Atrial Functional Tricuspid Regurgitation (AFTR) Is Associated with Better Outcome After Tricuspid Transcatheter Edge-to-Edge Repair (T-TEER) Compared to Ventricular FTR (VFTR)

Background: Transcatheter tricuspid edge-to-edge repair (T-TEER) is widely used to treat atrial (AFTR) and ventricular (VFTR) functional tricuspid regurgitation (FTR). Methods: The outcome of 136 patients treated with T-TEER for severe AFTR or VFTR was analyzed using a composite endpoint of all-cause death and rehospitalization for decompensated heart failure. AFTR was defined as TR in the context of left ventricular ejection fraction ≥50%, right ventricular fractional area change (RVFAC) ≥ 35% and sPAP ≤ 50 mmHg. Results: Patients with VFTR (N = 109) and AFTR (N = 27, 19.9%) were both elderly (82.0 {IQR: 74.5-84.5} vs. 82.0 {IQR: 75.0-84.0} years, p = 0.98) and had similar interventional risk according to the EuroScore II (6.1 {4.0-9.8} vs. 4.7 {3.6-9.6} %, p = 0.3). Atrial fibrillation was equally frequent in both groups (89.9 vs. 88.9%, p = 0.88). AFTR patients were significantly more often female (56.0 vs. 77.8%, p = 0.04) and had lower NT-proBNP (3600.0 {1706.0-6302.0} vs. 1988.0 {1034.8-3723.3} pg/mL, p < 0.01). While RVFAC (29.5 ± 8.6 vs. 42.1 ± 4.3%, p < 0.01) and LVEF (48.5 ± 12.3 vs. 58.6 ± 8.0%, p < 0.01) were expectedly lower in patients with VFTR, right atrial dilation (RA volume: 126.7 ± 56.5 vs. 127.6 ± 74.2 mL, p = 0.99) was similar. Successful T-TEER with TR reduction ≥ 2 degrees (96.3 vs. 92.6%, p = 0.34) was observed in both groups, and residual TR ≤ II was equally frequent (94.5 vs. 96.3%, p = 1.0). The incidence of the 1-year composite endpoint was significantly higher (34.3 vs. 12.0%) in patients with VFTR (log-rank p = 0.02). AFTR was inversely associated with the composite endpoint (HR: 0.21, 95% CI: 0.06-0.7, p < 0.01) in multivariate Cox regression. Conclusions: Despite equally effective TR reduction through T-TEER, a better outcome was observed in patients with AFTR.

Evolving Applications of Echocardiography in the Evaluation of Left Atrial and Right Ventricular Strain

PURPOSE OF REVIEW

Speckle-tracking echocardiography (STE) can assess myocardial motion in non-LV chambers-including assessment of left atrial (LA) and right ventricular (RV) strain. This review seeks to highlight the diagnostic, prognostic, and clinical significance of these parameters in heart failure, atrial fibrillation (AF), diastolic dysfunction, pulmonary hypertension (PH), tricuspid regurgitation, and heart transplant recipients.

RECENT FINDINGS

Impaired LA strain reflects worse LV diastolic function in individuals with and without HF, and this is associated with decreased exercise capacity. Initiating treatments targeting these functional aspects may enhance exercise capacity and potentially prevent heart failure (HF). Impaired LA strain also identifies patients with a high risk of AF, and this recognition may lead to preventive strategies. Impaired RV strain has significant clinical and prognostic implications across various clinical scenarios, including HF, PH, tricuspid regurgitation, or in heart transplant recipients. STE should not be limited to the assessment of deformation of the LV myocardium. The use of LA and RV strain is supported by a substantial evidence base, and these parameters should be used more widely.

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.

