Long-Term Hemodynamic Improvement after Transcatheter Mitral Valve Repair

Left and Right Ventricular Hemodynamic Response After Transcatheter Mitral Valve Replacement

Background

Transcatheter mitral valve replacement (TMVR) represents a novel treatment option for patients with mitral regurgitation (MR), but little is known about the hemodynamic impact of MR elimination following TMVR. We sought to investigate the hemodynamic impact of TMVR on left ventricular (LV) and right ventricular (RV) function using noninvasive pressure-volume loops.

Methods

All consecutive patients undergoing TMVR with dedicated devices between May 2016 and August 2022 were enrolled. The end-diastolic and end-systolic pressure-volume relationships were estimated from 26 patients using single-beat echocardiographic measurements at baseline and after TMVR at discharge. RV function was assessed by RV-pulmonary artery (PA) coupling and RV fractional area change. One-year follow-up was available for 19 patients. The prognostic impact of calculated end-diastolic volume at an end-diastolic pressure of 20 mmHg (VPed20) reduction was assessed by Cox regression.

Results

A total of 26 patients (77.0 years [interquartile range 73.9-80.1], N = 17 [65.4%] male) with successful TMVR were included (secondary MR [N = 21, 80.8%]; median LV ejection fraction was 37.0% [interquartile range 30.7-50.7]). At discharge, a decrease in VPed20 (p < 0.001) indicating leftward shift of end-diastolic pressure-volume relationship, and an increase of the end-systolic elastance slope (p = 0.007) were observed after TMVR. No changes were observed for RV-PA coupling (p = 0.19) and RV fractional area change (p = 0.22). At 1-year follow-up, LV contractility (end-systolic elastance) and RV-PA coupling remained stable. Vped20 reduction at discharge was significantly associated with 1-year all-cause mortality or heart failure hospitalization (hazard ratio 0.16, 95% CI 0.04-0.71, p = 0.016).

Conclusions

Noninvasive assessment of pressure-volume loops demonstrated early LV reverse remodeling and improved LV contractility, while RV performance was preserved. These results indicate the potential prognostic impact of complete MR elimination after TMVR.

Expert proposal to characterize cardiac diseases with normal or preserved left ventricular ejection fraction and symptoms of heart failure by comprehensive echocardiography

Currently, the term "heart failure with preserved left ventricular ejection fraction (HFpEF)" is based on echocardiographic parameters and clinical symptoms combined with elevated or normal levels of natriuretic peptides. Thus, "HFpEF" as a diagnosis subsumes multiple pathophysiological entities making a uniform management plan for "HFpEF" impossible. Therefore, a more specific characterization of the underlying cardiac pathologies in patients with preserved ejection fraction and symptoms of heart failure is mandatory. The present proposal seeks to offer practical support by a standardized echocardiographic workflow to characterize specific diagnostic entities associated with "HFpEF". It focuses on morphological and functional cardiac phenotypes characterized by echocardiography in patients with normal or preserved left ventricular ejection fraction (LVEF). The proposal discusses methodological issues to clarify why and when echocardiography is helpful to improve the diagnosis. Thus, the proposal addresses a systematic echocardiographic approach using a feasible algorithm with weighting criteria for interpretation of echocardiographic parameters related to patients with preserved ejection fraction and symptoms of heart failure. The authors consciously do not use the diagnosis "HFpEF" to avoid misunderstandings. Central illustration: Scheme illustrating the characteristic echocardiographic phenotypes and their combinations in patients with "HFpEF" symptoms with respect to the respective cardiac pathology and pathophysiology as well as the underlying typical disease.

Long-term clinical and haemodynamic results after transcatheter annuloplasty for secondary mitral regurgitation

AIMS

The study sought to investigate the long-term outcome after transcatheter mitral valve annuloplasty for secondary mitral regurgitation (MR).

METHODS AND RESULTS

Consecutive patients with symptomatic secondary MR undergoing transcatheter mitral valve annuloplasty with the Carillon device at Leipzig University Hospital between 2012 and 2018 were studied prospectively. Left ventricular (LV) function and MR severity were quantified by standardized echocardiography. 33 patients were included. Mean age was 75 ± 10 years, and 20 patients were women. A Society of Thoracic Surgeons score of 8.1 ± 7.2% indicated high-risk status. In 24 patients, MR resulted from LV remodelling and dysfunction, eight suffered from left atrial dilatation, and one patient had MR due to combined primary and secondary aetiology. LV ejection fraction at baseline was (median) 38% [inter-quartile range (IQR) 30-49%]. During the mean follow-up time of 45 ± 20 months, 17 patients died, two patients withdraw consent, and four patients were lost. Of the remaining patients, four were hospitalized for decompensated heart failure. Two of these patients underwent additional transcatheter edge-to-edge mitral valve repair. At follow-up, New York Heart Association (NYHA) functional class improved from 95% in Class III/IV at baseline to 70% in Class I/II with no patients in NYHA Class IV (P < 0.0001). Mitral regurgitant volume was reduced from 27 mL (IQR 25-42 mL) to 8 mL (IQR 3-17 mL) (P = 0.018) and regurgitant fraction from 42% (IQR 34-54%) to 11% (IQR 8-24%) (P = 0.014). LV end-diastolic volume index [92 mL/m2 (IQR 74-107 mL/m2 ) vs. 67 mL/m2 (IQR 46-101 mL/m2 ), P = 0.065] and end-systolic volume index [50 mL/m2 (IQR 44-69 mL/m2 ) vs. 32 mL/m2 (IQR 20-53 mL/m2 ), P = 0.037] decreased. Total stroke volume remained unchanged [38 mL/m2 (IQR 33-43 mL/m2 ) vs. 33 mL/m2 (IQR 26-44 mL/m2 ), P = 0.695], while LV ejection fraction increased [43% (IQR 35-49%) vs. 54% (IQR 46-57%), P = 0.014]. Forward stroke volume, heart rate, and forward cardiac output were not significantly altered.

