Percutaneous Mitral Valve Repair Preserves Right Ventricular Function

Changes in Right Ventricular-to-Pulmonary Artery Coupling After Transcatheter Edge-to-Edge Repair in Secondary Mitral Regurgitation

BACKGROUND

Preprocedural right ventricular-to-pulmonary artery (RV-PA) coupling is a major predictor of outcome in patients with secondary mitral regurgitation (SMR) undergoing transcatheter edge-to-edge mitral valve repair (M-TEER). However, clinical significance of changes in RV-PA coupling after M-TEER is unknown.

OBJECTIVES

The aim of this study was to evaluate changes in RV-PA coupling after M-TEER, their prognostic value, and predictors of improvement.

METHODS

This was a retrospective observational study, including patients undergoing successful M-TEER (residual mitral regurgitation ≤2+ at discharge) for SMR at 13 European centers and with complete echocardiographic data at baseline and short-term follow-up (30-180 days). RV-PA coupling was assessed with the use of echocardiography as the ratio of tricuspid annular plane systolic excursion to pulmonary artery systolic pressure (TAPSE/PASP). All-cause death was assessed at the longest available follow-up starting from the time of the echocardiographic reassessment.

RESULTS

Among 501 patients included, 331 (66%) improved their TAPSE/PASP after M-TEER (responders) at short-term follow-up (median: 89 days; IQR: 43-159 days), whereas 170 (34%) did not (nonresponders). Lack of previous cardiac surgery, low postprocedural mitral mean gradient, low baseline TAPSE, high baseline PASP, and baseline tricuspid regurgitation were independently associated with TAPSE/PASP improvement after M-TEER. Compared with nonresponders, responders had lower New York Heart Association functional class and less heart failure hospitalizations at short-term follow-up. Improvement in TAPSE/PASP was independently associated with reduced risk of mortality at long-term follow-up (584 days; IQR: 191-1,243 days) (HR: 0.65 [95% CI: 0.42-0.92]; P = 0.017).

CONCLUSIONS

In patients with SMR, improvement in TAPSE/PASP after successful M-TEER is predicted by baseline clinical and echocardiographic variables and postprocedural mitral gradient, and is associated with a better outcome.

Right Ventricular Function Improves Early After Percutaneous Mitral Valve Repair in Patients Suffering From Severe Mitral Regurgitation

Background

Percutaneous mitral valve edge-to-edge procedure (PMVR) using the MitraClip^® system (Abbot Vascular, CA) is an established therapy for severe mitral regurgitation (MR) in patients judged inoperable or at high surgical risk. Besides determining exercise capacity, right ventricular (RV) function has prognostic value in heart failure and after cardiac surgery. We therefore investigated the impact of PMVR on RV function in patients with severe MR.

Methods and Results

Sixty-three patients undergoing PMVR at our department were prospectively enrolled. Transthoracic echocardiography was performed before, early (2–12d) after PMVR and after 3 months, including advanced echocardiographic analyses such as 3D imaging and strain analyses. At baseline, all patients presented with advanced heart failure symptoms. Etiology of MR was more often secondary and, if present, left ventricular (LV) dysfunction was predominantly caused by ischemic cardiomyopathy. PMVR substantially reduced MR to a grade ≤ 2 in most patients. Echocardiographic assessment revealed a largely unchanged LV systolic function early after PMVR, while in contrast RV function substantially improved after PMVR [3D RV EF (%): pre 33.7% [27.4; 39.6], post 40.0% [34.5; 46.0] (p < 0.01 vs. pre), 3 months 42.8% [38.3; 48.1] (p < 0.01 vs. pre); 2D RV GLS (%): pre −12.9% [−14.5; −10.5], post −16.0% [−17.9; −12.6] (p < 0.01 vs. pre), 3 months −17.2% [−21.7; −14.9] (p < 0.01 vs. pre)]. Factors that attenuated RV improvement were larger ventricular volumes, lower LV function, secondary MR, and a higher STS score (all p < 0.05).

Conclusion

By using advanced echocardiographic parameters, we discovered an early improvement of RV function after PMVR that is preserved for months, independent from changes in LV function. Improvement of RV function was less pronounced in patients presenting with an advanced stage of heart failure and a higher burden of comorbidities reflected by the STS score.

