76%, and 96% in 3DSt, 3DTr, and 3DGl reconstructions respectively. In 26/30 patients a diagnostic incremental value was found with 3DTr vs. 3DSt and in 15/26 with 3DGl vs. 3DTr and 3DSt. Only 3DGl with perpendicular cropping of the clip allowed to visualize and measure the grasped portion of each mitral leaflets. 3DTEE imaging during MC may be improved by 3DTr and 3DGl providing a better evaluation of MV, of leaflet grasping and of residual MR jets after MC.

Acute Mitral Regurgitation and Transcatheter Mitral Valve Repair in an Emergency Case: Focus on the Mechanical Disorder of Mitral Valve Complex

Acute mitral regurgitation is an uncommon, challenging disease that requires emergent care and proper management. To evaluate its etiology, echocardiography is essential. However, echocardiography findings in these patients are often different from that of chronic mitral regurgitation owing to the acute elevation of left atrial and pulmonary artery pressure derived from the small left ventricle and atrium with low compliance. Although surgical correction is usually required owing to the hemodynamic instability, many patients are considered to be at high surgical risk. Transcatheter mitral valve repair using MitraClip (Abbott Vascular, Santa Clara, CA) may be a solution as a bail-out therapy.

Combined flow-based imaging assessment of optimal cardiac resynchronization therapy pacing vector: a case report

Background

There are still many pendent issues about the effective evaluation of cardiac resynchronization therapy impact on functional mitral regurgitation. In order to reduce the intrinsic difficulties of quantification of functional mitral regurgitation itself, an automatic quantification of real-time three-dimensional full-volume color Doppler transthoracic echocardiography was proposed as a new, rapid, and accurate method for the assessment of functional mitral regurgitation severity. Recent studies suggested that images of left ventricle flow by echo-particle imaging velocimetry could be a useful marker of synchrony. Echo-particle imaging velocimetry has shown that regional anomalies of synchrony/synergy of the left ventricle are related to the alteration, reduction, or suppression of the physiological intracavitary pressure gradients.

Case summary

We describe a case in which the two technologies are used in combination during acute echocardiographic optimization of left pacing vector in a 63-year-old man, Caucasian, who showed worsening heart failure symptoms a few days after an implant, and the effect of the device’s optimization at 6-month follow-up.

Discussion

The degree of realignment of hemodynamic forces, with quantitative analysis of the orientation of blood flow momentum (φ), can represent improvement of fluid dynamics synchrony of the left ventricle, and explain, with a new deterministic parameter, the effects of cardiac resynchronization therapy on functional mitral regurgitation. Real-time three-dimensional color flow Doppler quantification is feasible and accurate for measurement of mitral inflow, left ventricular outflow stroke volumes, and functional mitral regurgitation severity.

Conclusion

This clinical case offers an innovative and accurate approach for acute echocardiographic optimization of left pacing vector. It shows clinical utility of combined three-dimensional full-volume color Doppler transthoracic echocardiography/echo-particle imaging velocimetry assessment to increase response to cardiac resynchronization therapy, in terms of reduction of functional mitral regurgitation, improving fluid dynamics synchrony of the left ventricle.

Electronic supplementary material

The online version of this article (10.1186/s13256-019-2048-1) contains supplementary material, which is available to authorized users.

Percutaneous Mitral Valve Repair: Multi-Modality Cardiac Imaging for Patient Selection and Intra-Procedural Guidance

Percutaneous mitral valve repair is an important procedure for patients at high risk of surgical mitral valve repair. Multi-modality Cardiac Imaging plays a key role in these procedures. MitraClip is the first and most utilized percutaneous mitral repair device and experience is has grown to treat not only typical but atypical and complex lesions. Cardioband is an emerging percutaneous annuloplasty system with promising early results. This review will focus on the comprehensive multi-modality cardiac imaging for patient selection and intra-procedural guidance of the MitraClip and Cardioband systems.

Predicting the Number of Edge-to-Edge Repair Devices Needed to Adequately Treat Mitral Regurgitation Using Transesophageal Echocardiography

OBJECTIVES

Increased utilization and highly variable costs seen with percutaneous mitral valve edge-to-edge repair have made cost cutting strategies of significant interest. Mitral regurgitation etiology, the number of devices used, and experience all play a role in variability. Currently a paucity of data exists in predicting the number of devices. Any associations found between echocardiography parameters and the number of devices used could help with pre-procedure planning and device placement strategies, ultimately reducing variability and costs.

DESIGN

In this retrospective analysis the authors evaluated the ability of established and novel three-dimensional (3D) mitral regurgitation measures, namely 3D vena contracta area and vena contracta length, to predict the number of devices used. Other factors evaluated include mitral valve area and ejection fraction. All factors were compared using the Mann Whitney rank sum tests.

PARTICIPANTS

Patients over 18 years old undergoing the MitraClip procedure.

SETTING

Catheterization Laboratory.

MAIN RESULTS

No relationship was found between 3D parameters and the number of devices used, but mitral valve area was strongly associated with the use of multiple devices.

CONCLUSION

The 3D parameters of interest were not associated with the use of multiple devices, but the mitral valve area was associated. Further studies are needed to determine if this relationship is predictive.

