Risk factors and clinical significance of elevated mitral valve gradient following valve repair for degenerative disease

Combined Impact of Residual Mitral Regurgitation and Gradient After Mitral Valve Transcatheter Edge-to-Edge Repair

BACKGROUND

Reducing mitral regurgitation (MR) during mitral transcatheter edge-to-edge repair (M-TEER) may come at the cost of increased mitral valve gradient (MVG). The combined impact of residual MR and MVG on clinical outcomes after M-TEER is unknown.

OBJECTIVES

This study sought to evaluate the impact of postprocedure MR and MVG on clinical outcomes after M-TEER.

METHODS

EXPANDed is a pooled, patient-level cohort of the EXPAND (A Contemporary, Prospective Study Evaluating Real-world Experience of Performance and Safety for the Next Generation of MitraClip Devices) and EXPAND G4 studies, which were designed to evaluate real-world safety and effectiveness of the third- and fourth-generation MitraClip TEER Systems. Subjects were categorized by echocardiographic core laboratory (ECL) assessments into 4 groups according to 30-day MR grade and mean MVG: 1) MR ≤1+/MVG <5 mm Hg; 2) MR ≤1+/MVG ≥5 mm Hg; 3) MR ≥2+/MVG <5 mm Hg; and 4) MR ≥2+/MVG ≥5 mm Hg.

RESULTS

A total of 1,723 subjects had evaluable echocardiograms at 30 days: 72% had MR ≤1+/MVG <5 mm Hg, 18% had MR ≤1+/MVG ≥5 mm Hg, 7% had MR ≥2+/MVG <5 mm Hg, and 3% had MR ≥2+/MVG ≥5 mm Hg. MR≤1+ was sustained through 1 year in 93% of patients who achieved 30-day MR≤1+. MVG decreased from 30 days to 1 year in subjects with MVG ≥5 mm Hg (6.7 ± 4.0 to 5.5 ± 2.5 mm Hg MR ≤1+/MVG ≥5 mm Hg and 6.5 ± 1.5 to 5.5 ± 1.7 mm Hg MR ≥2+/MVG ≥5 mm Hg). One-year rates of all-cause mortality and heart failure hospitalization were lower for subjects who achieved MR ≤1+ at 30 days, regardless of MVG.

CONCLUSIONS

Reduction of MR to mild or less after M-TEER with the latest-generation MitraClip systems was associated with clinical benefit regardless of MVG.

Mitral valve repair with resection and non-resection techniques in Barlow's disease: A multi-center study

BACKGROUND

Various mitral valve (MV) repair techniques are nowadays in use. Non-resection techniques, that rely exclusively on Gore-Tex® neochords and annuloplasty, have been popularized; however, their efficacy in Barlow's disease, characterized by large myxomatous leaflets, is yet unclear.

METHODS

Consecutive patients undergoing MV repair for Barlow's disease between 2011 and 2019 were selected on the basis of being eligible for resection and non-resection techniques. Study endpoints included overall survival, freedom from MV reintervention and recurrent regurgitation.

RESULTS

Of 209 patients meeting the inclusion criteria, 135 (65%) underwent MV repair with and 74 (35%) without resection. There was one early reoperation due to residual regurgitation (resection group). Mean clinical follow-up duration was 6.1 (IQR 3.9-8.5) years. At 6 years after surgery, there was no difference in overall survival or freedom from MV reintervention. Mean echocardiographic follow-up (95% complete) duration was 3.5 (IQR 2.3-5.8) years. At 6 years, there was no difference in freedom from recurrent regurgitation rate (86.1%, 95% CI 78.5-93.7% vs. 83.0%, 95% CI 71.6-94.4%, P = 0.20) between the groups. Inverse probability-of-treatment weighting adjusted analysis demonstrated no significant difference between groups (HR 0.535, 95% CI 0.212-1.349, P = 0.20). Uni- and multivariable Cox proportional regression analysis did not demonstrate an effect of valve repair technique on the occurrence of recurrent regurgitation.

CONCLUSIONS

At mid-term, the clinical and echocardiographic results of valve repair for Barlow's disease were very good and MV reintervention was rarely needed. At this time point, the results of non-resection techniques were comparable to the "gold standard" resection techniques.