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

BACKGROUND

Transcatheter edge-to-edge mitral valve repair may lead to a reduction in mitral valve area (MVA) and elevated mean transmitral gradient (TMG). The objectives of this study were to assess the value of baseline MVA by different imaging methods and to explore the associations between MVA indexed to body surface area or left ventricular forward stroke volume and postprocedural TMG.

METHODS

Preprocedural echocardiographic images from 76 consecutive patients were retrospectively reviewed. MVA planimetry from two-dimensional (2D) transthoracic echocardiography (MVA_TTE), 2D transesophageal echocardiography in the transgastric view (MVA_{2D TEE}), and three-dimensional (3D) transesophageal echocardiography (MVA_3D) were measured. Postprocedural TMGs were assessed at 1 to 3 months and all-cause mortality at 1 year.

RESULTS

Postprocedural mean TMG > 5 mm Hg was associated with a 3.42-fold (95% confidence interval [CI], 1.08-10.87; P = .04) increased risk for 1-year all-cause mortality. Patients with postprocedural TMG > 5 mm Hg (25% [19 of 76]) had significantly smaller preprocedural MVA_3D (3.9 ± 0.8 vs 5.2 ± 1.3 cm², P < .01) and MVA_TTE (4.9 ± 1.1 vs 5.8 ± 1.5 cm², P = .01) compared with patients without elevated TMG. No significant difference was found for MVA_{2D TEE} (P = .20). The best threshold values for MVA_3D and MVA_TTE to be associated with postprocedural TMG > 5 mm Hg were, respectively, 3.9 cm² (area under the curve [AUC] = 0.80; 95% CI, 0.66-0.94; sensitivity 62%, specificity 87%) and 4.6 cm² (AUC = 0.68; 95% CI, 0.54-0.82; sensitivity 53%, specificity 80%). MVA_3D indexed to body surface area and to stroke volume showed overall the best associations with postprocedural mean TMG > 5 mm Hg, with optimal thresholds, respectively, of 2.5 cm²/m² (AUC = 0.88; 95% CI, 0.77-0.98; sensitivity 92%, specificity 74%) and 95 cm²/L (AUC = 0.87; 95% CI, 0.77-0.97; sensitivity 85%, specificity 82%).

CONCLUSIONS

Elevated TMG following transcatheter edge-to-edge mitral valve repair was associated with increased mortality. The present results indicate that MVA_3D, MVA_3D indexed to body surface area, and MVA_3D indexed to stroke volume may be considered potential predictors of postprocedural TMG > 5 mm Hg and could help optimize patient selection, while the use of 2D methods for valve area were poorly associated with TMG.

The Right Ventricle in the Trans-Catheter Era: A Perspective for Planning Interventions

Dysfunction of the right ventricle (RV) is common in patients with advanced left-sided valve disease and the significant impact of RV dysfunction on both short and long-term outcome is well established. However, considerations of RV function are largely absent in current management guidelines for valve disease and cardiac procedural risk models. As the indications and use of trans-catheter therapies rapidly expand for patients with acquired valvular disease, it is critical for clinicians to understand and consider RV function when making decisions for these patients. This review summarizes contemporary data on the assessment of RV function, the prognostic importance of baseline RV dysfunction on surgical and transcatheter procedures for acquired left-sided valvular disease, and the relative impact of these interventions on RV function. Baseline RV dysfunction is a powerful predictor of poor short- and long-term outcome after any therapeutic intervention for acquired left-sided cardiac valve disease. Surgical intervention for aortic or mitral valve disease is associated with a significant but transient decline in RV function, whereas trans-catheter procedures generally do not appear to have detrimental effects on either longitudinal or global RV function. Guidelines for therapy in patents with acquired left-sided valvular disease should account for RV dysfunction. Whereas surgical intervention in these patients leads to a predictable decline in RV function, trans-catheter therapies largely do not appear to have this effect. Further study is needed to determine the impact of these findings on current practice.