The Predictive Value of Right Ventricular Longitudinal Strain in Pulmonary Hypertension, Heart Failure, and Valvular Diseases

Right ventricular (RV) systolic function has an important role in the prediction of adverse outcomes, including mortality, in a wide range of cardiovascular (CV) conditions. Because of complex RV geometry and load dependency of the RV functional parameters, conventional echocardiographic parameters such as RV fractional area change (FAC) and tricuspid annular plane systolic excursion (TAPSE), have limited prognostic power in a large number of patients. RV longitudinal strain overcame the majority of these limitations, as it is angle-independent, less load-dependent, highly reproducible, and measure regional myocardial deformation. It has a high predictive value in patients with pulmonary hypertension, heart failure, congenital heart disease, ischemic heart disease, pulmonary embolism, cardiomyopathies, and valvular disease. It enables detection of subclinical RV damage even when conventional parameters of RV systolic function are in the normal range. Even though cardiac magnetic resonance-derived RV longitudinal strain showed excellent predictive value, echocardiography-derived RV strain remains the method of choice for evaluation of RV mechanics primarily due to high availability. Despite a constantly growing body of evidence that support RV longitudinal strain evaluation in the majority of CV patients, its assessment has not become the part of the routine echocardiographic examination in the majority of echocardiographic laboratories. The aim of this clinical review was to summarize the current data about the predictive value of RV longitudinal strain in patients with pulmonary hypertension, heart failure and valvular heart diseases.

Extent and determinants of left ventricular reverse remodeling in patients with secondary mitral regurgitation undergoing MitraClip implantation

Background

In secondary MR, data on left ventricular (LV) remodeling after MitraClip procedure are rare, even this information may impact patient selection. This study investigated changes in LV structure and function by cardiovascular magnetic resonance (CMR) following MitraClip implantation for secondary mitral regurgitation (MR) in order to assess extent and predictors of LV reverse remodeling (LVRR).

Methods and Results

Twenty-nine patients underwent CMR imaging prior to and six months after MitraClip procedure. LVRR was defined by a decrease of LV end-diastolic volume index (LVEDVi) > 15% compared to baseline. According to the definition of LVRR, 34% of patients displayed LVRR at follow-up CMR. Baseline LV stroke volume index (LVSVi), LV ejection fraction (LVEF), LV circumferential strain and MR volume at baseline were predictors of LVRR at follow-up. At second CMR, we detected an improvement in hemodynamic status as illustrated by an increase in effective LVSVi (28 ± 8 ml/m² vs. 33 ± 8 ml/m²; p = 0.053) and cardiac index (2.0 ± 0.5 vs. 2.3 ± 0.5 l/min; p = 0.016), while LVEF and LV strain parameters did not change (p > 0.05). Improvements in effective LVSVi were associated with the decrease of MR volume (r = 0.509; p = 0.018) and MR fraction (r = 0.629; p = 0.002) by MitraClip.

Conclusions

Together, MitraClip implantation is associated with LVRR in one third of patients. Baseline LV function and magnitude of MR are important predictors of LVRR. Improvement of hemodynamic status may be assessed by effective stroke volume index and correlates with the reduction of MR by MitraClip implantation, rather than an increase in LV contractility.

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.

Layer-Specific Strain Is Preload Dependent: Comparison between Speckle-Tracking Echocardiography and Cardiac Magnetic Resonance Feature-Tracking

BACKGROUND

Speckle-tracking echocardiographic (STE) imaging and cardiac magnetic resonance feature-tracking (CMR-FT) are novel imaging techniques enabling layer-specific quantification of myocardial deformation. Conventional echocardiographic parameters are load dependent, but few studies have investigated the effects of loading conditions on STE and CMR-FT layer-specific strain and the interchangeability of the two modalities. The aim of this study was to evaluate the effects of acute preload augmentation by saline infusion on STE and CMR-FT longitudinal and circumferential layer-specific strain parameters and their intermodal agreement.

METHODS

A total of 80 subjects, including 41 control subjects (mean age, 40 ± 12 years; 49% men) and 39 patients with cardiac disease (mean age, 47 ± 15 years; 92% men) were examined using STE and CMR-FT layer-specific strain analysis before and after saline infusion (median, 2.0 L) with quantification of transmural global longitudinal strain (GLS), epicardial GLS, endocardial GLS, transmural global circumferential strain (GCS), epicardial GCS, and endocardial GCS in addition to epicardial-endocardial gradients. Bland-Altman plots and Pearson correlation coefficients were used to evaluate agreement between the two modalities across all strain parameters.