Association between Mitral Valve Mean Pressure Gradient and Atrial Fibrillation in Patients with Rheumatic Mitral Stenosis: A Cross-Sectional Study

INTRODUCTION

Atrial fibrillation (AF) often occurs in patients with rheumatic mitral stenosis (RMS) and is associated with adverse clinical outcomes. Mitral valve mean pressure gradient (MVMPG) is utilized as an indicator to assess the severity of mitral stenosis and its hemodynamic implications. The aim of this study was to investigate the association between MVMPG and AF in individuals with RMS.

METHODS

We conducted a retrospective analysis of medical records from 360 consecutive patients diagnosed with RMS at the First Affiliated Hospital of Wenzhou Medical University between January 2018 and January 2023. Using both univariate and multivariate logistic regression models, the relationship between MVMPG and AF was evaluated. Restricted cubic splines were employed to test for linearity, and stratified and interaction analyses were performed to evaluate the stability of this relationship among different subgroups.

RESULTS

Based on the MVMPG levels, 360 RMS patients in total were categorized into three groups for the analysis: Q1 (<5 mm Hg), Q2 (5-10 mm Hg), and Q3 (>10 mm Hg). The average age was 60.6 years (Q1: 66.1, Q2: 61.9, Q3: 55.8), and 70.8% were female. The prevalence of AF was 39.6%, 56.5%, and 63.2% in Q1, Q2, and Q3, respectively. After adjusting for potential confounders, a significant association between MVMPG and AF was observed. In Q2, there was a 119% increase in AF (OR 2.19, 95% CI: 1.01-4.75), while in Q3, there was a 238% increase (OR 3.38, 95% CI: 1.39-8.19), compared to Q1. The relationship between MVMPG and AF was linear (p = 0.503). These results remained consistent in each subgroup analysis.

CONCLUSION

Our study reveals a significant positive association between MVMPG and AF in patients with RMS, which holds important clinical implications. It is necessary to conduct further research.

Mitral valve repair using a semi-rigid posterior band: a 10-year Japanese single-center experience of 244 patients

Background

Mitral valve repair (MVr) is an established procedure for patients who require surgery for primary mitral regurgitation (PMR). The Colvin-Galloway Future Band (CGFB) is a semi-rigid posterior band expected to improve the clinical outcomes of MVr. However, information on the hemodynamic and functional performance and long-term outcomes of CGFB is limited. We evaluated the quality, durability, and clinical performance after MVr using CGFB for PMR as the cohort study.

Methods

A total of 244 patients who underwent MVr with CGFB were enrolled. Clinical and echocardiographic assessments were performed (mean follow-up period, 4.0±2.4 years).

Results

Posterior mitral leaflet resection was the most common MVr procedure. CGFBs measuring 28 mm (35.2%) and 30 mm (36.5%) were used. The incidence of systolic anterior motion (SAM) was 1.6%. A total of 93.4% of the patients had no or trace MR at discharge. Over 90% of patients had no or mild MR at the last follow-up. The mean pressure gradient and mitral valve orifice area one year after MVr ranged between 2.6 and 3.6 mmHg and 2.3 and 3.4 cm2, respectively. At follow-up, 85.4% of the patients were New York Heart Association class I. Three patients underwent repeat mitral valve surgery.

Conclusions

The CGFB demonstrates satisfactory quality and durability in MVr for PMR. Other advantages include a low occurrence of SAM and acceptable hemodynamic outcomes, particularly in patients requiring a smaller annuloplasty device.

The impact of annuloplasty ring or band implantation on post-repair mitral valve haemodynamic performance

OBJECTIVES

The clinical importance of optimal post-repair mitral valve diastolic performance is increasingly being recognized. The haemodynamic effect of a partial annuloplasty band implantation, in comparison to a full ring, remains insufficiently explored.

METHODS

Patients undergoing mitral valve repair for pure degenerative disease between 2011 and 2019 at 2 experienced heart valve centres were eligible for inclusion. Exclusion criteria were concomitant procedures other than tricuspid valve repair and ablation procedures for atrial fibrillation. Pre-discharge and follow-up echocardiograms (1-4 years after surgery) were analysed to assess haemodynamic mitral valve performance.