Percutaneous Edge-to-Edge Mitral Valve Repair: Beyond the Left Heart

Right ventricular (RV) dysfunction and tricuspid regurgitation (TR) are known to be associated with adverse outcomes in patients undergoing percutaneous mitral valve repair (PMVR). Although the effect of PMVR on left ventricular function is well known, data on the response of the right ventricle to PMVR, and its impact on prognosis, are limited. In this review the authors summarize available data regarding the prognostic role of RV function and TR in PMVR recipients and the possible effects of PMVR on the right heart. Preprocedural tricuspid annular plane systolic excursion < 15 mm, tricuspid annular tissue Doppler S' velocity < 9.5 cm/sec, and moderate or severe TR are reported as predictors of adverse outcome after PMVR. Therefore, they should be carefully evaluated for patient selection. Moreover, emerging data show that the benefit of PMVR may go beyond the left heart, leading to an improvement in RV function and a reduction in TR severity. Among PMVR recipients, improvement in RV function and reduction of TR degree are observed mainly in patients with RV dysfunction at baseline. On the other hand, high postprocedural transmitral pressure gradients seem to be associated with lack of RV reverse remodeling. Timing of mitral intervention with respect to RV impairment and predictors of RV reverse remodeling after PMVR are unknown. Further studies are needed to fill these gaps in evidence.

Conventional echocardiographic parameters or three-dimensional echocardiography to evaluate right ventricular function in percutaneous edge-to-edge mitral valve repair (PMVR)

Introduction

In this study, we evaluated right ventricular (RV) function before and after percutaneous mitral valve repair (PMVR) using conventional echocardiographic parameters and novel 3DE data sets acquired prior to and directly after the procedure.

Patients and methods

Observational study on 45 patients undergoing PMVR at an university hospital.

Results

In the overall collective, the 3D RV-EF before and after PMVR showed no significant change (p = 0.16). While there was a significant increase of the fractional area change (FAC, from 23 [19–29] % to 28 [24–33] %, p = 0.001), no significant change of the tricuspid annular plane systolic excursion (TAPSE, from 17 ± 6 mm to 18 ± 5 mm (standard deviation), p = 0.33) was observed. Regarding patients with a reduced RV-EF (< 35%), a significant RV-EF improvement was observed (from 27 [23–34] % to 32.5 [30–39] % (p = 0.001). 71.4% of patients had an improved clinical outcome (improvement in 6-minute walk test and/or improvement in NYHA class of more than one grade), whereas clinical outcome did not improve in 28.6% of patients. Using univariate logistic regression analysis, the post-PMVR RV-EF (OR 1.15: 95% CI 1.02–1.29; p = 0.02) and the change in RV-EF (OR 1.13: 95% CI 1.02–1.25; p = 0.02) were significant predictors for improved clinical outcome at 6 months follow up.

Conclusion

Thus, RV function may be an important non-invasive parameter to add to the predictive parameters indicating a potential clinical benefit from treatment of severe mitral regurgitation using PMVR.

Acute and Long-Term Hemodynamic Effects of MitraClip Implantation on a Preexisting Secondary Right Heart Failure

Positive results of MitraClip in terms of improvement in clinical and left ventricular parameters have been described in detail. However, long-term effects on secondary pulmonary hypertension were not investigated in a larger patient cohort to date. 70 patients with severe mitral regurgitation, additional pulmonary hypertension, and right heart failure as a result of left heart disease were treated in the heart centers Hamburg and Göttingen. Immediately after successful MitraClip implantation, a reduction of the RVOT diameter from 3.52 cm to 3.44 cm was observed reaching a statistically significant value of 3.39 cm after 12 months. In contrast, there was a significant reduction in the velocity of the tricuspid regurgitation (TR) from 4.17 m/s to 3.11 m/s, the gradient of the TR from 48.5 mmHg to 39.3 mmHg, and the systolic pulmonary artery pressure (PAPsyst) from 58.6 mmHg to 50.0 mmHg. This decline continued in the following months (V_max TR 3.09 m/s, peak TR 38.6 mmHg, and PAPsyst 47.4 mmHg). The tricuspid annular plane systolic excursion (TAPSE) increased from 16.5 mm to 18.9 mm after 12 months. MitraClip implantation improves pulmonary artery pressure, tricuspid regurgitation, and TAPSE after 12 months. At the same time, there is a decrease in the RVOT diameter without significant changes in other right ventricular and right atrial dimensions.

Elevated Mitral Valve Pressure Gradient After MitraClip Implantation Deteriorates Long-Term Outcome in Patients With Severe Mitral Regurgitation and Severe Heart Failure

OBJECTIVES

This single-center study was performed to analyze the effect of an increased transvalvular gradient after the MitraClip (MC) (Abbott Laboratories, Abbott Park, Illinois) procedure on patient outcome during follow-up.