CONCLUSIONS

Among high-risk patients undergoing transcatheter mitral valve annuloplasty for symptomatic secondary MR, mortality was ~50% at 4 years. In the surviving patients, reduced MR severity was associated with reduced NYHA functional class, reverse LV remodelling, and improved LV function.

Hemodynamics rounds: Hemodynamics of mitral valve interventions

Mitral valvulopathy presents as regurgitation, stenosis, or mixed disease and can occur in both native and prosthetic valves. Such disease develops in conjunction with pathophysiologic changes in the left atrium (LA) and drives changes in LA compliance, pressure, and thus clinical syndromes. With advances in the understanding and treatment of structural heart disease and in the setting of higher-risk patient populations, less-invasive transcatheter approaches have become increasingly commonplace in the treatment of mitral valve disease. Over time, transcatheter mitral valve interventions have evolved to include paravalvular leak closure, mitral valve repair, and mitral valve replacement. Parallel to this evolution, advances in invasive intracardiac pressure monitoring, particularly at the level of the LA, have also occurred. These advances emphasize the unique interplay between mitral valve disease and LA function; account for limitations of noninvasive assessment; and guide beneficial outcomes in each area of transcatheter mitral valve intervention. As a result, continuous transseptal LA pressure monitoring has developed into an indispensable instrument in successful percutaneous mitral valve intervention, complementing traditional noninvasive assessment.

MitraClip and left ventricular reverse remodelling: a strain imaging study

AIMS

The purpose of this study is to identify echocardiography predictors of clinical response and reverse left ventricular (LV) remodelling in patients with functional mitral regurgitation (FMR) treated with MitraClip.

METHOD AND RESULTS

We retrospectively analysed 86 high surgical risk patients with severe FMR; of those, 58 were implanted a MitraClip, and 28 received medical treatment and served as controls. At baseline and at 1-year follow-up, we performed clinical and echocardiography evaluation to assess global longitudinal strain (GLS) and myocardial work [global work index (GWI), global constructive work (GCW), global wasted work (GWW), global work efficiency (GWE)]. Mitral regurgitation was significantly reduced after MitraClip implantation (3.7 ± 0.4 vs. 1.7 ± 0.8, P < 0.001), and the procedure was associated with improvement in brain natriuretic peptide levels (980 ± 1027 vs. 420 ± 338 pg/mL, P < 0.001), New York Heart Association class status (3.2 ± 0.55 vs. 2.0 ± 0.6, P < 0.001), 6-min walking test (233 ± 154 vs. 286 ± 114 m, P = 0.01) at follow-up and reduction of left ventricle end-systolic (LVESV) and left ventricle end-diastolic volumes (LVEDV) (152 ± 68 vs. 136 ± 43 mL, P = 0.004 & 219 ± 74 vs. 193 ± 66 mL, P = 0.001, respectively). MitraClip procedure was associated with improvement of LV performance and significant increase of GWI (607 ± 282 vs. 650 ± 260 mmHg%, P = 0.045) and GCW (854 ± 288 vs. 949 ± 325 mmHg%, P < 0.001). Baseline ejection fraction (EF), GLS, GWI, GCW, and effective regurgitant orifice area were the variables that were associated with reduction of LVEDV 1 year after intervention (P < 0.05 for all) and baseline GCW of the LV was the only variable associated with reduction of LVESV (P = 0.002). Receiver operating characteristic curve analysis identified that a GLS cut-off value of -8.65% (AUC 0.815, P = 0.007) was associated with a 20% reduction of the LVEDV with a sensitivity and specificity of 72% and 70%, respectively, and that a GCW cut-off value of 846 mmHg% (AUC 0.759, P = 0.007) was associated with a 10% reduction of LVESV with sensitivity and specificity 79% and 74%, respectively.

CONCLUSIONS

Mitral valve repair with MitraClip has positive clinical and echocardiographic impact in patients with FMR 1 year after implantation. Preserved GLS and GCW values appear to be associated with LV reverse remodelling post intervention.

Echocardiographic assessment of functional mitral regurgitation: opening Pandora's box?

Two recent trials of transcatheter mitral-valve repair in patients with functional mitral regurgitation (FMR) presented opposing results for the MitraClip® compared to medical therapy alone. The conflicting results gave rise to intensive discussions about assessment of mitral valve regurgitation (MR). A recent editorial viewpoint provided a potential explanation presenting a new pathophysiologic concept. However, the echocardiographic characterization of both trials' patients is inconsistent and the discussed concepts appear to suffer from plausibility weaknesses. It is well conceivable that limitations in the echocardiographic assessment of the trial patients introduced a bias regarding the selection of patients with severe (or less severe) MR that may be a more plausible explanation for the differences in outcome. We here illustrate our viewpoint regarding the two MitraClip trials and also illustrate the difficulties in assessing functional MR properly. It may indeed be "opening Pandora's box", but we will also make an attempt to provide a solution.