RESULTS

Of 535 patients meeting the inclusion criteria, 364 (68.0%) patients underwent full annuloplasty ring and 171 (31.0%) partial band implantation. On predischarge echocardiogram, post-repair mitral valve gradient and area did not differ between groups [2.89 mmHg (IQR 2.26-3.72) vs 2.60 mmHg (IQR 1.91-3.55), P = 0.19 and 1.98 cm2 (IQR 1.66-2.46) vs 2.03 cm2 (IQR 1.55-3.06), P = 0.15]. However, multivariable linear regression analysis demonstrated band annuloplasty as a determinant of larger valve area (coefficient 0.467 cm2, standard error 0.105, P < 0.001). On multivariable analysis, no significant impact on post-repair gradient was observed (-0.370 mmHg, standard error 0.167, P = 0.36). At follow-up, the differences between groups disappeared and multivariable regression analysis failed to demonstrate a significant impact of annuloplasty device type on mitral valve gradient (coefficient -0.095 mmHg, standard error 0.171, P = 1.00) or area (coefficient -0.085 cm2, standard error 0.120, P = 1.00). These results were confirmed with a linear mixed model analysis.

CONCLUSIONS

Partial band annuloplasty was related to an improved haemodynamic profile directly after valve repair for degenerative disease but the effect was short-lived. Our results suggest that the type of annuloplasty device has no durable impact on diastolic valve performance.

Risk Factors for Postrepair Elevated Mitral Gradient: A Post-hoc Analysis of a Randomized Trial

BACKGROUND

Predischarge elevated mean mitral gradients (>5 mm Hg) may occur after repair for degenerative mitral regurgitation. We sought to identify risk factors associated with elevated gradients and to evaluate its impact on functional outcomes at 12 months in this subanalysis of the Canadian Mitral Research Alliance CardioLink-2 trial.

METHODS

One hundred four patients with degenerative mitral regurgitation undergoing mitral repair were randomized to either a leaflet resection or preservation strategy. Logistic regression was used to identify risk factors associated with an elevated gradient. Functional outcomes at 12 months were compared between participants with and without elevated gradients.

RESULTS

Elevated gradients was identified in 15 participants (14.4%), which was not significantly different based on allocation to each repair strategy (P = .10). Patients with elevated gradients were more likely to be women (odds ratio [OR], 4.28; 95% confidence interval [CI], 1.29-14.19; P = .02) and to have a lower preoperative hemoglobin level (OR, 0.93; 95% CI, 0.89-0.98; P = .01) and smaller intercommissural diameter (OR, 0.86; 95% CI, 0.76-0.97; P = .02) and mitral annuloplasty size (OR, 0.71; 95% CI, 0.57-0.87; P = .001). The ratio of intercommissural diameter-to-annuloplasty size was similar between those with and without elevated gradients (both 0.8 ± 0.1, P = .69). At 12 months those with elevated gradients had a worse New York Heart Association functional status (P = .0001), lower peak oxygen saturation in exercise test (P = .01), smaller body weight-walk distance product (P = .02), and higher Borg scale (P = .01) in the 6-minute walk test.

CONCLUSIONS

Female gender, smaller mitral anatomy sizes, and lower preoperative hemoglobin levels were associated with postoperative elevated mitral gradients, which was in turn were associated with reduced functional status. Further research is warranted to investigate these potential risk factors.

Outcomes in Patients With High Transmitral Gradient After Mitral Valve Transcatheter Edge-to-Edge Repair for Mitral Regurgitation

Despite being highly effective in reducing residual mitral regurgitation and improving outcomes, mitral valve transcatheter edge-to-edge repair (MV-TEER) may be associated with high postprocedural residual mitral gradient (rMG). Conflicting results have been reported regarding the relation between rMG and adverse events. This study aimed to evaluate the predictors and the impact of elevated rMG after MV-TEER on clinical events in patients with functional mitral regurgitation (FMR) at 2 years follow-up. We selected a cohort of 864 patients with FMR who were treated with MV-TEER enrolled in the multicentre Italian Society of Interventional Cardiology (GISE) registry of transcatheter treatment of mitral valve regurgitation (GIOTTO). Patients were stratified into tertiles according to rMG. The primary clinical end point was a composite of all-cause death and hospitalization because of heart failure at 2-year follow-up. Overall, 269 patients (31.5%) with an rMG <3 mm Hg, 259 (30.3%) with an rMG ≥3/<4 mm Hg, and 326 (38.2%) with an rMG ≥4 mm Hg were considered. At multivariate logistic regression, ischemic FMR etiology, baseline MG, and the number of implanted clips were independent predictors of an rMG ≥4 mm Hg. Clinical follow-up was available in 570 patients (63.2%). Patients with an rMG ≥4 mm Hg experienced higher rates of the composite end point than patients of the other tertiles (51.1%, vs 42.3% vs 40.8% log-rank test: p = 0.033). In multivariate Cox's regression, both rMG ≥4 mm Hg (hazard ratio 1.54, 95% confidence interval 1.14 to 2.08) and residual mitral regurgitation ≥2+ (hazard ratio 1.36, 95% confidence interval 1.01 to 1.83) were independent predictors of adverse events at 2-year follow-up. In conclusion, we demonstrated that real-world patients who underwent MV-TEER who show an rMG ≥4 mm Hg are at higher risk of death or hospitalization because of heart failure during a 2-year follow-up. Further studies will be needed to confirm our results.