BACKGROUND

Percutaneous transcatheter repair of the mitral valve with the MC device has been established as a novel technique for patients with severe mitral regurgitation and high surgical risk. This study investigated the influence of an increased pressure gradient after MC implantation on the long-term outcome of patients.

METHODS

A total of 268 patients were enrolled, who received MC implantation between April 2009 and July 2014 in our institution (75 ± 9 years of age, 68% men, weight 76 ± 15 kg, median N-terminal pro-B-type natriuretic peptide 3,696 [interquartile range: 1,989 to 7,711] pg/ml, left ventricular ejection fraction 39 ± 16%, log European System for Cardiac Operative Risk Evaluation score 20% [interquartile range: 12% to 33%]). Pressure in the left atrium and left ventricle were measured during the procedure using fluid-filled catheters. The pressure gradients over the mitral valve were determined simultaneously invasively and echocardiographically directly after MC deployment. A Kaplan-Meier analysis was performed and correlated with the pressure gradients. We used a combined primary endpoint: all-cause-mortality, left ventricular assist device, mitral valve replacement, and redo procedure.

RESULTS

The Kaplan-Meier-analysis showed a significantly poorer long-term-outcome in the case of an invasively determined mitral valve pressure gradient (MVPG) in excess of 5 mm Hg at implantation for the combined endpoint (p = 0.001) and for all-cause mortality (p = 0.018). For the echocardiographically determined MVPG the cutoff value was 4.4 mm Hg. Propensity score matching was used to balance baseline differences between the groups. In a Cox model the increased residual MVPG >5 mm Hg was a significant outcome predictor in univariate and multivariate analysis (hazard ratio: 2.3; 95% confidence interval: 1.4 to 3.8; p = 0.002, multivariate after adjustment for N-terminal pro-B-type natriuretic peptide, age, and remaining mitral regurgitation).

CONCLUSIONS

It is recommended that the quality of the implantation result be analyzed carefully and repositioning of the MC be considered in the case of an elevated pressure gradient over the mitral valve.

Three-Dimensional Transthoracic Echocardiography in the Comprehensive Evaluation of Right and Left Heart Chamber Remodeling Following Percutaneous Mitral Valve Repair

BACKGROUND

Percutaneous mitral valve repair (PMVR) is an alternative treatment in patients with significant mitral regurgitation (MR) who are denied surgery. Although in surgical patients, outcomes have been related both to acute hemodynamic favorable results and to positive cardiac remodeling in the midterm, in the case of PMVR the effect on cardiac chamber remodeling has never been extensively studied. The aims of this study were (1) to evaluate the short- and mid-term remodeling induced by PMVR on cardiac chamber volume using two- and three-dimensional (3D) transthoracic echocardiographic (TTE) imaging and (2) to assess changes in left ventricular (LV) shape on the basis of 3D TTE data.

METHODS

Patients undergoing PMVR were prospectively enrolled. Two-dimensional and 3D TTE data sets acquired at baseline, and at 30 days and 6 months after PMVR were analyzed to assess LV and right ventricular (RV) volumes and ejection fraction and left atrial and right atrial volumes. Moreover, 3D endocardial surfaces were extracted to compute 3D shape indexes of LV sphericity and conicity at end-diastole and end-systole.

RESULTS

Six of the 64 enrolled patients did not reach follow-up and were excluded. The analysis was feasible in all 58 patients considered (26 with functional MR and 32 [55%] with degenerative MR). PMVR resulted in significant reduction of MR and in favorable remodeling: (1) effective PMVR was mainly associated with decreased LV loading, (2) PMVR-related reverse remodeling was observed in patients with degenerative MR and those with functional MR at 30 days and continued at 6-month follow-up, (3) favorable remodeling in LV shape from abnormally spherical to more normal conical took place in both groups after PMVR, and (4) RV volumes and systolic function were preserved after PMVR.

CONCLUSIONS

A comprehensive two-dimensional and 3D TTE analysis allows investigation from a double perspective (volume and morphology) of the entity and modality of changes following PMVR. In high-risk patients undergoing PMVR, postprocedural heart remodeling involves all cardiac chambers, occurs in the short term, and further improves at midterm follow-up.

Early Hemodynamic Improvement after Percutaneous Mitral Valve Repair Evaluated by Noninvasive Pressure-Volume Analysis

BACKGROUND

Mitral regurgitation represents a volume load on the left ventricle leading to congestion and symptoms of heart failure. The aim of this study was to characterize early hemodynamic adaptions after percutaneous mitral valve (MV) repair.