RESULTS

Acute saline infusion increased all STE and CMR-FT layer-specific strain parameters in both groups. STE and CMR-FT GLS increased by 1.4 ± 1.5% and 1.5 ± 2.0% (P < .001) in control subjects and by 0.9 ± 1.8% and 0.9 ± 1.9% (P < .001) in patients with cardiac disease. STE and CMR-FT GCS increased by 2.0 ± 2.2% and 1.8 ± 2.3% (P < .001) in control subjects and by 1.8 ± 2.3% and 1.7 ± 3.6% in patients with cardiac disease (P < .001 and P = .03). STE longitudinal strain correlated strongly with corresponding CMR-FT longitudinal strain (GLS, epicardial GLS, and endocardial GLS: r = 0.81, r = 0.82, and r = 0.81, respectively) despite poor intermodal agreement (bias ± limits of agreement, -2.84 ± 4.06%, 0.16 ± 3.68%, and 2.33 ± 3.52%, respectively) whereas GCS, epicardial GCS, and endocardial GCS correlated weakly between the two modalities (r = 0.28, r = 0.19, and r = 0.34, respectively) and displayed poor intermodal agreement (bias ± limits of agreement, -1.33 ± 6.86%, 4.43 ± 6.49%, and -9.92 ± 8.55%, respectively).

CONCLUSIONS

STE and CMR-FT longitudinal and circumferential layer-specific strain parameters are preload dependent in both control subjects and patients with cardiac disease. STE and CMR-FT longitudinal layer-specific strain parameters are strongly correlated, whereas circumferential layer-specific strain parameters are weakly correlated. STE and CMR-FT longitudinal and circumferential strain should not be used interchangeably, because of poor intermodal agreement.

Mechanical effects of MitraClip on leaflet stress and myocardial strain in functional mitral regurgitation - A finite element modeling study

Purpose

MitraClip is the sole percutaneous device approved for functional mitral regurgitation (MR; FMR) but MR recurs in over one third of patients. As device-induced mechanical effects are a potential cause for MR recurrence, we tested the hypothesis that MitraClip increases leaflet stress and procedure-related strain in sub-valvular left ventricular (LV) myocardium in FMR associated with coronary disease (FMR-CAD).

Methods

Simulations were performed using finite element models of the LV + mitral valve based on MRI of 5 sheep with FMR-CAD. Models were modified to have a 20% increase in LV volume (↑LV_VOLUME) and MitraClip was simulated with contracting beam elements (virtual sutures) placed between nodes in the center edge of the anterior (AL) and posterior (PL) mitral leaflets. Effects of MitraClip on leaflet stress in the peri-MitraClip region of AL and PL, septo-lateral annular diameter (SLAD), and procedure-related radial strain (E_rr) in the sub-valvular myocardium were calculated.

Results

MitraClip increased peri-MitraClip leaflet stress at end-diastole (ED) by 22.3±7.1 kPa (p<0.0001) in AL and 14.8±1.2 kPa (p<0.0001) in PL. MitraClip decreased SLAD by 6.1±2.2 mm (p<0.0001) and increased E_rr in the sub-valvular lateral LV myocardium at ED by 0.09±0.04 (p<0.0001)). Furthermore, MitraClip in ↑LV_VOLUME was associated with persistent effects at ED but also at end-systole where peri-MitraClip leaflet stress was increased in AL by 31.9±14.4 kPa (p = 0.0268) and in PL by 22.5±23.7 kPa (p = 0.0101).

Conclusions

MitraClip for FMR-CAD increases mitral leaflet stress and radial strain in LV sub-valvular myocardium. Mechanical effects of MitraClip are augmented by LV enlargement.

Acute Hypotension After MitraClip Implantation due to Acute Left Ventricular Failure

The MitraClip is a percutaneously implanted device approved for the treatment of symptomatic organic mitral regurgitation in poor surgical candidates. Despite its proven efficacy and safety for mitral regurgitation treatment, the MitraClip may unmask the true afterload of the left ventricle by removing the low-pressure left atrial system and may cause acute left ventricular systolic failure (afterload mismatch). Rapid diagnosis and treatment of afterload mismatch is crucial to ensure optimal patient outcomes. The authors present a case of acute hemodynamic deterioration after MitraClip implantation in a patient with chronic severe left ventricular systolic dysfunction. Transesophageal echocardiography was pivotal for the rapid recognition of acute left ventricular failure and aided in the intraoperative decision-making process and therapy.