Flow adjusted transmitral pressure gradient as a modified indicator of functional mitral stenosis after repair for degenerative mitral regurgitation

Background and Aim

After repair of degenerative mitral regurgitation (DMR), the focus is on functional mitral stenosis (FMS) when there is a decline of mitral hemodynamics. Yet, the clinical impacts and a standardized definition are still undecided. Since common mitral hemodynamic parameters are influenced by transmitral flow, the aim of this study is to seek the impact of flow adjusted transmitral pressure gradient (TMPG) by left ventricular stroke volume (LVSV) on the midterm outcomes.

Methods

Three hundred one patients who had undergone isolated mitral valve repair for degenerative lesions with annuloplasty prosthesis between October 2012 and June 2019 were included. Postoperative adverse events occurred in 20 patients (6.6%). Flow adjusted TMPG was defined as TMPG/LVSV.

Results

Common mitral hemodynamic parameters were not associated with adverse events. By multivariable analysis, patients’ age, left ventricular ejection fraction (LVEF) and mean TMPG/LVSV were isolated as independent predictors (adjusted hazard ratio: 1.05, 0.95, and 1.16; p = .037, .005, and .035). Flow adjusted TMPG was significantly higher in the full ring group compared to the partial band group (0.051 mmHg/ml, [0.038–0.068] vs. 0.041 mmHg/ml, [0.031–0.056]; p < .001) and had a significantly negative correlation with the size of the annuloplasty prosthesis (r = −0.37, p < .001).

Conclusions

Conventional mitral hemodynamic parameters were not associated with adverse cardiac events after repair for DMR. Adjustment by flow has a potential to advance pressure gradient to a more sensitive indicator of FMS associated with clinical outcomes.

Effect of Mitral Valve Gradient After MitraClip on Outcomes in Secondary Mitral Regurgitation: Results From the COAPT Trial

OBJECTIVES

The authors sought to evaluate the association between mean mitral valve gradient (MVG) and clinical outcomes among patients who underwent MitraClip treatment for secondary mitral regurgitation (SMR) in the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) trial.

BACKGROUND

In the COAPT trial, patients with heart failure (HF) and severe SMR who remained symptomatic despite guideline-directed medical therapy had marked 2-year reductions in mortality and HF hospitalizations after treatment with MitraClip.

METHODS

MitraClip-treated patients were divided into quartiles (Q) based on discharge echocardiographic MVG (n = 250). Endpoints including all-cause mortality, HF hospitalization, and health status measures at 2 years were compared between quartiles.

RESULTS

Mean MVG after MitraClip was 2.1 ± 0.4 mm Hg, 3.0 ± 0.2 mm Hg, 4.2 ± 0.5 mm Hg, and 7.2 ± 2.0 mm Hg in Q1 (n = 63), Q2 (n = 61), Q3 (n = 62), and Q4 (n = 64), respectively. There was no difference across quartiles in the 2-year composite endpoint of all-cause mortality or HF hospitalization (43.2%, 49.2%, 40.6%, and 40.9%, respectively; p = 0.80), nor in improvements in New York Heart Association functional class, Kansas City Cardiomyopathy Questionnaire score, or 6-min walk time. Results were similar after adjustment for baseline clinical and echocardiographic characteristics, post-procedure MR grade, and number of clips (all-cause mortality or HF hospitalization Q4 [44.6%] vs. Q1 to Q3 [40.3%]; adjusted hazard ratio: 1.23, 95% confidence interval: 0.60 to 2.51; p = 0.57).

CONCLUSIONS

Among HF patients with severe SMR, higher MVGs on discharge did not adversely affect clinical outcomes following MitraClip. These findings suggest that in select patients with HF and SMR otherwise meeting the COAPT inclusion criteria, the benefits of MR reduction may outweigh the effects of mild-to-moderate mitral stenosis after MitraClip.