Predictors of outcome in heart failure patients with severe functional mitral regurgitation undergoing MitraClip treatment

BACKGROUND

The prognostic predictors of outcome in patients with functional mitral regurgitation (FMR) undergoing MitraClip implantation (MCi) are still poorly known. The aim of our study is to identify the baseline predictors of outcome in FMR patients candidate to MCi.

METHODS

All patients with symptomatic moderate-to-severe or severe FMR undergoing MCi at our institution were consecutively and prospectively enrolled. Baseline clinical and instrumental data were collected. Primary endpoint was the occurrence of cardiac death; secondary endpoints were all-cause death and the composite of cardiac death or rehospitalization for heart failure.

RESULTS

74 patients (mean 71.6 ± 8.3 years) were enrolled. During follow-up (median 416.0 days), the primary endpoint occurred in 15 (20.3%), all-cause death in 26 (35.1%) and the composite endpoint in 25 (33.8%). At multivariate analysis, the left atrial volume index (LAVi; HR:1.02; P = 0.048) and the low peak oxygen uptake (peak VO₂; HR:0.73; P = 0.018) increased the risk of cardiac death at follow-up; atrial fibrillation (AF; HR:2.69; P = 0.027) was independently associated to all-cause death and the low level of peak VO₂ was an independent predictor of overall mortality (HR:0.70; P < 0.001) as well as of the composite endpoint (HR:0.73; P < 0.001). The ROC analysis identified a peak VO₂ cut-off of 10.0 mL/kg/min as the best predictor for the three study endpoints; the best LAVi cut-off for cardiac death was 67 mL/m². Kaplan-Meier analysis for the individual and combined outcome predictors confirmed their significant stratification ability during follow-up.

CONCLUSIONS

Peak VO₂, along with LAVi and AF, identify FMR patients with the worst prognosis after MCi.

Comprehensive Assessment of Mitral Valve Geometry and Cardiac Remodeling With 3-Dimensional Echocardiography After Percutaneous Mitral Valve Repair

MitraClip is a validated treatment for significant mitral regurgitation (MR) in high-risk patients. Aims of the study were to evaluate immediate changes in mitral valve (MV) geometry induced by MitraClip and correlations between baseline geometry and cardiac remodeling. Eighty patients who underwent MitraClip for primary (48%) or secondary (52%) MR were enrolled. Intraoperative transesophageal echocardiographic 3D images were acquired immediately before and after the procedure for MV annulus (MVA) morphology analysis. Transthoracic 3D echocardiography was performed preoperatively and at 6 months follow-up (6MFU). Patients were classified on the basis of MR reduction (ΔMR) at 6MFU as Optimal (ΔMR ≥ 2) or Suboptimal (ΔMR < 2). An optimal result was reached in 60 (75%) patients, whereas 20 subjects showed a ΔMR< 2 at 6MFU. The Optimal showed significantly smaller baseline MVA (antero-posterior diameter 4.05 ± 0.59 vs 4.43 ± 0.68 cm; anterolateral-posteromedial diameter 4.38 ± 0.56 vs 4.70 ± 0.73 cm; MVA circumference 14.1 ± 1.7 vs 15.1 ± 2.3 cm; and 3D area 14.8 ± 3.9 vs 17.4 ± 5.3 cm²), lower sphericity index and nonplanar angle compared with Suboptimal. A value of antero-posterior diameter ≥4.44cm was identified (receiver-operating characteristic curve) as a possible cut-off for preoperative identification of Suboptimal patients. Postoperatively, MitraClip induced reduction of MVA flattening (nonplanar angle), sphericity index, and size (as expressed by antero-posterior diameter, MVA circumference and area). At 6MFU, the Optimal showed significant decrease in left ventricular volumes and pulmonary artery systolic pressure. In conclusion, MitraClip induces remarkable changes in MVA geometry and favorable left ventricular remodeling is detected in patients with optimal mid-term outcome; a preprocedural antero-posterior diameter <4.44cm seems to be a potential predictor of mid-term optimal result.

Transcatheter Mitral Valve Repair Using the Edge-to-Edge Clip

Percutaneous intervention for mitral valve (MV) disease has been established as an alternative to open surgical MV repair in patients with prohibitive surgical risk. Multiple percutaneous approaches have been described and are in various stages of development. Edge-to-edge leaflet plication with the MitraClip (Abbott, Menlo Park, CA) is currently the only Food and Drug Administration-approved device specifically for primary or degenerative lesions. Use of the edge-to-edge clip for secondary mitral regurgitation is currently under investigation and may result in expanded indications. Echocardiography has significantly increased our understanding of the anatomy of the MV and provided us with the ability to classify and quantify the associated mitral regurgitation. For percutaneous interventions of the MV, transesophageal echocardiography imaging is used for patient screening, intraprocedural guidance, and confirmation of the result. Optimal outcomes require the echocardiographer and the proceduralist to have a thorough understanding of intra-atrial septal and MV anatomy, as well as an appreciation for the key points and potential pitfalls of each of the procedural steps. With increasing experience, more complex valvular pathology can be successfully percutaneously treated. In addition to two-dimensional echocardiography, advances in three-dimensional echocardiography and fusion imaging will continue to support the refinement of current technologies, the expansion of clinical applications, and the development of novel devices.