Immediate increase of cardiac output after percutaneous mitral valve repair (PMVR) determined by echocardiographic and invasive parameters: Patzelt: Increase of cardiac output after PMVR

BACKGROUND

Successful percutaneous mitral valve repair (PMVR) in patients with severe mitral regurgitation (MR) causes changes in hemodynamics. Echocardiographic calculation of cardiac output (CO) has not been evaluated in the setting of PMVR, so far. Here we evaluated hemodynamics before and after PMVR with the MitraClip system using pulmonary artery catheterization, transthoracic (TTE) and transesophageal (TEE) echocardiography.

METHODS

101 patients with severe MR not eligible for conventional surgery underwent PMVR. Hemodynamic parameters were determined during and after the intervention. We evaluated changes in CO and pulmonary artery systolic pressure before and after PMVR. CO was determined with invasive parameters using the Fick method (COi) and by a combination of TTE and TEE (COe).

RESULTS

All patients had successful clip implantation, which was associated with increased COi (from 4.6±1.4l/min to 5.4±1.6l/min, p<0.001). Furthermore, pulmonary artery systolic pressure (PASP) showed a significant decrease after PMVR (47.6±16.1 before, 44.7±15.5mmHg after, p=0.01). In accordance with invasive measurements, COe increased significantly (COe from 4.3±1.7l/min to 4.8±1.7l/min, p=0.003). Comparing both methods to calculate CO, we observed good agreement between COi and COe using Bland Altman plots.

CONCLUSIONS

CO increased significantly after PMVR as determined by echocardiography based and invasive calculation of hemodynamics during PMVR. COe shows good agreement with COi before and after the intervention and, thus, represents a potential non-invasive method to determine CO in patients with MR not accessible by conventional surgery.

Sympathetic Activity in Patients With Secondary Symptomatic Mitral Regurgitation or End-Stage Systolic Heart Failure

OBJECTIVES

This study shows the impact of secondary mitral regurgitation (sMR) and transcatheter mitral valve repair (TMVR) with the MitraClip system on sympathetic nerve activity (SNA).

BACKGROUND

An increase in SNA is associated with worse outcomes and limited survival in patients with chronic heart failure (CHF).

METHODS

Twenty CHF-patients without relevant sMR and 30 CHF patients with symptomatic sMR were enrolled prospectively. All patients underwent standardized laboratory testing and microneurography. Sixteen patients from the sMR group underwent the MitraClip procedure; 10 patients after TMVR and 9 untreated sMR patients completed 6 months of follow-up.

RESULTS

Comparing groups according to presence of sMR, we found no differences in left ventricular dimensions, and serum levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) and noradrenaline; sMR was associated with increased MSNA (106 ± 60 burst/min vs. 74 ± 48 burst/min, d = 0.58), an impaired sympathetic baroreflex gain (10 ± 7 burst/mm Hg vs. 5 ± 5 burst/mm Hg, d = 0.61), and a higher heart rate (90 ± 27/beats/min vs. 78 ± 12/beats/min, d = 0.58). TMVR led to improved New York Heart Association functional class (d > 0.05), reduced levels of NT-proBNP (5,251 ± 3,760 pg/ml vs. 3,710 ± 2,464 pg/ml; d = 0.58) improvement in 6-minute walk test (204 ± 33 m vs. 288 ± 45 m, d = 0.64), but unchanged levels of noradrenaline. TMVR decreased MSNA burst-frequency (130 ± 78 bursts/min vs. 74 ± 21 bursts/min; d = 0.58) and baroreflex gain (7 ± 4 burst/mm Hg vs. 4 ± 1 burst/mm Hg; d = 0.61).

CONCLUSIONS

In patients with CHF, concomitant sMR is associated with increased sympathetic nerve activity, which was independent from measured levels of NT-proBNP, noradrenaline, and left ventricular dimensions. Reduction of sMR with the MitraClip procedure reduced SNA and improved baroreflex gain, in line with improvements of functional capacity.

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.