METHODS

Forty-six consecutive patients with symptomatic high-grade MV insufficiency (mean age, 72 years; 54% men) were prospectively included in the study and examined before and after successful catheter-based clip implantation. Seventy percent of patients had secondary mitral regurgitation. Noninvasive pressure-volume loops were reconstructed from echocardiography with simultaneous blood pressure measurements.

RESULTS

MV repair reduced left ventricular end-diastolic volume index from 87 ± 41 to 80 ± 40 mL/m(2) (P < .0001). End-systolic volume index was 55 ± 37 mL/m(2) before versus 54 ± 37 mL/m(2) after repair (P = .52). Hence, total stroke volume decreased from 60 ± 23 to 49 ± 16 mL (P < .0001), as did total ejection fraction (from 41 ± 14% to 37 ± 13%, P = .002) and global longitudinal strain (from -11 ± 4.9% to -9.1 ± 4.4%, P = .0001). Forward stroke volume, forward ejection fraction, and forward cardiac output remained constant (43 ± 12 mL vs 42 ± 11 mL, 33 ± 17% vs 35 ± 18%, and 3.2 ± 0.9 L/min vs 3.4 ± 0.8 L/min, respectively). Parameters of left ventricular contractility (end-systolic elastance and peak power index) and measurements of afterload (arterial elastance, end-systolic wall stress, and total peripheral resistance) were similar before and after MV repair. Forward ejection fraction correlated more strongly with end-systolic elastance (r = 0.61, P < .0001) than did total ejection fraction (r = 0.35, P = .0007) or global longitudinal strain (r = -0.38, P = .0002). Total mechanical energy (pressure-volume area) decreased from 10,903 ± 4,410 to 9,124 ± 2,968 mm Hg × mL (P = .0007) because of reduced stroke work (5,546 ± 2,241 mm Hg × mL vs 4,414 ± 1,412 mm Hg × mL, P < .0001). At 3 months, symptom status had improved (76% of patients in New York Heart Association classes I and II), and 97% of patients had mitral regurgitation grade ≤2+.

CONCLUSIONS

Left ventricular contractility and forward cardiac output remained unchanged after percutaneous MV repair despite decreases in total ejection fraction and global longitudinal strain. The left ventricle was unloaded through reduced end-diastolic volume. Thus, MV repair is associated with an improved hemodynamic state in noninvasive pressure-volume analysis.

Impact and evolution of right ventricular dysfunction after successful MitraClip implantation in patients with functional mitral regurgitation

BACKGROUND

Right ventricular dysfunction (RVdysf) is a predictor of poor outcome in patients with heart failure and valvular disease. The aim of this study was to evaluate the evolution and the impact of RVdysf in patients with moderate-severe functional mitral regurgitation (FMR) successfully treated with MitraClip.

METHODS AND RESULTS

From October 2008 to July 2014, 60 consecutive high surgical risk FMR patients were evaluated and stratified into two groups: RVdysf group (TAPSE < 16 mm and/or S'TDI < 10 cm/s, 21 patients) and No-RVdysf group (38 patients). The overall mean age of patients was 73 ± 8 (83% male). Ischemic FMR etiology was present in 67%. Mean LVEF was 30 ± 10%. Overall mean time follow-up was 565 ± 310 days. The only significant difference between the two groups was a greater prevalence of stroke, ICD and use of aldosterone antagonist in RVdysf group. Acute procedural success was achieved in 90% of patients. At 6-month echo-matched analysis significant RV function improvement was observed in patients with baseline RVdysf (TAPSE 15 ± 3.0 vs. 19 ± 4.5, p = 0.007; S'TDI 7 ± 1.2 vs. 11 ± 2.8, p < 0.0001; baseline vs. 6-month, respectively). The mean improvement in the 6-min walking test was significant in both groups (120 and 143 m, RVdysf and No-RVdysf groups, respectively). At Kaplan-Meier analysis, the presence of RVdysf did not affect the outcome in terms of freedom from composite efficacy endpoint.

CONCLUSIONS

This study shows that successful MitraClip implantation in patients with FMR and concomitant right ventricular dysfunction yields significant improvement of RV function at mid-term follow-up. Further data on larger population will be required to confirm our observations.